# Do I need more than 100 psi?



## jfd986 (Jul 17, 2011)

I'm 5'6 144 lbs and on my way down. I'm running 700x25 slicks at 100 psi on smooth road with the occasional bumps or imperfections. (stock "duro" in the front, gator skin in the back)

My pump only goes to 100 psi because it's one of those Walmart pumps with no gauge and nothing fancy (it's probably not even 100 psi).

Will a higher tire pressure make me faster? Will it severely compromise smoothness of the ride if I'm popping up before each pump? Should I buy a new pump?

I read somewhere that 23s are not any faster than 25s and 25s are better for sharp turns, so now bike stores are going fire sale on all their basic 23s. Is any of this true? Can someone verify?


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## bayAreaDude (Apr 13, 2012)

I think that pressure is way too high for your weight. I'm 170 and run 75 in the front and 90 in the back with 23's, though they are tubeless. You will not go any faster with higher pressure and think if you lower your pressure to something even less than mine, you'll go just as fast or faster plus your ride will be infinitely more comfortable, which could easily make you pedal faster just because you feel better on the bike.


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## charlox5 (Jan 31, 2011)

100 psi is too much for you.

i'm running 90/95 on 25's at 200 lbs. zero pinch flats.


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## PJ352 (Dec 5, 2007)

Given your weight and road conditions I suggest dropping your tire pressures ~15% (to around 85) and experiment from there.

IME 23c's are no faster than 25c's, and 25c's (running at the proper PSI's for a given rider/ conditions) will certainly offer a more comfortable ride. In most respects, a win-win.

Here's a guide that should help you get started. One of the better ones, IMO/E.
Michelin Bicycle USA - A better way forward®


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## AndrwSwitch (May 28, 2009)

I do 80 and 95, weigh 15 lb more than you, and have skinnier tires.

Start with the Michelin guide, and then do some experimentation.

I find a pump with a gauge very useful. Even if the gauges are notoriously inaccurate in an absolute sense, they tend to have adequate repeatability.


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## kmak (Sep 5, 2011)

I found this article to be very helpful; lower pressure really is better:
http://www.adventurecycling.org/resources/200903_PSIRX_Heine.pdf


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## BostonG (Apr 13, 2010)

I agree that it's way too high and just want to add that cheap tubes will of course be more prone to pinch flats. So, if you go lower and find you get pinch flats a couple times with the same type of tube, it may be a cheap tube that's at fault rather than the pressure.

It's happened to me so I thought I'd mentione in case it happens to you or others.


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## JCavilia (Sep 12, 2005)

I second all this advice. I weigh about 6 pounds more than you (well, 8 this week ;-), and I run 25's at 85 front, 90 rear.

But you don't really know what pressure you're running, so I also endorse the advice to get a pump with a gauge. You don't have to spend a lot. 
Nashbar White Floor Pump - Floor Pumps


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## EHietpas (Feb 9, 2012)

Wow. I weigh more than you and I run around 115psi. Most the people I ride with run between 95 to 105psi. Most of them sit around 185lbs.


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## jwl325 (Feb 3, 2010)

Took me a while to figure out the advantages of lower tire pressure. Currently running 90s, a bit older and heavier than you. 

Based on some of the comments here, may adjust downward accordingly.


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## MPov (Oct 22, 2010)

Just want to add that, as you may have gathered from the posts, most people don't run the same pressure in both tires. Front can be less than the rear because when you ride less weight is put on the front than the back.

And yes, you should buy a new pump. The guage on that Walmart pump is likely not very accurate. I've also read that you should replace your pump every so often because guages lose accuracy over time.


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## JoePAz (Jul 20, 2012)

I run about 95-100 psi in my 700x23c tires. I am 5'7" and 155lbs. I only have 300 miles under my belt on this bike and I have never pinched flatted. I have run lower pressure at times the bike feels sloppy with less pressure. Not sure what the pressure is as this is when tubes bleed-down a bit. It could be as low as 60-70 psi, but I can't really tell as I just re-pump to 100.


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## jfd986 (Jul 17, 2011)

Joe I think you'd need a pump with a gauge to tell how low exactly you're running the tires, because I think that what everyone is saying is indeed right ( I'd be the last person to argue with a sports science article ) and I think that you and I could benefit from appropriately lowering our tire pressure. I'm waiting for my gauged pump to get here and then I'll start bringing 'er down.


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## tednugent (Apr 26, 2010)

190 here... and run 90 psi rear and 85 front.... 700x25c.

It takes trial and error to find that sweet spot for you... low enough w/o pinch flats.

You don't want it too high where ride is uncomfortable AND ... the tires are bouncing on every imperfection on the road


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## cxwrench (Nov 9, 2004)

JoePAz said:


> I run about 95-100 psi in my 700x23c tires. I am 5'7" and 155lbs. I only have 300 miles under my belt on this bike and I have never pinched flatted. I have run lower pressure at times the bike feels sloppy with less pressure. Not sure what the pressure is as this is when tubes bleed-down a bit. It could be as low as 60-70 psi, but I can't really tell as I just re-pump to 100.


i don't think that your pressure is too high, but i wouldn't recommend going any higher on 23mm tires. but think about this...
on a road bike your tires are you suspension. on a mountain bike you have a suspension fork and possibly a full suspension frame. you set your suspension up so that every now and then you bottom out on the biggest, hardest hits. if you're paying for 100 or 120 or 150mm of travel, you might as well use all of what you've paid for, right? doesn't make any sense to have a bike w/ 125mm of travel front and rear and only ever use 90mm of it. 
you can think of tire pressure the same way. you really don't know what's optimal for your riding style and terrain 'til you've gone past it and pinch flatted. or, if you're lucky and sensitive to such things, bottomed the tire on the rim and NOT flatted. i'd call that damn good luck and perfect pressure.


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## JoePAz (Jul 20, 2012)

cxwrench said:


> i don't think that your pressure is too high, but i wouldn't recommend going any higher on 23mm tires. ....
> you really don't know what's optimal for your riding style and terrain 'til you've gone past it and pinch flatted. or, if you're lucky and sensitive to such things, bottomed the tire on the rim and NOT flatted. i'd call that damn good luck and perfect pressure.


When have run the bike after re setting to 100 psi on my pump gauge the bike becomes a lot sharper. It is more harsh on the occasional seam in the pavement, but it responds faster when pedaling. Especially when standing I don't get slightly wallowing I get with lower pressures. Plus the bike seems to roll a little faster at 100 psi. I have pretty standard loop and the bike seems faster (Strava segment) times when pump the pressure back up. 

That said I have not tried 90 psi for example. Only 95-100 (100 on the gauge minus a little when pull off the valve) and what I feel is too low. Maybe 60 psi? Hard to tell since I don't trust the pump gauge when refilling. Plus I can't add air to the rear tube without lowering it first. The presta valve seems a little stuck. 

Anyway since most of my rides have been short (1-1:15) max effort rides I like the more responsive feel. Longest road ride so far for me was at 1:45 min and 31 miles.


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## cxwrench (Nov 9, 2004)

JoePAz said:


> When have run the bike after re setting to 100 psi on my pump gauge the bike becomes a lot sharper. It is more harsh on the occasional seam in the pavement, but it responds faster when pedaling. Especially when standing I don't get slightly wallowing I get with lower pressures. Plus the bike seems to roll a little faster at 100 psi. I have pretty standard loop and the bike seems faster (Strava segment) times when pump the pressure back up.
> 
> That said I have not tried 90 psi for example. Only 95-100 (100 on the gauge minus a little when pull off the valve) and what I feel is too low. Maybe 60 psi? Hard to tell since I don't trust the pump gauge when refilling. Plus I can't add air to the rear tube without lowering it first. The presta valve seems a little stuck.
> 
> Anyway since most of my rides have been short (1-1:15) max effort rides I like the more responsive feel. Longest road ride so far for me was at 1:45 min and 31 miles.


obviously i'm not talking about lowering the pressure by huge amounts. but when you get a chance, try 90 instead of 100 just so you know what it feels like. 
and...
you don't lose any pressure when you pull the pump head off a presta valve. that's air from the hose, not the tube.


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## PJ352 (Dec 5, 2007)

JoePAz said:


> When have run the bike after re setting to *100 psi* on my pump gauge *the bike becomes a lot sharper*. * It is more harsh on the occasional seam in the pavement, but it responds faster when pedaling.* Especially when standing I don't get slightly wallowing I get with lower pressures. Plus *the bike seems to roll a little faster at 100 psi. * I have pretty standard loop and the bike seems faster (Strava segment) times when pump the pressure back up.
> 
> That said *I have not tried 90 psi* for example. Only 95-100 (100 on the gauge minus a little when pull off the valve) and what I feel is too low. Maybe 60 psi? Hard to tell since I don't trust the pump gauge when refilling. Plus I can't add air to the rear tube without lowering it first. The presta valve seems a little stuck.
> 
> Anyway since most of my rides have been short (1-1:15) max effort rides I like the more responsive feel. Longest road ride so far for me was at 1:45 min and 31 miles.


Much of what you describe is perception. A harsher ride generally translates into _feeling_ faster, but you're really not. Not when comparing a 'reasonable' range of tire pressures (say, going from 90/100 to 80/90 f/r PSI) - or going from 23's to 25's.

That aside, I suspect you may be letting your pressures drop a little too much (you mention 60 PSI), in which case you _would_ feel (and probably be) slightly faster when pumping back up to your correct range - or above. Most cyclists that take the time to experiment a little find f/r pressures that keep (relative) speed up _and_ provide a more comfortable ride.


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## JoePAz (Jul 20, 2012)

PJ352 said:


> That aside, I suspect you *may be letting your pressures drop a little too much* (you mention 60 PSI), in which case you _would_ feel (and probably be) slightly faster when pumping back up to your correct range - or above. Most cyclists that take the time to experiment a little find f/r pressures that keep (relative) speed up _and_ provide a more comfortable ride.


I bet this is the case. I probably need to just change out the the tubes and spend some real effort dialing in the pressures. Should good tubes hold pressure pretty much all the time? Or can a good tube experience some bleed down over a week or two? Mtn bike tubes should hold air, but they are only 30-40 psi and slow leaks are signs of thorns. On my road bike I have never swapped tubes. I have the same ones on it when it got the bike used about 300 miles ago.


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## Erion929 (Jun 10, 2010)

cxwrench said:


> you don't lose any pressure when you pull the pump head off a presta valve. that's air from the hose, not the tube.



I always wondered that....just assumed I lost ~3 psi from the tube when pulling off the connector. Now I can sleep 

**


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## cxwrench (Nov 9, 2004)

JoePAz said:


> I bet this is the case. I probably need to just change out the the tubes and spend some real effort dialing in the pressures. Should good tubes hold pressure pretty much all the time? Or can a good tube experience some bleed down over a week or two? Mtn bike tubes should hold air, but they are only 30-40 psi and slow leaks are signs of thorns. On my road bike I have never swapped tubes. I have the same ones on it when it got the bike used about 300 miles ago.


your tubes are fine most likely. you should lose between 5-20psi overnight w/ butyl tubes, more if you switch to latex. i would pump them up every day for a week or so 'til you get a feeling for how much pressure you lose overnight. the higher the pressure you inflate them too, the more you'll lose. that's why your mtb tires lose very little.


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## PJ352 (Dec 5, 2007)

JoePAz said:


> I bet this is the case. I probably need to just change out the the tubes and spend some real effort dialing in the pressures. Should good tubes hold pressure pretty much all the time? Or can a good tube experience some bleed down over a week or two? Mtn bike tubes should hold air, but they are only 30-40 psi and slow leaks are signs of thorns. On my road bike I have never swapped tubes. I have the same ones on it when it got the bike used about 300 miles ago.


I'm not suggesting you test their limits, but I've used the same tubes for (literally) years and thousands of miles. They either hold air, or they don't. So as cxwrench stated, yours are probably fine. 

FWIW, I use only standard butyl (link below). No latex, lights, ultra-lights... 
http://www.performancebike.com/bikes/Product_10054_10551_1034767_-1_400233__400233

I'm a light rider and not very religious about checking pressures, but IMO while you're experimenting consider checking pre-ride every couple of days. That (IME) is when you lose the most pressure.


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## TheSlug74 (Aug 20, 2012)

Wow!!!! This thread is a real eye opener!!!!

Got into road cycling a few months back, and the moron at the LBS advised me to run b/w 110 to 115 PSI. I only weigh 142 lbs!!!! 

Was wondering why my rides have been so rough!!!!!

Can't wait to drop the pressure for tomorrow morning's ride and give me a few extra years before arthritis kicks in as a result of the idiotic advice I had received.....

Cheers,
TheSlug74


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## biker jk (Dec 5, 2012)

The Vittoria web site recommends 105 psi front and 110 psi rear for a 150 tpi clincher, rider+bike weight of 143-165lbs, and riding on wet/rough roads. That's the pressure I arrived at using trial and error before consulting the Vittoria web site (I have Rubino Pros).


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## MikeWMass (Oct 15, 2011)

cxwrench said:


> your tubes are fine most likely. you should lose between 5-20psi overnight w/ butyl tubes, more if you switch to latex. i would pump them up every day for a week or so 'til you get a feeling for how much pressure you lose overnight. the higher the pressure you inflate them too, the more you'll lose. that's why your mtb tires lose very little.


The only thing I would say about this is if you want to see how much pressure you lose overnight, you really need to get a separate pressure gauge. I pump my tires up before every ride and generally need to go up about 25 pounds. I noticed after a while that it did not seem to matter whether it was a day or a week later, it was still about the same. I tried pumping up the tire, removed the chuck and then put it right back on: sure enough, down about 25 pounds. I use a Blackburn Air Tower with a pretty long hose, but in the past I had similar findings with a Planet Bike and a Performance pump as well.


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## cxwrench (Nov 9, 2004)

biker jk said:


> The Vittoria web site recommends 105 psi front and 110 psi rear for a 150 tpi clincher, rider+bike weight of 143-165lbs, and riding on wet/rough roads. That's the pressure I arrived at using trial and error before consulting the Vittoria web site (I have Rubino Pros).


how low have your tried?


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## MPov (Oct 22, 2010)

I weigh 142, bike (Madone 5.2 with stock wheels) probably weights about 20-25 pounds when loaded with my saddle pack and water bottles. I find the best pressure for me on 23mm Conti GP 4000s tires is 105 rear 100 front. The two times I went lower I flatted. Maybe just coincidence but I don't like tempting fate.


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## cxwrench (Nov 9, 2004)

MPov said:


> I weigh 142, bike (Madone 5.2 with stock wheels) probably weights about 20-25 pounds when loaded with my saddle pack and water bottles. I find the best pressure for me on 23mm Conti GP 4000s tires is 105 rear 100 front. The two times I went lower I flatted. Maybe just coincidence but I don't like tempting fate.


20-25lbs is a HUGE range. actually, even w/ bottles and a saddle bag you're probably under 20. if you did actually pinch flat but still think you might like lower pressure you can always try 25mm tires. 80-90psi should be fine w/ a slightly bigger tire. 
as i've posted many times, i weigh 165-170 and run 23mm tires at 85/95, slightly less when using tubeless. if you pinch flatted twice in a very short time period i'd recommend going bigger on the tires, and trying to be more aware of the road in front of you. 
my opinion is to run the pressure for the ride quality you want, not to avoid the occasional pinch flat. if you pinch more than 'occasionally', then you need bigger tires, not more pressure. i think 100-105 is as much pressure as any rider should run, and if that doesn't prevent flats then bigger tires will.
that said, 105/100 is still reasonable. i'd go down to about 90 on the front, though. 5psi is a very small difference when weight distribution is more like 60/40%.


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## marinman39 (Dec 25, 2012)

Good post already, but answer is absolutely not! I used to ride 23mm, tut switched to 25 a few years ago because of the rough and often wet roads around Nor Cal. I used to pump the 23's to 105 in both tires, and the ride was kind of rough even though a ride a softer Ti frame. With the 25's I go 95 back, 90 front; and from what folks here are saying, since i weigh 152 (in season), I could probably use less and lose no efficiency. 100 on 25's is definitely too much.


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## TheSlug74 (Aug 20, 2012)

Just thought I would provide an update on the results of my experiment.....

Dropped front to 85 and rear to 95. Tyres are 700 x 23. I weigh 142 lbs.

What a massive difference!!!! Made a huge difference to the comfort of the bike and actually felt more controllable.....

I wish I had found this thread a few months back when I started riding!

Thanks to all on this thread for their posts and invaluable information. Much appreciated.... :thumbsup:

Cheers,
TheSlug74


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## PJ352 (Dec 5, 2007)

TheSlug74 said:


> Dropped front to 85 and rear to 95. Tyres are 700 x 23. I weigh 142 lbs.
> 
> What a massive difference!!!!


I go about 135 lbs. most days and run those same pressures on 25c's. Give that combo a try sometime. I think you'll be pleasantly surprised.


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## BostonG (Apr 13, 2010)

cxwrench said:


> and...
> you don't lose any pressure when you pull the pump head off a presta valve. that's air from the hose, not the tube.


Thanks. I didn't know that, always assumed it was from the tube and wondered if I should up my pressure to account for it. Now I know.


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## TheSlug74 (Aug 20, 2012)

PJ352 said:


> I go about 135 lbs. most days and run those same pressures on 25c's. Give that combo a try sometime. I think you'll be pleasantly surprised.


Thanks PJ, may give that a try on the next set of rubber purchased......


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## milesbgibbons (Jan 13, 2013)

this thread is seriously helpful,

cheers!


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## hdbiker (Aug 2, 2010)

I guess I'm really in the minority. I'm one of those "morons" who run at 110 front and 115 rear. I weght 180. I rode 6500 miles this year.
I got over 6000 miles on my 25c Gatorskins and had 2 flats. Neither were pinch flats.
I ride at least 5 to 6 times a week in good weather and pump my tires about every third time out. 
I will try a lower pressure on the front from now on, since I do get some numbness in my left hand. Maybe going down to 85 or 90 will help that. But if I start getting pinch flats, I'll go back to 110.


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## cxwrench (Nov 9, 2004)

hdbiker said:


> I guess I'm really in the minority. I'm one of those "morons" who run at 110 front and 115 rear. I weght 180. I rode 6500 miles this year.
> I got over 6000 miles on my 25c Gatorskins and had 2 flats. Neither were pinch flats.
> I ride at least 5 to 6 times a week in good weather and pump my tires about every third time out.
> I will try a lower pressure on the front from now on, since I do get some numbness in my left hand. Maybe going down to 85 or 90 will help that. But if I start getting pinch flats, I'll go back to 110.


or keep your eyes on the road a little more. seriously though, you want to inflate your tires to the pressure that provides the ride quality you want, not to avoid pinch flats. we'd all be riding around on rock hard tires if we did that. you may encounter the odd massive pothole every now and then that will cause a pinch flat, and if you're riding in a group you may not see it before it's too late. flats happen, it's part of riding a bike. it makes much more sense to inflate your tires to the pressure you want for the 99.9999999999999% of the time you're not flatting.


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## TheSlug74 (Aug 20, 2012)

hdbiker said:


> I guess I'm really in the minority. I'm one of those "morons" who run at 110 front and 115 rear. I weght 180. I rode 6500 miles this year.
> I got over 6000 miles on my 25c Gatorskins and had 2 flats. Neither were pinch flats.
> I ride at least 5 to 6 times a week in good weather and pump my tires about every third time out.
> I will try a lower pressure on the front from now on, since I do get some numbness in my left hand. Maybe going down to 85 or 90 will help that. But if I start getting pinch flats, I'll go back to 110.


But at 180 kg that may be appropriate. ....my reference too the LBS owner as being a "moron" for his advice to me is that I weigh 20kg less than you..... 

Since trying the lower pressures my rides have been an absolute joy and thrashing out 200 km a weekend has been a pleasure and comfortable. And as you said if you go down and then go back up again you have tried both and only be j n a better position in the end....

Good luck.


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## kmak (Sep 5, 2011)

TheSlug74 said:


> But at *180 kg* that may be appropriate. ....my reference too the LBS owner as being a "moron" for his advice to me is that I weigh 20kg less than you.....
> 
> Since trying the lower pressures my rides have been an absolute joy and thrashing out 200 km a weekend has been a pleasure and comfortable. And as you said if you go down and then go back up again you have tried both and only be j n a better position in the end....
> 
> Good luck.


Wow that is a big rider....


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## TheSlug74 (Aug 20, 2012)

kmak said:


> Wow that is a big rider....


Can tyres go up to 200psi for these circumstances?


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## PJ352 (Dec 5, 2007)

hdbiker said:


> I guess I'm really in the minority. I'm one of those "morons" who* run at 110 front and 115 rear. I weght 180.* I rode 6500 miles this year.
> I got over 6000 miles on my 25c Gatorskins and had 2 flats. Neither were pinch flats.
> I ride at least 5 to 6 times a week in good weather and pump my tires about every third time out.
> I will try a lower pressure on the front from now on, since I do get some numbness in my left hand. Maybe going down to 85 or 90 will help that. But if I start getting pinch flats, I'll go back to 110.


At your weight, Michelin recommends inflating tires to the max pressures stated on the sidewalls. However, following their chart (linked in my first post), a 180 lb. rider running 25c's should inflate tires to around 100 PSI. As the text states, there are a number of other factors to consider (style of riding, road conditions...), but I'd suggest starting at around that 100 PSI mark and tailoring from there.

Re: the left hand numbness, while it's possible road buzz is a contributing factor, IMO/E it's more likely to be caused by fit and/ or form. Excessive frontal weight is the most common cause, so if you suspect that (and have never been properly fitted) that would be the place to start. 

Below are some pointers on maintaining proper form:
- keep your upper torso relaxed, arms slightly bent
- _change hand position frequently_ (tops, bends, hoods, drops...)
- keep a slightly loose grip on the bars (avoid the 'death grip')
- keep forearms and hands aligned (don't twist at the wrist - refer to pic below)
- consider good quality gel gloves
- consider good quality bar tape
View attachment 273684


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## PJ352 (Dec 5, 2007)

TheSlug74 said:


> Can tyres go up to 200psi for these circumstances?


180kg = 397 lbs. But to answer your question, no, you shouldn't exceed max recommended PSI's.


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## hdbiker (Aug 2, 2010)

PJ352 said:


> At your weight, Michelin recommends inflating tires to the max pressures stated on the sidewalls. However, following their chart (linked in my first post), a 180 lb. rider running 25c's should inflate tires to around 100 PSI. As the text states, there are a number of other factors to consider (style of riding, road conditions...), but I'd suggest starting at around that 100 PSI mark and tailoring from there.
> 
> Re: the left hand numbness, while it's possible road buzz is a contributing factor, IMO/E it's more likely to be caused by fit and/ or form. Excessive frontal weight is the most common cause, so if you suspect that (and have never been properly fitted) that would be the place to start.
> 
> ...


I've been fitted, and have over 30 years of road riding. Gel gloves, IMO are the worst thing you can do for numbness. They actually create more pressure points.
My numbness comes from 50 to 100 mile rides on chip and seal roads in northern Ohio.
Again, since I ride over 6000 miles a year, avoiding flats is a big factor. I will be dropping the pressure just to test it out.


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## PJ352 (Dec 5, 2007)

hdbiker said:


> I've been fitted, and have over 30 years of road riding. Gel gloves, IMO are the worst thing you can do for numbness. They actually create more pressure points.
> *My numbness comes from 50 to 100 mile rides on chip and seal roads in northern Ohio.*
> Again, since I ride over 6000 miles a year, avoiding flats is a big factor. I will be dropping the pressure just to test it out.


I agree that too much padding (of any sort) can contribute to numbness. That's why I prefer gel gloves and Specialized bar tape that has minimal padding.

Specialized Bicycle Components

Points taken re: road conditions. Definitely a factor and hard to avoid. But since your numbness occurs in just the left hand, there may be other factors to consider; form being but one.

That aside, being a beginner's forum, my 'pointers' are my general advice to posters with less experience - or those that may not be aware of what can contribute to poor form. 

We log about the same annual miles, but (surprisingly) the roads here in upstate NY aren't that bad, so ::knock on wood:: I've managed to do this last 'season' (Mar thru Dec.) without flatting.

Good luck with your experiment.


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## AndrwSwitch (May 28, 2009)

25 mm tires are not that big. I'd like to go bigger for the rear tire on my commuter, and I only weigh 160 lb, or 72 kg.

If it's feasible, for riders big enough to need max pressure in the tires they have, IMO going bigger is a good approach. Touring tires can get all the way up to mountain bike sizes. While the maximum recommended pressure goes down as tire sizes go up, I think it doesn't go down as fast as a rider's needed pressure does. So cramming the biggest feasible tire between the stays could be the best solution for riders who are too heavy to use pressures within the recommended range.

IMHO, it's a weakness of the current major brands that they've been so weird about bikes with a larger clearance. Selling racing bikes to everybody is like selling sports coupes to everybody. Maybe some of us want a station wagon, or even a cargo van. So I realize that a lot of posters will be committed to nothing larger than 28, or even to smaller tires than that. But, bigger is better, until pressures inside the recommended range become feasible, or a bigger tire won't clear the stays or fork, IMO. Then it might still be, but the problem becomes more complicated.

Maybe people who are buying a second bike or haven't bought yet will see this. In that case, my advice is to buy a bike with enough clearance for a tire that can be run below its maximum pressure for what you weigh today.


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## MPov (Oct 22, 2010)

cxwrench said:


> 20-25lbs is a HUGE range. actually, even w/ bottles and a saddle bag you're probably under 20. if you did actually pinch flat but still think you might like lower pressure you can always try 25mm tires. 80-90psi should be fine w/ a slightly bigger tire.
> as i've posted many times, i weigh 165-170 and run 23mm tires at 85/95, slightly less when using tubeless. if you pinch flatted twice in a very short time period i'd recommend going bigger on the tires, and trying to be more aware of the road in front of you.
> my opinion is to run the pressure for the ride quality you want, not to avoid the occasional pinch flat. if you pinch more than 'occasionally', then you need bigger tires, not more pressure. i think 100-105 is as much pressure as any rider should run, and if that doesn't prevent flats then bigger tires will.
> that said, 105/100 is still reasonable. i'd go down to about 90 on the front, though. 5psi is a very small difference when weight distribution is more like 60/40%.


Thanks for the input. Sorry I didn't see your reply earlier. Maybe I'll try dropping a few more psi in each tire again and see how it goes.


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## Warpdatframe (Dec 9, 2012)

I usually ride with 110-120, front and back on 23s and I'm 120 pounds.


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## kmak (Sep 5, 2011)

Warpdatframe said:


> I usually ride with 110-120, front and back on 23s and I'm 120 pounds.


Try dropping by 30psi for one ride and come back here and let us know what you think....


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## cxwrench (Nov 9, 2004)

Warpdatframe said:


> I usually ride with 110-120, front and back on 23s and I'm 120 pounds.


why on earth?


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## maximus_73 (Dec 13, 2012)

my tires is 90 psi, and I am 155lbs


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## SlicedUpBeef (Dec 16, 2012)

I never run 100+ psi just because the pressure gauge on my pump is inaccurate.


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## passthestoke (Apr 8, 2012)

OMG raise your hand if you don't know and don't care what PSI your tires are at!!!


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## AndrwSwitch (May 28, 2009)

FWIW, I care even more when it's my mountain bike.

Hand firmly not raised.


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## GRAVELBIKE (Sep 16, 2011)

I outweigh you by 50 pounds, and run my tires around 75 front, and 85 rear. Granted, that's with 28mm (actual width) tires. No problems with pinch flats, despite riding stuff like this:




If the tire is too hard, it can't deform to accommodate imperfect surfaces, and that saps speed, etc. It's also less comfortable, and you fatigue easier/sooner.


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## odearja (Jan 22, 2013)

jfd986 said:


> I'm 5'6 144 lbs and on my way down. I'm running 700x25 slicks at 100 psi on smooth road with the occasional bumps or imperfections. (stock "duro" in the front, gator skin in the back)
> 
> My pump only goes to 100 psi because it's one of those Walmart pumps with no gauge and nothing fancy (it's probably not even 100 psi).
> 
> ...


 I am 242 pounds and I run 60/60 on 32's and I have no problems.


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## JoePAz (Jul 20, 2012)

kmak said:


> I found this article to be very helpful; lower pressure really is better:
> http://www.adventurecycling.org/resources/200903_PSIRX_Heine.pdf


I when through that and came up with the following

Rider + bike = 177lbs
40% front / 60% rear so weight is 71lbs front 106lbs rear. 

So tire pressure 73lbs front and 110 rear on 700x23 tires. Strangely close to 1 to 1. 

I have been running about 95-100 psi so far and I guess I need to go up in the back and lower in the front?


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## cxwrench (Nov 9, 2004)

JoePAz said:


> I when through that and came up with the following
> 
> Rider + bike = 177lbs
> 40% front / 60% rear so weight is 71lbs front 106lbs rear.
> ...


if you want to go by what that articles says, then yes. if you want to experiment a little and figure out what's best for you, who knows what you'll end up with. for your weight i'd say low-mid 90's in the rear and 10-15lbs less in front. 
if you ride on a lot of rough roads, or you're inattentive and tend to run over every hole and rock on the road, get bigger tires, not more pressure.


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## JoePAz (Jul 20, 2012)

I did a ride yesterday and ran about 80 psi front and 95 psi rear. Bike seemed quite comfortable and reasonably fast. It was windy on my normal ride loop so I could not compare times, but it seemed pretty good. I think I will keep it this way


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## AndrwSwitch (May 28, 2009)

Those are my pressures.


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## Yukikaze (Oct 24, 2012)

I usually run around 100/105 psi in my 700x23c tires. I am 5'9" and 155lbs. 

Then yesterday, I accidentally forgot to pump my tires for my weekend ride and I ran 75/75 psi. It felt great! The cracks and debris on the trail were much more dampened and speed did not feel slow. I actually hit a personal record on one of the segments.

Now I need to find my sweet spot of what psi I should keep my tires at.


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## Anant (Nov 28, 2012)

Yes, you need more than 100 psi.


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## cxwrench (Nov 9, 2004)

Anant said:


> Yes, you need more than 100 psi.


well done, you're still in single digits and your reputation for giving advice is sealed.


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## 126driver (Jan 16, 2013)

Wow. I will definitely be lowering my pressure down from 105 psi on my next ride I always thought harder was faster. Great thread


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## .je (Aug 25, 2012)

126driver said:


> Wow. I will definitely be lowering my pressure down from 105 psi on my next ride I always thought harder was faster. Great thread


I tried that online pressure calculator and it gave me 128 rear and 82 front - so I tried close to that, and wow, the ride was much less rough, and my speed was generally faster at any time! Interesting, I thought 82 would be low, and 128 would be rough, but it was interesting to take that recommendation for _a_ ride.


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## kjdhawkhill (Jan 29, 2011)

hdbiker said:


> I guess I'm really in the minority. I'm one of those "morons" who run at 110 front and 115 rear. I weight 180.


My specialized 23s all condition armadillos have only flatted once in about 4200 miles. Only one of them (the rear) pinch flatted when I didn't bother to top them off after not riding that bike for a couple days. The pressure was probably down to 80 or 75. 

I typically run 100 or 105 up front and 110+ in the rear at 185 lbs. Call me names all you want. I'll live.


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## giff (Jul 24, 2004)

I will have to go with the minority here too. I have been riding for 20 years on and off. Strictly road cycling. I used to run on 25s but now on 23s. I am 5'7" and at a normal weight about 157 (for me). I always ride within 10 psi of the max tire pressure on the sidewall. Currently I inflate to 110psi. Higher pressure will definitely make you faster. Lower pressure may feel smoother but it can also break down your tire sidewall if it is not inflated enough. To see this have someone sit on your bike at a lower tire pressure and look at the sidewall of the tire where contact with the road is made. You will always have some flex here but at lower pressures it can be quiet a bit.... and this is again in my opinion when you get more pinch flats. If you are on smooth roads as you originally posted this should be fine... of course this is my opinion. You may want to invest in the new pump or at least a quality pressure gauge. As far as the 23mm to 25mm tire, I dont know that it will be a noticeable difference and I cannot verify that one corners better than the other.


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## Indetrucks (Oct 8, 2012)

To add to this thread.
I'm 5'11 and 170lbs. Riding 2013 Michelin Pro4 700x23 tires.

105 psi front and rear (probably drops a few PSI when removing the nozzle.
Feels good.


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## PJ352 (Dec 5, 2007)

giff said:


> Higher pressure will definitely make you faster.


If pressures are set appreciably higher than is warranted (see below for criteria), it won't. It'll just feel that way because you'll be bouncing over all the road debris/ irregularities (which actually slows you down).



giff said:


> *Lower pressure may feel smoother but it can also break down your tire sidewall* if it is not inflated enough. To see this have someone sit on your bike at a lower tire pressure and look at the sidewall of the tire where contact with the road is made. You will always have some flex here but at lower pressures it can be quiet a bit.... and this is again in my opinion when *you get more pinch flats*.


If tire pressure is set low enough to have pronounced sidewall flex, you've already set yourself up for pinch flats. When pressures are set 'correctly' - meaning, _in a range that considers tire construction/ size, total rider weight, road conditions and style of riding _- there won't be appreciable sidewall flex.


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## JoePAz (Jul 20, 2012)

.je said:


> I tried that online pressure calculator and it gave me 128 rear and 82 front - so I tried close to that, and wow, the ride was much less rough, and my speed was generally faster at any time! Interesting, I thought 82 would be low, and 128 would be rough, but it was interesting to take that recommendation for _a_ ride.


I think what you are getting is a similar effect of suspension. The front wheel being so low soaks up the bumps and all the weight on the rear softens that up. Seems to me that if big weight split is 40% front and 60% rear you would want big spread in pressures. I find that most chatter and harshness some come from the front tire and that lowering that improves the ride. In the back you are not as sensitive to chatter and harshness. When I rode with 100psi front and rear I would hit these seams in the pavement and (cracks 2" wide) in my home ride and the bike would feel like it was going to split open due to the shock and I would cringe. Now at 80 psi front and 100 psi rear I still feel them of course, but they are no longer a big deal.

As for speed. My speed has is as good or better running 80/100 as compared to 100/100. I am not sure I want to go below 80 psi so that when I stand and put more weight forward I don't overload the front tire, but I see no need to go beyond 80 psi on my 23s. I am 5'7" and 155lbs.


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## giff (Jul 24, 2004)

PJ352 said:


> If pressures are set appreciably higher than is warranted (see below for criteria), it won't. *It'll just feel that way because you'll be bouncing over all the road debris/ irregularities (which actually slows you down).*
> 
> Bouncing off debris? As opposed to tire flex sucking up the debris by deflecting? I make a point of avoiding debris with my bike, though I agree at times it may be unavoidable.
> 
> ...


Not sure what you consider "pronounced" but any tire will have some sidewall flex. For instance take a look at your car tires. You will have a max cold tire pressure stamped on the sidewall of the tire. You also have a max tire pressure on your bike tires. On your car you will have a "recommended" tire pressure front and rear. usually in the drivers door jamb or on the door edge itself. The recommended pressure is generally for road comfort and suspension design. Truth is you can run the max cold tire pressure and conserve more fuel, because your car rolls easier, due to less tire flex. There are "possible" trade offs: rougher ride, diminished handling, wear on suspension components, etc. Same for your bike, you should do what works for you, but a more round wheel (less flex) will be faster. Either way there is a trade off.


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## AndrwSwitch (May 28, 2009)

An important part of these discussions is that roads are not perfectly smooth. If I'm riding my bike and the ride is harsh, so the bike is bouncing, some of the power I'm developing is going into making the bike bounce. That energy is lost to hysteresis. Lame. Although if it wasn't lost, it would make the bike uncontrollable, which would also be lame.

I guess I do claim to know the optimum, but I won't claim to be able to deliver an analytical proof of where it is. Qualitatively, though, I'm pretty confident that it's lower than the pressures that make my bike bounce and rattle, wasting energy in undesired vertical motion, and higher than the pressures that make my tires wallow, wasting energy in the tread scrubbing against the road surface and excessive sidewall flex. Where, exactly, that falls relative to the tire pressures I'm using, I dunno. But since I can feel the bouncing and rattling and I can feel weird handling and wallowing, I think I'm at least in the right ballpark.


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