# What tire size should I use?



## SFTifoso (Aug 17, 2011)

My Trek 1.2 came with 23s (seems all Trek roadies come with 23s). I weight about 206 and I'm losing about 0.5-1 pound a week. The closest thing to racing I do is trying to keep up with other riders that catch up to me. So I'm thinking either 25s or 28s. What do you think?


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## kbwh (May 28, 2010)

If you can get 28s into your frame do so.
If you only have room for a 25 in front but a 28 in the back do so.
Else do 25/25.

23mm is not for 200 lb riders. Cue Michelin:










This chart is basically saying that if you're above 180 lb 23 mm is a no go and 25 mm is ok @ 8 bar.


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## tihsepa (Nov 27, 2008)

Alot of 200+lb riders are on 23's. Who knows why but tey are. I am with the above poster. Ride he largest tire you can. Probably a 25 will be all that will fit.

You can ride the 23's if you keep them inflated to their max but why would you want to?


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## PJ352 (Dec 5, 2007)

tihsepa said:


> Alot of 200+lb riders are on 23's. Who knows why but tey are. I am with the above poster. Ride he largest tire you can. Probably a 25 will be all that will fit.
> 
> You can ride the 23's if you keep them inflated to their max but why would you want to?


Good advice, IMO. 

Re: kbwh's comment, while I agree that 23c's aren't the best choice for the OP, I'm not seeing where in the chart Michelin is saying they're a no go, so (again) I agree with the above.


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## kbwh (May 28, 2010)

No go because:
Even when inflated to max a 200 lb rider will deform a 23 mm too much and experience:
1) Increased rolling resistance
2) Increased pinch flat danger


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## PJ352 (Dec 5, 2007)

kbwh said:


> No go because:
> Even when inflated to max a 200 lb rider will deform a 23 mm too much and experience:
> 1) Increased rolling resistance
> 2) Increased pinch flat danger


In your opinion, maybe. But nowhere does Michelin state it, and that was my point.


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## PCCharger (Feb 28, 2011)

I'm 195 lb and ride on 23c Serfas Seca RS at 110 psi. That's all the local LBS's had so I went with it. Should I up the pressure to 130 psi? I have not had any problems so far but maybe that means I need to ride more.


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## PJ352 (Dec 5, 2007)

PCCharger said:


> I'm 195 lb and ride on 23c Serfas Seca RS at 110 psi. That's all the local LBS's had so I went with it. Should I up the pressure to 130 psi? I have not had any problems so far but maybe that means I need to ride more.


Below is a link to the chart that was posted earlier, sans some text. IMO the best answer to your question is contained there. That being, a number of factors influence a given riders optimal f/r pressures. Namely, style of riding, tire construction/ size and road conditions.

As Michelin recommends, experiment with your tire pressures, but if you've had good success with what you now run, there may be little reason to change.

Can't argue the with the 'ride more' comment. :thumbsup:

Michelin Bicycle USA - A better way forward®


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## kbwh (May 28, 2010)

PJ352 said:


> In your opinion, maybe. But nowhere does Michelin state it, and that was my point.


Brain usage allowed...


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## PJ352 (Dec 5, 2007)

kbwh said:


> Brain usage allowed...


... but not misquoting.

I think you may be misreading the chart, because in your first post, you also state:
_This chart is basically saying that... 25 mm is ok @ 8 bar._
... and that's not the case. Following the charts guidelines, using 25c tires at ~180 lbs. a rider would use a starting PSI of ~7 bar.


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## kbwh (May 28, 2010)

Hmm... I think we're both off?
Continuing again the 25mm line to 200 lb I get 7.5 bar. That leaves 0.5 bar for play upwards to at least these examples:
I checked the pressure limit on a couple of the tires in the Michelin Pro4 line and they were 116 lb (8 bar) for both models and all sizes.


Thanks for the shake up, PJ.


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## tihsepa (Nov 27, 2008)

PJ352 said:


> ... but not misquoting.
> 
> I think you may be misreading the chart, because in your first post, you also state:
> _This chart is basically saying that... 25 mm is ok @ 8 bar._
> ... and that's not case. Following the charts guidelines, using 25c tires at ~180 lbs. a rider would use a starting PSI of ~7 bar.


Kbwh is always making up true stories about that chart. This is the second time reciently. No big deal.


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## savagemann (Dec 17, 2011)

My first road bike wouldn't fit anything bigger than a 23c so i was pretty much forced to run those.
While not even close to ideal for a huge guy like myself, weighing nearly 300lbs, they worked.
But, i was running tires rated at a max psi of 160.
I ran them at 125-130psi and had no issues with pinch flats.
Having just built up a new bike with generous tire clearance, i threw on a set of gatorskins I had lying around in a 25c.
I believe they have a max of 110psi and they feel too soft at that.
Im picking up a set of 4 seasons in 28c.
They should work much better for me.
Hopefully this is helpful to any other uber clydes like myself out there.


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## RJP Diver (Jul 2, 2010)

PCCharger said:


> I'm 195 lb and ride on 23c Serfas Seca RS at 110 psi. That's all the local LBS's had so I went with it. Should I up the pressure to 130 psi?


First thing you should do is find a bike shop that stocks more than one tire...

:thumbsup:


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## PCCharger (Feb 28, 2011)

RJP Diver said:


> First thing you should do is find a bike shop that stocks more than one tire...
> 
> :thumbsup:


What I meant was, of the three shops I went to, nobody had 25c tires in stock. Bought the Serfas because the price was right.


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## RJP Diver (Jul 2, 2010)

PCCharger said:


> What I meant was, of the three shops I went to, nobody had 25c tires in stock. Bought the Serfas because the price was right.



Wow, that's three new bike shops you need to find!


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## PJ352 (Dec 5, 2007)

kbwh said:


> Hmm... I think we're both off?
> Continuing again the 25mm line to 200 lb I get 7.5 bar. That leaves 0.5 bar for play upwards to at least these examples:
> I checked the pressure limit on a couple of the tires in the Michelin Pro4 line and they were 116 lb (8 bar) for both models and all sizes.
> 
> ...


In this particular example, I agree that Michelin _states_ that above 180 lbs. a rider would inflate any of the listed sizes to max PSI - at least as a starting point. I disagree that one can 'extend the line' (on the chart) with any accuracy, or that their recommendations are specific to 25c's.

BTW, appreciate the comment. 

Moving on, I think savagemann's 'real world' examples speak volumes for just how much latitude is allowed re: rider weight, tire size and pressures. Rather than blindly inflating to max PSI, experiment to find the optimal f/r PSI's given your circumstances. Oftentimes, they can be lower than most would think.


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## kmunny19 (Aug 13, 2008)

I weigh 210, ride 23's at 115 psi. I have not had a pinch flat in the 5 years I've been riding. I ride conti gp4000s so that I know I have a pretty good tire holding me up, regardless of width. I understand the earlier comment, of being able to ride 23's if you keep them inflated, but why would you want to...but I haven't been showed yet why I wouldn't want to. 

it boils down to preference. I don't mind the harsh ride of 115 psi on 23's, but maybe I would if I'd tried something else. But there's absolutely no rule about weight v. width that can't be broken.


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## tihsepa (Nov 27, 2008)

kmunny19 said:


> I weigh 210, ride 23's at 115 psi. I have not had a pinch flat in the 5 years I've been riding. I ride conti gp4000s so that I know I have a pretty good tire holding me up, regardless of width. I understand the earlier comment, of being able to ride 23's if you keep them inflated, but why would you want to...but I haven't been showed yet why I wouldn't want to.
> 
> it boils down to preference. I don't mind the harsh ride of 115 psi on 23's, but maybe I would if I'd tried something else. But there's absolutely no rule about weight v. width that can't be broken.


If that works go for it. 
One thing, have you ever ridden the same tire in a 25?
Generally you can drop 10% in pressure and only expierence one thing that is a better ride. Sometimes you expierence two things, the second being a faster ride due to a tire that can better conform to the road. 

There is nothing that says bigger guys cant run a smaller tire. There is also nothing that says they have to. :thumbsup:


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## PJ352 (Dec 5, 2007)

tihsepa said:


> There is nothing that says bigger guys cant run a smaller tire. There is also nothing that says they have to. :thumbsup:


IME it can go the other way as well. I weigh ~134 lbs. most days and run 25c's on one of my bikes. Love 'em!


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## tihsepa (Nov 27, 2008)

PJ352 said:


> IME it can go the other way as well. I weigh ~134 lbs. most days and run 25c's on one of my bikes. Love 'em!


I also run 25's on all road bikes. Cant imagine ever going back to a 23. I am 170 though.


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## thebigred67 (Jun 8, 2007)

I am giant. 6'2" and 240 to 260. I have riden tires as small as 18's with no problem. I noticed that the smaller tire seems to grab the cracks in the surface less. BTW I was running that tire on a commuter because it was a small folding tire and I had it as a back up. The 25c tire that was on there picked up a sidewall slash somehow. So I ended up with the 18 for a while.


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## SFTifoso (Aug 17, 2011)

I ordered a set Vittoria rubino 25s. Not the 150 tpi model, but the 60 tpi model. Should still be an improvement over the 30 tpi trek brand tires the bike came with. Got a pretty good deal on them too. Thanks for all the info.


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## pigpen (Sep 28, 2005)

I prefer 25's on my go fast, that does not go fast, as I am pitiful, bike.
My commuter has 32's.


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## abrasive (Jan 18, 2012)

180 down from 190-ish, still love my 25's. (Conti GP4000s)


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## reesejr1 (Jul 26, 2011)

I had an error opening the link for the chart. I'm 180 lbs and run 23s at 110 psi. I never thought about trying 25s until I read this thread. Could I benefit from 25s? Worth giving them a shot?


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## PJ352 (Dec 5, 2007)

reesejr1 said:


> I had an error opening the link for the chart. I'm 180 lbs and run 23s at 110 psi. I never thought about trying 25s until I read this thread. Could I benefit from 25s? *Worth giving them a shot?*


IMO, definitely worth a try.

Yes, there's a problem with that link. Hopefully, it's a temporary situation.

If you reference the chart kbwh posted earlier, you'll see that at ~180 lbs. your starting PSI for 25c's is ~102. Given that you're successfully running 23c's at ~110, I think you'll find that you can run the 25's lower, but (as has been mentioned) experiment to find your optimal f/r pressures.


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## RoadBoy1 (Oct 1, 2011)

This is all good information but the question I have and the one no one seems to have addressed is what decent, quality tires are out there for road bikes that are available in 25mm and 28mm that don't cost a fortune (ie: Michelin Pro 3 at $60.00 per tire) or that don't weigh 400 grams (ie: Continental Gator Skins or Ultra Sport or the Vittoria Zaffiro). For all I see the 23mm tires pretty much dominate the market.

I don't race bikes anymore but I still appreciate a responsive and good riding tire and if I am going to spend my money I prefer to spend it on quality and once you know what quality is it is really hard to take a step down. Ideally I would be looking for a 25mm tire in the $20 to $30 range at a weight of between 250 to 300 grams.

Anybody know of anything that meets this criteria? Thanks.


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## tihsepa (Nov 27, 2008)

I dont know of any good light 25's. 

I run the Vittoria Open Corsas in a 25 and pay anout 45 each for them.


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## drmayer (Mar 24, 2009)

I like the Michelin krylion carbon 25's. Looks like you an get them for $30 each now.


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## velocanman (Jul 15, 2011)

My recommendation as a big guy: don't ride Michelins. 

They are soft and grippy and wear out fast not matter what you size (my experience and my opinion).

Ride Continental or Vredestein or something that will take 110-120 psi without a disclaimer. I ride Conti 23 mm at 110 psi.

And change them when the wear marks get low or you will get more flats.


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## charlox5 (Jan 31, 2011)

i'm riding 23's (lithion 2's @ 115 psi) at 200-210 lbs. they ride pretty nice. i'd like a set of 25's when they wear out.


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## PJ352 (Dec 5, 2007)

RoadBoy1 said:


> This is all good information but the question I have and the one no one seems to have addressed is what decent, quality tires are out there for road bikes that are available in 25mm and 28mm that don't cost a fortune (ie: Michelin Pro 3 at $60.00 per tire) or that don't weigh 400 grams (ie: Continental Gator Skins or Ultra Sport or the Vittoria Zaffiro). For all I see the 23mm tires pretty much dominate the market.
> 
> I don't race bikes anymore but I still appreciate a responsive and good riding tire and if I am going to spend my money *I prefer to spend it on quality* and once you know what quality is it is really hard to take a step down. Ideally I would be *looking for a 25mm tire in the $20 to $30 range* at a weight of between 250 to 300 grams.
> 
> Anybody know of anything that meets this criteria? Thanks.


IME tires in the $20-$30 range are fairly low end, so expecting a level of quality poses somewhat of a challenge.

That said, I have no firsthand experience with this particular model, but FWIW it seems to meet your price/ weight criteria - and _my_ TPI criteria, so you have a shot at quality.  

Continental Ultra Race Wire Road Tire - Road Bike Tires

Wire bead, if you care....


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## velocanman (Jul 15, 2011)

PJ352 said:


> IME tires in the $20-$30 range are fairly low end, so expecting a level of quality poses somewhat of a challenge.
> 
> That said, I have no firsthand experience with this particular model, but FWIW it seems to meet your price/ weight criteria - and _my_ TPI criteria, so you have a shot at quality.
> 
> ...


I love MAXXIS offroad tires so I might try out a pair of these folding tires, at $33 a piece. Anyone tried them out?

Maxxis Re-Fuse Tire 700x23c / 25c at Price Point


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## vagabondcyclist (Apr 2, 2011)

For 25C tires, I've had good luck on Conti GP 4000. Running some Michelin Krylion Carbon tires right now, but only have a couple hundred miles on them so.....


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## seewhatididther (Aug 7, 2011)

Im in the "run the biggest tire you can fit" mindset. I'm on 42s...


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## RoadBoy1 (Oct 1, 2011)

Thanks for all the great information everyone. I am a 220 lb rider and I may just check out a set of the Continental Ultra Sport tires in 25mm.

I have another question. Has anyone ever done a real world comparison of actual tire widths because it seems to me like the widths that are advertised by the manufacturers are pretty much a fairy tail. Even in this thread people talk about advertised tire widths not being correct.

Case in point, hearing many good things I bought a set of Vittoria Diamante Pro's in size 23mm. From the minute I put them on my wheels I knew they were not 23mm. At 120 psi and measured with a digital vernier caliper those tires came out to an actual 21mm. That plus the fact that they rode like I had a railroad tie up my butt I took them back to the shop I got them at and got a refund.

I would like to see a real world guide to actual tire widths. Put the tire onto a wheel and inflate to a safe, reasonable pressure, say 100 psi measure the tire and publish the results. I would rather the manufacturers not publish any information rather than to publish unreliable information that is only their guess.


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## PJ352 (Dec 5, 2007)

RoadBoy1 said:


> Thanks for all the great information everyone. I am a 220 lb rider and I may just check out a set of the Continental Ultra Sport tires in 25mm.
> 
> I have another question. Has anyone ever done a real world comparison of actual tire widths because *it seems to me like the widths that are advertised by the manufacturers are pretty much a fairy tail. Even in this thread people talk about advertised tire widths not being correct.*
> 
> ...


IME valid points. Some 21's run wide, some 23's run narrow, some 25's run wide, others.... so IMO the moral of the story is try some makes/ models, experiment with PSI's and settle on one or two that possess a mix of decent ride/ handling, flat resistance and decent wear - although the latter is much the same as motor vehicle tires. That being, the harder the compound used, the lower the ride quality, but the better the wear. So like most anything, there are compromises made. 

As far as manufacturers publishing unreliable info that's only a guess, I think they'd respond by saying that due to manufacturing tolerances there can be variances in stated specs within a certain percent, and I'd hazard a guess that any independent testing would reflect similar.


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## SFTifoso (Aug 17, 2011)

You can find good deals on tires on eBay. Just make sure to buy from reputable sellers, and note the location of the item before you commit to buy. If its cheap, it's probably from china and will take a month or more to arrive.

P.S. Found this interesting chart at Vittoria's site.


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## PJ352 (Dec 5, 2007)

SFTifoso said:


> P.S. Found this interesting chart at Vittoria's site.


The problem I see with that chart is that it only considers total rider weight and tire construction, versus Michelin's chart (which doesn't seem to be working, of late) that makes mention if those facets as well as tire size, riding style and road conditions, leaving experimenting (with PSI's) up to the user.


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