# 23mm tire on 25mm wheel?



## gravitywell (Aug 11, 2012)

I've ordered some wheels from my LBS, custom built. I currently have 23mm conti gp4000s on my bike. The new wheels are 25mm and one of the lbs guys told.me they would fit without problems.
My BS meter is already going off, but is there any truth in this? Or should I grab a set of 25mms myself?


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## cxwrench (Nov 9, 2004)

why do you think he's lying to you? don't you think it would make more sense if he was trying to sell you new tires that you didn't actually need? of course they'll fit. and they'll probably be a bit wider than 23mm on those rims. how many tires do you think actually match the width of the rim they're mounted on? pretty damn few...yours will work just fine. you can probably lower the pressure just a bit too...added bonus of wide rims. you'll love 'em.


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## gravitywell (Aug 11, 2012)

It just sounds weird to me. I'm new to the biking world, so when.I'm told a smaller tire will fit on a wider wheel is fine, it just doesn't jive right in my head. So what are the benefits, or downsides, to running 23mm on 25mm wheel? Will I notice a benefit to buying the 25's?


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## cxwrench (Nov 9, 2004)

you will have more air volume w/ the 25mm tires, so you can run them at somewhat lower pressure than the 23mm tires. very small downside is they weigh a little bit more. the larger tire will roll a tiny bit better. it will have better ride quality. it will have very slightly more traction. it will be a bit better at preventing damage to the rim. like i said...the only (very tiny) negative is the small increase in weight. it's really not even worth thinking about. unless you're below about 140-150lbs, i'd recommend the 25mm tires when you wear out your current tires. or if you just can't wait, you know what to do.


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## gravitywell (Aug 11, 2012)

Very much appreciated. I've been pretty confident with my LBS so far. They all seem very knowledgeable and very helpful. This was the only time something just didn't sit right with me. Thank you again.


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## wim (Feb 28, 2005)

Never heard of "25 mm wheels." Ask the guy what he means by "25 mm wheels," I'd be curious to know. And as said, rims take a range of tire widths, not just one width. I've run tires ranging from 20 - 32 mm all on one and the same rim.

Here's an excellent chart from Schwalbe. Note that a rim 25 mm wide properly measured on the inside takes tires from 44 - 62 mm wide. Hence my curiosity about what is meant by "25 mm wheels."


Schwalbe - Professional Bike Tires - Technical

/w


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## bikerjulio (Jan 19, 2010)

> Never heard of "25 mm wheels." Ask the guy what he means by "25 mm wheels," I'd be curious to know. And as said, rims take a range of tire widths, not just one width. I've run tires ranging from 20 - 32 mm all on one and the same rim.


This got me checking my wheels. I measure Mavic OP's at 20.0mm, Stans Alpha 340 at 20.75mm (20.0 nominal).

HED Ardennes are shown as 23mm nominal and will take a 23mm tire.

I don't know any road rims wider than these.


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## coachboyd (Jan 13, 2008)

wim said:


> Never heard of "25 mm wheels."


Gigantex has started producing a few 25mm wide wheels in both clincher and tubular and some companies are using them in their lineup. They are decent rims except for the fact that the maximum spoke tension is listed at 110KgF. . .which is way too low. It may be suitable for a front wheel but definitely not the rear.


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## gravitywell (Aug 11, 2012)

I'll check with them when I get a chance to swing by the shop. When we ordered, we decided on Ultegra rims, and I asked if I would be riding 23 or 25, he said they're 25mm rim but my 23mm tires would fit. Now I'm even more curious. Sorry for the newbie replies. I dove a bit head first into the cycling pool.


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## gravitywell (Aug 11, 2012)

I checked my receipt, it just says Ultegra rims, CX-Ray spokes and Chris King r45 hubs. I'm currently at 198lbs, we decided on 28/28 configuration. It doesn't give me specifics on the rim.


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## tlg (May 11, 2011)

wim said:


> Never heard of "25 mm wheels." Ask the guy what he means by "25 mm wheels,"


He's probably talking about the rim width











> And as said, rims take a range of tire widths, not just one width. I've run tires ranging from 20 - 32 mm all on one and the same rim.


Yup. Rims aren't made for one particular tire width.
https://www.jensonusa.com/Bicycle-Rims/Mavic-Open-Pro-700C-Rim
•Recommended tire widths: 19 to 28 mm


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## tlg (May 11, 2011)

gravitywell said:


> I checked my receipt, it just says Ultegra rims,


Then he's probably talking about the max tire size of the rim.
Applicable tire size: 700C (19C-25C)
http://www.shimano.com/media/techdo...0A/SI-4FP0A-002-ENG_v1_m56577569830753633.PDF


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## nhluhr (Sep 9, 2010)

gravitywell said:


> I checked my receipt, it just says Ultegra rims, CX-Ray spokes and Chris King r45 hubs. I'm currently at 198lbs, we decided on 28/28 configuration. It doesn't give me specifics on the rim.


Ultegra RIM??. The only Ultegra rim I'm aware of is a replacement part for the Shimano Ultegra wheelset so it would be either 16h symmetric for a front or 20h asymmetric for a rear. As far as I know, there is no such thing as a 28h Ultegra rim. What kind of frankenwheel is this you bought?

Ultegra Wheelset: http://bike.shimano.com/publish/con...els/product.-code-WH-6700.-type-.wh_road.html

Parts for 16h front wheel:
http://techdocs.shimano.com/media/t.../EV-WH-6700-F-2915B_v1_m56577569830753823.pdf

Parts for 20h rear wheel:
http://techdocs.shimano.com/media/t.../EV-WH-6700-R-2916B_v1_m56577569830753824.pdf


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## wim (Feb 28, 2005)

tlg said:


> He's probably talking about the rim width


That could be, but he's making the common mistake of referencing outside rim width (b) to the appropriate width of a tire. The width that matters (and is listed in the Schwalbe chart) is inside rim width (a). If all you know is outside rim width, you can estimate the inside width by subtracting 6 mm from the outside rim width.

I suppose there's nothing wrong with introducing yet another reference size ("outside rim width") into the cycling world. But in the bizarre and totally confusing world of tire size numbers, fewer "standards" would probably be better.


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## gravitywell (Aug 11, 2012)

So, I'm mildly ignorant, they were ordering me some Hed rims, for those wheels. Not sure where I got Ultegra from. Apparently they're back ordered, so I'm either waiting until October, or finding something else.


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## cxwrench (Nov 9, 2004)

you could have them built w/ Velocity A23's...Velocity - Content Template
they're not the widest things out there, but they are wider than 'normal'. they build up nice and don't weigh too much. we use them quite often. Velocity should have an off-center rim for use on rear wheels this month, iirc


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## DaveT (Feb 12, 2004)

gravitywell said:


> So, I'm mildly ignorant, they were ordering me some Hed rims, for those wheels. Not sure where I got Ultegra from. Apparently they're back ordered, so I'm either waiting until October, or finding something else.


If you can't get the HED rims, a great alternative is the Velocity A23 rim. Same width as the HED, has an excellent reputation and is considerably less expensive than the HED.


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## gravitywell (Aug 11, 2012)

I'm waiting for the wheel builder to call me back. I'll make the recommendation if the Velocity and I'll post back with the news.


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## Enoch562 (May 13, 2010)

cxwrench said:


> you could have them built w/ Velocity A23's...
> 
> they're not the widest things out there, but they are wider than 'normal'. they build up nice and *don't weigh too much*.




Little derail here...

What kind of weights are you seeing on the Velocity rim?


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## gravitywell (Aug 11, 2012)

I forgot to update, he started suggesting some DT Axis rims, and I asked about the A23. He admitted he didn't know much about it, his past experience with Velocity wasn't good. He did a little research and liked what he saw. He's ordering a few sets to play with, to see if he likes them. I also mentioned the off-site weight and he was intrigued, he's trying to see how long I'll have to wait on that gem.


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## danl1 (Jul 23, 2005)

cxwrench said:


> Velocity should have an off-center rim for use on rear wheels this month, iirc


This is an interesting something... A23 OC would be some sweetness.


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## cxwrench (Nov 9, 2004)

Enoch562 said:


> Little derail here...
> 
> What kind of weights are you seeing on the Velocity rim?


i'll have to grab a few this week and see what they weigh...i'll let ya know.


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