General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

Actual vs. Nominal Tire Width

Old 01-25-19, 08:54 PM
Junior Member
Thread Starter
Join Date: Jan 2019
Posts: 14
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Likes: 0
Liked 3 Times in 1 Post
Actual vs. Nominal Tire Width

I have an older bike with narrow chainstays. My Conti 4000IIs 23mm tires can just barely fit with a 17mm internal width rim. They measure 25.4mm when inflated to 100psi. Does anyone have alternative tire suggestions that would likely have less girth than the Conti 4000ís?

SpectrumTi is offline  
Old 01-26-19, 12:01 AM
fietsbob's Avatar
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,464

Bikes: 8

Mentioned: 183 Post(s)
Tagged: 0 Thread(s)
Quoted: 6718 Post(s)
Likes: 0
Liked 139 Times in 117 Posts
1 you measure, yourself, .. other you believe what you read online ....

I put Conti 28 on a Mavic e2 rim and they're measuring 25..

Insufficient Clearance? send the frame out to be indented carefully, for more clearance??

Only Sew up , Tubular tires, can control the tire width , ..Tufo tubular clinchers engage clincher rim's edges with 2 channel rings..

otherwise the rim choice effects the width, taking up a section of the circularity...


Last edited by fietsbob; 01-26-19 at 10:18 AM.
fietsbob is offline  
Old 01-26-19, 03:34 AM
Me duelen las nalgas
canklecat's Avatar
Join Date: Aug 2015
Location: Texas
Posts: 8,819

Bikes: Centurion Ironman, Trek 5900, Univega Via Carisma, Globe Carmel

Mentioned: 151 Post(s)
Tagged: 0 Thread(s)
Quoted: 2676 Post(s)
Liked 66 Times in 56 Posts
Depends on the rims. On my old Araya CTL-370 rims (14mm inside width) 700x23 and 700x25 Conti and Schwalbe tires measure right at their nominal widths. That's on an '89 Centurion Ironman, which was originally equipped with 700x18 or 700x19 tires on those rims. 700x23 feels like the sweet spot for handling and comfort. 700x25 felt a bit splashy on the front on fast curves -- not enough support for the wider tire.

Rims with 17mm inside width may be a bit too wide for an old school road bike like that. That's what I'd choose for 700x28, maybe up to 700x32 tires, but my road bike won't handle those.

Or, if not different and narrower rims, try some new/old stock Schwalbe One V-Guards in 700x23. They didn't run wide, and have more supple sidewalls than the Conti Ultra Sport 2. They're still available, around $30 each. Excellent road tires. A bit prone to nicks so avoid broken glass, etc. But even after many nicks and cuts mine kept going for months, long after I probably should have replaced them. Good puncture resistance for a lightweight tire with minimal puncture shield. Smooth and fast rolling too. Wish Schwalbe had kept making 'em.

I've switched to Conti Ultra Sport 2 because they'e a bargain for good performing tires. Heavier than the Schwalbes but much more resistant to nicks and cuts, and no more puncture prone despite lacking a puncture shield. Both the 700x23 and 700x25 measure right at nominal specs *on my rims*, per my calipers.
canklecat is offline  
Old 01-26-19, 07:53 AM
On Holiday
Hoopdriver's Avatar
Join Date: Apr 2017
Posts: 1,063

Bikes: A bunch of old steel bikes

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 389 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by canklecat View Post
Rims with 17mm inside width may be a bit too wide for an old school road bike like that.
I second this. If you want to run narrow 23mm tires, you'd be better off running rims with something like 13mm inner width. I'm gonna guess that these are not the original wheels for this bike, right? Sounds like you have some decisions to make.

Originally Posted by fietsbob View Post
Insufficient Clearance? send the frame out to be indented carefully, for more clearance??...
I've had to dimple the chainstays on a few frames for additional clearance. Sometimes you can get by with just a little bit of strategic flattening. This is an option, but I'd still recommend narrower rims.
Hoopdriver is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.