"Narrower" 23c tyres

[Beams]

I've got some clearance issues with my current Schwalbe Durano S 23c tyres rubbing the chain stay near the BB.

It literally needs to a 1mm narrower to be perfectly clear.

Went to LBS looking for a 21/20c and the guy said they are harder to find etc and mentioned some manufacturers claim 23c, but they are infact wider / narrower than other 23c tyres.

Can anyone confirm this before I run out and get 21c tyres? What would be a brand with slightly narrower 23c tyres.

[jacks1071]

You'll want more than 1mm of clearance to avoid frame rub. Probably best to go straight to a 21mm.

[Jean]

Sorry, I gotta ask. What sort of frame can't accept a 23mm tyre?

[2wheels_mond]

It's definitely aligned directly in the middle and the wheels are true?

I'm with Jean, strange that a frame wouldn't take 23mm tyres.

[rustychisel]

Veloflex Master 22c or 23c. None so narrow.

Echo the above, what frame is that gracile?

[Beams]

Sorry, I gotta ask. What sort of frame can't accept a 23mm tyre?

This thing unfortunately.



And the clearance issue:

It's definitely aligned directly in the middle and the wheels are true?

Rear wheel was recently built by a reputable builder, but I will have it checked tomorrow.

Found two manufacturers that produce tyres < 23c: Continental Grand Prix 4000S II (20c) and Vittoria Corsa CX Open Clincher (21c). How much does 1mm matter?

[rustychisel]

that's an old Teschner superlight, would be 6000x series aluminium I guess. Might be Easton tubing, but I doubt it. Predates Scandium, anyway.

tyres - bugger the 20c, get the Veloflex is my advice

[softy]

Tyres, hmmm.

Although manufactures give a size they vary from manufacture. Tubulars are always round, they have to be, but clinchers can be roundish or teardrop, which of cause varys the tyre.

Now some tyres can be sold as 25mm but are slightly smaller, veloflex are an example of this, they are 24-something, so under size. Rims can also affect the tyre and how it shapes from the rim, are your clinchers standard width?

Google is you friend, a few forums talk about this problem and what tyres are under size for their rating.

[redsonic]

How wide are your wheels? My 23mm tyres on Velocity A23 rims (23mm wide) barely fit into my front forks. Tyres were fine on Mavic rims (approx. 18mm wide).

[softy]

How wide are your wheels? My 23mm tyres on Velocity A23 rims (23mm wide) barely fit into my front forks. Tyres were fine on Mavic rims (approx. 18mm wide).

Ditto,
I have these rims on my commuter, but in tubular (velocity major tom 23mm). On my rims the tyre will still be round as tubulars are glued on, but on your rims the tyre at the bead is wider. They do this to try an achieve a more rounder tyre like a tubular, unfortunately this is making your tyre at the bead 4 to 5mm wider than a older style 18 - 19 mm rim.

I don't know if going to a smaller tyre will help, due to your rim always making the section round the bead wider.

Worse case sernario you may need to fit a narrow rim. I realise this is a pain as you need to buy a new rim and have it re-spoked.

[Blakeylonger]

Add some links to the chain, tension the ENO to the back instead of to the front.

Problem solved.

[jacks1071]

Add some links to the chain, tension the ENO to the back instead of to the front.

Problem solved.

[Blakeylonger]

* ENO eccentric hub being used for SS chain tension.
* Looks a lot like the axle centre is forward and below the axle bolt.
* Lengthening the chain will allow tensioning by swinging the axle centre behind the axle bolt.
* Moving the wheel backwards will increase tyre clearance.

[jacks1071]

* ENO eccentric hub being used for SS chain tension.
* Looks a lot like the axle centre is forward and below the axle bolt.
* Lengthening the chain will allow tensioning by swinging the axle centre behind the axle bolt.
* Moving the wheel backwards will increase tyre clearance.

Its a vertical drop-out, the wheel isn't going any further back unless I'm missing something?

[Blakeylonger]

* ENO eccentric hub being used for SS chain tension.

[Crawf]

Maybe its the angle but those tyres look like they are coming up bigger than 23mm when fitted, have you measured the actual width, now, fitted.

But whats mentioned above makes sense, rotate/move the hub backwards if to allows it.
https://www.youtube.com/watch?v=HokJ7O2MKHE" onclick="window.open(this.href);return false;

[mitchy_]

as crawf said, measure them then go from there.

on my wide clinchers, 25mm gatorskins came in at 26mm yet my 23mm ultremo zx's also came in at around 26mm wide. that suggests to me the gatorskin runs narrower, and may be worth looking into.

[Beams]

that's an old Teschner superlight, would be 6000x series aluminium I guess. Might be Easton tubing, but I doubt it. Predates Scandium, anyway.

Super impressive knowledge on the frame. Mr Teschner himself confirmed Easton tubing. Did you have a similar frame?

Add some links to the chain, tension the ENO to the back instead of to the front.

Problem solved.

The currently set up "back" instead of "front" position, as the tyre hits the brake bridge in the "front" position.

Wheels are Mavic Open Pro, so they are wider. Tyre measured in at 23.64mm on the vernier. Going to try a narrower tyre, fingers crossed that fixes the issue and avoids buying a new rim. Thanks for all the responses!

[Blakeylonger]

Drat, photo looked like the axle centre was forward of the dropout. Any way to add a link and go further back still?

Open pros aren't wide (inside width is the significant number) so changing rims won't help. Sucks to be stuck on super narrow tyres.

[eeksll]

If I understand the eno hub correctly, ie from the end of the video that crawf posted. The center of the hub is the "hole" and the dropout securing bolt is the off center bit. So to move the wheel back the bolt has to be in front of the hole. Is that how it works?

Just thought I might add my 2cents, the photo really does make the center of the rear hub looks forward and down. If the center of the hub was forward and up, that could cause the brake bridge clearance issue?

[softy]

If I understand the eno hub correctly, ie from the end of the video that crawf posted. The center of the hub is the "hole" and the dropout securing bolt is the off center bit. So to move the wheel back the bolt has to be in front of the hole. Is that how it works?

Just thought I might add my 2cents, the photo really does make the center of the rear hub looks forward and down. If the center of the hub was forward and up, that could cause the brake bridge clearance issue?

Yes sounds reasonable, you really want the offset to be at 7 or 8 o'clock to allow a little adjustment. Problem is the offset is reliant on how much adjustment you have in the brake caliper as the pads need to compress on the rim brake tracks.

[jacks1071]

* ENO eccentric hub being used for SS chain tension.

So you can get an eccentric in the rear hub? Very interesting. Thanks for sharing your knowledge on this, I'll have to google when I get some spare time.

[Blakeylonger]

So you can get an eccentric in the rear hub? Very interesting. Thanks for sharing your knowledge on this, I'll have to google when I get some spare time.

Yep. White Industries make it.

If I understand the eno hub correctly, ie from the end of the video that crawf posted. The center of the hub is the "hole" and the dropout securing bolt is the off center bit. So to move the wheel back the bolt has to be in front of the hole. Is that how it works?

Just thought I might add my 2cents, the photo really does make the center of the rear hub looks forward and down. If the center of the hub was forward and up, that could cause the brake bridge clearance issue?

Correct. The bolt is in the dropout and the wheel centre is able to rotate around it. so putting the 'hole' at ~3:00 (slightly lower depending on chainstay angle) is the most forward position, ~9:00 is the most rearward. You ideally want it tensioned at 7-8:00 as that way any hard impacts won't detension the chain like it would if it's at 10-11:00.



The photo does appear as if the centre is at ~5:00, so adding a link or two and tensioning to ~7:30 will increase chainstay tyre clearance but will slightly affect brake pad position, there may be enough adjustment to do this, but if not, a medium reach brake or a pair of BDOP offset pad holders will solve all.

[rustychisel]

that's an old Teschner superlight, would be 6000x series aluminium I guess. Might be Easton tubing, but I doubt it. Predates Scandium, anyway.

Super impressive knowledge on the frame. Mr Teschner himself confirmed Easton tubing. Did you have a similar frame?

I have a Teschner SC7000 frame, most excellent it is too. Nice to hear Peter still repsonds on a personal level, it's one of the great things to be able to talk with such an artisan.

As to the solution, I didn't know it was an ENO hub, but Blakeylonger has the answers.

[Beams]

The photo does appear as if the centre is at ~5:00, so adding a link or two and tensioning to ~7:30 will increase chainstay tyre clearance but will slightly affect brake pad position, there may be enough adjustment to do this, but if not, a medium reach brake or a pair of BDOP offset pad holders will solve all.

I just had another look and you are right, it was set at 5:00. After spending some time looking at it, it *might* be the chain too as I can't get adequate tension taking / adding a few links. Going to get a half link and hopefully that helps.

Correct. The bolt is in the dropout and the wheel centre is able to rotate around it. so putting the 'hole' at ~3:00 (slightly lower depending on chainstay angle) is the most forward position, ~9:00 is the most rearward. You ideally want it tensioned at 7-8:00 as that way any hard impacts won't detension the chain like it would if it's at 10-11:00.

Brilliant. I didn't even think about that, and was trying for 9:00. Definitely makes sense more sense to set at 7-8:00