Safety of 23mm tires on wide rims?

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cmcdonnell
Posts: 278
Joined: Sun Aug 02, 2015 7:50 pm

by cmcdonnell

That Michelin article is very interesting but makes me more convinced that for my wheels 23mm are the right choice. I was considering trying the Power Competitions in 25mm but now thinking 23mm. The article says the tyre should be narrower at it's widest point than the rim ("widening the rim for aero benefits is really efficient as long as the tyre remains narrower than the rim’s widest point"), as the 23mm GP4000 II comes up at 24.8 and the rim is 24.2 so in theory I should use an even narrower tyre for optimum performance but Michelin still say 17C needs a 25mm but comes up at 26.7mm and rubs my brake calipers!! All very confusing so probably will stick with 23mm which is a real world 25mm.
Bianchi Oltre XR2 + Campagnolo Super Record 11 + Campagnolo Bora 50C
Litespeed T1 + Campagnolo Chorus 11 + Campagnolo Shamal Ultra

fogman
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by fogman

@cmcdonnell. You mention a Michelin article. Are you actually referring to the above Mavic article or is there a separate Michelin article on the same subject?


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cmcdonnell
Posts: 278
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by cmcdonnell

Duh... my mistake... I was referring to the above "Mavic" article!!
Bianchi Oltre XR2 + Campagnolo Super Record 11 + Campagnolo Bora 50C
Litespeed T1 + Campagnolo Chorus 11 + Campagnolo Shamal Ultra

fogman
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by fogman

The article implies that if you have a 17c internal bead diameter you should use a 25mm tire as per the ETRTO chart. Mavic designs their system with a 13c internal diameter, but a 27mm outside diameter. So you can use 23mm tires with the Mavic system. This results in a heavier, but more aerodynamic setup. On the other hand, Campagnolo Bora have a 17c internal width and a 24.2mm outside diameter, so a 25mm clincher tire should be used. Use of a 23mm tire would be at the users discretion.
The advantages of a 25mm tire is more air volume, so you can run less pressure for a more comfortable ride without increased risk of pinch flats. Improved handling.
The disadvantages of a 25mm tire are less aero, slightly heavier, and possible clearance issues with certain frames.


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Delorre
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by Delorre

I'm using a conti force + attack combo on my Bora's. Front is a 22mm tyre, but on a 17c rim and inflated, outside is around 24mm. Perfect match to the Bora rim IMO. 24mm rear tyre is almost 26mm when inflated. You have to look at the real diensions of the tyre when inflated, and not blindly follow the width on the sidewall. Conti's run wide, but Veloflex and Vittoria f.ex seem to have the advertised width, at most.

nemeseri
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Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

Bump. I'd love to see some official opinion from the wide rim manufacturers on this subject. HED's 21c rims would require a 30mm+ tires based on that chart. That's also true for some of the newer rims like the popular pacenti sl23/sl25.
ENVE also have some 18c+ rims, Flo's alloy+carbon rims come with 19+ rim width.

Seems like the big ones like Mavic / Shimano / Fulcrum / Zipp all stays around 17mm internal width, and I have a feeling that they have a reason for that (maybe it's just because of legal reasons, but who knows).

kervelo
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Location: Finland

by kervelo

HED has some recommendations on their page: see tech notes tab.
https://www.hedcycling.com/rims-hubs/rims/belgium-rims

23mm C2 clincher rim recommended tire width: 21mm+
25mm Plus clincher rim recommended tire width: 22mm+
23mm C2 tubular rim recommended tire width: 20mm+

fogman
Posts: 1067
Joined: Fri Oct 30, 2009 10:36 pm

by fogman

Campagnolo is deferring to the ETRTO chart for the Bora Clinchers. This would mean 25mm tires on their 17c rims.
ImageImage


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Lugan
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by Lugan

Interesting discussion, but can anyone offer confirmed examples of modern clincher tires blowing off modern clincher rims due to a size mismatch of the kind we're discussing? I can't remember hearing or reading about a single instance.

Marin
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Location: Vienna Austria

by Marin

Back before the wide rim trend hit we rode 55mm MTB tires on 19c rims...

If you don't run them at insane pressures, 23s are fine on wide rims. They'll come out as 25 or 26 anyway.

mellett68
Posts: 6
Joined: Fri Aug 05, 2016 8:54 am

by mellett68

Apparently my Fulcrum 7 LGs are 17c internal width. I ran them with 23mm Gatorskins for 18 months with no problems. Hadn't even thought about it.

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F45
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by F45

Don't use Challenge clinchers on anything over 15mm inner.

Marin
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Location: Vienna Austria

by Marin

Why?
I've been running Challenge Strada Bianca 30mm on 18c rims without problems.

Sleepless
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Location: Istanbul, TR

by Sleepless

F45 wrote:Don't use Challenge clinchers on anything over 15mm inner.


I learnt that the hard way. :( I lost 2 Stradas and a friend lost a P-R clincher on 17C carbon rims. From brand new to trash just in 2 weeks. Luckily no crashes though but it was close.

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F45
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by F45

Marin wrote:Why?
I've been running Challenge Strada Bianca 30mm on 18c rims without problems.


Man, I've mounted Strada Bianca and Parigi Roubaix on 17mm iw and 18mm iw and both just blew off the rims randomly. These were new tires, too.

The third time it happened, my new neighbor I hadn't met yet thought it was a gun shot and came out to investigate, and we talked a bit. So that was good.

I got one very lightly used PR and three new in box sitting my my closet. No idea what to do with them. Don't trust them at all.

Sleepless, I was also lucky. It happened on the rear every time so no crashes. Different wheels too.

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