maartendc

Hey all,

I'm thinking of switching to 28C tires on my commuting bike for extra comfort over my 25C tires. I have enough clearance in the frame width-wise, but the height of the tire might be a problem.

I only have about 4-5mm of height clearance to my brake calipers right now with the 25C Continental Gatorskin. I am thinking of switching to the 28C Michelin Pro4 Endurance V2. On top of that, Michelin tires tend to run a bit wider than the average tire.

Would the extra height of the 28C be a problem you think?

Thanks!

Fiery

It's close, hard to tell without trying. But even if it fits, there will be so little clearance that any debris caught on the tire will likely scratch the brake bridge/inside of the fork.

rowebr

The best guess is that a tire that is 3mm wider will also be about 3mm taller.


However, since you are thinking of changing to a different model of tire and a wider size, that guess could easily be off by enough to run into clearance problems if you have only 4 to 5mm available under the brake caliper. Here's an idea, if the Michelins tend to run a bit large for the stated size then try the 25mm Michelin. Even if it measures 27mm on your rims that will provide a bit more cushion for your commute.

maartendc

Thanks for the advice!

Yeah.. I would assume this as well that 3mm wider is also 3mm taller.

I looked around online and found the measurement of the 25C Michelin is actually 2mm wider (28mm vs 26mm) and 2mm taller (25mm vs 23mm) already than my 25C Continental.

Michelin Pro 4 Endurance v2 Rolling Resistance Review
Continental Gatorskin Rolling Resistance Review

So the 28C Michelin would possibly be 5mm wider and 5mm taller than my 25C Continentals! The 28C Michelin actually probably measures around 31mm wide. I think the 25C Michelin would definitely fit, but I do want to run the widest possible tires for extra comfort over the potholes. I guess I will order both the 25C and 28C Michelins, and then return or Ebay the 28C if they prove to be too wide.

Thanks!

rowebr

Sounds good! Especially for commuting I think it really makes sense to run the widest tires that will fit in the frame. My commuter bike is an old steel MTB set up with 54mm slicks

Sy Reene

Don't necessarily take everything you read as gospel. My 25mm Endurance V2 tires measure exactly 25mm on my rims, inflated to 95psi, on 15C wheels. Michelin tends to use the ETRTO standards for their reference -- a 15C wheel sits somewhat in the middle of the supposed appropriate wheel width range on an ETRTO chart for 25mm tires. the links you posted from Bicyclerolling resistance use a 17C reference wheel, which is the lowest limit for a 25mm tire for ETRTO standards. Anyway.. I'm not making a judgement on what's safe, but just telling you why things are this way. The graphic below tells a similar story.. ie. a tire's width when inflated can change significantly based on what wheel rim width is (interior measurement). Michelin isn't intentionally misleading you IOW.

maartendc

Thanks, yes I was familiar with that diagram as well, and seems that wider tires are indeed taller as well.

Well that might be true, but bicyclerollingresistance.com measured both the Continental and the Michelin on the same wheel, and the Michelin was wider. So it stands to reason that, regardless of rim width, the Michelin will be wider on my wheels than the Continental as well? The difference between the two would just scale with the rim width I imagine.

Not sure which size my rims are. I think they are "old school 19mm rims", which I think means the 14mm inner width?

In any case, I guess the only way to find out for sure if it fits will be to try. I imagine the 25C Michelin will definitely fit, and the 28C Michelin will either barely fit or not fit.

gl98115

So true. I stopped reading at this point of the post.