28mm tyres on 20mm Meilenstein clinchers?

[Prawn]

According to the manual from Lightweight, 20mm wide Meilenstein clinchers are specified for up to 25mm tyres. However, a quick look at the ETRO chart suggests that 28mm tyres should be OK. Despite the aero disadvantage, I'd like to try 28mm tyres.

Has anyone tried this combination? Are there any safety or handling concerns that should be taken into consideration? Please let me know your thoughts.

[AJS914]

Is that 15-16mm internal? I'm sure they will fit and it will work but it won't feel good. I once tried 25mm GP4000s (about 27mm actual) on some older 15mm internal rims and the handling just felt sloppy. I went back to the 23mm GP4000s and it was a lot better.

[Calnago]

Concur with above... 25mm Conti 4000sii’s would fit fine on my Campy Neutrons but didn’t feel all that great handling wise. Lots of volume though. And they sat really tall as well so if you’re at all tight in clearance that’s another issue. A 28mm would be even worse and if you’re running rim brakes properly adjusted for those rims you would not be able to remove the wheel simply by flipping the brake caliper release. If you’re running discs then the clearance issue is moot but they still wouldn’t be ideal from a handling perspective. What I would suggest for those rims is the Specialized 24mm Turbo Cottons. Best riding clincher and the most perfect fit for that rim.

[Marin]

I'm running 28s on 15c, no problems.

[Prawn]

Thanks for your replies AJS914, Colnago, and Marin. I should have mentioned that I'm running 25mm Conti 5000 on the 20mm Meilensteins at the moment; they are OK in terms of handling and in terms of brake caliper release (just). The reason for experimenting with wider tyres is to try to improve my descending speed and technique: I lack the confidence to go fast downhill when my front end starts bouncing, and I've found that wider tyres (adimitedly on wider rims) and lower pressures help to reduce bounce and increase confidence. 24mm turbo cotton's may be the ticket; if I recall correctly they may actually measure wider than a conti 25mm and definitely more supple - perhaps a set of these in conjunction with latex tubes?? I wonder what the lowest safe pressure would be (given that I'm 69kg).

I received a helpful reply to my question from Lightweight. They told me that 28mm is the maximum size, but that I would feel that the tyre 'tilts' faster. I guess there are compromises associated with riding on a lightbulb-shaped tyre!

[AJS914]

On those narrower rims you would have more confidence on a 23mm GP4000.

[pdlpsher1]

Conti changed the way they mark tire width. 25mm GP5K is almost the same as the 23mm GP4K in terms of tire volume.


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[Calnago]

Yes, the new Conti 5000’s would be a better match than the 4000sii’s, but I think it’s funny that Lightweight now is ok with 28mm on those rims. They seem to change their max size recommendation to whatever the trend is. They used to recommend 23’s, then when it became apparent that 25’s were the new normal, they said 25’s could be used. Sure, a 28 will fit on that rim but it will be a horrible handling combo. But you could try it.
The specialized Turbo Cotton 24’s fit nicely on an internal rim width of 15mm. I use them on my Campy Neutrons. They certainly won’t be as voluminous as a larger tire, but they are very supple for a clincher. You may just have to experiment for yourself to see what works best for you and your riding.

[Alumen]

I ride 28mm on 19C rims and that is just perfect in terms of handling. So I would see no reason on why no 28mm on 20C Meilenstein rims ?

Btw. I had 23mm GP5k on my 17C Fulcrums and they measured 24.7mm.

[Calnago]

Don’t confuse external width with internal width (relevant to clinchers). The Meilenstein’s being talked about are 20mm external width. The internal width is only ~15mm.

[survivor]

I just mounted Conti 5000 on my Meilenstein 20mm external width and went for the first ride with no issue. Didn’t notice any apparent handling issue.

Quick off topic question, is there a specific rotation direction for Meilenstein front wheel? Rear wheel is fixed due to freehub location. I assume the front wheel Lightweight decal has to be aligned with rear wheel with respect to valve location?

[Prawn]

Well, I went ahead and tried it: Mounted Conti 5000 28mm tyres front and rear, inflated to 80psi front and 85psi rear. They measured 27mm mounted. Initial impressions were good; more confidence down hills in straight lines due presumably to better 'suspension'. However, the sudden flop on sharper corners was very disconcerting. I imagine that the flop problem could be reduced by pumping the tyres up more, but that would defeat the purpose. I may try the 26mm turbo cottons - otherwise it will be back to 25mm. Thanks again for the helpful inputs above.