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Re: Changing tyres!

Posted: 16 Jul 2020, 7:11pm
by Brucey
I think it is fair to say that roller tests give you a pretty good idea of how tyres of similar width/build are likely to compare with one another, when all else is equal. It is much less clear that they allow a good comparison of likely Crr values on real roads, when fitted to real bikes, between tyres of greatly different widths. Such comparisons may also vary with the quality of the road surface and the characteristics of the bike the tyres are on, too.

Until there is a test that allows for these things, 'hearsay' might be as good as it is going to get if you want to make such comparisons.

cheers

Re: Changing tyres!

Posted: 16 Jul 2020, 7:22pm
by reohn2
freeflow wrote:The rolling resistance data shows a 15W difference between GP5000 622 28C and Vittoria Hypers 622 37C. What that 15 watt difference means in terms of speed difference is rider dependent.

The GP5000 may very well be the fastest on paper and the difference would show on shorter rides.
But that's not the whole story,on longer rides comfort is an ever increasing factor,and when fatigue sets in the longer you're in the saddle,especially on UK crapmac roads when that fatigue robs the rider of power to the pedals.

Re: Changing tyres!

Posted: 16 Jul 2020, 8:23pm
by freeflow
Colin531, you converted me to Vittoria Hypers many years ago. The bike that used them was stolen, so I'm stuck with 28c tyres at the moment. The GP5000 have put a grin on my face. For me, that 15W makes areal difference in how the bike feels. I've no idea what it means for other riders.

Re: Changing tyres!

Posted: 16 Jul 2020, 8:32pm
by Brucey
freeflow wrote: ….For me, that 15W makes areal difference....


it might do, if it actually exists on real roads rather than rollers.....?

cheers

Re: Changing tyres!

Posted: 17 Jul 2020, 9:34am
by hamster
freeflow wrote:Colin531, you converted me to Vittoria Hypers many years ago. The bike that used them was stolen, so I'm stuck with 28c tyres at the moment. The GP5000 have put a grin on my face. For me, that 15W makes areal difference in how the bike feels. I've no idea what it means for other riders.


On the same bike, I reckon GP4000sII were worth 1-2 minutes on an 18 mile loop. I could make it under the hour with them, typically 1:01 or 1:02 on GP4Season. The ride was also more supple. I've not gathered GP5000 times yet.

There is undoubtedly a psychological effect of whether something 'feels fast' which isn't replicated in times, and (as said) what's good for a short TT can be eliminated by fatigue.

Re: Changing tyres!

Posted: 17 Jul 2020, 9:48am
by reohn2
In an attempt to answer the OP's question WTB Horizons get good reviews,as do Rene Herse Babyshoe Pass,neither tyre is cheap,but then quality rarely is.

Re: Changing tyres!

Posted: 17 Jul 2020, 9:26pm
by Jamesh
How do gp5000 compare to say Michelin pro4???

Cheers James

Re: Changing tyres!

Posted: 17 Jul 2020, 10:37pm
by reohn2
Jamesh wrote:How do gp5000 compare to say Michelin pro4???

Cheers James

Are they available in 650b?

Re: Changing tyres!

Posted: 18 Jul 2020, 7:15am
by freeflow

Re: Changing tyres!

Posted: 18 Jul 2020, 8:11am
by seph
[quote][/Agreed GP5000 are wonderfully fast and supple tyres. I love them.
If you ride roads with lots of trash and flints be warned that they may not last well. I typically get around 1000 miles out of one before it gets terminally cut. For me it's a summer-only tyre. Michelin Pro4 Endurance is not quite as fast, but way tougher in


....1000 miles.. is that it? Blimey.. :shock: I suppose you would get faster at swapping tyres.. :wink:

Re: Changing tyres!

Posted: 18 Jul 2020, 9:51am
by reohn2
freeflow wrote:https://conti-tyres.co.uk/road-and-track/clinchers/grand-prix-5000

Thanks,I was unware of that.