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Racing on Cobblestones.......couple of questions.(15 posts)

Racing on Cobblestones.......couple of questions.ATLien
Apr 29, 2003 6:40 AM
Since apparently no-one in the general forum cared to answer, I'm reposting here:

Does anyone have any preferred tires for cobblestone racing? I've got a TT coming up in a few weeks and am thinking of going from my 700x23 michelin axial pro's to a 700x25 at least but don't know which tire to choose(michelin doesn't make the pro in 25). Riding on Ksyrium's so I'm not so much worried about wheel strength as I am pinch-flats or punctures.

What pressure would you recommend riding?

Thanks in advance for the help!
What's the scenario?TJeanloz
Apr 29, 2003 8:40 AM
I think it depends a lot on the course. If the whole thing is badly cobbled, I would definitely run 25s. If it's just a steep climb or some isolated, short sections of cobbles, I'd run 23s.
Increase pressure to avoid the pinch flats. 25s. nmSpunout
Apr 29, 2003 9:16 AM
50% of 2.1mi course is cobbled, mostly on climbs and a coupleATLien
Apr 29, 2003 9:48 AM
of 90 degree turns.

I'm thinking of going with 25's just to be safe and running higher (120psi at least) than I normally ride (110psi)
few more thingsDougSloan
Apr 29, 2003 10:21 AM
I'd use 25's, as there is almost no speed penalty on the anyway. Some tires have stiffer sidewalls, which might provide further protection. The Conti Gatorskin would be good, as it also has thick rubber and sticks fairly well.

Heavier tubes can help; thin ones pinch flat more easily.

Depending on your weight, 120 probably will ensure no pinch flats.

Doug
Can you ride off the cobbles on the turns?brider
Apr 29, 2003 1:16 PM
Say, on a slightly softer shoulder or just against the edge of the cobbles? You'll be able to maintain more speed through the corners that way.
Be careful with the higher pressure recommendationsKerry
Apr 29, 2003 4:55 PM
Depending on your weight, you may not need higher pressure to avoid pinch flats, but higher pressure will definitely compromise your traction on cobbles. If they are true cobbles and well-polished from traffic, you run the risk of losing traction with all the surface discontinuities. Balance traction agains pinch flat protection. I'm thinking more like 6-7 bar, depending on your weight.
Agree on thisLDO
Apr 30, 2003 10:46 AM
Hi there. I do not race, but I have built up some experience of riding on cobble stone roads as I live in Belgium. I would keep the 23 (what I mount on my wheels) and would keep a slightly lower pressure than used on asphalt (8 to 9 in my case). It really depends on the type of cobblestones. If they are " gentle" ones (as you find often in European cities, in the historic centres: small size, well squared, well placed on the ground, to form almost a uniform surface), I don't really see a difference with asphalt. If they are " real" ones - big cobblestones, not well aligned, with some space in between, consumed and dis-aligned by years and years of use with no maintenance like the ones you can find some parts of the Flanders (see the Tour the Flanders), my experience is that a different (slightly lower) tyre pressure will help. If you already run pressures of 8 atm, I would not elect to go higher than this.

Again, oe word of caution: I am not a racer (but I really do like cobblestones, the " real" ones).

If you have wheels not radially laced, this should help as well (in particular rear wheel).

If you can test one of the parts in cobblestone before the race (e.g. the day before), that would be the best for you, so you can fine tune your bike.

Good luck with your race.

Luca
re: Racing on Cobblestones.......couple of questions.kenyonCycleist
Apr 29, 2003 8:12 PM
a TT on cobbles?? usually TT course are flat w/ good pavement. what is thee name of this hardcore TT?
re: Racing on Cobblestones.......couple of questions.Cat 4 boy
Apr 30, 2003 4:00 AM
After this year's Het Volk, the English rider Roger Hammond had a terrible battering on the cobbles & asked Frank Vandenbrouke what pressure he ran in his tyres, the answer was 6 bar front & rear, as opposed to the 8 bar Hammond was on.

If I were you I'd DROP the pressure as above, and go 25mm if it's a really long section of pave.

Good Luck
Thx for the advice......it's the TT portion of the Shelby CountyATLien
Apr 30, 2003 5:48 AM
Stage Race in Montevallo, AL. I've since spoken with several riders from last year who said that the "cobbles" are actually just regular brickwork and not akin to "english cobblestones". I'm just going to run my 23's and hope for the best!
Thx for the advice......it's the TT portion of the Shelby CountyCat 4 boy
May 1, 2003 4:16 AM
Sounds like a good choice if it's regular brickwork, anyway if you're TTing "properly" ie notfarfrompuking, you won't even feel the cobbles, go for it.
Hey ATLien....I_See_Fred_People
May 2, 2003 7:51 AM
...are you going to run any aero equip for this TT? i was told its not necessary.
Nah, might put on bars depending on course, but nothing else.ATLien
May 5, 2003 5:20 AM
aero bars may be good ideacielovia
May 5, 2003 8:04 AM
the first mile is smooth and fast. the cobbles start on the only significant (but short) hill. Once over that, it's a fast cobbled section to a round-about that once again would favor aero bars. Clip-ons that won't affect your hand postitioning or anything would be ideal. 700x23's will be fine as well. good luck.