Tyre pressures.....

[reohn2]

Is Boonen running above or below the 15% tyre drop rule of thumb?

Who know's?but one thing's for sure,you don't win races by being the slowest,or by continually puncturing

[PeterBL]

And he kinda did win...

[reohn2]

And he kinda did win...

Yep,that'd be right

[mig]

how many of the wheels will just be condemned by the teams though after that race using those pressures?

What's that got to do with anything?
The only time a wheel rim is damaged on a rough road is when the tyre is compressed to the rim making the rim take the hit,in that situation you'll most likely get a snakebite puncture.

well i have seen the occasional flat tyre in paris roubaix over the years!

[PeterBL]

Ok, I did the math. If he and his bike weigh 205 lbs incl clothes, water and what not, he should be running 68/84 psi to use the 15% rule. So he is well below that especially on the rear.

[reohn2]

how many of the wheels will just be condemned by the teams though after that race using those pressures?

What's that got to do with anything?
The only time a wheel rim is damaged on a rough road is when the tyre is compressed to the rim making the rim take the hit,in that situation you'll most likely get a snakebite puncture.

well i have seen the occasional flat tyre in paris roubaix over the years!

I've also seen punctures over the years on silky smooth tarmac too,but you'd be more likely to puncture on the kind of bad roads ridden in P/R.
The idea is to win the race,the race is won by going faster than anyone else,bigger tyres and lower pressures proved that in 2012.

As I said up thread many people I believe,run tyres at way too high TP's in the belief that they'll go faster, also that they'll puncture less and because "that's the way it's done" the reason for the thread is to try and dispel that myth.

[reohn2]

Ok, I did the math. If he and his bike weigh 205 lbs incl clothes, water and what not, he should be running 68/84 psi to use the 15% rule. So he is well below that especially on the rear.

So that's another myth taken care of............maybe

[Brucey]

and the bloke that came second was riding fatter tyres than the bloke that won....

..which proves....?

cheers

[reohn2]

and the bloke that came second was riding fatter tyres than the bloke that won....

..which proves....?

cheers

He wasn't fast enough

[mig]

As I said up thread many people I believe,run tyres at way too high TP's in the belief that they'll go faster, also that they'll puncture less and because "that's the way it's done" the reason for the thread is to try and dispel that myth.[/quote]

yes i see what you're saying. my point was is the downside of this damaged rims? these would mean nothing to a pro but something to most/all others.

[reohn2]

yes i see what you're saying. my point was is the downside of this damaged rims? these would mean nothing to a pro but something to most/all others.

If a pro was to get snakebite punctures continually on P/R there's a good chance he'll ruin the rim in the process,the fact that the winner and previous winner plus other similar events(Tom Boonan) doesn't,even though he runs(according to the article)the lowest TP's surely prooves that his TP's strategy is the correct one.

[Vantage]

Pinch flats have been very rare for me, from my fat tyred mountain biking days, skinny tyred road bike days and my current touring bike. The trick is finding the ideal tyre pressure, not too soft and not too hard and learning to "unweight" the bike in situations where a pinch flat is a possibility. Sort of like a mini bunny hop without the tyres leaving the surface.
I've found 40-45psi to be a nice number given my weight, 9 stone on 35's.

[mig]

the article states that many of the tyres used by teams have stiffer casings than the norm so the pressures mentioned aren't a direct comparison to the sort of kit widely available that matches for size.

[reohn2]

the article states that many of the tyres used by teams have stiffer casings than the norm so the pressures mentioned aren't a direct comparison to the sort of kit widely available that matches for size.

You're not convinced by lower TP's are you
FWIW almost all teams were running tubs,something the vast majority of cyclist don't.
Most were also running C/F rims again not something most cyclists have.
They also went far faster than most cyclists too.

Over quite a few years I've come to realise that big(ger) section tyres at lower TP's or even smallish section tyres run at lower TP's than is generally thought to be best,can make a bike more comfortable with no loss of speed or more energy input.That's more apparent on our badly surfaced and poorly maintained roads and also more apparent if load per wheel is taken into consideration.
If weight distribution on the two wheels of a bicycle is 40%Fr to 60%R,and(to make it easy) if the total psi in both wheels is 100psi the distribution is 40psiF 60psiR that would give correct tyre drop for each wheel loaded.
It isn't always that simple as weight distribution can vary though it would be unusual for it be anywhere near 50/50%.
TP's go higher if the tyre is smaller section,or stiffer carcass or both,but if a tyre is supple and bigger section the TP's go down.
It's easy to find the correct TP by putting enough air in to give 15% tyre drop when loaded as per this article,which I find very useful:- http://www.bikequarterly.com/images/TireDrop.pdf

There are still experienced cyclists who think that to get as much air in a tyre as it'll take or to put whatever maximum it says on the sidewall is best.
I am challenging that belief.
The linked article supports my own experience.

[mig]

no it's not quite that. saying that 70psi in a 28c PR special isn't going to get the same result as 70psi in a schwalbe 'xxx' 28c bog standard.
i'll let some steam out of the tyres in my commuter bike and see what difference i can feel. the roads around here are about 40% gravel, 60% hole so i'll see what the boonen effect has....