Tyre pressure advice for PR sportive

siddy1972

Hi all. Hoping someone out there has some knowledge about the Paris Roubaix sportive.
All booked in, the crosser is set up with a set of Challenge Strada Bianca tyres, but I'm a bit stumped with the pressure. Been cruising around with 100psi and they're lovely, but I reckon that's probably too much for the cobbles...
Any advice on the best pressure for a 70kg rider?
Thanks.

BrandonA

I have no idea what presure you will want/need. Have you thought though about simply starting the ride with the pressure where it is and if it seems a little high stop and deflat slightly?

dj58

How wide are your rims and tyres?

Bobbinogs

Might be worth thinking about tyre choice, aren't those Stradas renowned for being one of the worst to change particularly at roadside?

src1

30mm tyres at your weight of 70Kg - I'd say about 70 psi front, 75 psi rear. You might be able to go a bit lower with a large tyre like this, but much lower and you'll risk pinch flats.

siddy1972

Thanks for the input, the Strada Bianca aren't so bad to work with, as long as you're patient and make sure the tube isn't trapped. They're 30c, by the way. The rims are 19mm I think.

JoostG

I normally use Hutchinson sector 28mm tubeless tyres for cobbles. My weight is approx 71 kg. At Paris-Roubaix you can start with your normal pressure. At Arenberg you should lower the pressure as the fun starts there, and pavé sections after pavé section follows. From that point I ride with approx 65 psi front and 70 psi rear.

roger_merriman

I suppose it also depends on how wide in reality the Challenge Strada Bianca tyres are, at 90KG I run racing ralphs 700x33 at 60psi (my CXing is more 3 peaks like, ie I use it as a MTB *lite*)

ugo.santalucia

around 70-80 PSI seems about right. Remember it's not about comfort, it's about speed. If the tyre is too hard, it bounces more and slows you down. Comfort is a bit of a myth, there is virtually no difference between running a 120 PSI 23 mm tyre and a 60 PSI 30 mm tyre, when it comes to Paris-Roubaix.... but if you go quicker, 3 Km of a sector of pave' also go by quicker.

siddy1972

Thanks for the advice- I'll try 70 on the front and 75 in the back then. Was hoping it would make the Pave tolerable, but it seems not :-) Hoping the extra volume avoids pinch flats- should I switch out my latex tubes or keep them in?

ugo.santalucia

siddy1972 wrote:

Thanks for the advice- I'll try 70 on the front and 75 in the back then. Was hoping it would make the Pave tolerable, but it seems not :-) Hoping the extra volume avoids pinch flats- should I switch out my latex tubes or keep them in?

Nothing makes pave tolerable, except yourself... it's will power. I don't like latex inner tubes, but other people swear by them.
How to ride pave': seat way back on the saddle to avoid your front wheel sinking, place your hands on the drops or on the bars, don't ride with your hands on the hoods, never. Ride at your threshold, which means ride hard but make sure you can hold that power for 5-10 minutes. Don't brake, even when the pave' goes down. Find a good line and change line if you need to. Plan your overtakes so that you can choose a good line. If your speed slows to under 25 Kmh it won't go back up, so don't let it drop

siddy1972

Thanks for all the great tips. I guess you've done this thing before...it seemed like a good idea at the time my mate suggested it, but getting nervous now it's getting close. Should've stayed away from Google image search too...

ugo.santalucia

siddy1972 wrote:

Thanks for all the great tips. I guess you've done this thing before...it seemed like a good idea at the time my mate suggested it, but getting nervous now it's getting close. Should've stayed away from Google image search too...

It's an acquired taste. I like it, but it hurts. You have to light a candle to get dry stones, as wet pave' is pretty much like ice and the first half of the P-R is not as flat as you see on TV... going downhill on wet pave' is terrifying.
I second those who say light touch on the bars... if you grab them tight, your hands will cramp, hence my advice to stay on the bars or the drops... easier to keep a good hold without clinging too hard

onyourright

I’m not much of a cobbles rider, but in addition to Ugo’s tips, I find it a little easier if I use a higher gear than normal. Maybe this is because more weight on the pedals means less on the violently bouncing saddle.

If you’ve never ridden on cobbles before, this is going to be an experience. The Belgian racers on TV make it look way, way smoother than it really is. It is brutal beyond description.

Monty Dog

I first rode RvV and P-Rx in 2000, when you could simply rock-up and ride. PrX was the full-deal 269km, not the shandy-drinkers version ;-) I'd start at 60psi front/65psi rear - the point is to prevent tyre rebound. Technique is about driving the biggest gear you can cope with, getting your weight back over the saddle and driving from your quads - it also does a good job of keeping your butt 'hovering' over the saddle. Practise riding on long steady drags in your big ring, even better on fire roads.

bernithebiker

I cannot understand why people take pleasure in riding over cobbles.

Mostly when out in a group, everyone signals and avoids the holes/bumps.

PR is like deliberately riding towards them.....!

ugo.santalucia

bernithebiker wrote:

I cannot understand why people take pleasure in riding over cobbles.

Mostly when out in a group, everyone signals and avoids the holes/bumps.

PR is like deliberately riding towards them.....!

It's a fetish like another, some stick needles to emboss their skin, others pierce their tongue, we ride bicycles on cobbles...

olake92

An opinion: no different to what you would ride on a normal road. As mentioned, comfort is a bit of a red herring; cobbles aren't comfortable and there's nothing you can do to change that aside from ride as fast as possible and let the bike do what it wants by not really sitting on it a la cyclocross (check out some vids of Stybar and you'll see what I mean). Going slowly is what makes cobbles feel like a jackhammer, if you're fast you kind of glide on the top of them.

If you go for a lower pressure you increase the risk of pinch flats, which are very real dangers on cobbles, and negatively impact the rest of your ride (remember, most of the route is paved). As for gearing, whatever suits you is best - try not to change your style for cobbles as you're still just riding a bike. Personally, I am happy at 90-100rpm. Cancellara and Boonen spin over them like bosses and are magnitudes better than all of us.