Tire Pressure

roflomusic

I recently purchased a 2012 Scott Foil 20. It's a hell of a bike. I love it. After my first ride on the bike, I cleaned up the tires to remove any debris from the rubber. What I found the following day is that somewhere along my route, I suffered a puncture and a slow leak on the rear tire/tube - the tube was flat. Lesson learned - new tube purchased. On my 2nd ride, same route, after completion did post ride cleaning of the tires.

This time, there was no leak or puncture, yet the tire/tube did not feel as firm as when I rode the bike.

Now my question. How does the rider's weight and outside temperature affect the air/rubber of the tube?

At the time of both rides -
Weight: 245 lbs. (111 kg)
Outdoor temperature: between 45-50*F (7.2-10*C)The front tire/tube is fine. Nothing wrong.

Could my riding posture affect the tire/tube as well?

Please help! This my first big bike purchase and I love this bike. I don't want my first rides to be horrendous.

Bobbinogs

Hi there and welcome on board.

I take it you are checking tyre pressure before setting out? If you haven't got one already then I think a decent track pump (with gauge) is well worth the money and doesn't need to cost the earth (the Bonty Charger is less than £20 if you shop around).

There are lots of threads on the right pressure so I won't start that debate but there is a min and max stamped on the tyres...then you need to work out your min and optimum pressure setting based on your weight, comfort level and tyre size (for instance, I am 65k and run 23mm and have found 80-85f/90-95r to be dandy, anything less and I risk snakebite punctures, too much more and my fillings fall out...or feel like it). The CTC site gives a very good guide to min settings but you will need to be a bit subjective on weight distribution.

The tyres will deflate slightly over time so I always check over the bike before setting out (quick once over on the brakes, tyre pressure, cables look ok, etc.).

Tubes can be easily fixed (in most cases) at home for use again but you should always try and trace a puncture to work out if something is still stuck in your tyre (really important to do this at roadside otherwise you simply risk puncturing the new tube you have just put on the wheel).

desweller

Bobbinogs wrote:

Tubes can be easily fixed (in most cases) at home for use again but you should always try and trace a puncture to work out if something is still stuck in your tyre (really important to do this at roadside otherwise you simply risk puncturing the new tube you have just put on the wheel).

Chances are you've still got a piece of glass or something stuck in your tyre. They can be pretty tricky to spot sometimes, you can't always rely on running your finger round the inside of the tyre. Many people fit their tyres so the manufacturer's logo lines up with the valve to make tracking down the source of the puncture easier.

mamba80

Dont worry about air temp or your riding position. This Vittoria guide will give you a ball park figure of tire pressures/rider weight but you will need a track pump with a gauge.
Make sure you dont pinch the tube on fitting and that the rim bed and tire are free of anything that could re puncture the tube as has been said.
http://www.vittoria.com/tech/recom-tyre-pressure/

Nice bike as well

siamon

Your Foil is trying it's hardest with it's aero bits and rock hard rear triangle to give you every possible bit of help & encouragement to ride as quickly as you can. It's only fair that you maintain the tyres at the maximum pressure for least possible rolling resistance and therefore maximum performance. Dropping 5psi in the tyres for a bit of compliance/comfort will upset your bike's feeling's. It expects total commitment from it's pilot.

Pump them up to the maximum before every ride. Your bike will thank you.

Mr Flores, your decision to buy a beautiful Scott Foil as a first bike is inspired and should be roundly applauded!!

Hoopdriver

Like Babbinogs, I find that 80-85 front and 90-95 rear is excellent. I am about 80kgs myself

Pumping them up much harder than that is not really worth it and anything over 110psi on road surfaces (as opposed to track) has been shown to be counterproductive.

Thebigbee

Hoopdriver wrote:

Like Babbinogs, I find that 80-85 front and 90-95 rear is excellent. I am about 80kgs myself

Pumping them up much harder than that is not really worth it and anything over 110psi on road surfaces (as opposed to track) has been shown to be counterproductive.

All good and well but he is over 30KG heavier. The standards you specified are fine for your weight but you need more the heavier you are. At 110KG you're gonna need the tyres pumped up to the max

jthef

im about the 95 kg and run about 110 -115 psi
they do go lower to about 90 and any lower I start getting pich puntures.
But if you are getting a lot of puntures change the tyres.
When I got my bike I was getting a punture about every 30 miles changed to a gator skin and get about 1 per 1000 mile if I change the tyres when worn.

Jon

jthef

im about the 95 kg and run about 110 -115 psi
they do go lower to about 90 and any lower I start getting pich puntures.
But if you are getting a lot of puntures change the tyres.
When I got my bike I was getting a punture about every 30 miles changed to a gator skin and get about 1 per 1000 mile if I change the tyres when worn.

Jon