When To Check Tyre Pressures?

[billyt]

I doubt seriously that anyone could tell a one rear tire PSi differential at any pressure above 3 PSI in a blind test. 

 

A heavy riders weight could compress and flatten the foot print  4 PSI to 3 PSI just as much as  a light rider already set at 3 PSI.

 

I think it is more about consistent tire pressure from ride to ride. As long as your front and rear is in the appropriate ball park of 6>9 PSI front and 3> 5 rear then you are good to go.

 

If your suspension is set up correctly a one to two pound tire pressure will not matter. 

 

Your milage may vary.

 

 

 

 

Edited July 9, 2015 by billyt

[nigel dabster]

Anything much more than 6 is too hard for front

[cbf1000]

I know I'm just starting out in this trials game (and assuredly don't ride/practice as much as I should or could) but wow, I've got a long way to go before my riding skills don't mask, or I can feel, the difference of 1 psi

[jml]

Depending on the conditions a few PSI extra can really stuff you up. It started out as a cold day so I put 5 psi (generally do this to make up for my weight) in the rear, but we soon came up to some wet rocks and the ambient had gone up a few degrees and tyre had been in the sun. So I'm sure that 5 psi was more likely 6-7 psi, I'm also a fairly heavy rider using a 7N standard rear spring, so I guess I would rely fairly heavily on some tyre flex to make up for my my of travel

 

I guess what I was after in asking the initial question was if people checked their pressures throughout the day and adjusted it back to their target. In asking that I was trying to understanding if the warm pressure is the target or if the cold was the target. So If my target is 4 psi in the rear and I put 4 psi in and ride around for 10 minutes and return with 5 psi, should I lower this back to 4 psi?

Edited July 9, 2015 by jml

[jimmyl]

I doubt seriously that anyone could tell a one rear tire PSi differential at any pressure above 3 PSI in a blind test. 

 

A heavy riders weight could compress and flatten the foot print  4 PSI to 3 PSI just as much as  a light rider already set at 3 PSI.

 

I think it is more about consistent tire pressure from ride to ride. As long as your front and rear is in the appropriate ball park of 6>9 PSI front and 3> 5 rear then you are good to go.

 

If your suspension is set up correctly a one to two pound tire pressure will not matter. 

 

Your milage may vary.

1 psi is 25% at nominal of 4psi

 

I'm a bit OTT with tyre pressure but will check several times before the start of a trial especially cold night sunny day scenario. Also check 3 or 4 times each check to ensure I'm getting a good reading. 

 

Will check at first group of section if road trial - letting tyre cool down while I walk the section. On Multi lap would check when refuelling or coming back through start area. 

 

Better to check more often than not as the pressure will change through out the day

[rob214]

i think most are just a bit ocd about it all. unless the tires are way to hard or way to soft most mere mortals can attribute poor form over improper air pressure to bad riding or bad scores. especially a difference as small as 1 psi. i've ridden almost an entire loop with a flat front or flat rear. yes it's possible. i can remember watching a young up and coming rider bounce off every log / rock in a section. his rear tire was like a rock. i asked him about tire pressure and he told me that one of the top guys told him to run 6 or 7 in the big rock splats. well he wasn't riding big rock hits and his bike was all over the place and he was dabbing at everything. i told him that his rear tire pressure was to high and he flipped me off and said i didn't know what i was talking about. i said have a nice day and ended up beating him at days end. oh well to each his own.

rob

[timp]

Usual mistake with people new to the sport is putting too much air in.

Going from 4 to 5 makes a big difference! Most experienced riders will notice quite easily.

And going down to 3 will make a hell of a difference when it's really slippy.

As for the front anything above 6 would be too much for me.

Quite often you see well meaning parents putting 4 in the rear for their child who weighs 6 stone when really 2 psi would be better. I know one child who runs less than 1psi.

[jon v8]

8psi works well in the back of my AJS, never struggle for grip,(Well, much less than others on bikes with suspension do) check it when I fit a new tyre and leave well alone... The knobs were literally peeling off the last IRC I took off, and the gripping edge had a nice 5/16" radius on it - still gripping well. 

[hrmad]

I pump mine up to 30 psi after every ride, stops water collecting in the rims and stops the tyres coming off the bead. Usually check the front cold, get it down to 5 or 6. I can get away with 2/ 2.5 on the rear due to my weight, but I usually do that visually, until the tyre is almost flat when you press on the suspension. It's hardly ever dry down here, may as well get as low as possible on the rear.