air pressures for 92 kg guy on a 29er

M

myusernam

Squid
Hi, I am new to mountain biking.
I have a 29er (trance x1)
which the bike shop made tubeless.

Any ideas of pressures as a starting point?
I got a pinch flat when I had tubes on the rear in the low 30's.
I find I cant go below 30 on the rear even tubeless or I start touching the rim to the dirt. I tried running the front a bit lower and rolled the tyre off the rim.
How do I fix? remove the dirt and use a compressor?

cheers
 
ctguru

ctguru

Likes Bikes and Dirt
Funny

I run 30 rear and 25 up front tubeless for ages on a 29er and had no issues

I'm 100kg


Sent from my iPad using Tapatalk HD
 
F

frensham

Likes Dirt
30 psi in the rear should be perfect for you. I would check your gauge. I am 90 kg and run 25 psi (digital gauge) on a hardtail tubeless no probs ever.
 
pharmaboy

pharmaboy

Eats Squid
you shouldnt roll a tyre of a rim - thats a sign usually of the wrong rim/tyre combo. the tyre isnt tight enough on the rim - you can often solve this with either a new tyre that fits tighter or adding bontrager rythm strips to the tyre.

Stock giant rims dont hold tyres quite as well as some other options.
 
Z

Zam

Likes Dirt
Yeah does seem a little strange as i run between 25 and 30 psi and i am 100kg and havent had any issues at all
 
evObda2

evObda2

Likes Bikes and Dirt
A lot depends on the type of tyre, the casing thickness, the ground your riding, full suspension bike or hardtail, rim type/size and how aggressive you are.

Some casings (in particular thinner ones) need to be pumped up more to work properly. Thicker casings like more Dh tyres can be run at very low pressures as they have that extra support and often use a much wider rim.

So its all about finding the sweet spot on the tyres your using. You want good grip, but you don't want the tyre squirming or rolling over and want the rolling resistance to be decent as well.

Personally i think anything under 30psi front/back for xc is too soft, you wont get as good a rolling resistance or protection. I don't run tubeless to get my pressures lower, but more for weight benefit and the tyre tends to have a slightly more compliant feel which i like when pumped to my usual pressures.
 
fergo

fergo

Likes Dirt
Check your pressure gauge accuracy

Another thing to check is the accuracy of the tyre pressure gauge. I used a mates pump and went to 30psi like my pump and it felt rock hard. I then pulled out my BBB digital tyre pressure gauge to check it and it was reading 55psi.

Your gauge may be saying higher than reality so then the rims hit the ground because the tyre is low.

FYI, im 105kg and run 30psi front and 34psi back on my bikes. If I go much lower, the tyres burp. I have RaRa snakeskin on Giant (DT Swiss) 29er rims. It was the same with RoRo UST on Mavic 819 26" rims.
 
M

Mr_hANky

Likes Bikes and Dirt
Im 98kgs kitted and run 40psi front and rear with tubed high roller. Im must be a fucking machine.
 
donthucktoflat

donthucktoflat

Eats Squid
I can honestly say I've never checked my tyre pressures (on this bike)


Tubeless rocks though, never using tubes again ever. Zero flats in 3 months? That's my bag. Also I can't get over how soft I can run the tyre on a well matched combo. Maxxis and mavic and theres no sign of rolling a tyre
 
M

Mafra

Likes Bikes
At 90-95kg kitted, XTC 29er HT, Schwable Nobby Nic F(24psi), Bontrager 29-1 Team R(27psi).

Works for me at Wombat and a few other places - tubed

The digital tyre gauge is key, the gauge on your pump gets pretty badly abused.
 
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