[Closed] Tyre pressure confusion

what size tyres?

40psi sounds about right for a 2" wide rear tyre at your weight but you can almost always get away with slightly less pressure in the front.

Thanks 🙂 theey're 2.5s I think. Not that au fait tbh but theyre on a Patriot DH bike so heavy duty rubber. My GF's is a Trek Fuel 8 so chunky but not quite as heavy. I'd say 2" on hers.

She'd prob be fine at 30psi. You could give 30-35psi a go if they're 2.5s.

Also, has anyone used the slime inner tubes? Any good? Just popped them on ours to see if they are any good.

I'll try hers at 30psi then 🙂

2.5 dual ply DH tyres?
try 28psi front, 30 rear (if you can feel either tyre fold in turns up the pressure 2psi at a time til you're happy).

I'd recommend right around the same pressures for her. (narrower tyres with lighter sidewalls require higher pressures)

I'll have a play around then. All alien to me from when I used to road race in my youth & my tubs had 120psi. Thanks guys 🙂

I weigh about 175 lbs and currently run 20F 22.5R. Tires are Schwalbe Hans Dampf 2.3 with the snakeskin reinforced sidewalls. I run them tubeless w/Stan's sealant, and this is the lowest pressure that I have ever run. I have run other 2.3s in the mid 20s, and 2.1s in the upper 20s-low 30s. Rear tire is usually 2-4 psi higher than front for me.

There are many factors to consider, including rider weight, tire size and sidewall type, type of trails (sharp rocks?), riding style, sealant, tubes, etc. Really, trial and error is the only way to figure it out.

Stan's website has the following

To determine a starting tire pressure when running NoTubes tires with our ZTR rim use this simple formula.

Rider Weight in pounds divided by 7 = x
x - 1 = Front tire pressure in PSI
x + 2 = Rear tire pressure in PSI

Slime tubes with sealant weighs a ton and makes patching impossible. I would avoid.

mildly interesting, fairly confusing and wildly irrelevant!
Just in from the pub, aye?

Simple answer 40 is probably a bit too much.
Back it off to about 35 and see how you go.
If it's still a bit pingy then 30.

Run them too low and they will roll and squash making cornering rubbish.

Unless you have a serious problem with punctures probably avoid the slime tubes etc. (and generally if you do there is a better fix)

http://www.michelinbicycletire.com/michelinbicycle/index.cfm?event=airpressuremtb.view

It depends where and how you ride, I know from experience that if I let my pressures drop below 45 psi I get pinch flats, I'm twelve and a half stone.

It depends where and how you ride, I know from experience that if I let my pressures drop below 45 psi I get pinch flats, I'm twelve and a half stone.

Also what tyre your using (or abusing) Dual Ply DH tyres should cope at lower pressure than that, but light weight wafer thin sidewalled XC tyres might not.

I'd say GW's advice is spot on. Scary 😉

I think I'll drop them to 35 and see how I go then. I'm a big lump so won't go too low. Combined weight of rider (bodybuilder) and my patriot which weighs as much as the moon suggests to me that's probably my lower end limit from the comments above. Thanks folks:-)