Its all about Pressure

scrat

After a very long wait and lots of saving I finally have my dream bike. Orange 5

Anyway, it's running stock rubber. Continental Mountain King 2.4. :arrow:

So I set them at 35psi all round, just the same as I was used to on my old bike (h/t). Within a mile I was punctured (rose bush twig). Just my luck!! :roll:

I have bought a nokian d/h tube, which may help. But I thought I best check 35psi was the best setting. I did a search on here and loads of psi threads came up with all sorts of advise. I also checked the conti web site. It says they should be set at 50psi:

http://www.conti-tyres.co.uk/conticycle ... king.shtml

I ride 85% trials (going grafham water this weekend) & 15% road. I'm about 11.5 - 12.0 stone.

Surely conti know best and I should set them at 50 all round :?:

What are you other 5 owners running :?:

Thanks

dhxcme

It says recomended is 50psi with a max of 65psi. You have some sus front and back so I would say 65psi all round as you don't need the squashy back tyre as a suspension substitute.

Oh and I'm running Highroller 2.1 XC at 65psi on my Patriot 6.6 and Highroller 2.5 DH at 65psi on my 223.

smithy220

i would never run low pressures on my bike as its just asking for punctures especially on the trail then again some of the roads round here are far worse than any trail i run 50-60 wit slime tubes and all has been OK so far

Steve_F

I don't tend to go for much more than 40.

I used the Nokian d/h tubes for a while but I did notice the difference in rolling weight (or at least I thought I did!) when I changed back and haven't picked up a puncture yet - shouldn't have said that!

Andy B

Orange 5 with Panaracer Fire XC Pro, tyre pressure around 40psi.

The lower the pressure the more grip, but the greater the chance of pinch flats.

SuperCove

I run my Cove on 40psi if I am going to be spending most of the ride off road for the extra grip, never really had a problem with pinch punctures.... famous last words, but if the route has large road sections I will run at around 55psi

supersonic

30-40 psi off road. I like to have grip ;-)

BrightonMTB

40psi front

45psi back

for me anyway

Thewaylander

i hit 45 all round and seem to do fine on mine

ride_whenever

what would happen, aside from heavy wheels and assuming no leaks, if you filled your tyres with water instead of air?

Anonymous

I just checked earlier, and I seem to be running 21PSI rear, 25PSI front! :shock:

Mc Smiley

Depends if i have a slow puncture. around 30 as i am 9.5 stone. 40 if its rocky and 50 for the road.

Front a couple of psi lower.

big_southern_jesse

ride_whenever wrote:

what would happen, aside from heavy wheels and assuming no leaks, if you filled your tyres with water instead of air?

Well water doesn't compress, so you'd have a much harder ride. but You might have a slight problem with rotating masses! :shock:

dunker

45 front 40 rear on a ht here, about 9 stones and no punctures with my armadillos yet i was running them 50-50 but found grip was suffering a bit, better with 5-10 less in for me.

KonaMike

I run my Conti's at 40-45 PSI but still get the occassional pinch flat on the rocky local trails.

god1406

i run all my tyres at 65-70psi...

the only problem is shimano mech's smashing themselves to pieces on the chainstay over braking bumps, but Sram sorted that out

LordBanks

You could use helium to inflate your tires, that would make your bike feel lighter.

I heard that 15/20 years ago bike companies were experimenting putting helium in sealed frame tubing to make bikes feel lighter, does anyone know if thats true??

Mc Smiley

The helium in tyres wouldn't work with conventional tubes, the molecules are much smaller.

I think it was thought about and then had many con's such as lack of traction etc

schmako

40psi does the job for me on both bikes. Rarely get punctures. My mates who don't use a proper pump always get punctures.

Spamjavelin

Hmmm, I'll have to experiment after reading this, I'm running High Rollers on my norco at 35 psi all round, trying lower pressure than normal. Usually run 40 psi all round. I think just try various pressures and see what works for you. :roll:

Will Snow

Mc Smiley wrote:

The helium in tyres wouldn't work with conventional tubes, the molecules are much smaller.

I think it was thought about and then had many con's such as lack of traction etc

seem to recall a thread about this a while back... there was alot of science (and even more guess work...)

for the record i run stoopidly low pressures apparently, stock 2.3 high rollers at 32/35 front back... for XC. does this make me a bad person??

Anonymous

Not at all, Will. I tried higher pressures of 40PSI yesterday, and found that the bike's handling was massively compromised. The tyres just couldn't deform properly to absorb the trail.

As for helium in your bike to make it lighter, it wouldn't work. It would probably make your bike weigh a couple of tenths of a gram lighter, but that's all.

Did nobody see the mythbusters episode where they tried to make things fly using helium? it's much harder than you'd think!

Will Snow

i know a bmxer who says he runs 90psi in his tyres... wouldnt want to jumop anything on that...

Anonymous

Actually, with the smaller tyres, is 90PSI a lot? I know nothing about BMXs except "I want one" so excuse my ignorance!

supersonic

I worked out that Helium would have the effect of about 4grams less per wheel!

Will Snow

well a car still only runs 30psi, and a road bike around 100, so id guess that 90 would snap your wrists off (and funnily enough, i want one as well...) 60 on my mtb hurt a wee bit aswell!

edit: and itd prob cost about £20 per wheel as well...

Anonymous

supersonic wrote:

I worked out that Helium would have the effect of about 4grams less per wheel!

Ah, but have you taken compression into account as well as pure volume of the tyre?

supersonic

Yep! I have the workings somewhere - I think it was 4g per tyre at 3 atm (might have been 7g!) with a 2.00 inch tyre on a 26 inch MTB rim

Anonymous

Will Snow wrote:

well a car still only runs 30psi, and a road bike around 100, so id guess that 90 would snap your wrists off (and funnily enough, i want one as well...) 60 on my mtb hurt a wee bit aswell!

edit: and itd prob cost about £20 per wheel as well...

But, cars have huge air volume in their tyres, so 30PSI is fine. Road bike tyres have a smaller air volume, so 100PSI is about correct.

i know BMX tyres are pretty wide, but surely the amount of air they hold is pretty small, being 20" and all.

Will Snow

maybe???

Anonymous

supersonic wrote:

Yep! I have the workings somewhere - I think it was 4g per tyre at 3 atm (might have been 7g!) with a 2.00 inch tyre on a 26 inch MTB rim

Hmm, tha;t not too bad a saving for these uber-lightweight XC freaks!
However, you'd need some special tubes made that could actually contain the Helium!