tyre pressure?????

1986dc

hello! first post on here, prob. not the last

iv got a new cube sting pro. every things great but i dont feel very confident in the bends and berms ect.
i come from bmx racing background and i like to be agressive through the singletracks but iv lost the front wheel a few times when i shouldnt have and its feeling twitchy.
iv shortened the stem and im running rocket rons at 40psi, should i reduce pressure for more grab on the ground?

Northwind

Best advice- just fanny around with it. If you go too low you'll probably get more punctures (pinch flats) and the tyre can start to feel really horrible and squirmy, it's always a balance of rider weight, how you ride,etc etc so there's no one right answer.

The Northern Monkey

got my 1st pinch flat in 2 years last weekend.

trails were dry and rocky and my pressures were just too low... went for 40 psi and it was ok.

The Northern Monkey

but as with northwind... lots of factors to think about really!

Stu 74

On my 140mm full suss with 2.35" tyres I use about 18psi in the front.
On my 100mm hard tail with 2.1" tyres I use about 25psi in the front.
I have never had either a pinch flat or front end wash out at these pressures (I am only 10.5 stone though )

In my experience you can get away with less pressure in the front tyre than in the rear. As the others have said it is trial and error really.

To be honest I am not sure that Rocket Rons are going to be the grippiest tyres either as they are race tyres. Perhaps try something a bit chunkier on the front (e.g Nevegal, Minion etc).

Are you getting your weight over the front end (to give more traction) when you are cornering?

Stu

delta5

1986dc wrote:

. . dont feel very confident in the bends and berms ect.
i come from bmx racing background and i like to be agressive through the singletracks but iv lost the front wheel a few times when i shouldnt have and its feeling twitchy.
iv shortened the stem and im running rocket rons at 40psi, should i reduce pressure for more grab on the ground?

40 psi seem a bit high - could be the problem, but it could also be your forks. Is the rebound properly adjusted for your weight?

nicklouse

looked in the FAQs?

1986dc

thanks for the replys, ill double check my rebound and take a few psi out the front

1986dc

thanks for the replys, ill double check my rebound and take a few psi out the front

miss notax

40 psi seems quite high....

I run mine (2.25 Cinders) at about 30 psi - does that seem about right? Suddenly I am doubting myself :?

allthegearnoidea

40psi is what i run mine at, but the, i'm a heavy b*gger!! 100kg without bag on! not had any troubkes at those pressures with my hutchinson tyres, they grip fantastically infact!!
could also be a weight positioning case?? bit too far back and lightening the front end a lot to make it floaty feeling??

The Northern Monkey

allthegearnoidea wrote:

100kg without bag on! quote]

lightweight!

allthegearnoidea

The Northern Monkey wrote:

allthegearnoidea wrote:

100kg without bag on! quote]

lightweight!

hahhaha! thats made my day lol! trouble is me on a bike normally = a Blunderbus Coming through stylee!!

dan shard

I used to have a Racing ralph and a nobby nic and had to run them very low to get the grip I wanted. Unfortunatly I also got lots of pinch punctures and it was like cycling through treacle

I eventually bit the bullet and bout a set of 2.4 fat alberts and I can run them rock hard with no problems. DEFO work checking the suspension pressures and rebound front and rear. Having played around with mine it makes a huge difference to bike performance!

1986dc

ok iv reduced pressure in the front and added rebound to the front. i might switch to flat pedals as i think clip ons are having a mental affect :roll:

ill let you know the results tomorrow

getonyourbike

I'd not be happy with a ron upfront, a nic would be more appropriate.

Tyre Pressure:
I'm about 50kg and on my 120mm hardtail with 2.25 tyres I run 25PSI in the front and 28PSI in the rear.

delta5

1986dc wrote:

ok iv reduced pressure in the front and added rebound to the front. i might switch to flat pedals as i think clip ons are having a mental affect :roll:

ill let you know the results tomorrow

Not sure if you're going the right direction by 'adding' rebound, because the rebound rate is adjusted on a fast - slow scale.

If it's set too fast the wheel will bounce instead of absorbing the little bumps, and will easily skid / wash out. If it's set too slow the fork won't re-extend fully between bumps, and when riding over a series of bumps it will gradually sag.

In your situation it was probably set too fast - in which case you need to set a slower rebound rate. Apologies if that's what you've already done!

1986dc

Delta5 wrote:

1986dc wrote:

ok iv reduced pressure in the front and added rebound to the front. i might switch to flat pedals as i think clip ons are having a mental affect :roll:

ill let you know the results tomorrow

Not sure if you're going the right direction by 'adding' rebound, because the rebound rate is adjusted on a fast - slow scale.

If it's set too fast the wheel will bounce instead of absorbing the little bumps, and will easily skid / wash out. If it's set too slow the fork won't re-extend fully between bumps, and when riding over a series of bumps it will gradually sag.

In your situation it was probably set too fast - in which case you need to set a slower rebound rate. Apologies if that's what you've already done!

i was thinking that i hit the corner -forks compress sinking me and my weight deeper into the corner then to much stress on the tyre with to much inflation = front wheel slip?

ill take the advice and have a play around tomorrow

cheers for the help, much appreciated

sofaboy73

i was thinking that i hit the corner -forks compress sinking me and my weight deeper into the corner then to much stress on the tyre with to much inflation = front wheel slip

Kind of the other way round. you want some complience on the front end to get the grip. the easiest ways to achive it are softening the tyre pressure or making the suspension more supple (all though don't go too far on each). by having hard suspension with lots of rebound and hard tyres, you will make the sketchy feeling worse.

chedabob

getonyourbike wrote:

I'd not be happy with a ron upfront, a nic would be more appropriate.

Tyre Pressure:
I'm about 50kg and on my 120mm hardtail with 2.25 tyres I run 25PSI in the front and 28PSI in the rear.

Crikey! I'm the same weight and if I run them that low, I can pretty much crush the front wheel under braking. I found at about 30 psi on corners the tread was digging into the mud but the wheel was carrying on going, causing the front wheel to twitch and slide about.

I've got my Conti Speed Kings 2.3 at about 50psi (measured with an Aldi pump so it could be well out). A little on the high side, but I do ride on the road a fair bit so I want the lower rolling resistance and reduced tyre wear.

getonyourbike

I've never had any problems, no pinch flats and no tyres squirming and coming off the rims.

I have heard of contis needing to be run at a higher than average pressure though. I'm running Maxxis Advantage 2.25s

NatoED

running pressures can damage your cornering speeds . you need them to hold shape to bite into the soil with the shoulder of the tyre. i'm 110KG and run my conti mountain kings 2.0 at 45- 50psi . Grips really well when I corner on my hard tail rattles a bit over roots but then I just suck it up with my arms and legs .

1986dc

ok i got out to day and spent some time tweaking.

i rode to a downhill single track i know with some tight man made burms.
first checked the sag on my forks make sure there still right for my weight
added slight rebound to the front and dropped the front tyre pressure to 30psi

after a short time adjusting before each run i was very happy with the results.
dont think the rons will be staying much longer. but today was a big improvement.
and now im switching back to flat pedals!

thanks for all the replys