tyre pressures...

[chqshaitan]

hi guys,

I am wondering what peoples thoughts are on slightly under maximum inflated tyres.

currently my two tyres at at their max rating of 85 psi(hybrid 35mm tyres, marathon plus) but part of my route is full of rutts and potholes and is very uncomfotable to traverse.

i read somewhere that slightly under inflating can improve the comfort on the ride but i am not sure by how much to under inflate? also what are the pro's and con's of doing so.

thanks

 

[Ian H]

Maximum pressure is not the same as correct pressure.

 

[tyred]

A 35mm tyre should not need to be pumped up to 85psi.

Try 60 - 65psi.

I run 27 x 1 1/4" at 60 front and 65 back. I'm a heavy bloke and ride on poorly surfaced roads and have never had a pinch puncture.

 

[MrJamie]

Marathon+ have a bit of a reputation for being rigid and as comfortable as a wooden cart wheel. They're meant to be a bit like that though, you don't want them to deform very much, so that the part of the tyre in contact with the road and potential punctures is the protective strip in the center and the less protected sides are kept away from the road.

 

[chqshaitan]

Marathon+ have a bit of a reputation for being rigid and as comfortable as a wooden cart wheel. They're meant to be a bit like that though, you don't want them to deform very much, so that the part of the tyre in contact with the road and potential punctures is the protective strip in the center and the less protected sides are kept away from the road.

so you saying bud that they shouldnt really be under inflated?

 

[tyred]

It should also give you a minimum pressure on the sidewall, or even on their website.

edit: Min pressure is stated as 3.5 bar which of the top of my head would be around 52psi.

 

[chqshaitan]

just checked and the min is 50 psi, so thinking i will do as tyred suggests,

thanks guys

 

[tadpole]

Max pressure for the road you cycle, only you can know that. I inflate my tyres to 6 bar and 'ride light' and on the pedals over the bumpy and lumpy bits of the roads.

 

[chqshaitan]

yea, my butt cant take the hammering over the rough bits so i stand up lol

 

[BlackPanther]

On road bikes I always went to bang on the 'maximum' pressure. Modern tyres/tubes are capable of exceeding their maximums by a fair amount, and I believe that most serious (club members) go above by 20 or 30%, which will give them a bit more top speed. I tend to go for bang on half way between max/min pressures for commuting on the trike. Indeed, if the ride is a bit more spongy, then you can actually go faster on rubbish roads, due to the fact that it's a far less harsh ride so you don't tend to slow down as much. It's not a big job to just change pressures if you commute, and then want to go for a fast blast on a weekend. I'd recommend investing in a track pump, it's so much easier/faster than fiddling with mini-pumps.

 

[chqshaitan]

On road bikes I always went to bang on the 'maximum' pressure. Modern tyres/tubes are capable of exceeding their maximums by a fair amount, and I believe that most serious (club members) go above by 20 or 30%, which will give them a bit more top speed. I tend to go for bang on half way between max/min pressures for commuting on the trike. Indeed, if the ride is a bit more spongy, then you can actually go faster on rubbish roads, due to the fact that it's a far less harsh ride so you don't tend to slow down as much. It's not a big job to just change pressures if you commute, and then want to go for a fast blast on a weekend. I'd recommend investing in a track pump, it's so much easier/faster than fiddling with mini-pumps.

thanks mate, fortunately i have a track pump. i am commuting back in tommorow so will see how it goes on the lower pressures.

 

[Pale Rider]

I used to run about 80psi on the Brompton, but the ride - especially at the front - was harsh.

Dropping to nearer 60psi improved comfort a lot.

No problems with punctures - so far.

Some Brommie owners run 100psi, so there's a wide range to play with.

 

[chqshaitan]

great stuff, shows that we have a bit to play with

 

[MrJamie]

so you saying bud that they shouldnt really be under inflated?

I'm just adding to the information pool to help you make up your own mind I'd adjust it between max and min PSI based on rider/luggage weight, like if you're light go closer to the min, if you weigh about 2 pro cyclists go more towards the max. Like I said though, M+ do have quite a horrible ride but that's part of the price of awesome puncture protection... the rubbers very hard and the sidewalls are very rigid so that they deform as little as possible to keep the part of the tyre with the puncture protection in contact with the road.

 

[chqshaitan]

I'm just adding to the information pool to help you make up your own mind I'd adjust it between max and min PSI based on rider/luggage weight, like if you're light go closer to the min, if you weigh about 2 pro cyclists go more towards the max. Like I said though, M+ do have quite a horrible ride but that's part of the price of awesome puncture protection... the rubbers very hard and the sidewalls are very rigid so that they deform as little as possible to keep the part of the tyre with the puncture protection in contact with the road.

thanks, the more info, the better. weight wise, i am heavier, rather than lighter end of the day, i would prefer to have less/no punctures vs a slightly more comfy ride