Tyre Pressure

[bristol-dave]

can anyone tell me if im right in having a tyres a little less inflated than the max during wet/winter weather. Think i read somewhere that this can reduce punctures. i have specialized all condition 700x28 front and rear. The rear and front have different max psi's for some reason. The front is 115-125 whereas the rear is 75-100 . Am i ok having them this way round, and should i be underinflating ? When i checked them the other evening the front was down to about 55-60 , so took it up to 90, next morning going to work, 1 mile from home... Puncture on the front. Any advice is welcome , oh one last thing, have just ordered a mr slime inner tube, that are supposed to seal immediatley after puncturing , do they work any feedback on these ?

Happy new year to 1 and all.

Dave

 

[PpPete]

Slime tubes are fine on low pressure MTB tyres. Generally to be considered to be crap on 700c.

As a general rule higher pressures will give better protection from punctures (winter or summer). The only reason to reduce pressure in the winter is to allow tyre to flatten slightly and put more rubber on the road, thus theoretically increasing grip.

 

[HLaB]

Happy New Year!
I don't think lowering psi reduces p'tures but it does improve grip and comfort. I run mine around 95-100 psi front and 100-105psi rear and if it looks slippy they are not topped up so can be running around 20psi lower. I prefer the lower psi in the front for control purposes. I've never had slime my self but from reviews, its heavy and only good at sealing the smallest of pin pricks and is messy stuff.

 

[Norm]

I've had a slime tube in the front of my CX bike and gone from about 50 miles per puncture to about 300 miles without a puncture. It might be coincidence but it might also be the slime.

That's in a 700x32 tyre.

It is heavier but, unless you are maxing out speed for a reason, a heavier tyre can be better as it can give a smoother ride.

Lower pressure means more chance of puncture, as it is easier for the nasty to worm through a tyre with less pressure in it. Wet also increases the number of punctures as grit & glass sticks to the rubber rather than being flung off and water lubricates the nasty on it's journey into the inner tube.

 

[Blue]

Buy good tyres, keep them at a high pressure and clear them of any embedded glass etc., after every ride and avoid the gutter when riding, if possible - all that will keep p's to a minimum

 

[bristol-dave]

cheers guys, thanks for all your feedback , much appreciated

 

[ianrauk]

Buy good tyres, keep them at a high pressure and clear them of any embedded glass etc., after every ride and avoid the gutter when riding, if possible - all that will keep p's to a minimum

Wise words indeed.....

 

[Scilly Suffolk]

...The front is 115-125 whereas the rear is 75-100 . Am i ok having them this way round...

No-one has picked up on this and I'm curious.

At a guess I'd think that your tyres are different models, albeit the same brand (a Google found Specialized All Condition Sport, Elite & Armadillo varieties).

Ordinarily I would, if anything, expect to run the rear at a higher pressure than the front as it carries more weight, so I'd be inclined to run them the other way around. However the revered Sheldon Brown has words of caution on tyre rotation, so it depends on how worn they are.

Either way, plenty of people do run with lower pressures than the maximum quoted for reasons of both grip and comfort. However as already mentioned the risk of punctures is somewhat greater and you should never run with less than the minimum quoted.

 

[snailracer]

...Lower pressure means more chance of puncture, as it is easier for the nasty to worm through a tyre with less pressure in it...

I would have thought that a lower pressure tyre has more chance of a puncture because it has a wider contact patch and therefore "sweeps" a larger area of road and catches more debris.

 

[SquareDaff]

I run slime tubes in my 700x28's. I was getting about 1 puncture a month (or around 400 miles) on my rear tyre. As others have said - there's more weight on that one. Changed my rear back in early October and have had no rear punctures since. Had one puncture on the front tyre in November and replaced that standard tube with a slime tube then.

As people have said they do feel different.

I've upgraded tyres since to Marathon GreenGuards and will be trying normal inner tubes back in if/when I get another puncture.

 

[scouserinlondon]

I tend to have mine very slightly softer in the wetter months (particularly the front) as I just find it a bit less skittish, particularly on man hole covers and road paint. In the dry I run around 120 down to 100 ish in winter.