Tyre width and loose rock

[lulubel]

I'll stop hogging this board eventually, I promise!

When I was out on the trails yesterday, I realised the thing I find most unnerving is when the wheels "skitter" sideways as loose stone/rock pings out from underneath them. The back doesn't bother me so much because I understand it will sort itself out and follow the front, but I have an anxious moment every time the front does it, which results in a lot of anxious moments!

I'm currently running 1.95" tyres, which I think are quite narrow for a MTB, and the pressure is usually somewhere between 25-30psi. My new bike has 2.25" tyres fitted as standard.

Will I notice less skittering with wider tyres, or is it one of those things I'm just going to have to learn to live with?

 

[Motozulu]

I'll answer but can't promise to be much help!

My current (and first) bike also has 2.25" tyres and they do seem great on the loose stuff - there is a fair bit of loose gravel on some descents at cannock and though the rear will slide a bit the front has been rock solid - as you rightly say it's only the front you need to worry about. Where they HAVE caused me problems is in the mud - which is how I did my knee - but I have no idea if the mud situation is normal/due to my tyre size or due to my tyre make. I run them between 35 and 40 psi.

 

[Cubist]

25-30 psi is about right for a bloke on tubeless tyres. You could try reducing pressure a bit, as you aren't very heavy, but you do risk pinchflats at low levels. Tubeless is an option, but I can't remember what rims you'll have on the new bike. You will notice a difference in the Schwalbes that Cubes always come with, as they are a great grippy front tyre. Run as low as you dare, the pinging is often a sign that your tyres are too pumped up, but I am pretty sure that your new setup will be far grippier than you currently describe. Don't forget that your new fork, once setup properly, will track rather than bounce, so your currently cattled fork may well be a contributor.

 

[Bobario]

You could try putting a slightly wider tyre on the front. That way the back should slip before the front does.
re the rocks pinging out from under your tyres, I presume you mean single loose rocks rather than gravel/trail detritus kind of stuff? You could lower your tyre pressure, which would help, but the best way to stop this is not run them over in the first place. Easier said than done though.

 

[GrumpyGregry]

compound makes almost as much difference as width in the grip stakes. with two tyres of the same compound tread pattern can then make a significant difference. I run wider up front than on the rear because the front steers and I want the biggest possible contact patch on the steering bit.

but you've got to relax, and let it skitter, and let it shoot stones out to the side, it isn't going to track like a road bike on tarmac (and anyway wait till you start drifting it )

and you're more likely to find a solution to the arab-israeli conflict than get consensus from mtb-ers about tyres.

 

[Motozulu]

and you're more likely to find a solution to the arab-israeli conflict than get consensus from mtb-ers about tyres.

This! I've trawled tinterweb MTB forums and searched for 'best tyre' threads on all of 'em. I've decided that when it comes to new tyres in the spring I'm just going to settle on a budget and then go out and put the two tyres on that leave the prettiest tyre tread pattern in the sandy bits of the trails. Seems as good a method as any.

 

[zizou]

1.95" is quite narrow these days but compound and profile are as important and these are terrain and condition dependent too. Some tyres are great for mud (these tend to be narrower), some for hardpark, some for rocks etc. What i would use in Scotland is going to be different to what would be suitable for rocky trails in Spain.

Different companies size there tyres different too - a Maxxis 2.35 comes up equivalent to about a 2.1 on other brands. Maxxis tend to be a bit 'taller' though

 

[Lee_M]

go faster

HTH

 

[Motozulu]

Lee - ha ha - the amount of times my more experienced mates have said that to me.......easier said than done when you are bricking it on some downhill wet cobbles. As for compounds and tread patterns? well you're a bit buggered if the trail you're on has a bit of everything? just have to go with what you've got - it sounds to me like people think too much about it when really it's as much down to skill/confidence/experience of the rider more than what type of rubber is used.



*possibly*

 

[lulubel]

Thanks for the replies, guys. Yes, I know tyre choice is incredibly complicated and surface specific, and what suits one person's riding style won't suit another's, etc, etc. I suppose what it comes down to is "wait and see", but that's very hard!

25-30 psi is about right for a bloke on tubeless tyres. You could try reducing pressure a bit, as you aren't very heavy, but you do risk pinchflats at low levels. Tubeless is an option, but I can't remember what rims you'll have on the new bike. You will notice a difference in the Schwalbes that Cubes always come with, as they are a great grippy front tyre. Run as low as you dare, the pinging is often a sign that your tyres are too pumped up, but I am pretty sure that your new setup will be far grippier than you currently describe. Don't forget that your new fork, once setup properly, will track rather than bounce, so your currently cattled fork may well be a contributor.

Yes, I'm assuming the forks will make a massive difference too. The current forks are slow to respond to surface variation, even if they respond at all, so hopefully I'll find a lot of it will be absorbed by the lovely Rebas. I've reduced the pressure as much as I dare, to be honest. I'm not certain about the 25-30psi. They could be a bit softer, but I still haven't got around to getting a pump with a pressure gauge. I'll pop into the lbs tomorrow and see if he can sell me something decent without charging me a fortune for it - or it's back to CRC/Wiggle!

I don't think I'll go tubeless even if it's an option. If I damage the tyres badly enough for them to go flat running tubeless, I'll be a bit stuck if I'm halfway up a mountain. At least, if I've got a tube and a tyre boot, I've got a chance of being able to patch it well enough to get me home.

re the rocks pinging out from under your tyres, I presume you mean single loose rocks rather than gravel/trail detritus kind of stuff? You could lower your tyre pressure, which would help, but the best way to stop this is not run them over in the first place. Easier said than done though.

They are loose rocks, but they're not single ones! I'd certainly avoid them if I could.

As for compounds and tread patterns? well you're a bit buggered if the trail you're on has a bit of everything? just have to go with what you've got - it sounds to me like people think too much about it when really it's as much down to skill/confidence/experience of the rider more than what type of rubber is used.

I think some tyres are probably better all-rounders - jack of all trades, master of none, maybe - and if you're on a very varied surface, you just have to find some that will do an OK job. I do agree about experience being the most important thing, but when you're at the limits of your current ability (whatever that is), I guess small things can still help.

 

[GrumpyGregry]

lulubel. DO NOT rely on a pump with a pressure gauge when setting your tyre pressures so low. Notoriously inconsistent, espcailly over time, and inaccurate. Digital tyre pressure gauge is the way to go.

and you'll be wanting a (seperate) shock pump for your rebas, unless your new bike comes with same. I've a canyon one going spare (I've already got a topeak for the rebas on the boardman) for the price of posting it to you.

 

[GrumpyGregry]

This! I've trawled tinterweb MTB forums and searched for 'best tyre' threads on all of 'em. I've decided that when it comes to new tyres in the spring I'm just going to settle on a budget and then go out and put the two tyres on that leave the prettiest tyre tread pattern in the sandy bits of the trails. Seems as good a method as any.

I always stick with Conti's








or Bontragers









or Schwalbes now I've got a Canyon.

Dang it's hard to stay true to your convictions.

 

[Cubist]

No it isn't. Apart from the Contis, Maxxis, Panaracer and Kendas, I have always used Schwalbe.

Now I've tried a few I have a default tyre, which is a Nobby Nic Snakeskin.

 

[billflat12]

Could be combination of things,forks, tyres , braking technique, once your forks are setup correctly you can probably rule forks out, tyres vary wildly ,( check out reviews on the new tyres for suitability) less grippier tyres tend to roll better and loose grip progressively , whereas grippier tyres let go suddenly with less warning, try to avoid braking on loose corners, maybe practice balanced braking on a more forgiving surface until you develop more feel & able to brake/ease off smoothly, You shouldnt worry too much as It,s going to be a complete revelation once you get to ride a real bike instead of a toy.

 

[VamP]

lulubel. DO NOT rely on a pump with a pressure gauge when setting your tyre pressures so low. Notoriously inconsistent, espcailly over time, and inaccurate. Digital tyre pressure gauge is the way to go.

and you'll be wanting a (seperate) shock pump for your rebas, unless your new bike comes with same. I've a canyon one going spare (I've already got a topeak for the rebas on the boardman) for the price of posting it to you.

This.


Pump gauges measure pressure in the pump, not in the tyre and it's easy to be 30 psi out. A little digital checker like this one is what you want.

You guys think MTB tyre choice is strewn with pitfalls, you should visit the cyclocrosser's weekly dilemma. Tufo, Challenge, Dugast, FMB??? Diamond file, intermediate, mud or supermud? Pressures, pressures, pressures? 32mm tubs at 20 psi are quite an experience, feels like you're riding on rims half the time, but in certain conditions going from 25 to 20 psi can give you miraculous velcro like grip versus no grip at all.

Good thing about going from CX to MTB, is that you marvel at how much grip is suddenly available. I ride my MTB at around 22-25 front, 27-29 rear, and I am not light at 12.5 stone.