You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
I test rode a 27.5 3.0 hardtail and really liked it, except for the self steering and vagueness. I've read that it's not an issue at 2.6, has anyone else found this to be the case?
I run a 26x4.8 ,it use to self steer until I seated it properly on the rim ,I’m guessing maybe a similar reason to your experience of self steer
It's nothing to do with the size of the tyre.
I find it’s more to do with pressure than size. *cough*
I ride everything from 25mm to 4.8”
So it's a compromise between comfort and grip and self steering? Or is that over simplifying it?
Tyre, pressure, bike (and no doubt other factors) all play a part.
I've run a 4.8" jumbo Jim that self steered (a bit) at 6psi on one bike, but not on a different bike. Upping pressure to 8psi stopped it on the first bike. A 4.8" surly bud was also fine at 6psi on both bikes.
My fattie self steers badly on 4" tyres at 7.5 psi and at 8 psi it doesn't.
Its a function of size, pressure, tyre construction and treadpattern
@tjagain has it. I'd add age of tyre as well, especially with larger (read plus and fat) sizes, a new tyre is may be fine at 7psi but after a couple of years the sidewalls are much more pliant so 7.5psi is scary and you need 8.5psi.
I notice it more on tarmac and hard packed surfaces, such as canal tow path, because there's so much grip.
Start with high pressure and slowly work down until you notice it. Hopefully the pressure isn't so high that you are still pinging off stuff.
Thanks to everyone for helping.
Well its to do with the width of the contact patch, which is going to relate to tyre width and pressure.
How much you notice it depends on the steering geometry in addition to other things I think. I put a 2.8 in the front of an old school XC frame and the grab on the handlebars was quite noticeable, it is much less noticeable with a 2.8 in a slacker (68 degree) frame. It seems to disappear once you get going off-road anyhow. I have also noticed it with a 2.3" front tyre on tarmac when it had a slow puncture. In fact that was the first time I really noticed it.
It's IME mostly a tyre pressure issue, or at least that's about all you can do to control it.
Lower pressure makes tyres self steer, high pressure eliminates it in all the tyres I've tied. Stick 40psi in a road tyre or 10psi in 2.2" lightweight a mountainbike tyre and try and go round a corner if you don't believe me. The bike just wrestles you upright. I got the same problem on my cross bike trying to run tyres at 40psi (the max allowed by the rims), oodles of grip in mud, but unrideable the rest of the time because the direction the tyres was rolling in across the ground often bore no relation to the angle of the bike/wheel/leaning!
Some tyres are worse than others, some fat bike tyres do it at 15psi, some at 10, some are good down to 5. But if you add pressure to any of them it goes away.
Grip plays a big part, 5psi fat tyres on snow/mud don't self steer, 5psi at a trail center though and I struggled to get it round the berms!
So it's a case of picking the right tyre and pressure for the ground conditions.
So a narrower tyre won't self steer because it'll be at higher pressures.
So if a 3.0 tyre at say 18psi does it, but it goes away at 20psi, then you could try a 2.8 at 20 and get a bit more comfort (don't forget a wide tyre pumped up to 20psi is still pretty hard).