Stuck in the mud

[Dave42w]

Tonight I got stuck in the mud on a nearby bridleway. Both wheels clogged completely multiple times. They clogged even when pushing rather than riding.

See route and photos at Stuck in the mud.

This is 700c x 40 WTB Nano Comp tyres. The mud was not really gloopy but clumpy (I'm expecting to learn lots of new words to describe the consistency of mud at the Ford Fiesta) ie not sopping wet.

Would a slightly wider tyre have helped eg a Schwalbe Smart Sam 1.75?

Would a 29er with 2.4 tyres be likely to ride through?

What about a 29+ with 3" tyres or maybe with 2.4" tyres and huge clearances?

Or would I need a fat bike?

Or am I going to be walking it whatever?

Anyone wanting to come to Leicester and demonstrate their bikes ability on this few hundred yards of bridleway is welcome Note that unlike Wales we don't have much bridleway to choose from.

[Scattamah]

It doesn't matter what size tyres you run. If your wheels get to the point where the bike doesn't roll, and there will be times if you're in thick enough mud that this can occur irrespective of tyre size/width/clearance, resort to the following: a sturdy stick, patience and a good sense of humour. Poke the mud away, get past the offending piece of ground (usually by carrying your bike) and ride on.

Greetz

S.

[Bearbonesnorm]

I'm glad to report that Wales doesn't really have the type of mud you describe ... the rain's washed it all away

[whitestone]

In that type of clarty mud bigger clearances aren't going to help - you'll just pick up even more mud until everything clogs up and you've an even heavier bike to shift

The only real solution is to carry the bike.

PS. *clart* is that type of mud that sticks to teflon

[Zippy]

Narrower tyres to cut through mud, also cuts through the mud that has accumulated on the bike frame. Still a PITA!
References of both CX and er a few bad years at Mountain Mayhem where you'll see when it gets bad like that, tiny narrow CX tyres for MTBs are adorned!

[FLV]

a short while ago on a ride with mark and karl, my krampus on 3.0's stopped dead in the mud. The two other guys on about 2.2's 29ers rode through it. I had to clear it out 2 or 3 times.
So no, bigger tyres wont do it.

Proper mud tyres help as the shed better, but can still pick enough up eventually.

[Zippy]

Narrower tyres to cut through mud, also cuts through the mud that has accumulated on the bike frame. Still a PITA!
References of both CX and er a few bad years at Mountain Mayhem where you'll see when it gets bad like that, tiny narrow CX tyres for MTBs are adorned!

I was on a mobile device when I typed that, but since then I've given it a bit more thought and have broadly worked out the technical detail on why this is so.

For the type of mud that is clumping up like this, it will generally be a cohesive type (i.e. towards the clay end of the particle size distribution, as opposed to granular angle of friction type soil towards the sands and gravels end of the spectrum - not that this makes much difference to the next point I'm making...).

Anyway, I have a few points which I'll hopefully explain in a way other people can understand...:

1. If you have a wider tyre, you are picking up more soil in one revolution than if you had a narrower tyre. Ergo more material to clog the bike up with in a shorter space of time / number of wheel revolutions.

2. Wider tyres, generally even if the absolute clearance (i.e. number of mm) is larger than a frame or fork for narrower tyres generally, as a %age of the tyre width and mud picking up capability of the tyre versuse the mud capacity of the clearance / surface area on the frame/fork to stick to, you're worse off. [I realise this may not always be the case, but generally it is].

3. The ability to cut through this mud is dependent on the shear capacity of the mud we're trying to cut through on the frame/fork. Shear capacity of soil say measured in N/mm^2, where the force to cut through the mud will be exerted by the tyre. Looking at areas of tyre, we get: [ narrower tyre mm^2 < fatter tyre mm^2], therefore we have a greater pressure being applied by the narrower tyre if we were to assume the force by the wheel revolution is the same (again I know a gross simplification, but it's true enough for comparative purposes of fat and thin tyres). Anyway, basically you end up with a thin tyre being able to cut through the mud easier as it is acting though a smaller contact area with the mud on the frame/fork and therefore more likely to be able to cut through than a fat tyre which has to cut through a far greater area of mud.

In conclusion, narrower tyres cut through gloopy mud stuck on your bike more effectively.

p.s. haven't considered other things like ability to control bike through said conditions and for when it gets a bit wetter.
p.p.s. Note also the clogging of rear mechs and gears often happen at the same time and can stop forward motion before the tyre get clogged, depending on situation
p.p.p.s. Forward motion through pedals helps shed mud with enough speed + a bit more clearance can allow you to keep pedalling where you would have been buggered if you'd stopped and pushed.

And here's a photo from a wet and muddy mountain mayhem in 2012 where our team podiumed coz we didn't stop as opposed to being particularly fast that year, the mud is why people stopped! The singlespeed with large clearance and trailraker 1.95 mud tyres worked brilliantly.


Mountain Mayhem (2012) by zippyonline, on Flickr

[Dave42w]

Thanks for the very thoughtful and detailed responses!