Uneven chain-ring wear with Speedhub?

[ndt44]

Thanks to all for your input here - a much bigger response than I ever imagined!

I'll have to go and count the links in my chain - I'm running a 38/16 ring & cog pair. I wasn't particularly careful in how I put the chain back on, other than to make sure it was running in the same direction as before. I didn't mark a point on the chainring to 'sync' it with, but I doubt it will be an issue - the last 500km have felt fine while riding.

However, I've just had even greater dramas here in Erzurum today - when doing my routine 'bolt check' to make sure everything is nice and tight, I noticed one of my chainring bolts was missing! I had a hell of a time getting another one in eastern Turkey, but I finally found a bike shop that happened to have an old set of cranks with the stud bolts I needed. It also turned out that the threads were stripped on two of the remaining three bolts, so I pulled them all and put the 'new' ones in. I'm sure this hasn't helped my uneven wear problems... I kept the remaining good original as a spare. I recommend anyone touring away from big cities to take some spares too - today was a bit stressful!

[jawj]

This is an old thread which has just caught my eye, though I'm not sure why I missed it before.

There appears to be a lot of speculation on here about wear that isn't really relevant, though the out-of-roundness stuff is.

Every singlespeed or hub geared bike I've had or worked on has had tight and loose spots in the chain at points in the cranks' rotation, some more than others (e.g. cheapo BMXs I've seen have been atrocious, whereas my Nomad isn't that bad at all, though the spots ARE there).

Setting up chain tension is simply a matter of making sure the chain's not hindering rotation and accelerating wear of bearings at the tight spot and not falling off at the loose spot. That's it really...

[vik]

I've got two bikes [plus a friend's I built] that have clean chainlines [no derailleurs or tensioners].  Each bike has a tight spot on the cranks as you spin them around.  No chainring or cog will be perfectly round.  I set the tension on my chain with the cranks at the tightest position.  This means my chain will never be tighter than this maximum tension.  A little bit of slack won't hurt, but a chain that is too tight will wear very fast and may damage your bearings.

safe riding,

Vik
www.thelazyrando.com