Lemond Fillmore - chainline issues!

Momentum [quote]jhclare Hi,

I'm beginning to think that when manufacturers spec flip-flop hubs on freewheel bikes, they don't think about chainline on the fixed side. It certainly seems that way! It does seem weird that a flip-flop hub would give different chainlines. I thought the whole point was that you could quickly switch between them!

I'm tempted to sod the fixed thing and just run a freewheel until I need a new rear hub.

The hub isn't the problem - it's the fact that freewheels and fixed sprockets (apparently) have different chainlines. This problem will therefore occur with most track hubs, which are set up to give a 42mm chainline with a fixed sprocket. It seems, from your experiences, that freewheels give a different chainline. That would mean that the manufacturers of these bikes choose a bottom bracket axle which lines the chainring up with the freewheel, not the fixed side.

The way to solve it is to get a different length BB, not a new hub. Brixton Cycles are very helpful and will be happy to help you out and check the bike for you. They also do free labour for a year on bikes bought from them so could swap the BB for you if you want the chainline to work for fixed, not freewheel. Since new BBs cost about £15 this is a cheap fix.

If you want to fun fixed/free then I would get the chainline right for the fixed side, tolerate a wonky chainline on the fixed side and use a 3/32 chain with some flexibility to minimise the issue. Chainline is more important on fixed because the consequences of a dropped chain are worse.[/quote]

+1

Also I though the issue on the flyer ended up partly being a 1/8 track cog and a 3/32 chain and freewheel resulting in a problem.