Is it normal on a flip/flop 120mm track hub for the chainline to be different for the track cog verses the freewheel?

I mean it looks like the gear on the freewheel is going to be about 1/2" from the hub flange, and the track gear on the other side will only be about 1/4" from the hub flange.

Should I compensate by maybe having the front ring right in between, you know so that it is off 1/8" one way when fixed, and 1/8" off the other way when free?

Am I making any sense here?

thanks

Mine isn't exactly the same. It works fine.

An eighth (3mm) is too much to be off, especially on a fixed gear. I would respace the hub, or shim the freewheel side, until both cogs were the same distance from the forkend, then either shim the chainring or bottom bracket, or replace the BB axle, until both sides were within 1mm.

Well, you can use odd spacers, and that might help your chainline, but then your tire alignment will be off. If you redish the wheel and have uneven spacers, that will get you both a good chainline and good alignment.

Or, you can do what I did-go for dual chainrings. If you have a 2 or 3 tooth difference from fixed to free, have a second chainring with an opposite 2-3 tooth difference. Running 42/16 fixed? Try a 40/18 free.

If you redish the wheel and have uneven spacers, that will get you both a good chainline and good alignment.

Yep, that's what I starting thinking while driving home tonight, thanks for reaffirming that.

Unfortunately it looks like that hubs I have (IRO) do not afford the possibility of adding or moving spacers....Sheldon says something similar to that too on his website.

Still wondering if it is normal for track hubs to be built this way, basically requiring some manipulation of spacers and dish for equal track.

thanks to all

It may not be the hub that is causing the difference, various cogs and freewheels give different chainlines. There is some good info on this at http://www.sheldonbrown.com/chainline/



Yep, that's what I starting thinking while driving home tonight, thanks for reaffirming that.

Unfortunately it looks like that hubs I have (IRO) do not afford the possibility of adding or moving spacers....Sheldon says something similar to that too on his website.

Still wondering if it is normal for track hubs to be built this way, basically requiring some manipulation of spacers and dish for equal track.

thanks to all

Hi, I use the IRO 120mm hub with a D-Ace cog on one side and a Shimano freewheel on the other and the chainline is exactly the same.

Mark