Octalink chainset fitting

Guss

Fitted an old Octalink 2 chainset to my Trek SU600 frame, took care to have the BB squared by my LBS. I decided to fit the Chainset without the 2.5mm spacers to adjust my chainline, I actually only needed the one on the drive side as its a 73mm shell.

Now the problem is when pushing the chainset axil through the external cartridge bearings I found I couldn't push it all the way through by hand and had to use a hammer with a piece of wood to avoid damaging the chainset face of course. I am worried that the silvery coating on the axil which is coming off due to corrosion might be causing problems when fitting.

1. Should I just be able to slide it through by hand the whole way? I have also noticed that there is slight resistance when spinning the chainset.

2. Should the chainset be flush up to the external cartridge bearing and by not using the spacers am I risking anything?

Thanks
Guss

supersonic

I think you mean HollowTech 2 as octalink is a different system.

They can take some force to push through, but if it is binding or cathing on the opposite cup it indcates the shell may not have been faced properly, or the cups not installed properly. Though I don't think that is the case here.

The resitance can feel high, but make sure you have not over preloaded the sytem. The crank does fit very close to the cups.

dilemna

When you say you had the BB squared with your LBS, what does this mean? An Octalink BB is not square? :?

Will the Shimano Octalink Hollow tech 2 road chainsets fit the Shimano Octalink MTB bottom brackets of 73mm shells? As far as my experience shows me they will not as I tried to do just this but couldn't get my Ultegra chainset to fit. I didn't resort to bashing it on though as it was clear it wasn't going to fit the MTB Octalink 73mm ES 51 BB properly. Matched to the correct BB it should slip on smoothly and tightening with the crank bolts easily brings the spider up close to the BB face. It is then square and rock solid on the axle. If you compare a 73mm Octalink ES BB alongside a 105 or Ultegra Octalink BB they are actually quite different. The splines actually have a different spacing. The road chainsets require a road bottom bracket which only come in 68mm shells for English road bikes or 70mm for Italian bikes. From my experience you cannot mix MTB and Road bike systems. Sorry. BTW I got around it by fitting a Shimano UN54 square taper 73x113mm BB with a Campag Record chainset to my Trek 7500 hybrid.

supersonic

Yes, mostMTB Octalink sytems are different to Roadie ones (original XTR Octalink uses the same fitting as roadie ones)

I think he meant 'faced' but all is really besides the point, as Octalink is not an external bottom bracket fitting where you push the axle through the cups.

Guss

Grrr sorry folks I meant to say........



Fitted an old Hollowtech 2 chainset, took care to have the BB faced by my LBS. I decided to fit the Chainset without the 2.5mm spacers to adjust my chainline, I actually only needed the one on the drive side as its a 73mm shell.

Now the problem is when pushing the chainset axil through the external cartridge bearings I found I couldn't push it all the way through by hand and had to use a hammer with a piece of wood to avoid damaging the chainset face of course. I am worried that the silvery coating on the axil which is coming off due to corrosion might be causing problems when fitting.

1. Should I just be able to slide it through by hand the whole way? I have also noticed that there is slight resistance when spinning the chainset.

2. Should the chainset be flush up to the external cartridge bearing and by not using the spacers am I risking anything?

Thanks
Guss