Hello all. I'm in need of advice from someone who knows what the hell they're talking about when it comes to cranks.

I've got a lovely '97 Floval that runs super-smooth except for a standard 3-piece Profile with Hop-Up kit that refuses to run smooth and is consequently driving me nuts. It makes clicking noises when I'm cranking hard, you can feel a few slight hicks as it revolves, and the flush-fitting bolts need to be nipped tight every other week which ticks me off. I've tried everything I can think of to remedy these problems - replaced the bearings, copper-slipped the axle, used spring washers behind the axle bolts in an effort to retain tension, and so on...but nothing works. Any ideas, or is this simply how these cranks are? (I should add that I bought the bike second-hand with the crank in it and there are no visible signs of damage anywhere.)

Also, last year I decided to replace it with a new twin-pinch Redline Flight, but I ended it pulling it out soon after I fit it as the sealed bearing units felt awful. Really lumpy and a bit cheap. Is this how it is with taiwanese Flights now? Anyway, I kept it so it's still an option if I can find some smoother bearings for it (and before anyone suggests running the Flight crank with Profile bearings, I've tried it and you can't as the Flight axle is a slightly too small in diameter. Shame, as pinch bolt arms are a far better design.

So - is there a way of mending my current Profile, or do I simply buy another, or do I get some nicer bearings for my Flight crank which is gathering dust on a shelf, or start anew and go for a completely different make altogether? All suggestions welcome, as I'm fresh out of ideas.

Cheers,

Bob

I have a set of newer proline cranks. The bearings were a bit rough. the LBS had some sitting right on the shelf so apparently they are a fairly common/easy to obtain size. I thought I'd have a hard time finding replacements but he looked at me like it was no big deal.

Is the rotating disturbance in the BB bearings for sure?

Is it more evident when you crank hard?

If you spend about an hour cranking the pi$$ out of it, does it seem less noticable?


could the chainring be slightly bent or out of round, teeth not worn evenly, or possibly the chain isn't quite stretched enough?

I would bet that the tube spacer in between the
bearings is missing or the wrong size and the bearings are binding when tighten the bolts, with the right tube spacer you can use some mild loctite on the bolts. This is for the Profiles.

I'd say tube spacer as well. Go to the profile site and download the installation instructions (pdf). The non-driveside bearing cup should not be flush with the bb shell if installed with the correct length spacer. There should be a small gap between cup and shell which means you have full contact between all the parts. You'll then be able to fully tighten the spindle bolts and eliminate the binding effect.

Hello again chaps. Thanks very much indeed for the advice.

I just want to clarify - so should the tube spacer be flush with the inside edge of each bearing race, or should it have a tiny bit of play? I'm now almost certain this is the cause of my problems...

the tube should fit just perfectly in there so as: not too long where it pushes the bearings out, not too short so as to have play. this is what my bike mechanic tells me.