Well, that was a waste of money

[jpembroke]

I bought an FSA Gossamer 46/36 chainset for my cross bike a couple of weeks back to replace my chainset (Stronglight 48/34) I thought it would be a better ratio for 'cross and it was only £39.99 in the CRC sale (and that included the MegaExo BB). Well, the chainset arrived and I installed it quickly and without issues. First thing I noticed was how much friction there was - pushing the pedals the cranks wouldn't even turn a full revolution. Then I took it out for a test ride. I doubt I could notice the friction and there was some noticeable improvement in terms of stiffness over my old square taper Stronglight. However, by the end of the ride there was a squeak coming from the BB. One ride!!!! So today I took it apart, regreased etc. Then, whilst tightening it back up the fixing nut on the left rounded out and it was a hell of a job freeing it. What a pile of crap! I have now dismantled the bl**dy thing and refitted the Stronglight.

Square Taper rules!

 

[beancounter]

From memory I think you were warned but couldn't resist a bargain!

My Cannondale cross bike has the same crankset / bb. Not long after I got it, it started making horrible noises at the bb - terminal, I thought.

I took it back to Evans who had it for a couple of days, pronounced that it had not been "properly greased" and gave it me back. 2500 miles later I've had no further problems!

I did have my doubts at the time and I wonder if they quietly replaced it.

bc

 

[jpembroke]

Yes, was warned but went ahead anyway. I can always fit the chainrings to my original chainset so not too bothered. Hopefully CRC will send me a new fixing bolt. If they don't then the chainset is junk.

 

[02GF74]

you after the fixing bolt for square taper BB? I may have one lying round you can have.

oh, and ..

First thing I noticed was how much friction there was - pushing the pedals the cranks wouldn't even turn a full revolution.

WTF, hoiw can that be? the chainse runs on bearings, if you takethe chaiin off, it should spin merrily on its own for some time.

only think that can cause that, aside from lack of grease whcih shouldn't be the case on new item, is the bearings not being parallel or incorrect assembly - not famuiliar with that BB so can;t say.

 

[Dave5N]

Their BBs do have a certain reputation.

Thought the chainsets were ok though.

 

[jpembroke]

you after the fixing bolt for square taper BB? I may have one lying round you can have.

oh, and ..


WTF, hoiw can that be? the chainse runs on bearings, if you takethe chaiin off, it should spin merrily on its own for some time.

only think that can cause that, aside from lack of grease whcih shouldn't be the case on new item, is the bearings not being parallel or incorrect assembly - not famuiliar with that BB so can;t say.

Not square taper; I've put the square taper back on and that does indeed spin merrily. The FSA chainset in question is a Gossamer Compact (46/36) with a MegaExo BB. When I installed it (following the instructions to the letter) it had a great deal of friction particularly at one point in the turn. Even if I tried to spin it it wouldn't make a complete revolution. I remember the Truvativ Elita chainset on my fixie wasn't much better. This is different to other external BBs I've installed (Campag UT and Shimano Tiagra) which didn't have much drag at all.

I'm a bit p*ssed off about this as the chainset would have been perfect for 'cross racing - I have a race this weekend and was looking forward to using it.

 

[buddha]

Not square taper; I've put the square taper back on and that does indeed spin merrily. The FSA chainset in question is a Gossamer Compact (46/36) with a MegaExo BB. When I installed it (following the instructions to the letter) it had a great deal of friction particularly at one point in the turn. Even if I tried to spin it it wouldn't make a complete revolution. I remember the Truvativ Elita chainset on my fixie wasn't much better.

I've had similar issues with both of these.

The Elita (on my Pompino), when new wouldn't spin a whole rev (without the chain). So when the time came for a service I lightly rubbed the cups with 1200 wet and dry, re-greased and all was fine. It spins about 7-8 revs.
The Gossamer (newish bike) used to make a hell of a gritty racket for the first few weeks but has now settled down to a less noisy 'tinkleing' sound.

 

[Globalti]

Did you get the bb shell faced? This is particularly crucial with outboard bearings, which must be absolutely parallel.

 

[jpembroke]

Did you get the bb shell faced? This is particularly crucial with outboard bearings, which must be absolutely parallel.

Yes, very good point and one I arrived at yesterday after a bit of googleage. I noticed it's binding at one point in the revolution and that's no doubt the cause. I'm going to get the shell faced and hopefully that'll sort it.

 

[MartinC]

Sometimes the seals on new bearings stop them spinning freely. You wouldn't notice this when pedalling and it wears off pretty soon. IME BB's vary in this, pedals almost always don't spin freely 'til they've been ridden a few miles.

Facing the BB shell is a good thing but may not be the cause.

 

[jpembroke]

Well, the drag was significant to the point that I couldn't get it to spin a single revolution with the chain off. Added to that the fact that it was noticeably binding during a rotation does suggest that facing is an issue (there is quite a bit of paint of the shell and it does seem uneven). I'll stick with the good ol' square taper stronglight for now and get the shell faced at some point. Hopefully by then I'll have a replacement nut for the LH crank (CRC are trying to find one for me).

 

[asterix]

Hmm.. Have just re-fitted a 25 year old Stronglight on the basis if it ain't broke don't fix it. Have wasted enough buying tektro brakes only to find the longer brake shoe hasn't space under the fork crown

 

[fossyant]

Was going to add, are these external bearings - if so did you get the shell faced ? - Square tapers don't need a faced shell, but external ones do - if it's out, then you'll get drag, and eventual BB failure.

 

[dan_bo]

External BB's- solution looking for a problem.


Can look pretty good though.

 

[fossyant]

External BB's- solution looking for a problem.


Can look pretty good though.

Best invention ever was the cartridge BB for square taper - how flippin good were they, having had adjustable ones before. My XTR/Dura Ace and Ultegra ones have been exactly that - fit, forget, no maintenance in 10 years (not that you can maintain them)...........