Crank arm falls off...

vitesse169

I did the Bath RC hardriders Sun 22/3, and about 4 mile from the finish the left crankarm came off. Had to limp in as it would not stay on. It is a FSA megaExo gossamer c/set on a planet x stealth pro carbon. There was little/no indication that something was amiss until it came off. A chap at the race hq told me there has been a few failures in the last year of this type, anyone out there have any info or ideas to share with me please ?

C-S-B

had the same thing happen to me with a FSA mega exo team issue; after ~20km riding, the left arm would always come loose

I took the thing apart and regreased it a few times, but that never helped, nor did brutal tightening.

I ended up bringing the allen key to tighten it with me on all rides as it was gauranteed to come loose eventually.

However, when I tried to loosen the left crank arm a couple of weeks ago after not having used the bike for a month, I couldnt get it loose- it seems to have rusted and gotten stuck or something.

I had kind of resigned myself to buying a new one anyway, so this temporary solution suited me fine..


On the FSA website, they have the instructions online for how to take the chainsets apart/ put them back toegether, and I gathered that you are supposed to put loctite 242 on the threads of the screw holding the left crank arm onto the spindle.

Im gonna buy the loctite stuffand see if I can get it off and put it back together properly again anyway

heres the link to the gossamer on the website;
http://road.fullspeedahead.com/fly.aspx ... ut=product

adh038

I had the same problem with my FSA SLK cranks..... I have found the solution is to retighten with loctite applied as recommended in the FSA online docs for fitting cranks. Should pretty much solve the problem. You might have to reapply after 500 miles or so but mine withstood a battering over many a cobbled section last spring so should be OK!

warrior4life

It happened to me back in 1994 with a deore XT mountain bike crank.

I dont think its just an FSA problem, just nuts and bolts working loose,

vitesse169

Thanks guys, I'm waiting for a couple of screws/end plug to arrive to replace the lost one. I will be using copious amounts of loctite threadlock on rebuilding - if I let myself down on a race it's my fault; when my equipment lets me down that's another thing altogether......grrr

zanes

I found once my (square taper) crankarm had loosened enough to fall off the BB axle had rounded off the crankarm enough so that everytime I tightened it back up it could move slightly and become loose. Not sure that would be an issue here, but something to think about.

John.T

Are these the Gossamer cranks that fit on the same way as Shimano HT2. I run 2 sets of these and have just fitted them using my clicking elbow as a torque wrench and no Loctite just a smear of grease. They have been on for some time now with no trouble (3000 miles +). I did have a set of SRAM Rival cranks which fitted by tightening an allen bolt in the end of the axle the same as some FSA ones. These were a sod and for ever coming loose. The finish was cr*p as well so they were binned and one of the sets of Gossamer bought on E-Bay. End of problem.

Monty Dog

Put some Loctite 243 on the screws and use a torque wrench to get even tightness.