Bicycle Mechanics - FSA SLK carbon cranks problem!

The crank arm fixing bolt that holds my cranks on the bike loosened on me today. I noticed it after my crank arm moved out from the BB about 1/2 inch! I tightened it as much as I could. After another 8 miles, it was loose again! AAAARRRRRGHHHHH! Another cyclist told me that FSA cranks were known for that. Bummer if its true.

Anyone know how to fix it????????? :eek:

That happened to a friend of mine's two week old Specialized Roubaix Comp except that his left crank arm fell off completely destroying the left bearing cup in the process. Read the roadbikereview.com reviews on that crankset. It is a common problem and some say it's not fixable, even with loctite. If you bought the bike from an LBS, take it back and complain. You might also try calling FSA but they'll probably just refer you to the LBS. You can always try loctite but only use the medium strength "blue" stuff and not the permanent strength "red". Note that all loctite comes in red bottles. The color refers to the color of the liquid.

That happened to a friend of mine's two week old Specialized Roubaix Comp except that his left crank arm fell off completely destroying the left bearing cup in the process. Read the roadbikereview.com reviews on that crankset. It is a common problem and some say it's not fixable, even with loctite. If you bought the bike from an LBS, take it back and complain. You might also try calling FSA but they'll probably just refer you to the LBS. You can always try loctite but only use the medium strength "blue" stuff and not the permanent strength "red". Note that all loctite comes in red bottles. The color refers to the color of the liquid.

thanks...I read many reviews. I guess I'll replace it and spreasd the work!

thanks...I read many reviews. I guess I'll replace it and spreasd the work!

Why don't you try Loctite first?

I went through 2 replacement FSA SL-K cranksets before just getting sick of the problem(s). Do yourself a favor and see if your LBS can get a credit from FSA or your bike manufacturer and buy Shimano or Campy cranks. I went with the Shimano R700 and would not EVER bother with FSA cranksets again. How much is your peace of mind and time worth to you?

2 threads I started regarding the crankset in question.

http://www.bikeforums.net/showthread.php?t=254891

http://www.bikeforums.net/showthread.php?t=258112

Why don't you try Loctite first?

going with the loctite-even though I heard that it doesn't make a diff. I have nothing to lose. The lbs out of state is shipping me a new crankset...they said they'd call me and give me my options. I'm interested to get feedback on the replacement crank offer....

I went through 2 replacement FSA SL-K cranksets before just getting sick of the problem(s). Do yourself a favor and see if your LBS can get a credit from FSA or your bike manufacturer and buy Shimano or Campy cranks. I went with the Shimano R700 and would not EVER bother with FSA cranksets again. How much is your peace of mind and time worth to you?

2 threads I started regarding the crankset in question.

http://www.bikeforums.net/showthread.php?t=254891

http://www.bikeforums.net/showthread.php?t=258112


Has FSA acknowledged the problem? More importantly, are they working on a fix? This could really damage their reputation.

Tim

The issue relates to the alloy crank bolt on the non drive crank, it flexs under load and backs itself off. The FSA fix is to replace this with a stronger steel one which supposedly resolves the problem. The newer models have steel crank bolts.

Two brands I never touch again, not even with a poker

FSA and American Classic.

Whether they acknowledge their problems or not is not an issue.
There's just too many recalls and failures.
I don't like being a crash test dummie.

The issue relates to the alloy crank bolt on the non drive crank, it flexs under load and backs itself off. The FSA fix is to replace this with a stronger steel one which supposedly resolves the problem. The newer models have steel crank bolts.

FSA uses rubber coated crush washers to take up play in the system and account for differences in frame bottom bracket shell width. The crank bolt smashes down these crush washers when you tighten it. After time, the pinched rubber squeezes out and tension in the crank bolt decreases, which causes it to loosen - bolts stay tight because they stretch which keeps tension on the threads. A steel bolt with thread-lock should help but close monitoring of the bolt is still recommended in my opinion.

My understanding is that FSA has updated this design for their new top of the line cranks: the BB spindle is now tapered and the bolt has Loctite. Too bad they didn't update the entire line of cranks. FSA clearly doesn't do the testing and research that some other component company’s do. Buy their stuff at your own risk.

The issue relates to the alloy crank bolt on the non drive crank, it flexs under load and backs itself off. The FSA fix is to replace this with a stronger steel one which supposedly resolves the problem. The newer models have steel crank bolts.



posted by Nessism-FSA uses rubber coated crush washers to take up play in the system and account for differences in frame bottom bracket shell width. The crank bolt smashes down these crush washers when you tighten it. After time, the pinched rubber squeezes out and tension in the crank bolt decreases, which causes it to loosen - bolts stay tight because they stretch which keeps tension on the threads. A steel bolt with thread-lock should help but close monitoring of the bolt is still recommended in my opinion.

My understanding is that FSA has updated this design for their new top of the line cranks: the BB spindle is now tapered and the bolt has Loctite. Too bad they didn't update the entire line of cranks. FSA clearly doesn't do the testing and research that some other component company’s do. Buy their stuff at your own risk.-


AHHHHH...thats what I need to know. The tech. info will help me get this working or replace it.

thanks good stuff!

Has FSA acknowledged the problem? More importantly, are they working on a fix? This could really damage their reputation.

Tim

Both times I had my LBS take care of the phone work/etc...since I had just bought the bike not even 3-5 weeks earlier. To my understanding, it was FSA both times. I honestly didn't care to inquire about a possible fix or solution either or even what FSA said...I just wanted out after the 3rd. The design is just inherently inferior to what Shimano uses. It's ridiculous how the pinch washers and crankarms are attached and used. In the long run there's more guess work, tighter instruction procedures (torque specs), maintanence, and time spent on their cranks vs Shimano...so given a choice, why bother? I'm fine with other FSA products though (stems, bars, seatposts, misc)...but their cranks are beyond positive recognition in my eyes now.

update: A LBS put some blue loctite on the cranks ( for free-nice of them). It's still lose! the LBS that I purchased the bike from is sending me a steel bolt, so I will see what happens..