Need 50/36 crank

dbackmtg

My bike has a Truvativ Elite GXP 50/36 crank on it. Last summer it started to creak. It's really not a creak, but sounds more like stressing. I took it to the shop had the crank and bottom bracket serviced and it quit only to start up last fall. I had it serviced this spring and now with about 500 miles on it came back. I CAN'T STAND any noises from my bike and this is really becoming bothersome, so I'm getting a new crankset. I just need to know who makes a 50/36 in a 9sp. Thank you for your assistance.

huboon

My bike came new with one of those crappy Truvativ cranks. It lasted less than 400 miles before I got fed up with that stupid bolt that won't stay tight. It's a horrible, moronic design. Do yourself a favor and ditch that piece of junk.

I wound up getting a Shimano FC-R700 (Ultegra class but not named "Ultegra") 50/34 compact crank and haven't had a problem in almost 5000 miles.

gclark8

I suggest you investigate Specialties TA square drive cranks, no outboard bearing problems there..

__________________
Cheers,
George.

alfeng

Who did the ORIGINAL installation?

Just out of curiosity, did you/(anyone) grease the spindle before inserting it into the bearings?

Was/Is the BB properly faced?

BTW. When in doubt, choose Campagnolo.

dbackmtg

Raleigh did the original installation
I'm sure everything was greased properly when I had it worked on. Reputable shop.
what do you mean by faced?

dbackmtg

While looking at cranks, some descriptions would say 10 sp. compatable. How would this matter?

alfeng

The light coat of grease on the spindle is probably the most easily overlooked part of the installation ... so, I wouldn't be so confident about the installation.

The BB shell probably does NOT need to be faced ... if the spindle could be inserted, then it was probably good-to-go. Facing is the term used to bring the BB shell OR headtube into squared parallel alignment.

BUT, the spindle CAN be inserted if the cups are slightly off square with one another. One way that I found to tell if everything is square with a MegaExo/Hollowtech-II/UT crank & external BB is to remove ONE chainring bolt. The imbalance will more than likely (i.e., should) cause the crank to rotate, accordingly, to compensate WHEN A CHAIN IS NOT ATTACHED to any of the chanirings.

Supposedly, FSA BB bearings are notorious for failing prematurely. I don't know. I suppose the same could be true for your Truvativ BB's bearings.

The bearings can be replaced separately & you do NOT need to buy a new BB assembly.

BTW. I thought the GXP BB was supposed to mitigate stress by using a larger (25mm) inner diameter bearing on the drive side ...

Presuming the prior service was under warranty, now that you will probably have to pay for them to attempt to "fix" the creaking noise, I would suggest that YOU:

• get some light OIL (e.g., 3-in-1) and put a couple drops between the crank arms & the BB cups.

If THAT eliminates the creaking for only a brief period of time, then take the crank apart and grease the spindle ... reassemble.

alfeng

It is meant to indicated that the cranks are a "universal" substitute for an existing crankset OR a new build & can be used with Shimano-compatible 10-speed drivetrains which use a narrower chain than Campagnolo drivetrains -- it is really the chainrings which & not the actual cranks which are 10-speed compatible.

It shouldn't matter to you regardless of what your Raleigh (?) has ... it MAY mean that shifting will be slightly expedited if you have an 8-/9-speed drivetrain because the chain will contact-and-engage the larger ring a fraction of a second sooner.

On SOME 10-speed (earlier) Campagnolo chainring sets, the backside of the larger chainring was milled a fraction of a millimeter in the chainring bolt area to allow the outer chainring to sit fractionally closer to the inner chainring.