merlinextraligh

Had a K Force carbon crank on one of my single bikes, and the BB always creaked, (despite repeated adjustments) and failed prematurely.

Now, both BB's on our new tandem are shot after 1100 miles. (FSA Tandem Gossamer cranks with mega exo BB).

I realize that Tandems put extra stress on components, however, 1100 miles for a BB is rediculous.

Rather than pursuing a warranty claim, and just getting another crappy FSA BB, the LBS is going to get us SRAM ceramic bearing BBs at cost. In theory they should last much longer, spin a little smoother, and add a bling factor.

WheresWaldo

Interesting, our upcoming tandem will have the FSA carbon crank set and now I am beginning to wonder if I should just have a different bottom bracket installed from the start.

dvs cycles

Perhaps the sideload adjustment was set too tight?

TandemGeek

Having done a lot of homework on the current state of tandem cranksets last year, my understanding is using the specified torque values and Loctite during assembly / installation of MegaExo cranksets is critical to bearing longevity... not that the bearings last all that long even when the cranks are properly installed.

However, with regard to your replacement bearings, it's something you'll really want to make sure your LBS addresses. In other words, if they don't have Loctite and a torque wrench in hand when they start to do the installation you might want to ask if you can read a copy of FSA's installation instructions and see their shop copy of the torque specs. If none of those things are on hand...

merlinextraligh

^^^I believe that's the same BB. Obviously some people must have success with them. However, my personal experience is lousy, and a lot of people in the road forum complain about them.

The SRAM Red ceramic BB's are around $175 each. If you're building a high end tandem, that's not a huge percentage of the total cost, and adds a little bling.

I've tended to think cereamic BB's are in the overhyped, not worth it category. The weight saving, and alleged watt saving is so miniscule. However, if they'll last longer, that will be worth it for us.

WheresWaldo

My two road bikes both have ceramic bearings, one using SRAM Red and the other using a DA bottom bracket with ceramic hybrid bearing instead of the standard DA bearings. It would not be a real issue for me to remove the FSA bearings from their bearing cups and replace them with a better grade stainless steel or hybrid ceramic bearing set. Might be worthwhile insurance against premature wear.

Forgot to mention, they seem to be super smooth too!

bikeriderdave

I'm curious: What is the failure mode?

Also, is your dealer sure that the GXP bottom bracket is compatible with the FSA axle? I recently acquired a TruVativ crankset and see that the bearing ID is larger on the drive side than the non-drive side. At the same time, I believe that the the FSA BBs on our Co-Motion triple have have the same bearing on either side. (I could be wrong, of course... but you might look into this.)

merlinextraligh

the bb is making a squeaking noise, and the bearings feel rough.

The LBS reportedly has used sram ceramic bearings on FSA cranks for several other customers with success. Apparently it just requires a spacer.

tandem_dude

We went away from the FSA cranks when we ordered our tandem and built it up with Phil Wood BB and Da Vinci cranks. In fact, the shop where we bought our Co-Motion has replaced a number of FSA tandem cranks with our same set-up because of ongoing problems with the FSA cranks. I am sure some people have used the FSA cranks with no issue, but we didn't want the potential headache.

joe@vwvortex

Yup - installation is key. I've seen both the stock bearings AND ceramic bearing BB's fail with FSA cranks because of this. Spacing (BB shell and outboard bearing) and torque is critical due to how they are attached. I've had no problems with mine - but my buddy had nothing but trouble. It came down to overtightening and poor bearing alignment.

KendallF

Sorry to hear it. The 1994 (?) BBs on your old tandem are just fine, BTW. Rode it 55 miles Sunday.

dfcas

Curious: Were the BB shells faced? Although chasing does not ditectly help the new outboard style BB's, many facing sets used the chased threads as a pilot and guide to face the shell.

I've had no BB problems since I started chasing/facing about 4 years ago, but I don't have any outboard type BB's at this time.

I do notice that all types of BB's,including internal ISIS, turn more freely after chasing/facing.

merlinextraligh

ended up putting enduro ceramic bearings in the FSA BB.

And the bike flies now. Did TT intervals tonight and our speed was up 2mph. Of course we also changed tires from 28mm to 24mm, and I forgot to recalibrate the computer.

But I'm sure the speed increase had to be the ceramics, not the calibration error.

lhbernhardt

My Kuwahara tandem is still running the same Sugino bottom brackets that it came with in 1980 or thereabouts. Right now I've got 175mm Shimano tandem cranks on the front and the original 170mm Sugino cranks on the rear attached to the square-taper bb's. I replaced the original 9-ball Sugino ball retainers with the 11-ball Campagnolo retainers the first time I overhauled the bb, and things still looked fine at the last overhaul. The bike has 16,000 recorded kilometers on it (10,000 miles), most of them in the past four years.

I guess they just don't make bottom brackets the way they used to...

L.

uspspro

All these issues are why I went with square taper BBs and DaVinci cranks. I just couldn't find a good "modern" option.

selasphorus

Just installed new Mega Exo BB & SL-K. Bearings grind, even with only the drive-side crank on. WTF? The Ultegra I replaced had ~12K miles, and is still clean and smooth.

WheresWaldo

I just need some clarification. Is it the actual crank that has problems or is it the poor grade bearings?

If its the bearings, Shimano and FSA use the same bearings so swapping out the cups for Ultegra should be a cheap solution. Slightly more expensive would be to go to hybrid ceramic bearings like the Enduro.

mikeybikey101

After 9k, I had my front Megaexo BB disintegrate on on the second day of DALMAC. The only thing LBS had that would work was a Shimano 105. It got me through the last day. I'm now considering replacing both BBs with something more reliable. Thinking of going Durace 7800. Would this be a better choice, or should I bite the bullet and go ceramic?

Ritterview

I am no fan of FSA cranks, the last time I got one on my single bike, the left crank arm fell off after 27 miles. There are tons of stories about how crappy FSA cranks are.

What exactly are the options if you want to build a tandem without FSA cranks?

uspspro

Square Taper BB Plus any of the following tandem cranksets:
- Ultegra (Actually Octalink)
- 105
- Sugino
- DaVinci

I like the daVinci cranks the best. Light, stiff, look cool, quality, simple.

I chose them and square taper because:
- I like the crankset (see above)
- Proven and reliable BB format
- Choice of many BB MFGs
- Choice of spindle lengths, so you can tailor your Q-factor and chain-line to your tandem setup.
- etc...

tandem_dude

We continue to have nary a problem with the DaVinci square taper set up.

WheresWaldo

Unless you go ceramic do not go for the Dura-Ace BB cups, they are more expensive than the Ultegra and there is absolutely no difference (they even use the same exact bearings) other than color.

Soil_Sampler

good choice. the Zero's or the grade 5's?

WheresWaldo

The other good thing about these bearings is that they eliminate the use of the stupid plastic bushing that everyone used since they wanted to go with a "standard" sized bearing. I have these on my DA single and they spin very smoothly. Was some of the best money I have spent in recent purchases.

mikeybikey101

thanks for the heads-up, Waldo.