BB replacement question
 

I have a BB-7000 on our Co-Motion Tandem that will need replacing. The crankset is a FSA Mega Exo. Is the BB-7000 the only "model" I can use?
Thanks!

I think I may have figured it out! I think all I need to do is measure vthe BB she'll on the frame. Correct?

Generally the Bb axle length is also needing to be measured. Especially on a tandem which can have longer the typical BB axles to allow for a triple and LH timing chainring. Andy.

I don't think the BB-7000 is available in different widths, what difference would that make?

Tandem Tom, I'm new to bottom brackets but was just recently researching Mega-Exos. So I'm no pro but it seemed that in my reading there were some that were compatible with Shimano hollowtech II bottom brackets but it was hit and miss. I think the difference was the FSA aluminum road cranks were Shimano-compatible but carbon ones were not. Like the carbon ones were a fraction of a millimeter larger bore or something like that. However, the BB-7000 appears to be for their mountain cranks so I'm not sure. What crankset do you have ("Mega-Exo" is not the model of crankset but the style of the bottom bracket interface)?

TT, see if you can make use of this... http://www.stilen.com/bike_stuff/Meg...l_040820-1.pdf

You may want to check the reviews on this site: FSA BB-7000 V-Drive Mega Exo BB | Chain Reaction Cycles

You mentioned that your current BB 7000 has quit, but you didn't say how long it lasted. Others complain that it has a short life expectancy.

I will answer both questions. The crankset is FSA Gossamer Tandem Crankset. Not sure how many miles on this BB but I rebuilt them with Phil Wood bearings. We don't put a lot of miles on but it did seem to wear out pretty fast.
After doing a bit more reading I am totally confused!! Cannot figure out what will be a good substitute. Maybe I will start another more specific thread.

In the link I gave you, some reviewers said Shimano has a more durable BB that will work in this application. I have no idea how you can tell what will work with your existing crank set. With this system, you have a shaft that runs through the hollow BB, right? So you need a BB that will accommodate the diameter of your shaft. I hope more knowledgeable people will chime in.

BTW, Phil Wood bearings are supposed to be the best there are, yet yours quit? Hmmm....

"I don't think the BB-7000 is available in different widths, what difference would that make?" T Stew

You are right, I was thinking separate spindle VS one piece that is referenced. But in my defense much of my answers are for others too. Guess I was lost in these possible readers who might have tapered square or splined Bbs and thought only shell width was important. Andy.

Here is some previous discussion I found on this matter. Yeah the Gossamer should be compatible (I bolded that part)...

Check out http://www.bikeforums.net/road-cycli...ml#post8412886