Best captain's Eccentric and Bottom Brackets?
 

In your opinion what is the best bottom bracket available for a captain? Why?

Anything titanium is out (this is for me), and will be used with 200mm cranks. I need stiffness and great bearings. Also this is going to be for a Cannondale tandem.

I was thinking Phil Wood, just because it is the lazy default choice. However, lately I've been thinking SKF. However, the SKF BB assumes the drive is on the left side which would be wrong for my captain cranks. Does SKF make a tandem captain specific BB? Can I just install a regular SKF BB "backwards," that is left on right?

Also may want to go with a new eccentric.

Has anyone used a less wide BB spindle on the captain's crank where the length of chain means you can "cheat" to get a lower Q-Factor?

Bonus points for contributing meaningful information BEFORE TandemGeek answers all!

Take a look at Steve Bushnell's eccentric.
http://www.rodcycle.com/

I second the Bushnell eccentric. I bought one after I discovered the eccentric that came with my Calfee could not work. There is no problem with using a shorter spindle on the front. I have a standard Ultegra crankset on front and a Gossamer tandem crankset on the rear. You just won't be able to use a belt drive. I would think the BB could be installed backwards, but depending on how it installs it might tend to loosen due to pedaling torque. This is not a problem if you use a newer type BB with the outboard bearings.

More durable but heavier BB.
http://www.compasscycle.com/SKFbb.html

Wayne

From another thread I can assume you'll need JIS square taper since you've decided to go with some custom-length daVinci cranks; Yes?

Phil Wood, always a good call when you need a JIS square taper: wide range of axle lengths, off-set axle options, 5mm of off-set adjustability using two adjustable cups instead of a fixing cup & adjustable cup, and different spindle options. Down side is, they're not really sealed so if you ride in the wet a lot you could end up with long-term durability issues and you need to buy a special set of splined cup installation tools.

Shimano's UN72's were my favorite, but the UN73 has turned out to be a really great option too. A LOT less expensive than a Phil in 4 axles lengths for 68mm wide BB's. This is what we use on our off-road tandem. I think Jensen sells them for under $20/ea. UN54's are OK, also cheap but a bit portly.

SKF... Everyone seems pretty happy with them. I haven't had an occasion to use them, as our Phil Wood & Shimano UN72/73s have been doing just fine. You are correct in that you could install them "backwards" to put the roller bearings on the left side of the tandem by flipping your eccentric so long as you use Blue 242 or Red 271 Loctite (apply heat to remove) on the cups to keep procession from causing them to back-out. For any doubters, this is the easiest way to make sure Italian BB's don't unscrew themselves, noting my '98 Calfee Tetra Pro single has an Italian-threaded BB: been there done that. Anyway, not sure there's a more durable BB on the market than the SKF, but they're 1/3 heavier than Phil Wood BB's (if that matters to you, ~300 gr vs. ~200). Our friend Alex is an SKF dealer: http://www.mtbtandems.com/SKF.htm

As already noted by brother jnbrown, running a spindle that is a different width or even at a different off-set than the rear on a tandem's sync drive is no big deal. I've been running 108's up front with 111's and 113's in the back for over 10 years on three different tandems. The length of the drive chain nulls out any offset issues with a chain... not so with a belt drive.

Finally, who the heck is Steve Bushnell? I think you mean Dennis Bushnell... currently the master framebuilder for R&E Cycles. Dennis came up with his expanding eccentric design back in the 90's and got around to patenting it in 2007/2008. By then, he'd had some help in refining the design from Todd Shusterman at daVinci designs, who doesn't typically get credited for his work on the refined version.

That said, Mel Kornbluh at Tandems East has come up with a modification to Cannondale's newer eccentric that makes them a pretty good choice as well. Cannondale almost got it right with their latest eccentic, but went cheap on a critical part. Mel had his machinist come up with a replacement part that solves the problem. Just something to consider. I've stuck with the Bushnell for our Calfee as I've been a Bushnell fan for a long, long time (since '98) and have them on all of our tandems.

The suggestion about turning the SKF BB backwards would work with Loctite but even when installed in the normal manner you still have larger bearings on the left side than other square taper BBs and should get a much longer life.

Wayne

I know the OP cannot change BB shells so this is a little off topic but having switched from Co Motion to Santana I find there very simple solid aluminum eccentric to be a great idea. Very light and I have less problem with slippage than the stock Co-Motion eccentric. I can also adjust the chain line left and right a few mm similar to a Phil BB. I am not a big guy only about 155 lbs so others may have different results. Very simple design but simple can be a good thing.

Wayne

Better link to the Bushnell: http://www.rodcycle.com/eccentric.html

It is a great design for spreading the EBB pressure evenly. You gotta wonder about all those drilled holes though as there is a ton of empty space inside there. Is anyone ever concerned about all those drilled holes letting a lot of water and gunk accumulate in their BB shell?

Even if you live in the Mojave, eventually you'll want to wash your bike instead of taking a shower from your reserve.

Get the glue gun out and plug em all I say. Sorry, weight weenie spoiler.