Australian Cycling Forums - Bicycles Network Australia

Guys, please excuse my lack of experience on this, but i have the chance to pick up a basically brand new ultegra crankset, for buttons (take off from a mates bike). Would it be a straight swap onto my Roubaix with a FSA Gossamer, BB30 fitted? This is my training bike and tends to rack up the kms and i just had it in my mind this is a decent and in this case, low cost upgrade.

It's not a direct swap. You'll need a pair of adaptor cups to step down from the BB30 to the Shimano system.

Thanks Duck, so its this sort of thing you are talking about? http://www.ebay.com.au/itm/BB30-Bottom- ... 4613c80bea" onclick="window.open(this.href);return false;

colinmc400 wrote:Thanks Duck, so its this sort of thing you are talking about? http://www.ebay.com.au/itm/BB30-Bottom- ... 4613c80bea" onclick="window.open(this.href);return false;

Wheels Manufacturing company makes very good adaptor inserts. I have been using them with no problems.

They are on special on Torpedo7 at the moment as well. $25 from memory.

Make sure u use carbon paste.
The ultegra will be a massive improvement in shifting (if it's a 6700 crankset).


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colinmc400 wrote:Thanks Duck, so its this sort of thing you are talking about? http://www.ebay.com.au/itm/BB30-Bottom- ... 4613c80bea" onclick="window.open(this.href);return false;

That's not the exact thing I was thinking of, but yes, that will do perfectly.

Thanks guys. I have Specialized Pro fact cranks on my weekend warrior and they just seem, i dunno sturdier, with less flex maybe, so i reckon this ultegra will be a 1/2 way house. Its only a 105 groupset on the bike, with some upgrade wheels so far (for a big lad) and this will be the last $ spent on it for now.

Thanks again!

Alternatively if you want an adaptor that you don't have to press in but will press itself in as you screw it together with standard Shimano BB tools (you need two), then this KCNC gadget works well:

http://compare.ebay.com.au/like/1510473 ... 1047370380" onclick="window.open(this.href);return false;

+1 on the Ultegra being a massive improvement.

The Wheels adapters are hardly press in,I found the went in easily with a light tap with the mallet. They work perfectly too!

not a good sign if they're that easy to get in

pawnii wrote:not a good sign if they're that easy to get in

Requiring a "light tap with a mallet" as in the previous post indicates that it's still a suitably snug fit, similar to the crank through the bearings. I'd be worried if they could be fitted without any kind of resistance.

OT - I dunno why everyone dislikes the FSA cranksets and BB30 so much. Since April this year I have done 5,300Km on my CAAD10 - BB30 / FSA SL-K Light crankset - and have had no issues whatsoever. I have removed / cleaned / regreased the crankset after some riding in nasty weather where it got stupidly wet, but have had no creaking issues to speak of and the shifting on the front rings is as good as my DA7800, so why no love from others?

cheers

Not all FSA cranks are created equal; there's a greater performance difference between their good & cheap ones than there is with Shimano (whose cheap cranks still perform very well). The Gossamer in the OP is in a different league to your SL-K.

And BB30 fit requires tight tolerances to work well. Not just the BB itself but also the BB shell on the frame.

I've had unresolvable issues on 5 or so frames.


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OK so have a mate in a similar situation at the moment, had already pointed him in the direct of the adaptors. The one thing im not sure on is whether the adaptors adapt to the crank or the BB, i.e. which BB do you use, the original one or one that is compatible with the new cranks?

wouldn't you use the adaptor that reduces the BB30 to 24mm O.D. so you stay with a larger BB bearing?

im_no_pro wrote:OK so have a mate in a similar situation at the moment, had already pointed him in the direct of the adaptors. The one thing im not sure on is whether the adaptors adapt to the crank or the BB, i.e. which BB do you use, the original one or one that is compatible with the new cranks?

The Wheels MFG ones linked earlier fit into the BB30 bearings & step out & down to accept the Shimano crank. Others I was originally thinking of press into the frame in place of the BB30 bearings, so the end result is more of a BB90 format. All press-fit, whether BB30, BB86 or BB90 rely on correct tolerance from the frame manufacturer to work properly.

Cul wrote:The Wheels adapters are hardly press in,I found the went in easily with a light tap with the mallet. They work perfectly too!

The Wheels Mfg adaptors don't replace the bearings (which ARE a press fit). You keep the original BB30 bearings and you can think of the adaptors as a kind of shim that allows the smaller diameter cranks to match up with the internal diameter of the BB30 bearings.

Whereas the KCNC adaptor that I linked to completely replaces the existing BB30 bearings. It's really more like a conventional BB. The benefit is that it screws itself together and simultaneously presses its bearings into the shell, so you can completely remove and replace the whole assembly without the need for a bearing press.

Which, given the amount of trouble that a lot of people have with BB30 creaking, is a nice feature.

$7qp
M.








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Duck! wrote:Not all FSA cranks are created equal; there's a greater performance difference between their good & cheap ones than there is with Shimano (whose cheap cranks still perform very well). The Gossamer in the OP is in a different league to your SL-K.

Fair enough, wasn't aware of such discrepancy.

cheers

http://praxiscycles.com/pages/conversion Praxis makes a BB that fits into BB30 to suit shimano and it's getting good reviews.

I'm currently riding DA on a Felt F4 with wheels adapters to the original bearings. Because of my weight, I can see the adapter setup not lasting as long as I'd like, but I'm yet to make an experienced call on that. My plan is to replace everything with a Praxis BB when the time comes to replace bearings or adapters.

OK, so it looks like the difference between the Praxis and the KCNC bottom brackets is:

The Praxis has an expanding "wedge" that clamps the unit radially outwards to the inside of the bearing shell, and this clamp is what stops the whole thing moving laterally. The bearing carriers are not torqued super hard laterally into the shell - they end up wherever the stop on the wedge leaves them.

The KCNC doesn't have the expanding wedge. It relies on torque to clamp the left and right side sections together. The bearings carriers are clamped laterally into the shell with the full force of the fitting.

Hard to say which system would be superior and lead to less movement between bearing carrier and shell.

Thanks for the replies guys. Ultegra crankset and KCNC bracket on its way to me as we speak. I'll post a reply in a few weeks when it all gets fitted up.