Swapping out FSA crank for Ultegra

[dianne_1234]

As the title of my post states...I am wanting to swap out the FSA SLK carbon crank on my Cannondale Synapse for an Ultegra one. I have not been happy with the FSA crank from day 1, and I want it gone. I also believe that the big chainring on the FSA crank may be playing a role in the awful shifting problems I've been experiencing on the front ring. I know that I could just swap out the chainring itself, but at $120 for the big ring alone, I'd rather spend the extra $$$ and get the entire Ultegra crank. In addition to the Ultegra crank, it is my understanding that I will also need to replace the bottom bracket...as my current BB, an FSA BB30, is not compatible with the Ultegra crank. In speaking with a mechanic over the phone from Performance Bike, I was also told that I will need some kind of "adapter" because of the way the FSA bearings are in a sealed cartridge. This part has me a bit confused. Has anyone else here been in a similar situation, swapping out a different brand of crank for an Ultegra one? I'd be interested to hear what exactly was involved in the swap. I would not be doing the work myself, of course (have no clue on how to do it), but would like a good grasp on the parts involved. Thanks!

Linda

Hi Linda, good decision to ditch the FSA crank. They have a history of mediocre shifting. Nearly everyone who switches prefers Shimano.

The BB30 shell in your Cannondale is 42mm inside diameter, and the Shimano bottom bracket screws into threaded frames that are about 36mm inside diameter (and threaded). The adpter you need is LocTited into your frame and provides the threaded interior your Shimano bottom bracket cups need. Here's an image of one made by, ironically, FSA, along with the Shimano BB that threads into it:


http://www.labicicletta.com/edatcat/...SA-BB30ADAPTER
http://www.bikepartsplace.com/discou...-cups-italian/

Another option is an aftermarket bottom bracket that fits into your 42mm frame and whose bearings provide the 24mm inside diameter your Shimano crank needs, such as KCNC's:


http://fairwheelbikes.com/kcnc-bb30-adapter-p-2926.html
This replaces the Shimano thread in bottom bracket bearing cups, no need to buy them if you go this route.

A third option is to slip some Wheels Manufacturing shims into your frame's existing cartridge bearings. THey step down the 30mm bearings to 24mm to fit your Shimano crank.

http://www.competitivecyclist.com/pr...9081.19.1.html
These are a little different; they load your crank's axle slightly differently than Shimano intended and are said to shorten the fatigue life of the axle. Nevertheless lots of people use them. No idea how long we'll have to wait to see the rash of breaking crank axles. Maybe never?!? I'd use them if they were convenient.

Hope this helps!

[Cataboo]

For what it's worth, I've got FSA carbon cranks on all my road bikes. I've swapped ultegra and 105 level cranks for the FSA ones since FSA actually makes carbon cranks in shorter lengths.

I haven't noticed any difference in shifting since the changes or that I have mediocre shifting.

You should just need a new crankset, bottom bracket, and the BB30 adaptor that they're talking about.

[nscrbug]

Thank you all SO very much...you have been most helpful! And the pics of the adapter were especially helpful since I now have a "visual" of how it all works.

Linda

[Becky]

Thanks, Dianne! That info and pics were really helpful!

[aicabsolut]

Why not get another BB30 crankset? There are several options now that aren't FSA, such as Cannondale's proprietary cranks, SRAM, Specialized, etc. Once you put the threaded insert in there, it is a real pain to remove if you ever decide to go back to BB30. I really like my Shimano cranksets, but I think if I got a BB30 frame (my Specialized framesets came threaded unlike their complete bikes), I think I'd stick with a BB30 crank.

[nscrbug]

Why not get another BB30 crankset? There are several options now that aren't FSA, such as Cannondale's proprietary cranks, SRAM, Specialized, etc. Once you put the threaded insert in there, it is a real pain to remove if you ever decide to go back to BB30. I really like my Shimano cranksets, but I think if I got a BB30 frame (my Specialized framesets came threaded unlike their complete bikes), I think I'd stick with a BB30 crank.

Yeah, in the back of my mind I worry a bit about that adapter insert having to be loctite'd into place. Is there any chance of that thing slipping or coming undone somehow? I'm probably over-thinking this...which is common for me.

Call it a strange "quirk" of mine, but I'm of the mindset where I believe that things just seem to work better when components are all the same. Hence, my reason for insisting on an Ultegra crankset...since the rest of my drivetrain is Ultegra. But I am a bit concerned over this whole BB30 thing....ACK!

[nscrbug]

I have another thought that was brought up by someone on another forum. Would it be possible to swap out only the chainrings (both big and small) on the FSA crank for Ultegra chainrings? I guess it would depend on if the bolt patterns are the same, right? Has anyone here ever done this with good results? My main gripe isn't with the actual crank itself, but rather the chainring...especially the big one. But I would think that if one were swapping out the big one, then they would likely do the small one as well, yes?