the chainrings on my cannondale synapse need to be replaced, could use some advice on these options (or others). currently every other component in my drivetrain is ultegra (6800 derailleurs, new CS-R8000 cassette), however the bike came stock with FSA chainrings. seems like it'd be ideal to have everything matching. my first thought was to just replace them with ultegra chainrings, but the 5 bolt chainrings are nearly impossible to find. next thought was to just replace the whole crankset with ultegra, but i'm questioning that after reading about the recall.
here's a pic of my current crankset:
would appreciate any input on the following options, or other options i haven't considered:
- replace with similar FSA chainrings
- replace full crankset with ultegra FC-R8000 (performance bikes claims they won't shipped a recalled crankset)
- replace full crankset with 105 crankset
should i be concerned about buying an ultegra FC-R8000, even if it's not in the recall? if i were to replace the full crankset, should i also replace the bottom bracket? are the cannondale cranks that came with the bike significantly better or worse than ultegra cranks? will an ultegra crankset ride/shift better than the cannondale/FSA one that came on the bike?
thanks in advance for any help 🙏 i'm new to this, so still have a lot to figure out
by unclechett
9 Comments
Having things match is purely an aesthetic choice. If there’s nothing currently wrong with your FSA crankset, there’s no functional benefit to changing it to an Ultegra crankset.
As far as replacing chainrings goes, any 5 bolt 110 mm BCD chainrings will work, FSA or otherwise.
Buy direct replacement FSA rings and be happy. I can’t tell from the pics which version of the Si cranks you have, but all of them are expensive parts and the hollow ones are extremely expensive and light. Replacing them when it’s not really needed doesn’t make a lot of sense, especially since you’re also talking about buying a BB30 to 24mm conversion BB or adapters too (the conversion BBs are the better way of doing it, and even the plug-in adapters are kind of expensive these days in addition to having the massive disadvantage of retaining the poor bearing stance of BB30).
There are higher end 110 50/34 ring sets in the world if you wanted to get fancier, like TA. That would be a reasonable choice too, since they’re way nicer than FSA.
Just buy FSA chain rings. There’s absolutely no reason to waste money on a new crank set.
This is the first I’ve heard of someone considering moving *to* an Ultegra crankset. I’ve enjoyed a lot of different Shimano innovations over the years. The Ultegra cranks have not been their best.
https://www.cpsc.gov/Recalls/2023/Shimano-Recalls-Cranksets-for-Bicycles-Due-to-Crash-Hazard
If you haven’t been having issues with the Cannondale/FSA setup, I would probably just get new FSA chainrings.
If you really want that Shimano branding: You’re having trouble finding 5-bolt Ultegra chainrings because 11-speed Ultegra 5-bolt chainrings don’t exist. The only 11-speed, 5-bolt, 110 BCD crankset Shimano ever made was the FC-RS500. Looks like 50T ‘rings are still available online but the 34T inner is hard to find. The inner (without the shift ramps/pins) is less important to match speeds, you could pair the 50T RS500 outer with a “10-speed” 34T inner meant for a 7950, 6750, 6650, 5750, 5650, 4650, R565, or R460 crankset.
I am not a cannondale expert but you are going to be going down a rabbit hole if you want to swap the crankset itself. Yes you’re going to have to change the BB to switch to a Shimano crankset; Cannondale cranks have 30mm spindles and Shimano cranks have 24mm spindles. I don’t know what BB standards Cannondale uses on their frames nowadays but I can guarantee you that it’s NOT BSA threaded or BB86 press-fit. So you won’t be able to just by a Shimano-branded BB, you’ll have to buy a conversion BB from a third party.
If you are insistent going through with the crankset swap, I would go with the 105 R7000 crankset. I’m not convinced that the post-recall R8000 cranks won’t eventually fail, while the R7000s are constructed using techniques that Shimano perfected 20+ years ago and are completely bulletproof.
SI cranks are a nice signature feature of C’dales. I’d definitely keep them.
UPDATE: definitely going to just replace the chainrings – don’t want to deal with BB conversation and would like to keep the si cranks. the FSA chainrings are backordered (i can find them, but not places i’d prefer to order from). i’m considering these [praxis works chainrings](https://praxiscycles.com/product/road-rings/) (version: buzz, 110 BCD, 50/34) instead. does anyone have an opinion on praxis vs FSA chainrings? i know forged metal is preferable in many other applications, is it also better for chainrings?
I have an old FSA SL-K Crankset and an Ultegra R8000 Crankset. Honestly both feel completely fine and I can’t tell the difference between them. Both have worked quite well for me so far, though the Ultegra one always has the chance of failing.
If you’re gonna get a new crankset, go Campagnolo Super Record carbon