ArgoMan

Hey all. I was going to get a new Shimano R9100 BB (Dura Ace), but I have a new Ultegra R8000 crank. Are they compatible? Maybe I should just get the Ultergra BB?

Also, in researching this issue on the Google machine, I learned that Shimano had a recall on Ultegra and Dura Ace cranks? WTH was wrong?

veganbikes

It should work fine. If you want to upgrade consider Kogel for Ceramic or my general go to of Wheels Manufacturing. However if you are just replacing DA is fine

Yes they recalled some older cranks for a few delimitation issues. Basically keep an eye on your cranks if they fall into the recall and if something is awry they will send you a new one. So far my old 6800 cranks are just fine and I haven't made plans to replace them yet and haven't noticed issues and I am not a small rider. However that doesn't mean much because it is purely anecdotal and I have a bunch of bikes and haven't ridden that one in a while but have had the cranks since 2016 I think maybe before.

ArgoMan

Thanks, Vegan (I just noted the "Clark W. Griswold" name...best Christmas movie of all time!) The crank is new and Shimano has a guide online to determine if it's one of the affected cranks. If so, they'll replace it.

Iride01 

You should note that there are some differences among the speed groups. 12 speed Shimano road cranks have a chain line of 44.5 and 11 speed cranks are 43.5. Just a Benson&Hedges silly millmeter longer thing. But for older versions of the groups that have fewer speeds will be even more difference.

The chain rings between the 3 groups, 105, Ultegra and Dura-Ace will interchange, but color, finishes and the profiles might not quite match if you worry about how they look.

And you can always go to these documents if you want to see what Shimano has to say.....

https://productinfo.shimano.com/en

ArgoMan

This is a concern of mine. I'm setting up a TT bike. To that end, I didn't want to go larger than a 10-speed cassette. Following that thinking, I purchased a Tiagra 4700 RD. It's designed for 10-speeds. I was going to go with a 105 5701, but I think the Tiagra will work out better for me. BUT, my Ultegra crank is advertised as an 11-speed. I don't think it will be a problem though. I plan on switching it out to a 1x. Any thoughts or suggestions? Thank you!

Iride01 

I've no idea what might be the big concerns on a TT bike. However if precise shifting is one of them, then I'd keep all the major components from the same group and same version number of that group. But that's mainly because my days of wanting to experiment are long gone and over with. Perhaps mixing any of the groups together won't make that big a deal. But since I can't know for certain, ergo the advice on not mixing them.

Chain line of the crankset are fixed. But they are based on the expected position of the rear cassette of the same speeds the crankset is made for. Your build on that bike along with the wheel you select might have that cassette with a different chain line that is better or worse. Essentially... try it and see.

SoSmellyAir

Both Dura Ace (BB-R9100) and Ultegra (SM-BBR60) bottom brackets would work with an Ultegra FC-R8000 crank, but they require different installation tools because their respective external cups are different sizes.

datlas 

Good point. Also annoying as it seems Shimano changes the size or spline pattern on their BB’s too often for my taste. I keep having to buy a new tool or a POS plastic converter. I can’t understand why.

But yeah, the spindle should fit ok.

ArgoMan

Thanks all. I think I'll just get the Ultegra. I can't imagine that the DA BB will give me any significant advantage anyhow. Save myself the trouble!

SoSmellyAir

The BB-R9100 is most likely at least a whole gram lighter for not much more money. I chose it (over the SM-BBR60) for my CAAD4 build because its smaller external cups have a shorter diameter than the tube that forms the bottom bracket shell, which looks better than the other way.

ArgoMan

Guys (and gals), bad news! The Ultegra crankset I have is defective! I got it "barely used" for a great price, and it clearly has some delamination. I'll see if I can address it with Shimano directly.
I have a new FC-RS510 crankset. It's kinda sharp looking with a glossy finish. Compact, 165mm. It was never subject to recall. In fact, I've read that it was produced in response to the recall issues. It seems very strong, but it's somewhat heavy. I'm thinking about using it on my build. It's marked as an 11-speed. Will it be compatible with my Tiagra 4700 (10 speed)? I'll only be using the RD in friction mode, if that makes any difference. If not, I can just jump for a new crank. I'm likely to convert the RS510 to a 1x anyway.

PeteHski

This is not true, although it is true that it wouldn’t be affected by the recall. This is basically a cheaper version of the 105 crankset, which is also unaffected by the recall.