will not arrive any time soon. I work for Delta Airlines at the local airport and spoke with one of the Shimano exhibitors from yesterday's show.
In regard to wireless, the company will be concentrating on improving the platform while working on a 1x system. He also stated that they like the stiffness of alloy.
Shimano Wireless Di2 And Carbon Cranks...
Moderator: robbosmans
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I, like the facts, don't see the benefits of wireless Di2 and carbon cranks. Wireless derailleurs and shifters means four separate batteries that do not last as long as the one big battery Di2 uses. More frequent, less convenient charging. Probably the same weight too. Now days both batteries and/or wires are both hidden in the frame or seatpost so appearance is probably better with Di2 than wireless SRAM. Since SRAM has to attach huge ugly batteries to the derailleurs. Where is the benefit, improvement of wireless? As for carbon cranks, I suspect Shimano looked at the carbon cranks and decided they don't offer any improvement over their aluminum cranks. Maybe a little weight savings but not much. And more cost for carbon than aluminum. So where is the advantage, improvement? All cranks work equally well. So performance is nothing. Its kind of like aluminum, titanium, carbon stems. Same functionality. Very little weight savings with titanium and carbon stems. Huge cost increase. No benefit going with titanium or carbon stem over aluminum stem. Just because you can do something does not mean you should do it.
I'm going to add appearance too. A carbon crank does not fit with aluminum everything else. With Campagnolo, when they went with carbon crank, their rear derailleur and front derailleur and Ergo levers were black carbon too. With Shimano, everything is aluminum now on Dura Ace. I think that is correct. (Just looked up 9100 group and it appears Shimano is making Dura Ace black now. So a black DA carbon crank would fit aesthetically.) And everything is dark gray in color. Going with a black carbon crank would look very out of place on a Dura Ace bike. Dark gray aluminum colored Dura Ace does not equal black carbon crankset. With SRAM I think everything is black now so a carbon crank fits the color scheme easily.
I'm going to add appearance too. A carbon crank does not fit with aluminum everything else. With Campagnolo, when they went with carbon crank, their rear derailleur and front derailleur and Ergo levers were black carbon too. With Shimano, everything is aluminum now on Dura Ace. I think that is correct. (Just looked up 9100 group and it appears Shimano is making Dura Ace black now. So a black DA carbon crank would fit aesthetically.) And everything is dark gray in color. Going with a black carbon crank would look very out of place on a Dura Ace bike. Dark gray aluminum colored Dura Ace does not equal black carbon crankset. With SRAM I think everything is black now so a carbon crank fits the color scheme easily.
Last edited by RussellS on Tue Mar 19, 2019 7:13 pm, edited 3 times in total.
My biggest concern with Shimano creating a carbon crank is perhaps their cranks are the biggest aftermarket for powermeters (and indeed they themselves are late-coming manufacturers). Their latest cranks seems to be already harder to read deflection in alloy for some (see 4iiii's pendiiiing podiiiium), much less dual-sidedly in carbon.
The main reason why Shimano prefers alloy is cost. Alloy components can be manufactured with very little human input. Any kind of carbon manufacturing (apart from injection moulded carbon) requires human intervention and it means higher production costs. And also the comment about the very little marginal improvement of one material over another is correct. Alloy manufacturing has gotten so good that there's virtually no benefit to use carbon to save weight. With that being said I have a Quarq PM with carbon arms. I don't trust Shimano with their first generation PM so I went with the tried-and-true PM from Quarq.
And they have perfected the manufacturing process over years of experience. It never hurts to stick with something you're good at.pdlpsher1 wrote:The main reason why Shimano prefers alloy is cost. Alloy components can be manufactured with very little human input.
Also, to get a carbon crank to meet all their geometry, stiffness, durability, and compatibility requirements leaves you with a crank that weighs at least as much as an aluminium crank........ and yes, costs more to make.
And none of this is news really, shimano have made semi regular statements to the same effect. Wireless is a good way off as it gives us no tangible benefits and the US patents tie us pretty thoroughly in knots, carbon isn't the right material for cranks.
Ummm..... a Chorus 11 2015+ crank (including the bearings, hirth joint bolt and the light alloy cups appropriate to your frame) weighs less than the Dura Ace 9100 crank *without* a bottom bracket. Plus, it costs less!
Nothing wrong with the geometry, stiffness, durability of a Campagnolo UT crank!
No, nor do I care 
BUT hey, FwB did some testing so why not look look at the results:
As measured:
An SR 2015 crank came in at: 5.5 mm deflection average. 8th of 20 tested.
A DA 9000 crank came in at: 5.83 mm deflection average. 15th of 20 tested.
Interestingly, DA's drive side was the 2nd stiffest of all tested, while non-drive was the worst! So Shimano's requirements can't be all that flash. Not sure where a 9100 crank falls as it wasn't tested.
EDIT: Oh yeah, and I forgot to mention all those glue failures causing Ultegra/DA cranks to snap... was that on Shimano's "requirements" list?
But like I said, I don't care And I don't feel that, at the measurements we're looking at, the power loss would be perceptible at all.
BUT hey, FwB did some testing so why not look look at the results:
As measured:
An SR 2015 crank came in at: 5.5 mm deflection average. 8th of 20 tested.
A DA 9000 crank came in at: 5.83 mm deflection average. 15th of 20 tested.
Interestingly, DA's drive side was the 2nd stiffest of all tested, while non-drive was the worst! So Shimano's requirements can't be all that flash. Not sure where a 9100 crank falls as it wasn't tested.
EDIT: Oh yeah, and I forgot to mention all those glue failures causing Ultegra/DA cranks to snap... was that on Shimano's "requirements" list?
But like I said, I don't care
And I don't feel that, at the measurements we're looking at, the power loss would be perceptible at all.
Last edited by robertbb on Tue Mar 19, 2019 9:16 pm, edited 1 time in total.
The exhibitor said there was a carbon version in the past.RussellS wrote: ↑Tue Mar 19, 2019 12:20 amI, like the facts, don't see the benefits of wireless Di2 and carbon cranks. Wireless derailleurs and shifters means four separate batteries that do not last as long as the one big battery Di2 uses. More frequent, less convenient charging. Probably the same weight too. Now days both batteries and/or wires are both hidden in the frame or seatpost so appearance is probably better with Di2 than wireless SRAM. Since SRAM has to attach huge ugly batteries to the derailleurs. Where is the benefit, improvement of wireless? As for carbon cranks, I suspect Shimano looked at the carbon cranks and decided they don't offer any improvement over their aluminum cranks. Maybe a little weight savings but not much. And more cost for carbon than aluminum. So where is the advantage, improvement? All cranks work equally well. So performance is nothing. Its kind of like aluminum, titanium, carbon stems. Same functionality. Very little weight savings with titanium and carbon stems. Huge cost increase. No benefit going with titanium or carbon stem over aluminum stem. Just because you can do something does not mean you should do it.
I'm going to add appearance too. A carbon crank does not fit with aluminum everything else. With Campagnolo, when they went with carbon crank, their rear derailleur and front derailleur and Ergo levers were black carbon too. With Shimano, everything is aluminum now on Dura Ace. I think that is correct. (Just looked up 9100 group and it appears Shimano is making Dura Ace black now. So a black DA carbon crank would fit aesthetically.) And everything is dark gray in color. Going with a black carbon crank would look very out of place on a Dura Ace bike. Dark gray aluminum colored Dura Ace does not equal black carbon crankset. With SRAM I think everything is black now so a carbon crank fits the color scheme easily.
2015 Pinarello F8: 13.13lbs/5.915kg(w/Roval 64's). Sold.
2016 Rca: 11.07lbs/5.048kg.
2015 Rca. 11.15 lbs(w/Roval CLX 32's)
2015 Rca/NOS(sold).
2018 S-Works SL6 Ultralight 12.03lbs(w/Roval CLX 50's)
2016 Rca: 11.07lbs/5.048kg.
2015 Rca. 11.15 lbs(w/Roval CLX 32's)
2015 Rca/NOS(sold).
2018 S-Works SL6 Ultralight 12.03lbs(w/Roval CLX 50's)
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Yes, it's a shimano thing.
Yes. They made a small run of 7800 cranks, 60 or 70 pieces. There were pictures all over the net for 2 or 3 years. At least.
I don't *think* very many actually made it into the hands of the public.
