Shimano Wireless Di2 And Carbon Cranks...

Discuss light weight issues concerning road bikes & parts.
tabl10s
Posts: 412
Joined: Wed Aug 23, 2017 5:40 am

by tabl10s

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.
2016 Orbea Orca OMR:

15.0lbs/6.804kg.

2013 Wilier Zero.7:

13.02lbs/5.906kg.

2016 Rca:

11.07lbs/5.048kg.

2015 Pinarello F8(build in-process).

2018 S-Works SL6

RussellS
Posts: 846
Joined: Wed Feb 03, 2010 1:31 am

by RussellS

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.
Last edited by RussellS on Tue Mar 19, 2019 7:13 pm, edited 3 times in total.

by Weenie


Cemicar
Posts: 99
Joined: Mon Aug 21, 2017 7:40 am

by Cemicar

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.

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pdlpsher1
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Location: CO

by pdlpsher1

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.

RussellS
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Joined: Wed Feb 03, 2010 1:31 am

by RussellS

...

Jugi
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Joined: Sun Jun 24, 2018 8:10 am

by Jugi


pdlpsher1 wrote:The main reason why Shimano prefers alloy is cost. Alloy components can be manufactured with very little human input.
And they have perfected the manufacturing process over years of experience. It never hurts to stick with something you're good at.

mattr
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Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

pdlpsher1 wrote:
Tue Mar 19, 2019 4:23 am
The main reason why Shimano prefers alloy is cost.
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.

mattr
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Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

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.

robertbb
Posts: 793
Joined: Thu Jul 23, 2009 3:35 am
Location: Melbourne, Australia

by robertbb

mattr wrote:
Tue Mar 19, 2019 8:47 am
pdlpsher1 wrote:
Tue Mar 19, 2019 4:23 am
The main reason why Shimano prefers alloy is cost.
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.
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! :smartass:

Nothing wrong with the geometry, stiffness, durability of a Campagnolo UT crank!

mattr
Posts: 4351
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

robertbb wrote:
Tue Mar 19, 2019 8:53 am
Nothing wrong with the geometry, stiffness, durability of a Campagnolo UT crank!
Do you have a full listing of all shimanos requirements, or just guessing?

robertbb
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Joined: Thu Jul 23, 2009 3:35 am
Location: Melbourne, Australia

by robertbb

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? :lol:

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.

Hexsense
Posts: 706
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

robertbb wrote:
Tue Mar 19, 2019 9:29 am
Interestingly, DA's drive side was the 2nd stiffest of all tested, while non-drive was the worst!
There were speculations that it is 24mm hollow axle that is to blame on DNS stiffness but we can't be totally sure about that.

robertbb
Posts: 793
Joined: Thu Jul 23, 2009 3:35 am
Location: Melbourne, Australia

by robertbb

Hexsense wrote:
Tue Mar 19, 2019 6:45 pm
robertbb wrote:
Tue Mar 19, 2019 9:29 am
Interestingly, DA's drive side was the 2nd stiffest of all tested, while non-drive was the worst!
There were speculations that it is 24mm hollow axle that is to blame on DNS stiffness but we can't be totally sure about that.
Did the 24mm hollow axle continue through to 9100?

tabl10s
Posts: 412
Joined: Wed Aug 23, 2017 5:40 am

by tabl10s

RussellS wrote:
Tue Mar 19, 2019 12:20 am
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.
The exhibitor said there was a carbon version in the past.
2016 Orbea Orca OMR:

15.0lbs/6.804kg.

2013 Wilier Zero.7:

13.02lbs/5.906kg.

2016 Rca:

11.07lbs/5.048kg.

2015 Pinarello F8(build in-process).

2018 S-Works SL6

by Weenie


mattr
Posts: 4351
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

robertbb wrote:
Tue Mar 19, 2019 9:15 pm
Did the 24mm hollow axle continue through to 9100?
Yes, it's a shimano thing.
tabl10s wrote:
Tue Mar 19, 2019 9:42 pm
The exhibitor said there was a carbon version in the past.
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.

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