Comments on: Review: Shimano Ultegra R8100 12-Speed Road Group

By: Greg

Greg — Tue, 30 Jan 2024 23:52:30 +0000

In reply to Dan. I suspect you'll see GRX Di2 in a few months.

By: Anonymous

Anonymous — Tue, 30 Jan 2024 08:24:16 +0000

In reply to Ed ed. A lot of frames have a big taper from the BB for maximum stiffness mumbojumbo. It sometimes interferes with FDs. I don't think that there really was supposed to be a spacer, or that things were out of spec. I don't think Shimano officially specs clearance there either. What happens is the frame mfgs build out the frame as far as they can with one generation of parts, then keep using the same molds even if the new parts don't fit.

By: Brad

Brad — Mon, 29 Jan 2024 17:56:28 +0000

In reply to Ed ed. Shimano's frame design guide tells bike manufacturers how to build their frames to be compatible with Shimano's products. Spaces on the crank spindle are NOT part of that spec and they are something that is determined by Shimano. With so many BB standards out there one crank axle has a lot of variations to deal with- hence the spacers. Sram does the same thing. This is where reading the instructions at installation is critical.

By: BBB

BBB — Mon, 29 Jan 2024 15:27:52 +0000

To echo Ed ed’s comment, I don’t believe that a 1mm spacer assymetrical bodge is a good enough solution when you spend a few thousands on a bike. Trek had the same problem and even issued an official bulletin offering exactly the same mod. It just shows how bad the industry is when it comes to engineering design and testing.Based on actual experience, not just jist reading forums.

By: Evan

Evan — Thu, 25 Jan 2024 20:32:09 +0000

I charge my di2 bikes with a power bank because it’s easier to bring that to the bike than the bike to an outlet

By: Dan

Dan — Thu, 25 Jan 2024 18:33:50 +0000

Considering putting this on my dedicated gravel bike that I use as my road bike, bc it seems 12 speed GRX Di2 isn’t being release anytime soon. How would this group hold up on regular gravel events? Would be nice if they still made an Ultegra RX clutched rear derailleur, that would solve this question.

By: Ed ed

Ed ed — Thu, 25 Jan 2024 08:14:55 +0000

How is everything to spec but you still need a spacer?
The spindle length is fixed and the chainring’s aligment should be as the manufacturer descyibes, so it can only mean that the bb shell is mis-aligned or it’s dimentions don’t meet shimano’s spec. Every frame engineer should have figured that out and the frame maker should provide their clients with this info as it means the frame and the system are not 100% compatible out of the box.

By: Grillis

Grillis — Wed, 24 Jan 2024 16:54:42 +0000

In reply to nooner. Dura Ace has a new spline, but it's backwards compatible.

By: Paul

Paul — Wed, 24 Jan 2024 16:13:26 +0000

In reply to nooner. Shimano’s 12 speed road groups can use the same HG road freehub bodies as 11 speed. Microspline is for 12 speed MTB cassettes with a 10 tooth small cog

By: nooner

nooner — Wed, 24 Jan 2024 15:14:39 +0000

Hey great review T. The hubs have a gray anodizing to match the rest of the group and come with a standard HG freehub body. With 12 speed, wouldn't the freehub be microspline not HG?