Ultegra Di2 mech with Shimano clutch

[motorapido]

waiting for the finished parts to turn up but here is a quick teaser of the mech with RP parts.
it fits to the existing Ultegra Di2 mech armsand is designed so that it can be drilled tofit either the 6770 or 6870 mechs,
It uses the clutch and spring units from a Shimano mtb mech, these are all available as spares or by sacrificing an MTb mech such as a Zee +
more to follow when the finished parts come back from the RP company and anodisers.

[bikewithnoname]

Nice work!

[boots2000]

Are you going to make this for sale?

[motorapido]

Might have a few parts for sale, dependent on what parts i have left after some testing, or if there is interest i might be able to do another run of RP parts.

[JackWalk]

Could we see more photos?

[motorapido]

will post some more photos up later today if i get a chance.

[eliflap-scalpel]

why a clutch mechanism ?

not required on road

[motorapido]

Your right not required for road, but pretty useful if you gravel race or cyclocross, which is my intended use, i will also be using it on my MTB with a different cage, a One Up Radr cage, longer and offset pulley so it will work with 10 speed 11-42 or 11 speed with XT 11-42 cassette for a budget Di2 mtb setup.

As promised some more photos and info,

It runs the clutch, cage spindle, lever, spring and seal from a deore mech, in this case mated to a modified road cage, this keeps the offset top pulley that you would loose if you ran a Saint or Zee MTB short cage. So effectively the mech is the same as an Ultegra mech except for the clutch.

The main body and lid are in an EOS sintered Nylon12 RP material with very high strength, this then has new brass pivot bushings for the pivots with an Aluminum aero grade rivet for the lower pivot pin and the upper pivot pin and seals are reused from the Ultegra mech. the cage spindle runs in a pivot bush made of Aluminium 6082 T6 with a reamed bore which is then hard anodised.

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[rasmussloth]

why a clutch mechanism ?

not required on road

This is a cyclocross thread...

[jooo]

This is really cool. Looking forward to seeing the finished part.

I think I remember reading that you started this project a while back, but now that XTR Di2 is available, is there any reason you'd bother to go custom again when there's something off the shelf that basically works already?

[motorapido]

Your right, since my first version which was for my Scott Scale 29er, Shimano have finally bought out an MTB version,

but, its only available as 11 speed and for some like me is prohibitively expensive.
there is still no short cage version suitable for 2x cyclocross or gravel racers, albeit that some are moving over to 1x drivetrains with the developments that have taken place in large range cassettes.

At least for me it is still worth it, including the RP parts, the mech and ancillary parts the costs involved, still working out at about half the cost of an XTR mech , and will suit all my 10 speed wheels and has the clutch feature i desire.

Also partly its the fun of doing it, and having something different.

[eliflap-scalpel]

but i rode a 7970 Di2 10 speeds short cage on my Flash 29er last year with narrow wide ring and chainguide with no chain falls ....

worth the mission, this long work , for sure ... your goal is your greatness.

but IMHO it is not required ...

[eliflap-scalpel]

hope your next step will be an internal battery

[jooo]

Also partly its the fun of doing it, and having something different.

This is as good a reason as any

I guess you're right in that there is nothing specifically designed for double chain-rings and road cassettes that comes with a clutch. People have used SRAM XO type2 RD's for that combo (it also works with 10 and 11 speed shifters), but it's not helpful if someone wants electronic shifting.

[boots2000]

Let me know- I would be interested.

Might have a few parts for sale, dependent on what parts i have left after some testing, or if there is interest i might be able to do another run of RP parts.