My Frankenstein Di2

Discuss light weight issues concerning mountain bikes & parts.

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ahki
Posts: 42
Joined: Mon Jun 20, 2011 6:03 pm

by ahki

Hi Guys, This is my first post here.

Just like to share with you and maybe get some feedback and hopefully help some of you who may want to try Di2 on their MTB but does not want to spend $475 on K-Edge Ki2.

You may want to take a look at this.

I wrote this last night, It may work, It may not, it has not been tested. I only have the rear mech for now and nothing else. But it looks promising and hopefully provide some inspiration.

http://flwrider.com/2011/12/09/frankenstein-di2/#more-47046

I use to do cars, taking Blocks from other models of cars and mating it to different heads from the same manufacturer. so mixing and matching was the idea behind this.. Most companies tend to keep similar design for different models in their range. This helps cut development cost.

enjoy.

Geoff
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Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

Welcome!

Ok, now that's interesting...

by Weenie


fat tire
Posts: 354
Joined: Wed Mar 19, 2008 6:54 pm

by fat tire

Wow awesome. Keep us posted. That looks better than the K edge cage as well. I did not realize they cost that much. That is explains why you do not see them often.

Colin
Posts: 709
Joined: Mon Mar 02, 2009 4:50 am

by Colin

Very cool! Surprised no one's tried this yet!

I wonder if it would clear a 36t cog? Or would it still need a really small upper pulley?

fat tire
Posts: 354
Joined: Wed Mar 19, 2008 6:54 pm

by fat tire

The yumeya cage will clear a 34 with a little room left so I think a 36 should just fit.

krzysiekmz
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by krzysiekmz

I have fitted rear Di2 mech on my MTB with 32 cog using smaller pulley.

However, I have purchased the Yumeya cage from Pricepoint sale a while back too. It did not fit my shadow as well (surprise:) It is sitting unused so I'll try to copy you and see how it'll work out.

I have tried to match the original xtr shadow cage to Di2 rear with no success...so not sure how Yumeya would fit.

Chris.
Orbea Oiz - xxxx
MSC Koncept Carbon Di2 - 6955g
Leichtkraft Team Carbon - 6868g.

thisisatest
Shop Owner
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by thisisatest

the difference between the ki2 derailleur cage and any stock shimano mountain cage is in the amount of offset K-edge uses on its upper pulley. that is how they get real upper-pulley-to-cog clearance. that, and i hear one of the pivot springs is different.
a long cage on a road derailleur does not make a mountain derailleur. if you look at shimano's long cage road derailleurs, you'll notice that they still have the same max cog, just more capacity.
after comparing mountain and road derailleurs closely, it turns out the mountain derailleur's parallelogram is at a steeper angle than the road ones. it makes sense, since the slope of the cogs is steeper.

maxxevv
Posts: 1960
Joined: Wed Feb 09, 2005 4:51 am

by maxxevv

krzysiekmz wrote:I have fitted rear Di2 mech on my MTB with 32 cog using smaller pulley.

However, I have purchased the Yumeya cage from Pricepoint sale a while back too. It did not fit my shadow as well (surprise:) It is sitting unused so I'll try to copy you and see how it'll work out.

I have tried to match the original xtr shadow cage to Di2 rear with no success...so not sure how Yumeya would fit.

Chris.


XTR 'Shadow' have different linkage designs compared to road RD's. I'll be very surprised if it did fit.

If you have a regular XT or XTR cage and pulley, maybe you can try mating those instead as the regular MTB derailleurs have a very similar design to the road ones, with tweaked angles and dimensions to accommodate the requisite MTB gearing.

eme999
Posts: 44
Joined: Tue Nov 17, 2009 10:22 pm

by eme999

hmm.. it looks very interesting!! but i think a akku on a mtb is not the best .. water,dirt ...??
i thing for this is the hydraulic gear better !!
CANNONDALE SCALPEL 29 ULTIMATE BLACK PEARL POWER TUNING !!!

http://emanuelschicher.wordpress.com/" onclick="window.open(this.href);return false;

ahki
Posts: 42
Joined: Mon Jun 20, 2011 6:03 pm

by ahki

Hi,

Kyzysiekmz, yes the Yumeya Cage was designed for the M970-SGS. NOT the M972.
The M972 which is the shadow will defo not fit the Di2 or DA7900.

If you do try it. please remember there is a spacer/washer this needs to be after the bolt has passed through the Plates/sleeve.

Thw spacer will only has a lip this must be facing towards the bolt, which sits into the gove. This stops the plates binding to the mech.

thisisatest, yep I have noticed the offeset of the of the top pulley. However has anyone tried it it with a smaller pulley? I am not sure about the pivot spring you are referring to. There are 4 springs on the Di2. The steeper angle can be adjusted with a screw? no?

maxxevv, yep M972 shadow cages will not fit, not only the linkages but the metal sleeve is different too. However from my pictures.
Image
You can see the Yumeya plates has the same fittings as the DA79xx.

eme999, hmm... you need to see this.. It may shock yo a bit. :shock:
Image
This is taken from Nathans long term review. http://range.wordpress.com/2010/03/07/nathans-long-term-shimano-dura-ace-di2-review/

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eliflap-scalpel
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by eliflap-scalpel

NICE WORK !!

shared on my blog too :beerchug: :beerchug:
http://eliflap.it/

thisisatest
Shop Owner
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by thisisatest

ahki wrote:thisisatest, yep I have noticed the offeset of the of the top pulley. However has anyone tried it it with a smaller pulley? I am not sure about the pivot spring you are referring to. There are 4 springs on the Di2. The steeper angle can be adjusted with a screw? no?

people have tried a smaller pulley, apparently with some success. probably not 36t-cog success, but maybe for 32t cogs.
i believe k-edge changed either/both the B-spring (mounting bolt spring) or the P-spring (pulley cage pivot spring) to change the balance of cage/body movement. screw adjustments, such as the b-tension screw, can help pulley clearance, of course, but it does not fundamentally change the path that the derailleur takes, when looking at the bike from behind. from behind, the derailleur moves upward to the smallest/hardest cog, and downward to the easiest cog, roughly following the angle made by the cogs themselves. the road parallelogram is at a shallower angle than the mountain ones. this is most evident when comparing the shadow derailleurs to road ones, but i'm fairly confident it's still different between 970/971 derailleurs and road derailleurs.

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eliflap-scalpel
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by eliflap-scalpel

please , look at the K-Edge cage

the upper pulley wheel is mounted around 30-35 mm backwards

this is the reason it works on 36T :smartass:



i installed a RED on a 32T cassette ( 10 speed 11-32 XX Sram ) with Extralite 10T pulley wheels . easy to fit , quite easy to fine adjust , on a Scalpel 2009 bike.
Attachments
shimano-di2-hack-on-niner-mountain-bike3-444x600.jpg
HPIM0806.JPG
http://eliflap.it/

thisisatest
Shop Owner
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by thisisatest

i think K-edge actually did a very good job placing the offset of the derailleur cage in a good spot. it would be easy to mess that up, providing adequate clearance when in the small ring, and then way too much clearance in the big ring. so as the pulley cage moves forward, the b-pivot has to swing forward "just so" to keep the gap equal in different rings. when i first saw it, i thought it was just a bodge job.
their shifters, OTOH, need work.
eliflap-scalpel wrote:i installed a RED on a 32T cassette ( 10 speed 11-32 XX Sram ) with Extralite 10T pulley wheels . easy to fit , quite easy to fine adjust , on a Scalpel 2009 bike.

my god, trim that excess cable! you could poke someone's eye out! :)

by Weenie


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eliflap-scalpel
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by eliflap-scalpel

thisisatest wrote:
eliflap-scalpel wrote:i installed a RED on a 32T cassette ( 10 speed 11-32 XX Sram ) with Extralite 10T pulley wheels . easy to fit , quite easy to fine adjust , on a Scalpel 2009 bike.

my god, trim that excess cable! you could poke someone's eye out! :)


uh ... was a never ending modification ... that set up is gone ...
http://eliflap.it/

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