Mountain Bike Reviews Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter · #1 · (Edited)
Hi everybody, I'm reading through both threads from cosmoworks

Hammerschmidt with ISCG Adapter on Nomad 1 - Part Deux

Hammerschmidt with ISCG Adapter on Nomad 1 with Grip Shift

and saw the nice custom adapter - Great CNC Tooling!!!:thumbsup:

I currently wan't to install a E.13 DRS on my Nomad 06 but I do not have checked installation before so I bought a E13 ISCG 05 adapter and the DRS with ISCG 05 backplate.
After installing the parts I recognized that I still need a distance ring on my BB, otherwise my inner chain ring will slide on the E.13 backplate.
ISCG 05 adapter + distance ring makes 2,5mm offset of my chain line from what is standard - :nono:
So I run my Catia and try to design a adapter for my Nomad without cutting of 2,5mm of the Nomad BB or still adding a 2,5mm spacer to avoid chain ring sliding.

Check my pictures with this adpater it is possible to install a E.13 DRS or any other ISCG 05 chain guide with a 55mm boring

This adapter will not work with a Hammerschmidt !!!!
 

Attachments

·
Registered
Joined
·
38 Posts
Discussion Starter · #3 ·
check the attached pictures with the colored faces...

On the first pic you can see a common ISCG 05 Adapter with one even face (green color) where as the chain guides backplates can be mounted.

Problem: If you mount the ISCG adapter and the ISCG chainguide backplate to your bottom bracket you have in summary 5mm spacers (ISCG adapter + chain guide backplate) added. To avoid that your chain ring is touching the ISCG backplate during cycling you have to add one more 2,5mm spacer under the bottom bracket.

Effect: your chain line is 2,5mm out of line!:nono:

Solution:
The showing ISCG 05 adapter in the second pic has 2 colored faces a green and a blue one. the green one is still the one from a standard adapter - 2,5mm thickness.
The blue one is 2,5mm deeper than the green one and this is the face where the ISCG backplate can be mounted.
So effectiv you only have one 2,5mm spacer added to your bottom bracket (like on every 73mm bracket) - the ISCG adapter. The front face of the ISCG backplate is now on the same even face with the green surface.

Result: no aditional 2,5mm spacer is needed if you mount a chain guide using this adapter
 

Attachments

·
Registered
Joined
·
270 Posts
Hammerschmidt BB requires a 73mm width shell width... so your solution look like it'd work for your chainguide, but won't work with the 73mm Hammerschmidt BB on a Nomad 1 without removing material like I did.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #6 ·
If the ISCG mounting plate of the Hammerschmidt have 55mm hole diameter, it's possible to slip it over the green face and than it's possible to attach it on the blue face which is exactly on 73mm level.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #7 ·
Replaced pictures with a real Nomad ISCG 05 Version.
The adapter has now a anti-twist protection like the first build from cosmoworks.

I also found someone who will CNC machine it from 7075 Aluminium. If it's done I will post pics.
 

·
Former Ninja
Joined
·
427 Posts
While this is a solution in your particular case GT, it is simpler and cleaner to simply bottom bracket mount the other version of the DRS (or DSS, or other manufacturers dual ring guides). In my experience, many bikes also have very little space around the bottom bracket area as is, with all the suspension linkages being right up next to the edge of the BB shell. This is why we strongly recommend running the BB mount version, as effectively you will space out the backplate with a normal adapter 5mm.

As for Hammerschmidt, the reason why Sram recommends a welded on ISCG mount is because there is a high chance of the system slipping on the BB mount when in overdrive mode. While I have also seen a few people get away with a BB mount setup (usually with some kind of mechanical stop bolted onto the frame)...it isn't recommended unless you're willing to do custom work to make it work correctly...including voiding any warranties on your frame.

Cheers,
philip
 

·
Registered
Joined
·
270 Posts
GT98 said:
If the ISCG mounting plate of the Hammerschmidt have 55mm hole diameter, it's possible to slip it over the green face and than it's possible to attach it on the blue face which is exactly on 73mm level.
Yes the alignment would be the same on the drive side with your adapter, but the effective BB shell width of your setup would be more than 73mm.

So.... like I said before, still need to remove frame material to run a 73mm HS BB on a Nomad 1 with an ISCG adapter, even if it's your adapter shown above (the difference is you'd remove material off the non-drive side instead of the drive-side like we did with the MRP adapter).
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #10 ·
Thanks philip for your infos.

I agree with you it would be the easiest way to get the BB mount version of the DRS, but if I change to another frame in the future (don't thinks so:D ) hopefully the new frame have ISCG 05 welded.
As you can see I have added new pictures with a anti-twist protection included into the construction. So the adapter can bear on the bottom bracket area.
For me Hammerschmidt will not be a thing I will stick on dual chain rings with a e.13 chain guide, but if Hammerschmidt will be matching than this adapter can't rotate in the overdrive mode. Adapters like thsi one or cosmoworks selfmade ones can hold up a lot more dynamic torque than the "on 3-point welded" ISCG adapters which standard on nearly every new Enduro and above-class frames.

Cheers

GT98
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #11 ·
cosmoworks said:
Yes the alignment would be the same on the drive side with your adapter, but the effective BB shell width of your setup would be more than 73mm - will not work.

So.... like I said before, still need to remove frame material to run a 73mm HS BB on a Nomad 1 with an ISCG adapter, even if it's your adapter shown above (the difference is you'd remove material off the non-drive side instead of the drive-side like we did with the MRP adapter).
Thanks cosmoworks for your input.
I've checked theHammerschmidt manual and realized that the max. effective BB shell width is 73mm.
With my adapter (which is not build for Hammerschmidt using) the collar assembly is on the 73mm level BUT the front shifter with the crank is on the 75,5mm width.

I'm sorryfor any confusion but have not checked that before:eek:

So my adapter is good for a chain guide using on a 73mm shell width non ISCG 05 supportetd frame to keep the chain line on the same level as before adding the adpater.

Thanks
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top