Road short cage RD with a 9-46t cassette!

Discuss light weight issues concerning road bikes & parts.
Post Reply
User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

Absolutely loving this. Things the cycling industry don’t tell us. I’m very close to make this work:

Road 11sp SHORT cage RD (Sram Red-141.6g) with a 11 speed e13 9-46 cassettes! Since it’s still not reaching the 46t (stopped at the 39t), the RD is being shifted by a 10sp MTB trigger shifter. I didn't even know that 10sp MTB shifter spacing was the same as a 11sp road RD!

Only two additions to the RD so far: a derailleur hanger extender and a longer screw adjuster to pull the RD as back as possible. Waiting on a 10t upper pulley (looking for a 9t) or a after market off-set cage to bring the upper pulley down to clear the 46t. I want to try the 10t pulley first, if doesn’t work I’ll spend the cash on the offset cage.

I WILL have enough chain and the RD WILL move close to full stretch to manage the 46t, I checked already.

Awesome!...the cool part is that I'm still getting 433.33% range missing the last cog.

OBS: Saving 100g on the RD alone coming from a XTR M9000 RD with a Rolf tooth tanpan adapter.

Image
Image

Temporary 10sp trigger shifter bolted to the stem face plate with titanium hardware.
Image

Next Step is to solve the 46t, sell the heavy 105 hydra STI’s and think about what I want for brake/shift solution Image, got something in mind already.
Last edited by andreszucs on Sat Jun 08, 2019 8:52 am, edited 10 times in total.

by Weenie


Finx
Posts: 67
Joined: Wed Jun 15, 2016 1:14 am

by Finx

I'm pretty sure you'll have some pretty poor shift quality with that setup ( hangar extender and longer B screw).

Long cage derailleurs don't just wrap more chain. They also keep the derailleur closer to the cassette across the range of cogs to keep the shifting crisp.

Sent from my Pixel 3a using Tapatalk


User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

Finx wrote:
Sat Jun 08, 2019 5:01 am
I'm pretty sure you'll have some pretty poor shift quality with that setup ( hangar extender and longer B screw).

Long cage derailleurs don't just wrap more chain. They also keep the derailleur closer to the cassette across the range of cogs to keep the shifting crisp.

Sent from my Pixel 3a using Tapatalk
I don't think there is a relationship between closer RD to cassette with crisp shifting. If I try hard to find a 'downside' on this would be less teeth engagement on the smaller cogs, but that shouldn't be a problem, I will not blown the teeth since I can't deliver 1500 watts of power.

Shifting on the stand is perfect!

User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

Pleased to report that real world shifting for 45 miles this morning was flawless.


Sent from my iPhone using Tapatalk Pro

bm0p700f
in the industry
Posts: 4890
Joined: Sat May 12, 2012 7:25 pm
Location: Glermsford, Suffolk U.K
Contact:

by bm0p700f

Flawless now but shifting will probably deteriorate more quickly with this kind of setup than if you kept everything standard.

User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

bm0p700f wrote:Flawless now but shifting will probably deteriorate more quickly with this kind of setup than if you kept everything standard.
Why?


Sent from my iPhone using Tapatalk Pro

Nefarious86
Moderator
Posts: 3124
Joined: Sun May 25, 2014 4:57 am
Contact:

by Nefarious86

This whole experiment just screams why...

Sent from my SM-G975F using Tapatalk

Using Tapatalk

User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

Nefarious86 wrote:
Sat Jun 08, 2019 11:57 pm
This whole experiment just screams why...

Sent from my SM-G975F using Tapatalk
Because might be unecessary to use a 240g monster derailleur to shift a wide range cassette? or should I ask why are you here on a weightweenie forum? :thumbup:

Nefarious86
Moderator
Posts: 3124
Joined: Sun May 25, 2014 4:57 am
Contact:

by Nefarious86

Red 22 levers with the left lever gutted and a non clutch mtb mech would surely be lighter than the setup you're running and would actually have reliable chain wrap without the ghetto shifter setup. 10 speed mech with 11 speed shifters should play nice due to the 1-1 ratio Sram uses. Image

Sent from my SM-G975F using Tapatalk

Using Tapatalk

User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

I've used the XX 10sp for a long time with a 11-42t cassette. Since I moved to 11sp 9-46t I'm checking to see how far I can push the limits of a small derailleur. I'm using the 10sp trigger bolted to the stem as a temporary setup while I solve the last issues. The plan is to use a Sram 11sp R2C (TT version) with a custom clamp with this, lets do the weight math:

Cassette e13 9-46t race: 303g
Sram Red short cage: 141g
TT R2C shifter (without the base): about 25g?
Total: 469g.

for perspective: a Sram Eagle 12sp cassette 10-50 weight 450g alone....and has a smaller range than the e13 9-46T :lol: :lol: :lol:

can't get lighter than that.

Nefarious86
Moderator
Posts: 3124
Joined: Sun May 25, 2014 4:57 am
Contact:

by Nefarious86

So what brakes would you use? Most options will still negate the savings compared to the R22hrd mechanical shifter setup..

Red 22 HRD levers are meant to be around the 300g mark with post mount calliper then but 20g pdd from the left lever assembly.

XX Mech is 181g and doesnt requre the extra link.



Using Tapatalk

User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

Nefarious86 wrote:
Sun Jun 09, 2019 1:05 am
So what brakes would you use? Most options will still negate the savings compared to the R22hrd mechanical shifter setup..

Sent from my SM-G975F using Tapatalk
MTB Magura Mt8 older version with 3d printed adapter 170g for the pair including the adapters.

Nefarious86
Moderator
Posts: 3124
Joined: Sun May 25, 2014 4:57 am
Contact:

by Nefarious86

Good luck with it.

While I can appreciate the WW motivation behind it the ergonomics of it seem horribly compromised.

Sent from my SM-G975F using Tapatalk

Using Tapatalk

User avatar
andreszucs
in the industry
Posts: 544
Joined: Mon Nov 28, 2011 7:15 am

by andreszucs

Nefarious86 wrote:Good luck with it.

While I can appreciate the WW motivation behind it the ergonomics of it seem horribly compromised.

Sent from my SM-G975F using Tapatalk

Thanks! I’ve worked on the brake adapter last year and I used it for a few months to test, no compromise with ergonomics I can totally brake with my hands on top or the drops. The only new design that I still need to do is the R2C receiver, I have a clear idea already and is going to be perfect in theory; reachable also from the top or drops. Can’t wait to start designing and test, will take some time.


Sent from my iPhone using Tapatalk Pro

alcatraz
Posts: 2153
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Do you want mtb or road shifters?

Is it a 1x or 2x setup?

That rear derailleur is pure crap for that cassette. If you answer the questions we can suggest something good to enable the use of the 46t without sacrificing high gear shifting.

The shifting can't possibly be flawless. With an 11-36 cassette and the wifli red derailleur it's impossible to smoothly shift the highest gears without special modification and "help" like overshifting to make the jump.

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post