New Red crank info, must read! :)

Discuss light weight issues concerning road bikes & parts.
CaptainP
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by CaptainP

I have been trying to install a 50t Stronglight CT2 chainring on my compact 170mm BB30 Exogram cranks. I've filed the hidden arm and it fits in the curve, but i still need to press the chainring on the crankset to get it to fit. When i install the bolts and all, the chainring ends up beeing uneven where the hidden arm is (closer to the frame). So the chain will run a bit to the left and right in the cage. Anybody had the same problem?

alexalecu
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Joined: Tue Sep 28, 2010 5:13 pm
Location: BC, Canada

by alexalecu

CaptainP wrote:I have been trying to install a 50t Stronglight CT2 chainring on my compact 170mm BB30 Exogram cranks. I've filed the hidden arm and it fits in the curve, but i still need to press the chainring on the crankset to get it to fit. When i install the bolts and all, the chainring ends up beeing uneven where the hidden arm is (closer to the frame). So the chain will run a bit to the left and right in the cage. Anybody had the same problem?


I had the exact issue with mine and I was conviced it was something wrong with the crankarm. I took it to the bike shop and, to my embarrassment, they fixed it in 5 minutes; the interface between the crankarm and the chainring was not clean, and all they did was to remove the chainring, clean both parts and reinstall - problem solved.

It sounds as if you filed down the crankarm; I suggest you to file the chainring down instead (i.e. round the corners).

CaptainP
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Joined: Sun Jun 24, 2012 11:02 am
Location: Danmark
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by CaptainP

alexalecu wrote:
CaptainP wrote:I have been trying to install a 50t Stronglight CT2 chainring on my compact 170mm BB30 Exogram cranks. I've filed the hidden arm and it fits in the curve, but i still need to press the chainring on the crankset to get it to fit. When i install the bolts and all, the chainring ends up beeing uneven where the hidden arm is (closer to the frame). So the chain will run a bit to the left and right in the cage. Anybody had the same problem?


I had the exact issue with mine and I was conviced it was something wrong with the crankarm. I took it to the bike shop and, to my embarrassment, they fixed it in 5 minutes; the interface between the crankarm and the chainring was not clean, and all they did was to remove the chainring, clean both parts and reinstall - problem solved.

It sounds as if you filed down the crankarm; I suggest you to file the chainring down instead (i.e. round the corners).


I've already tried cleaning both parts, and the original Sram chainring fits like a glove, but the Stronglight just need at little pressure to settle, but then when fastened with the bolts it's uneven.

And don't worry i filed the chainring and not the cranks :D

MichaelB
Posts: 435
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

I had to file the hidden arm of the chainring on my Praxis rings, but other than that, no problems. 1,500km so far and no issues.

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gazzaputt
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Location: Bexley, Kent, UK

by gazzaputt

So can anyone confirm that Stronglight chainrings will fit SRAM Exogram?

I have 34 and a 51 110BCD that I would want to fit.

ttigg
Posts: 34
Joined: Wed Nov 13, 2013 1:07 am

by ttigg

prendrefeu wrote:They do work, if you rotate them.
Praxis does not market them to work with the new exogram cranks, but they do work. See the difference? All you need to do is rotate the two chainrings a bit so that they are still oriented together/aligned but now match the crank arm hole pattern. You can file down the catch pin, it is really unnecessary but included "just because" - Adam has even mentioned somewhere that the length of that catch pin was made fairly standard and it can be filed down to make it fit for various arms.

and for those of you still asking: READ THE THREAD!!! THIS WAS ALREADY COVERED IN THIS VERY THREAD!!! WHY ARE YOU ASKING QUESTIONS WHICH HAVE ALREADY BEEN ANSWERED IN THIS THREAD?? READ, PLEASE, READ!!!!!


OK I'm new (to this forum anyhow) and have just read through (twice) the 18 pages of this thread. Here is what I'm seeing if I'm reading the info correctly.

- they work if you rotate them 180 (pin in the wind)

However the 2 main pictures posted show the pin in the wind but just above or just below the crankarm (not 180 rotation)? So with this I would like to "clarify" the following..

1. They work if you rotate them 180 (pin in the wind)
2. They work if you rotate them (pin in the wind) either just above or just below the crankarm
3. They work if you file down the pin so you can install in the regular rotation with the pin behind the crankarm

Thanks in advance

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prendrefeu
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by prendrefeu

1. Yes, 180° work perfect, as-Praxis-intended (ie, their "shift" system)
2. Yes, it will work, but not absolutely-as-Praxis-intended perfect.
3. This last one... it won't install that way on a Exogram crank because on the back of the arm there is a mounting hole, but the pin is located in between mounting holes. So yes, you can file it down since the pin won't be put in use, but it won't be behind the Exogram crank arm. That's not possible.
Exp001 || Other projects in the works.

ttigg
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Joined: Wed Nov 13, 2013 1:07 am

by ttigg

Thanks so much, I will order some up while I wait for the official SRAM ones. I know they'll be heaiver but I like the look.

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Juanmoretime
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by Juanmoretime

I'm bumping this thread with a question. Is anyone now making aftermarket rings designed to work with the hidden bolt Sram cranks?
RESIDENT GRUMPY OLD MAN.

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Kayrehn
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Joined: Thu Mar 24, 2011 6:06 pm

by Kayrehn

Is there a need? Even my Osymetric rings can be used as intended on the sram red cranks, so there shouldn't be any reason why any round chain rings can't go on it.

drainyoo
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Joined: Sun Jun 17, 2007 6:56 pm

by drainyoo

I know that the Extralite Octaramp RC2 rings work with the new crank.

jooo
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Joined: Wed Feb 02, 2011 3:48 am

by jooo

Kayrehn wrote:Is there a need? Even my Osymetric rings can be used as intended on the sram red cranks, so there shouldn't be any reason why any round chain rings can't go on it.

:| but you don't have the same cranks...

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Gearjunkie
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Location: NZ

by Gearjunkie

Hi

TA Specialites Hegoa (53/39) work fine on mine.

Cheers
GJ

Foxtrot
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Joined: Sun Jan 12, 2014 3:44 pm

by Foxtrot

My Sram 39 T gear is only 29 grams (130 mm).

MNX1024
Posts: 286
Joined: Thu Apr 28, 2011 1:21 am

by MNX1024

Out of curiosity, anyone using the Praxis/Red crank configuration with Di2? I'm tempted to go this route if there's no problem with it.

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