SRAM Etap and Cannondale Supersix : clash in the spokes !

Discuss light weight issues concerning road bikes & parts.
Didier
Posts: 2
Joined: Mon Dec 19, 2016 1:48 pm

by Didier

I'm owner of a Cannondale Supersix EVO ( previous model ) equipped originally with a SRAM RED 22 groupset.
I've bought a SRAM Etap mini group and made the swap of both derailleurs and brake levers .
My concern is the following :
when reatching the 11th sproket with the Etap rear derailleur , without chain , I observe a mechanical clash between the cage ( low pulley area ) and the spokes of the wheel .
I noticed that the rear derailleur is moving not parallel to the bike axis when going from right to left ( upwards ). It's like he's turning around a virtual pivot , a bit like the "Yaw" front derailleur .
Rem : With a mechanical RED 22 derailleur , when chain is removed, there is approx a gap of +/- 3-4 mm between derailleur cage and spoke in the 11th position .

I've made the following tests , without success :

- replaced the Cannondale hanger by an other Cannondale hanger , comming from an other Supersix EVO .
- tested different rear wheels
- tested the Etap rear derailleur on an other Cannondale Supersix Evo frame .

Result is always similar : clash with the spokes .

I do not understand what's the origin of this problem .

goodboyr
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by goodboyr

You need to align hanger with a hanger alignment tool such as the park tools DAG. New hangers and bikes do not come pre aligned. They almost always need alignment.

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by Weenie


Nefarious86
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by Nefarious86

Limits set correctly?
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PinaRene
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by PinaRene

Didier wrote:I'm owner of a Cannondale Supersix EVO ( previous model ) equipped originally with a SRAM RED 22 groupset.
I've bought a SRAM Etap mini group and made the swap of both derailleurs and brake levers .
My concern is the following :
when reatching the 11th sproket with the Etap rear derailleur , without chain , I observe a mechanical clash between the cage ( low pulley area ) and the spokes of the wheel .
I noticed that the rear derailleur is moving not parallel to the bike axis when going from right to left ( upwards ). It's like he's turning around a virtual pivot , a bit like the "Yaw" front derailleur .

Rem : With a mechanical RED 22 derailleur , when chain is removed, there is approx a gap of +/- 3-4 mm between derailleur cage and spoke in the 11th position.

I do not understand what's the origin of this problem .


This is normal , I have the same issue. With the rear derailleur under tension there is no problem. If you push the low pully forward you see that it will line perfectly with the sprockets. And I cannot imagine there are a lot of people riding without a chain. :smartass:

sungod
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by sungod

^^^this

on my bike even a mechanical red (10-speed) just touches, with 11-speed i think it's more pronounced - the hanger is perfectly aligned

broken chains aren't common, i do wonder about the consequences if it should happen with the rd on the biggest cog, but presumably i'll be going slow in that situation!

shotgun
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Location: Philippines

by shotgun

I'm running ETap + TCR ISP '16 + Reynolds carbon clinchers. Clearance is really tight!

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sugarkane
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by sugarkane

It needs the chain it's in the tech docs but with out the tension of the chain ( SRAM mechs don't use a sprung pivot like campag and shimano ) the mech will go into the spokeS.. Put the dam chain on already :smartass:

itguy
Posts: 131
Joined: Tue Jan 20, 2015 3:43 pm

by itguy

PinaRene wrote:
Didier wrote:I'm owner of a Cannondale Supersix EVO ( previous model ) equipped originally with a SRAM RED 22 groupset.
I've bought a SRAM Etap mini group and made the swap of both derailleurs and brake levers .
My concern is the following :
when reatching the 11th sproket with the Etap rear derailleur , without chain , I observe a mechanical clash between the cage ( low pulley area ) and the spokes of the wheel .
I noticed that the rear derailleur is moving not parallel to the bike axis when going from right to left ( upwards ). It's like he's turning around a virtual pivot , a bit like the "Yaw" front derailleur .

Rem : With a mechanical RED 22 derailleur , when chain is removed, there is approx a gap of +/- 3-4 mm between derailleur cage and spoke in the 11th position.

I do not understand what's the origin of this problem .


This is normal , I have the same issue. With the rear derailleur under tension there is no problem. If you push the low pully forward you see that it will line perfectly with the sprockets. And I cannot imagine there are a lot of people riding without a chain. :smartass:



Yup, my eTap RD without chain will touch my 404 Firecrest spokes, just a tiny lil' bit. Enough to destroy the spokes if the wheels flexed. But then again, i dont think I will ride my bike wihtout a chain... :mrgreen:

djwalker
Posts: 165
Joined: Sat Oct 31, 2009 7:35 pm

by djwalker

I second the idea of checking the hanger alignment. That vintage SuperSix has a really flexible hanger. I was constantly tweaking mine in normal use ( no crashes or falling over). I would worry about what might happen if my chain broke with that interference.

Valbrona
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Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

djwalker wrote: That vintage SuperSix has a really flexible hanger. I was constantly tweaking mine in normal use ( no crashes or falling over). .


This is why the pro-team had stainless steel hangers made for these bikes.

2old4this
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Joined: Mon Jan 13, 2014 7:26 am

by 2old4this

I have a super six himod, and yes, I always keep a spare hanger on the side. They seem to go out of alignment (no, it is without a crash...)
Going back to the original issue, what would happen if the chain brakes or drops. They shouldn't happen but what if?

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Dan Gerous
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by Dan Gerous

I noticed this too when I built my Evo eTap, even with correctly set limits. I wasn't sure if it was normal or not so I checked the derailleur hanger alignement, mine was a bit off but not critically so. I aligned the hanger and that still happened but as everyone says, once the chain is installed, it's okay. I checked the distance between each pivot of the rear derailleur's parallelogram, it's actually not a perfect parallelogram so it seems like they designed the cage to pivot a little bit to 'aim' at the chainrings throughout the cassette range, not unlike the Yaw front derailleur.

I guess if a chain snaps or drops and you are on the biggest rear cog, it could create a mess, although the direction the spokes would go when riding, maybe each spoke would just ramp and rub the cage and push it as the cage angle makes it so the lower pulley end is what contacts the spokes, without chain tension, it would be pointed toward the rear and the now front pointing top of the cage wouldn't hook the spokes... Not ideal but, maybe not ripping everything off. But it wont touch the spokes when you are shifted on smaller cogs.

TheDarkInstall
Posts: 723
Joined: Sun Jan 26, 2014 3:44 am

by TheDarkInstall

Yeah, the original Evo hanger was soft as hell.

They updated it, adding some strengthening dimensions to it and perhaps using harder material. I had my first Evo go out of alignment with a bent hanger, with no crashing too, and just through constant shifting putting force on the it.

I suppose there is a cut off point for how hard a hanger can be, or it wont do its job when it comes to the crunch, but Cannondale went a bit too soft on this one for sure.

RyanH
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by RyanH

It's not an Evo issue, it's the eTap rd. I've had it on two different bikes, neither an Evo and both touched the spokes without the chain. It's a moot point since the chain is necessary to function...
Strava
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strayduck
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by strayduck

Just to cross-pollinate overlapping threads, a similar discussion is happening over here: viewtopic.php?f=3&t=143893&p=1319259#p1319259

The long and the short of it:

• Dropped and broken chains happen. This is absolutely without question a problem that should have been designed for. You will not have 'more serious problems' than a dereaileur running into the spokes of your wheel while you are moving. This situation will CAUSE 'more serious problems'

• Whether you have the problem or not really depends on the exact make, model and year of all of your parts involved. Some combinations are easier to solve for than others. The case of 10sp mavic wheels appears to have a resolution. Others hopefully will follow.

by Weenie


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