[Closed] Do clutch rear mechs prevent chainsuck?

Chainsuck is generated by the chainrings primarily. I doubt there's much the mech can do about that. Happy to be proved wrong, though!

Chainslap on the other hand...

Maybe, the pull on the chain might stop the chain travelling round the chainring too much.

I think they do, or at least reduce it- certainly had less since I fitted mine.

Agree with northwind, had chain suck issues, changed the mech, everything else is the same, no more chain suck problems!

I have never had chain-suck on a single one of my bikes. What are you all doing wrong?

Not being as awesome as you!

I had a lot of chain suck issues on xtc composite ht from new! everything kept in good condition - but used to get it a the slightest sign of slop etc, so got a clutch mech as reduction looked probable - glad to say its appears sorted.

Quite impressed with all the other benefits of the clutch mech as well.

Not being as awesome as you!

Clearly 😆

Generally what I wanted to hear, I've built up a C456 with brand new 9 speed XT drivetrain at the end of May & had chainsuck after only 300 miles on it, chain lubed before every ride & hardly any mud involved.
I moved the whole drivetrain to an elevated chainstay bike & it works perfectly so I'm hoping the clutch mech will keep the chain away from the chainstay on the C456 when I fit 10 speed to it this weekend.

Chainsuck is generated by the chainrings primarily. I doubt there's much the mech can do about that. Happy to be proved wrong, though!

I dunno about proving you wrong but I have a different opinon. My experience with chainsuck and the bike industries response to it is that it is caused by frames. Here is my anecdotal:

1) People, including me have had chainsuck with a brand new drivetrain, in almost any combination..

2) My very high chainstay bullet never ever got chainsuck, I used to transfer all my old drivetrains onto it when they were too worn for my 456

3) Brant responded to 456 chainsuck by designing ragleys and other bikes with narrow chainstay bits to give good clearance. He also advised people to ding their 456 chainstays for more clearance.

4) Other larger bike manufactures who have been in the marketplace longer than Brant and his ilk * have much greater chain clearance since year dot. I give you my 1996 giant xtc which has asymmetric chainstays with massses of clearance on the inside.. (and spec, and trek ect etc)

*(no criticism, I love my on-ones/planetx babies, but lets face it they used us customers as a development/learning platform until they got it nearly right..)

5) I have seen a sram video testing chainsuck (which I wish , wish I could find to show you) which shows the effect of decreasing chainring clearance on the likely hood of chainsuck, where they also had hooked wrecked chaingrings that did not suck with loads of clearance.

6) I am not saying that worn rings do not keep the chain on, but by 9oclock position they will pull off, unless there is a close chainstay which keeps it on. But the sram video and mine and other experience shows that even brand new drivetrain gets it. Brant said it was like herpes, once you get it, it never goes away...

7) In theory [b]I reckon[/b] a clutch mech would defo help, stronger return force on the lower chain run will act to pull the chain off the rings...

How can a frame [u]cause[/u] chain suck? The design may make them more prone to the [u]effects[/u] of it but cause it? No. That is why elevated chainstay bikes don't suffer the effects of chain suck - there is nothing to get sucked in to so you don't notice the chain coming further round the chain ring than it should.

The chain failing to disengage from the chainring causes chain suck. I've had it with entirely new drivetrains (chain grease too sticky, degreased and relubed - problem went away), with worn and tatty drivetrains (fault has usually been the chain having stretched too much or a twisted/stiff link) and sometimes for no discernible reason (but most likely crap in the chain and rings or using too thick a lube without cleaning the chain first).

Given all of that I think a clutch mech would help prevent chain suck, but not actually solve the original problem.

1) People, including me have had chainsuck with a brand new drivetrain, in almost any combination..

yup.

& I would presume a clutch mech would help.

That is why elevated chainstay bikes don't suffer the effects of chain suck - there is nothing to get sucked in to so you don't notice the chain coming further round the chain ring than it should.

sorry but my experience on Turners shows that they can experience chainsuck, the reality is that there are multiple causes but a common symptom and the impact depends on the frame design

I've had it with entirely new drivetrains (chain grease too sticky, degreased and relubed - problem went away), with worn and tatty drivetrains (fault has usually been the chain having stretched too much or a twisted/stiff link) and sometimes for no discernible reason (but most likely crap in the chain and rings or using too thick a lube without cleaning the chain first).

Of course I understand what you mean, if the chain always released at the tangent at the bottom then we would have no issue. BUT I think it is a bit of semantics no?
It just depends on what you define as chainsuck, for me chain suck is when the chain gets caught up on the frame...
My point is that all drivetrains could get the chain carrying on round the chainring, I would not define this as chainsuck. It does not matter whether new or not, as you have experienced, the actual suck (for me) is only when the chain gets caught and graunches. Hence [b]for me[/b], it is caused by the frame. If you have great frame clearance, you will not get chainsuck, even if the chainring/drivetrain is knackered. I like taking my drivetrain to long lives, so I like to avoid frames with a chainsuck problem, and why the bullet was so great at using up knackered drivetrains.

Is "Shadow +" the proper name for clutch mechs? And are they available in 9 speed or only 10? Ta.

Turners shows that they can experience chainsuck, the reality is that there are multiple causes but a common symptom and the impact depends on the frame design

I suppose the chainstay on the turner was just not elevated high enough? If there is no frame to contact with how can there be a problem? So there must be frame in the way yeah? Unless have you actually experience the chain coming around to 11-11:30 so that it catches the top chain run??

PS which turner?

Unless have you actually experience the chain coming around to 11-11:30 so that it catches the top chain run??

I'd have thought that the bottom chainrun would have contacted the front mech before it got to this point (that might actually be enough to dislodge the chain from the front ring)

I'm sure that the upward movement of the lower chainrun as it flaps about on rough trails will have a big influance also.

yeah I dunno, never experienced it going that far myself, it could tuck under it maybe?

Unless have you actually experience the chain coming around to 11-11:30 so that it catches the top chain run??

Managed this on my Rockrider this morning. Probably under lubed and it was very dusty out there this morning. Didn't touch the frame at all so I just had to back pedal it out. A clutch mech is on my list of upgrades/next bike specs.

Managed this on my Rockrider this morning. Probably under lubed and it was very dusty out there this morning. Didn't touch the frame at all so I just had to back pedal it out. A clutch mech is on my list of upgrades/next bike specs.

Blimey!

What is chainsuck?

patriotpro - Member
What is chainsuck?

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I got chainsuck regularly with a clutch mech and double chainset on recent Alps trip. I've now fitted a chain device.

Is "Shadow +" the proper name for clutch mechs? And are they available in 9 speed or only 10? Ta.

Yeah that's right. 10 speed only last time I checked.

dazzlingboy - Member

Is "Shadow +" the proper name for clutch mechs? And are they available in 9 speed or only 10? Ta.

Shadow+ is Shimano's name, SRAM call it type 2. Currently only 10 and 11 speed, buuuut, you can adapt a Shimano 10-speed quite easily to run on SRAM 9-speed.

Gotcha, cheers prawny.