Chainsuck: drivetrain compatibility?

[lukeheller]

I am running a Shimano Tiagra 4650 34/50 with a SRAM 11-30 (8spd) and SRAM 8spd chain. I run the 8spd stuff because it's cheaper and lasts longer; beyond that, i can't argue. This is a relatively new build and I've had nasty chainsuck 2x now and can't figure 'er out. I'm wondering if the chain is too wide? I really don't want to move away from 8spd; I'd change out the crankset to something retrogrouchy like the Sugingo XD2 before losing my 8spd. Thanks

[Steve530]

Do you mean the chain gets hung on the chainwheel?

[zmudshark]

Correct BB? Sounds like a chainline issue.

[lukeheller]

Chain gets stuck on chainring when it should release and gets sucked between chainstay and chainring. Simultaneously, a thousand virgins die every time it occurs.

[Steve530]

And then the cranks lock up?

[lukeheller]

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[Richard]

Chainsuck is about a worn inner ring, a hooked tooth, a worn chain or a combination of all of them.

[Peter P.]

I'm with Richard on this, assuming the chainrings are older than the rest of the drivetrain.

But your post implies you put everything on NEW at the same time.

So if the chainrings are older than the rest of the drivetrain, replace at least the inner ring. The larger rings last longer because the load is shared by more teeth.

If everything was installed new at the same time, then the cheap route to finding a solution would be to try a Shimano chain first, then new chainrings.

By the way, should you order a new inner chainring, save yourself some time and order a large ring at the same time to keep on hand because you'll eventually need it.

[Richard]

Also, before I did anything else, I would do a complete cleaning and relube of the drivetrain and check for a sticky link. That could also cause suck.

[Vientomas]

New chain? I had a SRAM chain that was all sticky out of the box with some kind of "lubricant" which I attributed to causing chain suck on a new mountain bike build. When I dropped into the little ring the chain would get sucked up into the chain stay. I removed the chain, cleaned off all the goop and lubricated the chain with some decent lube. The problem went away.

[lukeheller]

Everything was new, relatively. It all came off another previous build that I rode for about 300 miles. I can't imagine the rings are worn.

So, to be sure, spacing compatibility with the chain and chainrings shouldn't be an issue?

If not, I'll go ahead and just try a new chain and see what happens. I had the same thing with this chain as described, the pre-lubrication gooey gunk. I didn't wipe it clean or lube it when it was new because it seemed lubed already. Then, chain suck. Even after lubing from there, chain suck.

[Ken Robb]

the pix aren't super sharp but the chain looks dirty/dry to me.

[Peter P.]

If you didn't have a problem with the crank and BB when they were paired on another bike, then it's not a spacing issue.

The suggestion that you could have a stiff link is a good possibility, since you did reuse the same chain on the new installation.

[josephr]

Chainsuck is about a worn inner ring, a hooked tooth, a worn chain or a combination of all of them.

^^^^ This ^^^^

Recently had a similar issue and while my chain wasn't skipping indicating wear, it would drop during shifts up front. Replaced the chain and everything was tight again. A bike mechanic buddy referred to it as 'lateral chain stretch.' Might be time to replace some parts.
Joe

[Cat3roadracer]

Limit screw?

[lukeheller]

limit screw is good. chainrings are near new (300 miles when i built the bike + 800 miles since built).

i scrubbed the chain till it shined last night, felt each link for stiffness, and lubed it up with rock 'n road lube. rode a metric century this morning in the appalachian mountain rains this morning (will it ever stop raining?) without issue.

i'm gonna hope and bank on the theory that the chain had a sticky spot and it just needed some attention. for my paint job's sake, i hope we can move on from this one :bike:

thanks all

[CNY rider]

I just notice that "SRAM" and "suck" frequently appear in the same posts.
So I stick with Shimano and Campy.