I've just built a 14" 456 up for my girlfriend using brand new quality kit. I used the same transmission set up as I run successfuly on my own 18" 456.... Middleburn Square taper cranks, 68/113 bottom bracket, Middleburn Hardcoat Slickshift Chain rings and XT kit with a £40 KMC chain. On her first ride out she started getting chainsuck when changing down and the chain travelled round middle ring and up round the chain stay, scratching the new frame. I rode it and got the same thing. We took it back to the workstand but everything was set up properly so I swapped out the Middleburn chainrings for a brand new set of Blackspire rings. The result was perfect, trouble free changing with no hint of the problem recurring.
I've used Middleburn Chainrings for ages and never had this problem and visualy I'm struggling to identify any obvious fault with these. I can't think of any other explanation except that there is something wrong with these Chainrings. Thus I've sent them back to Middleburn with a covering note and I'm waiting on their reply.
Has anybody any other ideas as to what went wrong?
Can you shorten the chain at all?
think this is a fairly common think for the 456, my bro and my old man both got terrible chainsuck on theirs. i them a retro style chainsuck plate on to an iscg tab and problem solved. i dont understand why though, they were both using new shimano stuff.
Some new chains have a waxy protection and therefore need a good clean and lube before use.
slowrider - it's not actually the frame that causes chainsuck - it's just that the on-ones tend not to have much clearance between the chainrings and the stays meaning that if you do get chainsuck it causes damage but doesn't actually cause the chainsuck in the first place (if that makes sense!)
billy - any stiff links? Maybe where you joined the chain? Otherwise, it does sound like something's off with the middleburn rings - never heard of it before, mind.
No stiff links Clubber and the system worked faultlessly once I'd put the Blackspire rings on.
DeVs,
Chain was on the optimum, any shorter and it would've locked up if she had gone big to big on it.
i'm sure a 115 BB would still work okay and provide a little more clearance
I had exactly the same thing a while back. Middeleburn slickshift hardcoat rings that just wouldn't shift cleanly. Switched to raceface rings and it's all fine. I got the shop to swap them over for me and then deal with Middleburn. So, if Middleburn tell you it's never happened to anyone before, it's not true!
Thanks for that Onzadog.
I think these chainrings have to be faulty. I've just done around 3,000 miles on another set of Middleburn rings and then replaced them with more of the same and I've had no problem at all. Must be a duff batch!
Could the new rings be a bit 'grippy' when new? The edge of the teeth maybe need to 'wear in' to allow the release of the chain. Wet chain lube too thick/sticky?
Not sure just thinking out loud.
I had exactly the same problem with a 36t/22t slick shift hardcoat ring. I rang Middleburn and and they recommended a Shimano chain instead of a SRAM and I must admit, it seems to have worked. There is a very slight sucking now and again but it doesn't drag the chain all the way up, I hear a little click and it drops off.
What Blackspire ring did you get? I may consider changing
Never been a massive fan of Middleburn rings, but they always work better with Shimano chains than any others IME
They said the same to me about the chains. I swapped chains, tried it and it was no better. I've got a lovely clip of the chin sucking while the bike is on the workstand. I set it to a Queen track! How sad.