To my fury, my Shimano 12 speed chainring disassembled itself on a ride today - it’s a two piece design with 8 security Torx holding the ring to the spider. What are my options for 30t chainrings that fit this mount?
I’m running a 12 speed XO1 chain on a singlespeed, so I presume any narrow wide will work? I’ve always noticed a big range of prices and quite a lot of variability of how well alloy rings wear from brand to brand though…
One option I’ve seen is a Works Components oval - is that viable on a singlespeed without tensioner that’s being ridden hard downhill?
Unite? Reasonably, priced made in Wales, but apparently indifferent to their customers.
Was it SLX? Only heard of it happening to them.
I keep eyeing up the works chainrings for when my slx chainrings wear. I hadn't considered an oval one. I'd be interested to see if they're compatible with ss too.
Yes, it was SLX! I noticed one slightly loose recently and decided to buy a security torx to tighten it but before I did so the singlespeeding fully removed two which I found when my chain get dropping. Totally idiotic design…
I’ve had Works rings before and they were decent.
I’ve just found out I need a special tool to change this chainring - WTAF? Shimano SLX cranks used to be such a sensible buy…
I've used cheap Chinese ones for a few years now as it used to be difficult to get Shimano 30T ones. I just change them with the chain but that's probably unnecessary. They also make oval ones.
The tool you need
Oval works totally fine with SS 🙂
I've run oval rings on a Middleburn crankset in the past, and am currently running one on a Hope crankset on my Stooge.
The chain does get slightly tighter/looser as it goes around on an oval, but not enough to fall off, and you just need to make sure you tension to the tightest spot, so it can only get a bit looser, not tighter (hope that makes sense!)
The only issue I've had is that with a 34t ring on an EBB bike the ring fouled the chainstay when the BB was set to the furthest back point. Luckily I was able to adjust it ok without it touching the stay, and it could be properly solved with a smaller ring.
Nothing fits those 8bolt shimano things. You just need a “shimano direct mount” chainring, lots of sellers.
Apparently shimano will replace the whole ring as it’s not supposed to be user servicable. I had this happen … Singlespeeding, but I didn’t try as I bought a lovely works chainring.
Re oval on singlespeed without tensioner, I have never had success.
One thing to consider is a shimano one will be made from steel and the aftermarket ones aluminium so won’t last as long, assuming the shimano one doesn’t fall to bits again obviously
I've had a SLX chainring disintegrate. The same XT cranks are on all my bikes so I've gotten through a few of them. Dunno if Shimano changed anything but subsequent chainrings have been fine. Since 5 out of 8 bolts vanished in quick succession I'd have expected it to happen again. Did wonder if Shimano changed the loctite, or if some lube got in and weakened it. Silly design though.
Just to play a practical joke on us all the new electric groupset chainrings are one peice, but a different offset, if I'm not mistaken?
I’d just get an XT one. Can be had cheap, and are way more durable than aftermarket rings. The loosening security torx bolts only seems to affect the SLX ones for some reason.
Where are XT ones cheap?
SLX and XT are exactly the same chainring except for colour. I assumed there were more complaints about SLX because more riders have that model, being cheaper and more readily available?
They look similar, but must differ in some way as they are different weights, and SLX rings are the only models that seem to separate.
Halfords have them at £35, and Biketart at £36.95
but must differ in some way as they are different weights
I'd be interested to know how? 5 grams is small enough to just be the different anodizing
I really don’t trust this design - I’m not the world’s strongest pedaller but I will try to grind, trackstand, ratchet and basically single-leg deadlift my way up things on my singlespeed that some with gears will push up. With an 18 tooth cog on the back and a 29” rear wheel that involves a lot of chain tension and thus forces on those security T15’s.
I’m thinking that an alloy chainring will wear out at about the same rate as the steel rear sprocket and chain, so I can replace them all at once.
Have ordered a Works round one for £40. I might be able to get something much cheaper from China but as someone who runs a UK manufacturing business I like to support others in the same boat!
I've run oval chainrings on singlespeeds for years now. There's no chain growth, but apparently it does look a bit funny.
One thing I would note is that some aftermarket rings wear quite quickly compared to Shimano ones; this is on the penultimate design which was a smaller four bolt, but the SLX ring on one of my bikes is still trucking while whatever the Absolute Black diffusion brand for Chiggle was on my other one is long gone. The security Torx thing probably makes sense somewhere but just seems a bit off to me; they aren't intended to be taken apart, so why use fasteners that can be loosened or tightened?
