[Closed] Play in Cotic frame?

If it's a clunking type noise when lifting/dropping it's probably a shock bush. Regarding bearings, mine needed changing after 8 months and probably aren't far off needing doing again at 18 months and 3,300k (less mileage recently due to lockdown).

None in my Rocket.

I would take some time to cup each area with your hands while recreating the issue. You can normally feel slight play like that.

Shock pivots can be held with thumb and finger and gently moved. You can usually feel any play.

I had this.

It turned out to be that the axle on the main pivot had come loose, but because the pinch bolts were tight, I hadn't realised.

Slacken off the pinch bolts, torque up the axle, and redo the pinch bolts, and it was all fine again.

I've now put a spot of loctite on the threads of the axle to discourage it from doing it again. I don't know whether you're supposed to do this, but these days I just put loctite on everything.

@oldnpastit

This is exactly what I suspect it is, can you get to the axle directly to tighten it up or is there a cap over it?

There's nothing tricky or complicated. No caps AFAIK.

In my case it was the bottom pivot. There's a clip to hold the brake cable on the NDS, just ignore that. Slacken off the pinch bolts. Then hold the NDS-side bolt with a 17mm spanner and tighten with an 8mm hex on the DS.

Check your pivots. I’ve had a few come loose since I’ve had mine, especially the main pivot bolt. Every now and again I’ll go around with a spanner and Allen key to check. Should really take apart and put some loctite on.

Had exactly the same thing on my LS Rocket after about 8-10 months. Bike shop said the frame was dead and the main pivot bolt had ovalized the frame went back to Cotic turned out the main pivot was loose. Cy explained to me (after taking it apart and putting it back together himself) it was sorta like a headset and needs to be tightened every once an a while.

Did they warranty it for you or did you end up bikeless?

I have the one up chain guide on mine which annoyingly means my crank set would have to come off in order to be able to tighten it up on the DS. Booked it in for new bearings now which means it will be getting re-assembled anyway

The headset analogy is a good one. People are talking about tightening it up, but remember that over tightening can cause just as many problems due to excessive side loads on the bearings. Just treat the two main pivots like headsets. Take out the play and tighten up the pinch bolts. Then regularly check for play.

I find it’s the droplink bearings that go (notchy) on mine and need replacing about once a year (despite me being a committed mincer). I stripped the main pivot down after two years just to check, but they were fine.

Aye, I think to be safe I may as well get the bearings changed. I'm lucky enough to be able to ride 2-3 times a week so they are probably over due any way!

Not the best built bikes....

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JEEZUZ!

Ouch! What were you riding on the lead up to that failure out of curiosity?

Getting bored of that photo turning up on every thread that mentions Cotic. We get it, you've been unlucky and no other brand ever suffer breakages...

Not sure a wobbly pivot caused that?

What did Cy say about it?

Also curious as to me (admittedly no engineer) the bend appears to be 'backwards' for any normal riding impact?

Sorry to offend.
Pic deleted.

Me too. It's almost like someone has an axe to grind. It's bordering on breaking rule 1 now.

(EDIT reply to cyclelife's ninja edited post)

Weird that it happened twice granted. But the issue is the bolts breaking not the frame? I guess it could be an alignment issue creating undue force on the bolt but if it happened on two frames that would be unlikely.

Rocket or Flare?

Not seen anything like that elsewhere though - if it was a design or manufacturing issue then you'd expect other examples to have turned up?

Me too. It’s almost like someone has an axe to grind. It’s bordering on breaking rule 1 now.

Feels somehow familiar - a poster highlighting someone else's broken Cotic at every opportunity...

The same bolt did come loose a few times on my Flaremax. Cleaned it then torqued it up and no problems since. No issues on my rocketmax. Its a shame as I think the failure is interesting but the point gets lost in the clickbait style.

At least now I can go and get it sorted and maybe sound like I know what I'm on about, thanks for everyone's help on the issue!

Following this with interest - my flare`max has developed a "rattle" when it goes over the rough stuff. It doesn't seem to be stuff in my rucksack, it doesn't seem to be the rear mech / chain ( which is clutch, so shouldn't rattle anyway).

Loosened the rear axle pivot bolt - and relighted ( as above). There seems to be no play in either the bearings or the shock bushes ( and the front was only replaced 3 month ago under the CC recall).

The bearings have not been done in 2.5 years. Are these the most likely culprit?

Thanks

Sam @ Cotic told me the bearings are most likely to be the culprit. If you have no play in the axle itself or if it is done up correctly. I would say that is the cause of your rattle, he did also mention out of the all the bearing it is most likely to be the dropout bearing on the seat stays.

The headset analogy is a good one. People are talking about tightening it up, but remember that over tightening can cause just as many problems due to excessive side loads on the bearings.

Not sure this applies to the main swing arm bearing which is the one that has come loose a few times on mine. I called Cotic and asked about torque levels the chap I spoke to just said tighten it up a decent amount. I’ve done that a few times now. The swing arm moves free and smoothly. No bearing issues yet.

Have you been able to tighten it with the chain guide in the way? I can't get an allen in due to the plate for the chain guide being in the way

Aye I've got that, I understand what I need to do but I can't access the head of the axle bolt because of the chain guide being in the way. I'm wondering if I can move it somehow to get the allen in to tighten?

@wobbliscott How long ago was that out of interest?

My experience is mostly with the droplink pivot as that's the one that seems to go more frequently on my FlareMax, but I'm tending to use the same approach on the main pivot too now.

I know they used to say to tighten them up quite a bit (which can put large side loads on the bearings) and that's what's in the (original) manual but the advice seems to have changed a bit recently to "treat it like a headset". But as I say, that might just be for the droplink pivot.

Do you remove the chain guide first??

Thanks Malteser,

I will have a look at the bearings today - it is pissing down, so that is a sign from god ...

The chainguide is just one bolt (plus a couple for the holder). I knock the cranks out too (might as well check the BB bearings while I'm at it) but it's probably not necessary.

and that’s what’s in the (original) manual but the advice seems to have changed a bit recently to “treat it like a headset”

The manual is being updated… and as far as I know that is broadly what the change is. I think the order of bolts to check has changed as well, but I’m not sure. I have to admit I tend to ignore all the bolts on my own frame ‘till something is obviously loose, so I’m not the best person to give any advice here!

Just had a look, I can't do the lower pivot on mine without taking the cranks off as the ring obscures the chain guide bolts and there is nothing to stop the pivot shaft spinning. Maybe I could make a tool that uses the cable clamp hole but not sure as thread is a bit small to get much preload in. Cranks are mk1 hopes so just got to find all the special tools...

By do I just mean tighten as obviously I'd need to take cranks off to change bearings.