Hi
Does anybody have a problem with their lock rings pop’in of the sprocket then unwinds from the hub while riding ?
It’s happened to me a few times, I’ve had them screwed back on tight with a C spanner, but after a couple of hard sessions, skids and back pedals, it come lose again. It gets pretty worrying while your flying down the hills of Sydney and losing all traction and control as the sprocket unwinds.
Can anybody recommend a way to fix this ?
Thanks
I’ve heard this come up a few time in the last month or two. I guess this is my theory on two the two scenarios I helped with. Let me know what you guys think.
depending on your combo of parts, (hub, lockring, and cog) sometimes there isnt enough pressure between the lockring and cog. so there isnt enough effective surface area for the lockring to positively LOCK onto (the meeting point of the inside of your lockring and the outside of your cog). hence there will be a minute amount of play once you have really tightened the cog on by pedalling and being a sick c**t. as the lock ring does not tighten WITH the cog, but can remain stationary.
Once you give it a good kick back (in an aggressive skid or skip stop) the cog can undo that fraction of a turn and but up against the inside surface of your lockring. That is what i think is your ‘slip’.
Scenario1: I had this when i was running a Miche Primato Pista hub with an quite average cheap lockring from abbotsford cycles (excuse me i was in a rush and needed to ride) and rear cog. The cog was slightly narrower than a few more on the market that i had seen.
So i put the cog and lockring assembly together and took it for a spin… SLIP! i shat myself as i had no brakes on this sexy little number. i managed to bring her to a halt by soft pedalling and i took the wheel off to have a look. Sure enough the lockring was done up bloody tight.
Solution: To test out my initial idea i used a stainless washer from the underneath of a cassette lockring and slid that on before my track cog, did her up, took it out for a spin and it was fine.
Now I guess this isnt the ‘Proper’ way to do things, and it was meant to be just a temporary thing. But i’ve ridden that set up for some time now and its sweet. BUT just buy some decent parts in the first place and I dont think you should encounter that problem.
I would recommend getting a good name brand cog (dura ace, phil, surly etc) they are a little bit more expensive, but they are also a little more substantial. in material thickness. hence giving it more pressure between surfaces once locked up.
Scenario2: a friend of mine was riding a dura ace cog AND lockring together on a novatec hub. This hub was brand new off ebay, but the online shop was offering them in a range of powercoated colours. There was no novatec logo left on the hub so my guess is that the ebay store had a whole bunch custom powdercoated and hadnt done a good job of protecting the threads. After riding for a week and learning skip stops and skids my mates hub slipped, in the same manner as mine had previously. I pulled it apart and found that the surface of the hub that the cog aligns with had some work powdercoat on it. I think that that excess paint wore through or cracked etc and allowed some play to develop between the two parts.
solution for that scenario: I took the cog and lock ring off, and sanded the intersecting and painted surface that touches the cog back to the aluminium ever so carefully. (just to remove the paint, not taint the flat surface of the hub step.)
I put it back together and locked her up good, and he hasnt had a problem since.
So i put it down to a bad tolerance between the surfaces due to a paint finish.
CONCLUSION:
I basically think it comes down to the tolerances between the three components. Hub, Cog and Lockring. They need to have sufficient locking ability and a mismatch of brands and qualities can jepordise this. As too could the quality of a surface finish. Dont skimp on these parts as you will have the possibility of messing up your hub aswell by stripping threads.
hope that helps, and I’d love to hear some others ideas on this. Especially if they dont agree!
end rant.
Just make sure the threads are clean, the cogs are good and do your cogs up tight enough.
Unless you are using a Miche carrier thingo, the ‘lock ring’ should not do anything except in an emergency… when for some reason the cog loosens and starts to unthread. When this happens, the lock rings ‘locks’ against the unwinding cog, and allows you enough stopping power (not much) to safely stop yourself without winding the cog (and chain) right off the hub.
If your cog is done up properly and the threads on your hub are good enough, your cog should never unwind. But if, in some exceptional circumstance, it does there’s that little backup or the locking ring to save you.
Search ‘rotafix’ for some ideas.
I have had the same problem and mine was a very simple fix (and a stupid mistake). Make sure that the cog is screwed on nice and tight before you put the lockring on, otherwise you can have the lockring as tight as you like but if the cog has a bit of play it will slip a bit.
^^^^Yep, exactly the same with me. If your cog is on tight enough the lockring will become pretty much obsolete. I had a damaged hub that couldnt allow a lockring for a couple of months, skidded it excessively no problems. However when I got a new wheel and put a cog on with little force, then put on a lockring and started having the same problems discussed here.
My tip: Whip it, whip it good!*
*With a chainwhip 
I don’t even have a lockring, I just rotafixed my cog on and it has withstood my fat bastard skids for the last four months
This is what we call a ‘suicide’ set up, with good reason. Best avoided.
Worst case, I would just grab a handful of brake in the event that my sprocket came off.
Now riding without any brake at all, that’s suicidal.
Second that
+1 for Simes point, I have had both uber tight (done up by a bike shop) and another totally different (not so tight, also from memory the bloke at Cecil Walker said “the cog appears to have been over-tightened”) Quandos hubs let go on me. Yes I have been accused of poor mechanical skilz, However the point remains one was a bike shop job.
Im sold on the quality idea, I just cant afford a Phil hub just yet…
Even better than using the chainwhip go for a ride around the block and crank as hard as you can, up a small hill is good. if you don’t back pressuer the pedals before you get home then at the end the cog should be on tighter than poppeye could manage whith a whip. Tighten the lockring on and should be good
i don’t even use a cog, you guys are so '07.
Scooterbikes reprezent!~ yo
Rotafixing is much better. It’s equivalent to wrenching on the cog with a breaker bar the same length as the radius of the wheel. Pedalling doesn’t really apply that much torque, comparatively speaking as the lever of the pedals is much smaller and the torque is reduced through the chainring, not to mention limited by the traction of the wheel on the road.
Here are some instructions:
Thanks a mill everybody, buying the chain whip and C spanner is a bit of dosh just for a simple need. The rotafixing (http://rotafixa.org/fisso/eng/schpignone.htm) trick is magic. hope it sticks. if not, new part need to be ordered. Does anybody have a good site to order from ??
Thanks again.
Rotafixing will rock your world. Works a treat.