Forum

[Roeland]

Hi,

I'm not sure if this was already discussed in the past but today after a 600 km trip including about 50 km on gravel my rear sprocket lost 18 teeth from the 38 at a speed of 111 km/h GPS; 9 teeth in a row and the others ad hoc. Not a pleasant experience. I could hear the hole thing breaking up and the chain skipping over the sprocket teeth.
Before the trip I adjusted and lubricated the chain which has 19k on it. We managed to cover the last 100 km home at very low speed. Why does this happen?
Thanks
Roeland

[Robin]

Hi Roeland! I've had a rear sprocket tooth or two break off when riding through a pothole with a rear chain which was too slack, but 9 in a row!!?

[Craig]

What Bike Modle (Make) and Year is it Roland? ? ..."In Defense of The Calassic 4 Speed Iron..Both 500 & 350 I Have Never Even Needed to Change theRear Sprocket on 50'000+..(Though I Have Broken a Few Chains)...SO Sprockets?? Are They Now Cast or ?? Or (Could Be) an After Mrkt Blunder??...But Sprockets (Touch Wood) Clasic & Avl :No Problem... ;0)

[Roeland]

Hi,
It is a 2011 (registered 2012) EFI model upgraded to 535 cc. Somebody mentioned that most likely it could have been a stone the jammed between the sprocket and the chain?
Regards
Roeland

[Norm]

Out here we had 2 sprockets loose numerous teeth on the recent AGM ride to Alice Springs, it does happen.

[Alan R]

-------Lost your TEETH ??-- maybe this might help ??}---------- http://www.nhs.uk/NHSEngland/AboutNHSse ... ntist.aspx ------------Seriously though, that's no joking matter...If you had been "at speed" then it could well have been lethal !!........ can you post some pics of the breakage area ?? Were the teeth ripped off or did the metallurgy fail ??...From your description a stone does seem the most likely candidate...

[Roeland]

The sprocket is still on the bike but I hope to get a replacement today and will post a picture once removed.
PS. Alan R - at "111 kmph" it felt "at speed".

[Paul]

Hi,
I've had the same when I was too lazy/busy to tighten the chain. The chain adjustment can be a bit fiddly as it changes when you tighten the wheel nuts up. It jumped teeth and knocked the points off. I usually replace the chain every 20K. Does anyone know of a really good quality 'o' ring or 'X' ring chain that fits an old 500 bullet without rubbing on the primary case?

[TimG]

I went through three rear sprocket/brake drum units in six years' ownership of my 2006 iron barrel 500 Classic, despite oiling and adjusting chains....quality of replacement chain doesn't/didn't seem to affect frequency of knackering, swingarm was aligned OK. I just eventually came to accept it as part of the not-too-brilliant Indian implementation of a basically sound design...cheers, TimG

[Roeland]

Still waiting for the sprocket but in the interim I purchase a DID 530 zvm-x chain - I hope this one does not require too many adjustments?