Forum

[Barry N]

I intend fitting a 19 tooth gearbox sprocket to my Sixty5 and am wondering about chain length. Although some say that the standard chain will just about manage this if the wheel is adjusted as forward as possible, I would prefer the wheel to sit at least halfway back in the slots, or even further, to accommodate a TT100 (K81) tyre with clearance to spare for wheel alignment. Would I need to add a half-link or a full link to achieve this? Bearing in mind the possible weakness of a half-link I'd prefer a full link, but would the chain be too long then? Would a half-link cope with the power of the 612 performance kit?

[Beezabryan]

Did a sprocket 15 years ago been using a half link ever since.

[Alan R]

Hi BarryN ---- a 19t sprocket equals a 5.5% change in the overall ratio in one go. If you can afford it why not try a different approach and buy our hosts rear drum convertion kit ?? That way you can try different sprockets to see which will give you the clearance in the swing arm you need consistant with as near to a 5.5% change that you can get. You won't have to remove the clutch etc either. If you are worried about power transmission then use a modern riveted chain ( Are they available in our size pitch/width ??). OR }---- If you really want to go the whole hog then change your swing arm to a trials type. Bags of room there for "fat" tyres. Finally there's the 18"x 4.00 wheel idea ??  Food for thought.  I had a 65 a few years back----found a trials swing arm for half price----used the 18x4.00 set-up. Smashing.

[Barry N]

Thanks for the input Alan, but I've spent enough already on the 612 kit! I know a lot folks here have run 19T sprockets and I just wondered what they did regarding chain length and in particular, the suitability (or not) of using a half link. The TT100 tyre is a popular choice, but I think there would be a clearance issue if the wheel was set in the most forward position. I haven't done the build yet - just making sure I have all the bits to hand before I start! Thanks Bryan also - thats one vote for the half-link!

[Alan R]

Hi BarryN---- where are you ? I have a spare standard swing arm that you might like to try out the TT100 set up in---it's the one left over from the trials convertion I mentioned and I use it for wheel building etc. Is the TT100 much different than the Avon Safety Mileage tyre in terms of width ??  Let me know what you think ??

[Barry N]

Thanks for the kind offer Alan, but I'll not be getting the TT100 for a while yet, as the Avon SM's still have some life in them and will be good enough to use while running-in the engine. Besides, I have my own swinging arm on the bike of course! I just need to know if the 19T sprocket will require a half-link or full link, so I can get one in advance. I'd hate the job to be on stop just for the sake of a chain link! I'm in South Wales by the way. Cheers!

[Alan R]

Hi BarryN ---- ok matey, fully understand---I've not had a TT100 on any of my Enfields so not much help I'm afraid. Plenty of hills and valleys for the old bike to thump up  in S Wales ---- how's the brakes for the decents ??? Regards----

[John N]

Hi Barry,  Check out page 139 of the on-line catalogue which give an indication of chain pitches for sprockets used, I think you will be ok.  I remember I went up one link only when I added 2 teeth on my Elelectra.


 

[Martin C]

I fitted a 19-tooth and then a 20-tooth speocket to my 612 cafe-recer without any problems over the chain location, and the rear wheel spindle is about halfway back, on an un-worn chain.

[Martin C]

Hmm, I'm totally sober at the moment, so I'll have to work on improving my typing!