Chain, sproket, disc brakes

[motorbreath]

I just bought a 81 650 special, i noticed that when i drive the chain kinda seems like its going to pop of the rear sprocket and it also sounds like its making a noise in side the case to? My next question is, can i use any rear sprocket size? Last but not least, Can i buy a rear drum to disc conversion kit or is there anyway of switching?

 

[gentlemanjim]

You can buy the disc brake set and the swig arm to go with it on ebay or fom some members here. I do not believe there is an after market kit.

Change both sprockets and chain together. Standard rear is 34 teeth, front is 17 and are availabe in 32, 30. I run a 30 and am very pleased.

 

[inxs]

- is the chain worn?...if you grab it from the rear of the sprocket can you lift the links from the sprocket?
- is the chain line straight?...look along the length of the chain, does it kink a little?
- need to check it out before it becomes an expensive problem
- sprocket size will depend on what gearing you want...std is 17-33
- can convert to disc if you want...you need a disc brake swing arm, the caliper mounting, disc brake rear wheel-will be mag, no spoked disc brake wheel was used, master cylinder and the rear brake shaft

 

[motorbreath]

Thanks guys, um what would u recommend for sprocket size or would u keep oem size? And for the spoked rim, would i have to use a diff. one off a dif. bike if i want disc?

 

[gentlemanjim]

No spoked rim with disc. Mag wheel only. Sprockets depends on the type of riding you do. Around town go stock 17/34, highway 17/30, 17/32, 17/33. I like 17/30, but I live in FL and its mighty flat here.

 

[Inked Monkey]

My chain was making that popping noise when I first set up the bike. It's the alignment of the rear sprocket and front. Just adjust the rear wheel spacing until it stops.

 

[BigJimmyW13]

There is the Omars kit for the drum to disc conversion. That's if you are running spokes.

 

[gentlemanjim]

There is the Omars kit for the drum to disc conversion. That's if you are running spokes.

I checked Omar's site and all I could find is a kit to convert a front 19" wheel for rear disc applicaton. If I missed something let me know.

 

[cooltouch]

Motorbreath,

Optimum rear sprocket size is also determined by rider weight. If you're a fairly light guy, say 160 lb or so, you can get by with as tall a ratio as 17/30. If you're heavy like me, you might not want to go much below a 33-tooth rear.

About chain adjustment, this is really a two-person job, since you have to be sitting on the bike to see how tight or loose the chain is. While sitting on it, have someone push down on the chain about midway between the two sprockets. It should deflect about 3/4" if I recall correctly. Make sure you have the rear wheel centered evenly after adjusting. If both sides are not the same distance, you'll get a side-to-side wobble at higher speeds. DAMHIK.

If you go with a rear disk conversion, there will be no shortage of folks here wanting to buy your cast rear with drum brake from you. Lots of folks prefer the cleaner lines of a drum rear. The '81 SH was the only bike sold in the US with that combination.

 

[motorbreath]

thanks for the advice, sry i havnt been on lately