Rear Sprocket HELP!

The Busted Nut

The Busted Nut

Member
I am trying to assemble the rag joint and none of the screws line up after going through the rag joint. We cant get any of the screws do line up! We are putting the rubber things in boiling water to loosen them up. Any other suggestions?
 
Do the holes mate up w/o the rubber donuts in there? ...just checking...
NOT a lot of QC at the mfg's...

You could set the donuts on a block of wood and take a spin at them with a drill bit to open them up a bit. They are just spacers, to prevent spoke damage. Even then, the bolts will get ate up and the spokes will be damaged... The bolts on my basketcase were.

Are you lined up in the best position?
There's a number of threads here on how to set up a rag joint.
They helped me out the first time I hated doing it!

A hub adapter is a VERY valuable improvement to a MAB. REALLY

Good luck
rc
 
So I have had my bike for a few months now but I just recently noticed my sprocket is off center and my chain is really loose any ideas on how to re-center my sprocket?????
 
syates234 said:
So I have had my bike for a few months now but I just recently noticed my sprocket is off center and my chain is really loose any ideas on how to re-center my sprocket?????
Click to expand...

Here is one way....
...

OR

Take a string, make a loop on one end, place loop over axle, use the string like a compass.
 
Last edited:
HI,

On my bike I centered my rear sprocket by cutting paper clips (yes paperclips) of the appropriate diameter wire size and using the small pieces as shims to insert in between the sprocket center bore and the hub itself....do this before tightening and it will help center the sprocket.

As a side note, I did try pulling out the small pieces of wire for fear that they would later fall out and possibly cause a flat but they were lodged in there very tight and would not come out using the small needle nose pliers I had at the time (I did cut them very small because originally I did plan on leaving them in but later thought it best to remove because of the potential flat issue)...

I never did remove the pieces because I forgot about them and they still have not fallen out to this date.....I suppose if one were to keep their bike outside subject to rain etc....the paperclips may eventually rust to the point where they get small enough to fall out tho (should not be a problem at that point tho since the bolted assembly will hopefully be tight and not shift.).

Hope this helps you.

Andrew
 
ok, so i got the sprocket on but noticed that after the thing it tightened, i noticed it was wobbling side to side. The problem is it is tight enough already, so i dont think it will go any more.
 
The Busted Nut said:
ok, so i got the sprocket on but noticed that after the thing it tightened, i noticed it was wobbling side to side. The problem is it is tight enough already, so i dont think it will go any more.
Click to expand...

If the center hole in the sprocket isn't OVER the hub on the bike..they never will line up and stop from wobbling. Are you working on a coaster brake set up?
As far as the rag joint, using the sprocket and rubber only, you can insert a bolt in every 3rd hole. This will where the metal spacers center hole will be used. Take a drill and drill through the sprocket through the rubber.

Use #1,#2, and #3 to align the rubber to the sprocket. Each of these bolts will be inserted through the center hole of the metal washers. The rubbers are for protecting the spokes. Once installed the rubber will won't be able to be moved..the spokes imbed their selves in the rubber.
Also this one way of the tightening pattern.
 
Last edited:
the sprocket is around the hub and fit perfectly. I just need to know how to make it true.

EDIT: Yes i am working on a coaster brake setup. Firmstrong urban with Hi-Stop brake hub. I did order a front hand brake btw.
 
Last edited:
HI,

To attempt to make the sprocket run true (not wobble side to side), the bolts will have to have uniform tightness....If you squish the rubber on one side too much it will make the sprocket wobble when the wheel is spun....NOTE: also check to see that the rubber mounts you are using are uniform in thickness and density because that can throw things of as well.....Finally. although unlikely, check to make sure the sprocket itself is flat and not bent or you will drive yourself crazy trying to adjust bolts forever).

Tightening the bolts in a criss cross fashion is the proper way to tighten the bolts.

Getting a sprocket to mount perfectly (no wobble) is nearly (well probably IS) impossible
using the factory rubber / rag joint mounting method but with patience you can get it pretty close (or close enough to be usable at least).

A perfect mount (wobble free) can be easily achieved by using either a Top Hat Sprocket Adapter (must be used with a disc brake hub) OR a clam shell type hub adapter (for non disc brake hubs)..

Hope this helps you.

Andrew
 
Last edited:
... I getcha BN...

U got the sprocket running concentrically true, NOT in a egg shaped motion, but now have the warble wobble side to side.

Tightening them all the same WILL NOT fix this as the nice helpful fellow just said... Reason? Components of the rag joint are probably among the worst of an ht kit.

What << I >> did....

Use my clip idea I posted to hold a marker against the sprocket while spinning the wheel. Get the spot marked with a felt tip pen where the runout is worst.
Loosen all the bolts opposite that area and pry the sprocket away from the outer rag joint spacer... with that bolt out, slip a washer in there and re-assemble... I did 3 of em and got my sprocket running a lot true-er.
...and I've had NO further probs with it!...

A sprocket adapter from one of the vendors really is the best investment you can make in your ht kitbike! IMO really really !

Best
rc
 
Thanks guys. Rusty, i am going to be honest with you. Every time you tell me your paper clip idea, i have no idea what parts/area you are refering to. Can u pm/post some pics or diagram for me.
 
Hey BN,

Well that makes two of us!
Most the time I don't know what I'm talking abt, either! :-)

...follow me here...

You can true your bike wheel by spinning the wheel and seeing how it might hit one of the brake pads, right? kinda crude, but it helps...

Of course it's btr to use a fancy truing stand!

or, you can clamp a small piece of wire to the seat stay, or chainstay of your bike, and use that. the wire, bent into one position will give you a guide to see if the wheel is egg shaped. with the wire to the side of the rim, where the brakes make contact, it will tell you how far the rim is out side to side.

you can use this method to check your rear drive sprocket.

...if your sprocket is off center and running in an egg shape, in relation to the axle, it will be tight, then loose, during a single rotation.
...a power robber, and u will notice vibration, and the chain 'strumming' like a guitar, but not so nice. :-)

if the side to side is out of 90 degree plane with the axle, it will wobble...
this, or the other, will cause the chain to come off at a bad moment.

did that help?

I think I got one pic posted over in the DeathDoll post, but I dunno...

I use copper wire, but anything will do to get it close enough for our purposes.

I'm sure Lance Armstrong has someone use a dial indicator on his bike wheels.

Sry I can't do diagrams yet... I'm still at the finger painting level. :-)
and there's really MUCH btr wheel guys than me... I just talk a lot.

Best
rc
 
BN, just dawned on me that someone else had mentioned paperclips to center the sprocket on the wheel hub...

Same thing as wrapping the dust cover with tape, or slipping some zip ties in three opposing places... I used insulation off some electrical wire...

Put something that can be compressed in there at 2 o'clock, 6 o'clock, and 10 o'clock. or use tape.

All methods help with getting it centered...

The rag joint is just a shotgun method of sending the ht power to a majority of bicycles. Way far from perfect and leaves a machined hub adapter to be desired!

Best
rc
 
You must log in or register to reply here.
Back
Top