Rear sprocket seating

[HarleyXLH666]

I got a new bike today to switch my motor on to. Rear sprocket is not seating on the rim with the rubber spacer.

Pictures 1 & 2 is with spacer
Pictures 3 & 4 is without spacer

I'm guessing *NO* but am unsure so am asking Is it OK to use it as shown in the first 2 pictures with proper torqueing?

If not how can I get this to seat on the hub with the spacer or what am I doing wrong on this install?

1st hub I have seen that did this. Are there different style of hubs? What style do I have in the pictures and what kind of hub is needed for these motors?

Just bought a new bike so I REALLY hope I dont have to go back and buy a new rim also.


(EDIT: The 5th picture shows the OLD/PREVIOUS rim WITH the rubber spacer and it has few mm of hub sticking above the sprocket hole level like it should)

 

[maniac57]

I always try to line the spacer up exactly with the old spoke creases whenever I switch a ragjoint.
You might also find a spacer to fit the sprocket hole EXACTLY and center it on the hub taper. If you find the right size ring, it will work fine. Keeping the sprocket centered perfectly is the hardest part of any ragjoint. Don't worry about spacing unless it rubs or tosses chains.
Get it dead centered and your chain won't have tight and loose spots.

 

[2door]

If you're asking if you can just tighten the sprocket against the spokes without the rubber, the answer is most definitely 'no'. The rubber is there for a reason. A metal to metal installation will not work. You'll bend or break spokes.
Take Maniac's advice.
Also the rag joint is designed for a 36 spoke rim. If you have 32 spokes you have a problem.

Tom

 

[HarleyXLH666]

The spokes werent lining up so I just flipped em & started with the flat side.

Once I put the bolts in and tightened them I now have hub sticking above the sprocket level but there is about a mm gap between the hub and the sprocket (Which I wasnt able to center)

I dont build often but when I do I seem to remember all the others had metal to metal contact between the sprocket and hub. Now sure about this the gap. For lack of better description, its as if the sprocket is "floating" around the hub.

If that gap between hub and sprocket is OK then I will spend the hour or 2 it takes nicely centering the sprocket but if the gap is a problem then no use wasting time on this rim.

 

[HarleyXLH666]

If you're asking if you can just tighten the sprocket against the spokes without the rubber, the answer is most definitely 'no'. The rubber is there for a reason. A metal to metal installation will not work. You'll bend or break spokes.
Take Maniac's advice.
Also the rag joint is designed for a 36 spoke rim. If you have 32 spokes you have a problem.

Tom

No the rubber will always be there. I was having trouble getting the hub to poke up above the sprocket but it is now that I tightened stuff but there is a gap between the hub and spoke (previous post)

(EDIT: Spoke count = 36)

 

[2door]

Harley,
I see nothing wrong with your installation. One thing to keep in mind is that the center hole in the sprocket and the gaps between it and the hub isn't the important thing. What you want is good concentricity with the outer diameter, the sprocket teeth and the hub. I've seen brand new kit sprockets that were not made well and the center hole wasn't exactly centered.

I like to attach a pointer to the bike frame, spin the rear wheel and watch to see how the tip of the pointer meets the outer ends of the sprocket teeth. The sprocker hole could be oval shaped, square or much larger than the hub. That's not where you want to concentrate your centereing process but at the outer edges of the sprocket teeth.

Even tightening of the nine bolts is also critical so you don't get a side to side, lateral, wobble.
Good luck.

Tom

 

[maniac57]

Like I said, make a small spacer for the center hole to fill the gap. Any cone shaped hub is easy to center perfectly this way. Then just clamp it down.
Think a 1/4-1/2" chunk of pipe that fits the center hole. The cone on the hub automatically centers it when tightened.
Should still check like 2door said, but it's easy when you use a spacer since most sprocket holes are good.

 

[HarleyXLH666]

OK if it looks good then I will go around it star pattern with a torque wrench to even it out.

Could I please get an explanation of what a "pointer" is?

I am spinning it by hand and will say there is some visible side to side sprocket wobble but the kits is over a year old. My previous pictures looking at the teeth probably says time for a new one but this sprocket has to work for me for the time being.

I didnt understand the pipe thing at first but I do now. Good idea.

 

[2door]

A 'pointer' can be made with anything, a clothes hanger wire, welding rod, any rigid wire that you can temporarily attach to the bike's frame so it doesn't move. The end of the pointer is bent so it almost contacts the sprocket teeth at their outer edge. As you spin the wheel you'll easily see if the sprocket is centered. Movement of the teeth toward or away from the end of the pointer will tell you which way the sprocket needs to move to be centered.

You can get away with a small amount of wobble, no more than 1/8th inch or so but try to get it as precise as possible. This takes time and patients but it can be done by tightening or loosening the bolts. Just don't leave any of them loose

Tom

 

[maniac57]

A 'pointer' can be made with anything, a clothes hanger wire, welding rod, any rigid wire that you can temporarily attach to the bike's frame so it doesn't move. The end of the pointer is bent so it almost contacts the sprocket teeth at their outer edge. As you spin the wheel you'll easily see if the sprocket is centered. Movement of the teeth toward or away from the end of the pointer will tell you which way the sprocket needs to move to be centered.

You can get away with a small amount of wobble, no more than 1/8th inch or so but try to get it as precise as possible. This takes time and patients but it can be done by tightening or loosening the bolts. Just don't leave any of them loose

Tom

I agree 100% and I have installed a BUNCH of rag joints.
All it takes is patience and a good pointer to get it perfect. Small blows with a soft hammer can help get it to move where YOU want it too.
I use a screw gun clutch to evenly tighten the bolts in stages. Usually cuts down on fumbling around and is MUCH faster once you get the hang of it.
I can do an average ragjoint install in about 15-20 minutes usually.
2door knows his stuff.

 

[Kioshk]

As a recovering OCD sufferer, I must say that rag-joint sprocket installation can really be torture if you over-think it. I have learned to be patient and not TOO exacting with my sprocket alignment. I hand-tighten the four bolts on the outside edges of the 4-hole/5-hole rag plates. This keeps all the crap in place, and I then fine-tune the center of the sprocket in relation to the hub using a flat-head screwdriver; wedging and rocking along their boundaries until the gap between them is close to even all around. After that, I install the remaining 5 bolts, hand-tighten, then I start ratcheting them gently in a circular fashion...every other bolt, this assures a reasonably well distributed load. I continue to do this until all bolts resist gentle ratcheting, and I leave it at that. I've never had any appreciable wobble problems. Keep in mind, there really isn't much you can do with a wobbly sprocket if it's properly installed except for flattening it in a press or bending it on a vice. Essentially, when installed correctly, the sprocket's plane will match the hub's. As a wise man once said: "And that's that.".

 

[2door]

Although I warn about the possibility of the center hole not being in the center, in all honesty I've only found two sprockets that were that way. They were as much as 1/4" out. Probably 90% or more kit sprockets will be drilled correctly. It was those two that made me adopt the pointer method as opposed to centering the hole on the hub.

Like many things in this hobby, there's more than one way of doing things. Just do what you're comfortable with, as long as it works.

Tom

 

[Kioshk]

Just do what you're comfortable with, as long as it works.

I used to tell my ex-wife this all the time.