Where might I find a sprocket like this

[fredintoon]

Struggling to comprehend

Hi guys,
this string is like only reading the middle 3 chapters of a detective novel, WTF is going on?
About the original photo:-
What bike is it?
11 tooth sprocket won't last very long, I'd put 15T as the absolute minimum for reasonable longevity.
That sprocket looks to be held on with a twist of wire???
About the bearing sketch:-
Which side is the sprocket on?
As shown, the retaining ring looks to be resting on the side of the housing.
If the retaining ring is held on by anything, it ain't shown.
Presuming the retaining ring IS holding the bearing in place by means not shown the shaft cerclip (sic) is not needed because the larger OD of the shaft between the bearings stops it moving.
The circlip groove does provide a neat weak point for the shaft to snap off at though.

[79XS11F]

Hi guys,
this string is like only reading the middle 3 chapters of a detective novel, WTF is going on?
About the original photo:-
What bike is it?
11 tooth sprocket won't last very long, I'd put 15T as the absolute minimum for reasonable longevity.
That sprocket looks to be held on with a twist of wire???
About the bearing sketch:-
Which side is the sprocket on?
As shown, the retaining ring looks to be resting on the side of the housing.
If the retaining ring is held on by anything, it ain't shown.
Presuming the retaining ring IS holding the bearing in place by means not shown the shaft cerclip (sic) is not needed because the larger OD of the shaft between the bearings stops it moving.
The circlip groove does provide a neat weak point for the shaft to snap off at though.

The sprocket goes on the left hand side in the photo and the retaining ring on the back side is held to the housing with 3 screws.
The photo with the twisted wire holding the sprocket in place is what the PO was doing. A circlip will be used at that location on my bike. The bike is an xs11 and the unit is a chain drive conversion.
Rob.

[fredintoon]

The sprocket goes on the left hand side in the photo and the retaining ring on the back side is held to the housing with 3 screws.
The photo with the twisted wire holding the sprocket in place is what the PO was doing. A circlip will be used at that location on my bike. The bike is an xs11 and the unit is a chain drive conversion.
Rob.

Hi Rob,
thanks for the explanation. The old "fasteners not shown for clarity" trick, eh?
I still have concerns that an 11T sprocket just won't stand up. 11T as a jockey sprocket on a corn binder, maybe, but not on a motorcycle.
What's the biggest sprocket that will go on there without the chain chewing into the casting?
Have you considered going to a 1/2" duplex chain to get more teeth in a smaller circle and still keep the strength up?
I used to see big bike duplex chain adapter kits for sale in accessory shops back in the '70s.

[xschop]

sprocketus maximus

A 14T will go on with a light skimming of the case area where the halves meet. I believe a 15T would go on with about 3mm case skimming and I have seen the area where it needs to be done and It will NOT affect the case strength in that location. It is actually quite thick there.
The Housing I designed mimicks the Factory Middle drive housing and uses a modified XS11 middle shaft and is locked in just like the factory housing. I can honestly say that I have checked 6-7 different factory empty XS11 middle drive housings with locating micrometers/dials and they are off concentrically by more than 0.015 on some( I think made a comment about Mr. Miyagi hittin' the Sake at the factory). I bored the billet all the way thru and even machined 2 opposite holding jigs to ensure the front and aft bearing were DEAD-ON concentrically.
There is a MAJOR problem with a home-made housing that Rob pointed out. If the exact dimensions were not transcribed off a factory middle drive housing. The bearings more than likely are not axially concentric and will wear out bearings, sprockets and chains very quickly. AND MOST IMPORTANTLY THE MIDDLE DRIVE GEAR WILL ESPECIALLY WEAR OUT IT'S SPLINES AND YOU ARE SPLITTING CASES!

[xschop]

The 13T 530 sprocket I have on at the moment has over 2500 miles now and still looks new. I am running a 530 O-ring chain from a ZX6 that I got from ebay for 58 Bucks. You can calc. your chain size on Sprocket Specialists and then hunt down a match form another bike like I did to get the best deal. You calc. the front and rear sprocket size with the sprocket C-2-C's

[79XS11F]

A 14T will go on with a light skimming of the case area where the halves meet. I believe a 15T would go on with about 3mm case skimming and I have seen the area where it needs to be done and It will NOT affect the case strength in that location. It is actually quite thick there.
The Housing I designed mimicks the Factory Middle drive housing and uses a modified XS11 middle shaft and is locked in just like the factory housing. I can honestly say that I have checked 6-7 different factory empty XS11 middle drive housings with locating micrometers/dials and they are off concentrically by more than 0.015 on some( I think made a comment about Mr. Miyagi hittin' the Sake at the factory). I bored the billet all the way thru and even machined 2 opposite holding jigs to ensure the front and aft bearing were DEAD-ON concentrically.
There is a MAJOR problem with a home-made housing that Rob pointed out. If the exact dimensions were not transcribed off a factory middle drive housing. The bearings more than likely are not axially concentric and will wear out bearings, sprockets and chains very quickly. AND MOST IMPORTANTLY THE MIDDLE DRIVE GEAR WILL ESPECIALLY WEAR OUT IT'S SPLINES AND YOU ARE SPLITTING CASES!

I think I will be going with the 12 T or 13 at most. Trying to stay at the 3:1 ratio. I did a dry run set up of the unit a few minutes ago. It plugs into the output shaft nicely and the housing sits right into the opening in the cases. The locating dowel also fit with just a little bit of pressure. The hollow cavity of the cases behind the unit will become the oil reservoir for the bearings. I don't have my camera here but will take some photos of the unit before it is fully installed. It will be interesting to how this unit does once installed and in use. Once the bike is together I will be keeping an eye on this unit.
Rob

[79XS11F]

So here are a few photos of the chain drive units. I installed it a little while ago and it went on pretty smoothly. There is not detectable free play at the output shaft. I will have to reroute the timing cover wiring to get it out of the way of the chain and find a different place to ground the engine but both those jobs should be easy enough.
So far as a search for a sprocket goes I had no luck at the bike shop other then to confirm that a 530 chain is a match for the rear sprocket. They had only one 14 notch sprocket but the teeth were not pointed enough to slip onto the output shaft. So now I am not sure how to get a sprocket. Perhaps I can send some information off to a sprocket manufacturer and see what they have to say.
SO what information would they need?
Rob

[xschop]

Spline pattern

You have to measure the OD of the splines and count the splines. Also yo need the spline valleys measurement and the peaks width.....
I don't see how that sprocket stays on safely.

[79XS11F]

You have to measure the OD of the splines and count the splines. Also yo need the spline valleys measurement and the peaks width.....
I don't see how that sprocket stays on safely.

Thanks chop. The sprocket is held on with a circlip. I will guess that a washer would go between the sprocket and the circlip but I will not know until I get a sprocket and put it on there. I'm going to have to make real sure that the front and rear sprockets are lined up PERFECTLY with only a circlip holding that puppy on. I also still have to figure out how the chain tensioner mounts to the frame and how it's suppose to work.
Rob

[xschop]

Chain tensioner?

You've got me on that one.
If you decide not to go with the housing I designed. I will take it off your hands or point you in the direction of 2 other people that want one right now. I just built a wider custom one for an XS850.

[xschop]

JT Sprockets Website has all the dimensions

http://www.jtsprockets.com/40.0.html

[79XS11F]

You've got me on that one.
If you decide not to go with the housing I designed. I will take it off your hands or point you in the direction of 2 other people that want one right now. I just built a wider custom one for an XS850.

Hey Chop, I will be keeping both of them until I make a final decision but one of the 2 units will be sold in the end. I also get many requests for the units on my "my space" site. I opted to try this unit because other then the missing sprocket it is as close to plug and play as anyone could expect. I would however be kicking myself in the backside for weeks if I were to sell the unit and swing arm conversion kit you made and then have this unit fail soon after. I also have the ZXR11 swing arm so if I do find myself selling one of the 2 units it will be all or nothing deal. I also may just decide that I want a BIG FAT rear tire which this unit will not allow for.
Rob

[xschop]

You will need at least a 170-180 with your setup.....
Plan ahead for that and raising your footpegs

[79XS11F]

Well I had no luck whatsoever finding a counter shaft sprocket for this conversion unit. This is why there has been no real advancement with the project. Anyway I managed to contact the lad in South Africa who I bough the unit from and the BAD news is... It is a custom part that I will not find off the shelf. The GOOD news is, he has 4 of them and will ship them to me 2 are new 2 are used.
Once those sprockets arrive, the project will move forward quickly
Rob