Ducati Monster Forum

Moto Board => Tech => Topic started by: junior varsity on June 23, 2011, 01:59:47 PM

Title: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 01:59:47 PM
I'm looking for an offset front sprocket - 520 pitch, 14 tooth, plate & two-bolt fastening style, with offset to move teeth further out laterally from shaft...

Not sure where to begin looking really, any ideas?
Title: Re: Offset Front Sprocket (In Search of...)
Post by: Speeddog on June 23, 2011, 02:55:16 PM
How far?
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 03:12:12 PM
It looks just like this little guy:

(https://lh6.googleusercontent.com/-4yVtjOjZOl4/TgO56XYB-HI/AAAAAAAAHNQ/pAc4nTSrDUw/s800/Offset%252520Sprocket.jpg)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 03:13:10 PM
which should be suspiciously familiar as belonging to this kit

(http://www.tpr-racing.nl/pics/fe039.jpg)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: DarkStaR on June 23, 2011, 03:14:08 PM
Machining the area where the plate mounts should give more offset, but would suck to do every time you have to replace the sprockets.

EDIT: I typed too slow...
Title: Re: Offset Front Sprocket (In Search of...)
Post by: stopintime on June 23, 2011, 03:14:57 PM
Buy the kit  ;D
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 03:17:25 PM
i've got everything but the front sprocket...
Title: Re: Offset Front Sprocket (In Search of...)
Post by: stopintime on June 23, 2011, 03:21:55 PM
Quote from: j v on June 23, 2011, 03:17:25 PM
i've got everything but the front sprocket...

Like I said - buy the kit  8) The other parts will be spares....

Tell us about the swinger, please
Title: Re: Offset Front Sprocket (In Search of...)
Post by: Ddan on June 23, 2011, 04:03:43 PM
Check with Chris Kelly, the front sprocket for a '00-'01 M900 is offset, it might work for you
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 04:20:22 PM
Interesting... Will do.


Quote from: stopintime on June 23, 2011, 03:21:55 PM
Tell us about the swinger, please

Not much to share I fear - its a Febur unit, replaces the rocker and hoop with a different billet rocker and ride height rod, uses small-axle rear wheel (916/748, Hyper, 848, S*R, etc).  Its black.   It may or may not be a direct fit.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 04:26:35 PM
Quote from: Dan on June 23, 2011, 04:03:43 PM
Check with Chris Kelly, the front sprocket for a '00-'01 M900 is offset, it might work for you

I will have to contact him, the ones pictures are 'offset' the wrong way. I need one that is "dished" for lack of a better word.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: ducpainter on June 23, 2011, 04:30:09 PM
Quote from: j v on June 23, 2011, 04:26:35 PM
I will have to contact him, the ones pictures are 'offset' the wrong way. I need one that is "dished" for lack of a better word.
Like Speeddog asked...

how far?
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 04:35:59 PM
two smidges, one skoatch.   got to figure out a good way to measure this. (ideas?)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: ducpainter on June 23, 2011, 04:39:14 PM
Quote from: j v on June 23, 2011, 04:35:59 PM
two smidges, one skoatch.   got to figure out a good way to measure this. (ideas?)
Install the swinger and a standard front sprocket and use a straight edge to measure.

Then have a sprocket machined with the dish. ;)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: stopintime on June 23, 2011, 04:39:53 PM
Profi Laser CAT chain alignment tool short demo (http://www.youtube.com/watch?v=9NC8p5hbJSA#normal)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 04:47:37 PM
not clear on how to measure outward to find the needed offset distance since there's no common reference point...

and I don't own no fancy lasers that aren't already attached to zompocolypse rifles.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: ducpainter on June 23, 2011, 04:53:53 PM
Quote from: j v on June 23, 2011, 04:47:37 PM
not clear on how to measure outward to find the needed offset distance since there's no common reference point...

and I don't own no fancy lasers that aren't already attached to zompocolypse rifles.
A straight edge from the rear sprocket to the standard front...

measure the distance it misses by. ;)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: stopintime on June 23, 2011, 05:00:57 PM
Quote from: j v on June 23, 2011, 04:47:37 PM

and I don't own no fancy lasers that aren't already attached to zompocolypse rifles.

They are quite affordable. Batteries ARE included ;D
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 05:29:06 PM
Quote from: ducpainter on June 23, 2011, 04:53:53 PM
A straight edge from the rear sprocket to the standard front...

measure the distance it misses by. ;)

guess my warped ruler is not going to be helpful. Time to invest in a quality steel rule more than a foot long.

I suppose the rear sprocket will also need to be bolted to the sprocket carrier, cush drives installed, and everything tightened up correctly... drat. I don't have cush drives yet.   Had thought about waiting until i knew whether or not the rear sprocket was the same as a 748/996 or also "unique". hmm....Can't exactly walk down the street asking folks if they'll sell me some cush either...
Title: Re: Offset Front Sprocket (In Search of...)
Post by: ducpainter on June 23, 2011, 05:46:38 PM
Quote from: j v on June 23, 2011, 05:29:06 PM
guess my warped ruler is not going to be helpful. Time to invest in a quality steel rule more than a foot long.

I suppose the rear sprocket will also need to be bolted to the sprocket carrier, cush drives installed, and everything tightened up correctly... drat. I don't have cush drives yet.   Had thought about waiting until i knew whether or not the rear sprocket was the same as a 748/996 or also "unique". hmm....Can't exactly walk down the street asking folks if they'll sell me some cush either...
Yup...all that...and the swinger needs to be shimmed to align the front and rear wheels too.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 23, 2011, 06:02:02 PM
sumpregnant dog. that means the motor needs to go into the frame. and the triples need to go into the frame. and the forks need to go into the triples. and the front wheel needs to go onto the forks. and and and and and... *forehead smack*
Title: Re: Offset Front Sprocket (In Search of...)
Post by: Speeddog on June 23, 2011, 07:33:04 PM
Quote from: j v on June 23, 2011, 06:02:02 PM
sumpregnant dog. that means the motor needs to go into the frame. and the triples need to go into the frame. and the forks need to go into the triples. and the front wheel needs to go onto the forks. and and and and and... *forehead smack*

Welcome to custom motos.  [bang]

Give Jeff at Monsterparts a call, I think his wife has an M750 with the Febur kit on it.
You may be able to find the original source that way.

Failing that, a pocket could be cut in a standard sprocket.
But sprockets are generally case-hardened, so the first .060" or so of material doesn't come off easy.

----------
edited for bad memory
Title: Re: Offset Front Sprocket (In Search of...)
Post by: Desmo Demon on June 24, 2011, 08:14:44 PM
Quote from: j v on June 23, 2011, 03:12:12 PM
It looks just like this little guy:

(https://lh6.googleusercontent.com/-4yVtjOjZOl4/TgO56XYB-HI/AAAAAAAAHNQ/pAc4nTSrDUw/s800/Offset%252520Sprocket.jpg)
Looks like the ones that are on the '87-'88 Ducati Paso 750, but they are only offset by 2-3 mm. A friend in Germany had one made with a custom offset, but it cost him about $150.

This is the only picture I seem to be able to find of one, so far...
(http://i32.photobucket.com/albums/d32/Kramer_Krazy/Paso_sprocket.jpg)

And this is a diagram of one. I believe this is from somewhere on the JT Sprockets website...
(http://www.jtsprockets.com/fileadmin/Code/images/large/jtf495.jpg)



Edit - OK. I just found a picture that my friend had posted on another forum. The sprocket on the left is the stock Paso 750 sprocket, and the one on the right is the one that he had made for a custom application for about $150.

(http://i241.photobucket.com/albums/ff283/paso750/DSCF1970.jpg)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 26, 2011, 10:52:42 AM
That JT might just do the trick.  For $22-25 its worth experimenting...
Title: Re: Offset Front Sprocket (In Search of...)
Post by: stopintime on June 26, 2011, 11:22:14 AM
I'm having a 4-5mm allignment problem myself.... (Wieres carrier and sprocket)

What decides the offset - where the plate sits or the depth of the sprocket?
Title: Re: Offset Front Sprocket (In Search of...)
Post by: DarkStaR on June 26, 2011, 12:16:23 PM
Quote from: stopintime on June 26, 2011, 11:22:14 AM
I'm having a 4-5mm allignment problem myself.... (Wieres carrier and sprocket)

What decides the offset - where the plate sits or the depth of the sprocket?

The  (surface) plane in which the plate mounts in relation to the teeth.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 26, 2011, 12:37:20 PM
What carrier is it?  Is there a different output shaft length on the superbikes than on the Monsters? (if so, I'm so very close to already splitting the cases, if one could simply swap the trans for a SBK set to get the proper length and avoid needing oddball sprockets in the future, I'd do it. I've already got all the gears on the LH and RH sides removed...  and they've been that way for some time - I keep thinking ProItalia surely has to have my bearings and such in stock for the driven gear, but apparently I'm a very low priority...)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: DarkStaR on June 26, 2011, 12:48:28 PM
Will the BIG nut (1KDS) output shaft fit? Seems easier to shim out a sprocket with that set-up.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 26, 2011, 12:54:03 PM
I'm not in the garage currently, but iirc the output shaft is not threaded on this bike, but I will look at the 02 900 trans shaft I have to see what its configuration is (sure would be neat if I already had it...)
Title: Re: Offset Front Sprocket (In Search of...)
Post by: stopintime on June 26, 2011, 03:18:17 PM
Quote from: stopintime on June 26, 2011, 11:22:14 AM
I'm having a 4-5mm allignment problem myself.... (Wieres carrier and sprocket)

What decides the offset - where the plate sits or the depth of the sprocket?

Forget about it - I just made a fool of myself with the laser tool. The beam exits 5mm from the surface of the rear sprocket, of course it's going to hit the front sprocket 5mm left offset.

A shame really - it would have been cool to fix this with a Paso sprocket and some work on the rear set-up.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: Düb Lüv on June 26, 2011, 07:07:42 PM
Quote from: j v on June 23, 2011, 03:17:25 PM
i've got everything but the front sprocket...

so you're the one who bought that on ebay. i saw your name when you asked the guy a question about it. good score.
Title: Re: Offset Front Sprocket (In Search of...)
Post by: junior varsity on June 26, 2011, 08:21:39 PM
indeed.  only good if i can make it work though.