Offset countershaft sprocket.

fj johnnie · April 21, 2013, 08:31:26 AM

I have an FJ with a 2002 FZ1 rear swing arm conversion. The counter shaft sprocket is an offset type that is a quarter inch offset to the factory sprocket. Can anyone tell me how to source a new good quality replacement? The sprocket on it is fine but I am wanting to change from 17 to 18 teeth. It had the 17/44 combo which pulled like a freight train but was spinning at 4100 rpm at 100k, 60 mph. The 44 was replaced with a 39.

movenon · April 21, 2013, 09:17:24 AM

A question. During the conversion did you change the output shaft to an XJR unit? 1/4" offset over stock is quiet a bit.

I have a GSXR conversion and used a modified Honda VF 1000 18 tooth front sprocket. The VF 1000 sprocket you will have to grind down the outboard raised boss so the retaining nut will fit back on. A Honda 929RR has the correct spines also but I didn't see one any larger than 17T and be aware it is wider. Out of memory the VF sprocket after the mod off set was around 2mm.

The stock FJ sprocket is 10.8mm overall width

VF 1000 Sprocket 14.5 mm

CBR 929 RR 16.7mm

Probably doesn't help much but that what I know about the front sprocket. I am sure some else that has done the FZ1 conversion will show up shortly.

Here is the JT sprocket site and the spec's on the VF unit. You can check out the sprocket dimensions / spline spec's etc here and compair it to the FJ spec's http://www.jtsprockets.com/catalogue/model/4845

Have a good one !
George

fj johnnie · April 21, 2013, 02:58:16 PM

No my bike does not have the longer XJR countershaft sprocket. I realize this would be the best solution! I thank you for your help. I don't quite understand exactly what you mean describing the sprocket you are using. I am sure if I saw one it would be clear to me. The existing sprocket is difficult to bolt onto the bike as the socket will not fit into the sprocket. I had to grind one down to fit inside. Also it makes it very difficult to tighten with the bolt with the ears of the lock washer interfering. I hope that once I find an 18 tooth sprocket similar to the one I have now the socket will fir inside it. Making it much easier to tighten properly. I will google the sprockets you told me about to get a clearer picture. ( pardon the pun).KOkaloo John

fj johnnie · April 21, 2013, 05:17:55 PM

PBI Sprockets actually has listed on their website a quarter inch off set sprocket available in various tooth counts for around 30 bucks. There are a number of bikes that they fit and the FJ 1200 is one of them. The PO gave me this info. Don't know if it helps any one else out there . Seems like a simple thing to order.

movenon · April 21, 2013, 06:01:31 PM

Quote from: fj johnnie on April 21, 2013, 05:17:55 PM
PBI Sprockets actually has listed on their website a quarter inch off set sprocket available in various tooth counts for around 30 bucks. There are a number of bikes that they fit and the FJ 1200 is one of them. The PO gave me this info. Don't know if it helps any one else out there . Seems like a simple thing to order.

The PBI ones look good if you need that much offset. The price is right. If your socket face is ground down you should be able to get a good enough bite on the nut. I think the TQ is only around 60 ft lbs with out looking the exact number up, anyhow 60 - 70 ft pounds.
Good information on the PBI I bookmarked it.
Cheers George

fj johnnie · April 21, 2013, 07:17:25 PM

George the sprocket is the same width as stock at the attachment point. Because of this it does not need to be ground down. Unfortunately with a 17 tooth sprocket a socket will not fit inside the chamfered out area. Am I making any sense? I hope the 18 tooth sprocket is large enough in diameter to allow a socket to go inside it. I took a socket and ground it down until it fit inside, for the 17 tooth, however the hole was so small that the lock washer needed to be made smaller as well. Meaning the "ears" where ground down slightly to fit inside the opening. John

movenon · April 21, 2013, 08:24:31 PM

I think I am following you OK

. Hoping someone that has done this will show up .

The grinding down was in reference to the 36mm socket. Grinding down the face (the inside beveled area at the entrance of the socket) letting the socket get a full bite on the nut. I see what you had to do in reducing the socket outside circumference. I had to do the same in reference to a BMW RT 100 swingarm. Made it a large thin wall.

I would guess PBI machines all the center's the same. You might sent them an e mail and ask. Or they might have there own lock washer.
Will it clear the cover ? What you are going through is the nature of modifications, I seem to live in that world myself.

George

fj1289 · April 21, 2013, 08:58:23 PM

fj johnnie,

On the dragbike I used a 1/4 inch offset sprocket from trac dynamics for an R1. Too expensive in my opinion at $70, but the good news is there are no clearance issues with the countershaft nut. Also only available in 16 and 17 teeth (wasn't an issue for my application!)

Here's a link so you can see the sprocket. Looks like the inside shoulder on the PBI sprocket could be machined to match the shoulder on the trac dynamics sprocket to give needed socket clearance. http://tracstore.myshopify.com/collections/parts-and-accessories-1/products/off-set-front-sprockets

Does a thin wall socket fit the PBI sprocket?

Chris W

fj johnnie · April 21, 2013, 09:21:36 PM

George I have installed an XJR cover along with the corresponding clutch pushrod and shift shaft. It is 8mm wider and allows plenty of room for the off set sprocket. These parts where purchased from RPM ( who else?) . And yes that is exactly what I meant regarding the grinding. I cant talk without my hands helping.

fj johnnie · April 21, 2013, 09:26:22 PM

Chris I did see that they would custom make one for me. Does an R1 sprocket fit the FJ output shaft? It looks similar but.... Thanks for the input though. I realize now that an off set sprocket is more common than I thought. I will need to purchase one and provide some additional info once the sprocket has been ordered and installed, with regards to order number website etc. Thanks again for your help. John

fj1289 · April 21, 2013, 09:48:48 PM

John,
Yes, the R1 countershaft has the same spline pattern. The thickness of the sprocket also works with no issues (can't recall if the shoulder is thicker, thinner or the same) but do remember it fit noproblem.

Chris

Arnie · April 21, 2013, 10:04:09 PM

I'm wondering if you could drill the c/s nut and shaft and use a cotter of some sort instead of the lockwasher. Just a thought

Arnie

racerrad8 · April 21, 2013, 10:40:36 PM

I believe I can supply the sprocket you are looking for. I will research it tomorrow.

Randy - RPM

movenon · April 21, 2013, 11:17:29 PM

Quote from: fj johnnie on April 21, 2013, 09:21:36 PM
George I have installed an XJR cover along with the corresponding clutch pushrod and shift shaft. It is 8mm wider and allows plenty of room for the off set sprocket. These parts where purchased from RPM ( who else?) . And yes that is exactly what I meant regarding the grinding. I cant talk without my hands helping.

You telling me ! Half my family is Italian.............. RPM is great. Sounds like you are now making some headway.

George

fj johnnie · April 22, 2013, 04:47:03 PM

Yes I am George Thanks to both you and Chris. I did not know that an R1 sprocket would fit on an FJ. Perhaps the PBI unit is cheaper than the ones Chris is using. I wonder if the ones Chris is purchasing for the R1 are much better? The sprocket on this bike currently is of very good quality.
I had an FZ 750 with the threads pulled out of the shaft. I am hesitant to use something that I am not 100 % on. So the idea of a cotter pin set up would worry me. Also is the shaft not extremely difficult to drill? JOhn

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