Offset Counter Sprockets: Nose or No Nose

Hey all,

In my research for an offset counter sprocket (1976 KZ900-A4) with a ZX6RR rear swing arm, rim & Sprocket
that is a 520 width. Thanks to Steell, I have found a cross for a 530 rear sprocket. All was good, so I thought!

In contacting some of the sprocket manufacturers they only offer the 630 without noses. The 530 CC sprockets are available with noses.

Question, WTF is the nose for?
Assumption is for bearing support but not sure, is this correct?

I just don't see how this (nose version) would work...
any ideas out there?

Thanks,

Old Man Rock

Yep...the nose is for it to fit in the bearing support.If you don't run a bearing support (some don't on the street)then you don't need the sprocket with a nose. 5/8" over offset or more should run a bearing support just for the added strength although I have seen a dragbike running in the 8's without one, but most racers will tell you that is taking big chances on your trans.

And if you want to use the bearing support you have to get rid of the nicely shaped stock sprocket cover???

When I used to dragrace a 1979 Z1R about 10 years ago, I had a 5/8 offset sprocket and a outer support plate, but no bearing , I had a countershaft sprocket come off going through the traps at the big end of the track, going 140+, in my opinion you should never NOT run a bearing support, I could have been serioulsy hurt or killed when the chain rapped up around the rear wheel and sprocket!!

Yep
With a good rear tire and lots of traction a KZ frame wont take it.
You also need to change the upper rear motor mount. (The long bolt+spasers)
I RUINED a motor and trans that way. (pulled the countershaft out of the case)

XENU

After reading postings on the matter I decided to stay with an 1/2" offset to clear the frame. I just don't like the idea of weakening(heat/clamp/hammer) the frame due to the 5/8" length.

Mill the rear wheel hub down and go with a 170mm vs.180mm tire if required.

As for the bearing support, I don;t think I'll be needing it for I just don't see my old ass going 140mph :woohoo: for may cause me to crap my pants...lol!

Thanks for the reply guys,

Old Man Rock

FastKaw1 wrote:

Yep
With a good rear tire and lots of traction a KZ frame wont take it.
You also need to change the upper rear motor mount. (The long bolt+spasers)
...
XENU

What do you "do" at the rear motor mount?
-KR

quote]

What do you "do" at the rear motor mount?
-KR[/quote]

Build/buy one.
It's a solid aprx. 5/8 bar stock with tabs welded to the bar for the mount.
Bar is then drilled on each end. gut to fit in-between the frame were the old
OEM mount went and then bolted from the out side in.
Hope I explained that well enough?

That type of mount is a must for large tire
traction. It keeps the motor from torquing in the frame.
I made several about 15yr. ago, worked quite well. I may still have a couple
in a box some were. If you need one. I used to have mounts, oil gates, an windage trays
that I would sell at the track. Help out the cost of entry fees. I know I have some.
Finding them, now thats different story.

XENU

Yes, that clears it up. Email sent.
-KR