Author Topic: Norton AMC gearbox sprocket  (Read 6221 times)

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Offline Rosco86

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Norton AMC gearbox sprocket
« on: March 11, 2014, 07:11:25 pm »
Have had an amc/Norton/Matchless gearbox refurbished internally. The final drive exterior sprocket was a 16 tooth. Wondering if I should buy a new norton type sprocket which has the locking ring for the nut. They have 2 drilled holes into which a screw is inserted to ensure the nut does not come loose. Unfortunately the smallest Norton type seem to be 17 teeth which will change the final drive ratio but can compensate buy running a smaller engine sprocket by a tooth. I like the safety feature but wonder if it's really a non issue as the nut is reverse thread.

 Buy a new 16 and use a little loctite or go to the 17 with locking ring? What have others done in the past and present?
Rosco86

Offline JAP 454

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Re: Norton AMC gearbox sprocket
« Reply #1 on: March 11, 2014, 08:54:17 pm »
Langy, in his book, recommends going up to an 18 countershaft, and compensating with the rear sprocket, I always ran 16, for no real reason, except that was what was fitted, I'd go the 16 and loctite route.
Foss

Offline Rosco86

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Re: Norton AMC gearbox sprocket
« Reply #2 on: March 11, 2014, 09:07:57 pm »
Hey Foss spent a fortune and a heap of time setting up a braked back wheel in my long tracker , very little clearance on the chain side on my godden. Even had John Titman on the tools counter sinking the sprocket bolts on the rear sprocket he made for it. So a new 16 tooth and some loctite is looking like the go. Thanks for the input.
Rosco86

Offline matcho mick

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Re: Norton AMC gearbox sprocket
« Reply #3 on: March 11, 2014, 11:38:57 pm »
did you do the common mod on the layshaft,(under sleeve gear end) swap ballbearing for the roller bearing,slightly tapered from memory??,NTN801C or something like that,stops the shafts seperating under load, :P
work,the curse of the racing class!!
if a hammer dosn't fix it,you have a electrical problem!!

Offline Rosco86

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Re: Norton AMC gearbox sprocket
« Reply #4 on: March 12, 2014, 07:18:56 pm »
Wasn't aware of that before I started. Next on the bench is either a 4B JAP or 2v Jawa in a Hagon frame. Have the 2 motors and can't decide on which to put in the speedway farme and which in the hagon. JAP motor is a biggun that Ron Bergmier used in his dirt track sidecar. Will look to do that mod on that one

Offline SlideRulz

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Re: Norton AMC gearbox sprocket
« Reply #5 on: March 12, 2014, 08:35:59 pm »
G'day Rosco, my choice would be to put the JAP in the Hagon and the Jawa in the Speedway frame.
JAP's hung in there a lot longer on DT, they both need diff engine plates though.

Offline JAP 454

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Re: Norton AMC gearbox sprocket
« Reply #6 on: March 12, 2014, 09:39:36 pm »
G'day Rosco, my choice would be to put the JAP in the Hagon and the Jawa in the Speedway frame.
JAP's hung in there a lot longer on DT, they both need diff engine plates though.

Shit yeah Rosco, put the JAP in the Hagon, much easier and exciting to ride on DT than the JAWA, in my opinion, I'm not biased, much !!  specially if it's a ( ahem ) biggun !!, but then the class is 263cc and over these days !!.
Be great to see whatever way ya go!!
Foss

Offline Rosco86

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Re: Norton AMC gearbox sprocket
« Reply #7 on: March 13, 2014, 12:51:36 am »
Not too sure of the motor size but it's running but has about an inch spacer under the barrell. Have it sitting in the frame now just need to look at the rear tank mount as the rocker cover sits right on it. Funnily I rebuilt a hagon jap for a Steven Ireland back in the day as he was looking for a specific short circuit bike. It actually seemed quicker than my cole Elstar. He sold the thing before he had even had a ride and didn't offer me right of first refusal. Probably more miffed now than back then. Sold the Cole back to Donny Stafford in exchange for a mk1 godden weslake long tracker. Would have been good to keep the Cole in hindsight but it never seemed to work for me. The godden is pretty close to finished except for some cables, chains and setting up a magic box.

Offline pancho

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Re: Norton AMC gearbox sprocket
« Reply #8 on: March 13, 2014, 04:31:27 pm »
  From past experience I would keep away from a smaller Engine sprocket, It will put extra load on the gearbox and clutch etc. and will soon find any weaknesses there.
cheers.
dont follow me i'm probably off line!

Offline matcho mick

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Re: Norton AMC gearbox sprocket
« Reply #9 on: March 13, 2014, 04:59:26 pm »
did you do the common mod on the layshaft,(under sleeve gear end) swap ballbearing for the roller bearing,slightly tapered from memory??,NTN801C or something like that,stops the shafts seperating under load, :P
errr,close  ::),NJ203E ,yep agree pancho,to the point of bigger engine sprocket too,to spin the gearbox faster ,takes all the torque loads off the cogs/shafts,go  big on the rear wheels the go,chains last longer too,not gettting pulled round pissy little 16t arc, 8), :P
work,the curse of the racing class!!
if a hammer dosn't fix it,you have a electrical problem!!

Offline Rosco86

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Re: Norton AMC gearbox sprocket
« Reply #10 on: March 13, 2014, 06:55:54 pm »
Thanks Mick, just goes to show an old dog can learn a new trick! Still need to catchup with you for  a tank and seat/guard for my ccm Trackmaster flat tracker . Really like the look of the long slim Trackmaster tank but want to ensure the tank/seat have a good line to them. Will take some measurements and a photo and send them to you for some advice.
Rosco 86

Offline jimg1au

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Re: Norton AMC gearbox sprocket
« Reply #11 on: March 13, 2014, 07:20:03 pm »
thats what micks making for me a trackmaster style tank for my triumph pre65 racer
jim
all this slider talk remindes me to get back to mine on hold again working on my race bikes insted

Offline Rosco86

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Re: Norton AMC gearbox sprocket
« Reply #12 on: March 13, 2014, 09:36:21 pm »
Hey Jim
Haven't had a slide since I stopped riding in 82. Got involved in VMX at the nats in 92 but finished VMX in 2010 when I had to have the lower back fused. Sold all my mx gear except my garage queens of a 73ccm and an original 63 triumph Metisse. Have got the spirit back and I'm really keen to finish the wessie godden and also the ccm Trackmaster. Very keen to have a ride myself and also setting up some things for my 22 year old son. He left dirt track and mx at 14 to concentrate on swimming. Has run 4th the at the Aussie champs last 3 years in the 50 back. A 3rd in the old days would have seen him on the Commonwealth Games team but with all the sport cutbacks after the last Olympics they are only going to take 1 and 2 in the 100 and 200 back . If doesn't make the team he has a couple of swim meets in the USA and UK before retiring. He'll enjoy being a novice and in a field that will hopefully be friendly and helpful. Won't mind having him back at the bikes cos he loves them but won't deny him any chance in the pool. He actually enjoys polishing the nickel and chrome! Certainly not going to dampen that enthusiasm. Hope to catchup with yourself,Foss, Pancho , Sliderulz and all the other like minded souls.
Rosco86