Author Topic: norton gearbox  (Read 6998 times)

Offline john mepstead

  • Advanced Member
  • ***
  • Posts: 3
  • Karma: +0/-0
    • View Profile
    • Email
norton gearbox
« on: November 25, 2014, 11:04:30 AM »
can someone help identify the year  and ratios of a norton gearbox   STAMPED G102 thanks

Offline R

  • Advanced Member
  • ***
  • Posts: 1475
  • Karma: +26/-10
    • View Profile
Re: norton gearbox
« Reply #1 on: November 25, 2014, 10:16:07 PM »
Norton 4 speed laydown boxes circa 1949 to somewhere around 1952 or 53 seem to be where G102's came from.
In theory they would been fitted to Norton dommie twins.

But like about all Norton boxes, will accept gears and shafts from earlier and later boxes,
and can be made to fit and suit everything from sidevalves to manx racers.

Opening the box and counting the teeth is the only sure way to know what gears/ratios are fitted inside.
Or twirling the clutch shaft, and counting how many turns the output shaft turns in response.
Top gear is of course 1:1 ratio.
Stock, it would have been Nortons standard gearset for twins, neither close ratio nor wide ratio.
Can supply gear teeth counts and ratio sets, if any need for them.
Cheers.

Offline john mepstead

  • Advanced Member
  • ***
  • Posts: 3
  • Karma: +0/-0
    • View Profile
    • Email
Re: norton gearbox
« Reply #2 on: November 26, 2014, 04:37:37 AM »
thanks for the prompt reply,its fitted to an   11m2 frame ,which I believe is 30m ,1954,cheers johnm

Offline R

  • Advanced Member
  • ***
  • Posts: 1475
  • Karma: +26/-10
    • View Profile
Re: norton gearbox
« Reply #3 on: November 26, 2014, 04:46:24 AM »
Those numbers would make it a manx, so you wouldn't expect it to have a kickstarter.
If it has, its probably a dommie box substituted to give wider more useful ratios, maybe for road use ?

If you plan to use it, it would be wise to look inside at the condition.
And count the teeth while doing so.
Norton gear pairs teeth count always sum to 42, or thereabouts.

Offline john mepstead

  • Advanced Member
  • ***
  • Posts: 3
  • Karma: +0/-0
    • View Profile
    • Email
Re: norton gearbox
« Reply #4 on: November 27, 2014, 12:16:51 AM »
thanks for info ,much appreciated,im in melb aust.

Offline john.k

  • Advanced Member
  • ***
  • Posts: 586
  • Karma: +4/-0
    • View Profile
    • Email
Re: norton gearbox
« Reply #5 on: November 28, 2014, 11:12:09 AM »
On the subject of laydown boxes,can anyone tell me if gear pairs from an AMC box can be fitted directly to a laydown ,specifically first, second and third gear pairs.I know the ratios will be different to some extent,but that doesnt matter.I was in the NOC,and no one on the forum would answer this question,instead posting pretty color pictures of how gearboxes work.I dont want to spend money on stuff that doesnt fit, and postage.Regards John.

Offline L.A.B.

  • Advanced Member
  • ***
  • Posts: 1529
  • Karma: +32/-4
    • View Profile
Re: norton gearbox
« Reply #6 on: November 28, 2014, 11:19:30 AM »
On the subject of laydown boxes,can anyone tell me if gear pairs from an AMC box can be fitted directly to a laydown ,specifically first, second and third gear pairs.I know the ratios will be different to some extent,but that doesnt matter.I was in the NOC,and no one on the forum would answer this question,instead posting pretty color pictures of how gearboxes work.I dont want to spend money on stuff that doesnt fit, and postage.Regards John.

Give Mick Hemmings a call: http://www.mickhemmings.com/
L.A.B.