QUESTION GEARBOX
I have a quadrant that we believe is from a Norton lay down gearbox.The quadrant is for use in a Summerfield six speed gearbox and the person assembling this box has found that the lay down quadrant causes a gear selection problem. That is why we are looking for a quadrant from a AMC gearbox.
ANSWER
I got a look at them and there is a difference, whilst the shape seems the same, (laydown was still in the shell so I could not compare 100%) the laydown one has wider teeth where they engage with the camplate. I would imagine fouling could occur. A new AMC style Quadrant would be £39.90 plus VAT and post.

QUESTION GEARBOX
Do you have gearbox sprockets for norton dolls head-box? I need the third gear sprockets first i think? plus some other parts, but if you have parts for dolls head or you know who has them please let me know. Thank you again.
ANSWER
Its a slightly difficult question as the gears are all to some ex-tent interchangeable except some of the earlier gearboxes had four dogs when on the later gears you would only find three. With a little work shortening the sleeve gear and mainshaft first an AMC cluster would fit the dolls head. As it stands at the moment we have not made any gears specifically for the Dolls head but I do intend to make some later in the year, lots of work to do but hopefully this year. Of course there is always a problem with the very old gears in that they could easily be changed over the years and not original. I can see what we have if you could describe the gear, ie where it fits and number of teeth and dogs. All though in fairness if its the four dog set up we would not have any at the moment.

QUESTION GEARBOX
Can you supply an 18 tooth tapered engine sprocket for a MANX engine?
ANSWER
Yes we have those, 18, 19, 20 or 21 teeth, pre featherbed with teeth in the middle and Featherbed with the teeth on the outside, typically the featherbed Manx had a splined sprocket and just the Inters used the taper but there is bound to be a bit of mix and match.

QUESTION GEARBOX
I put the new gears in a parts washer prior to starting to rebuild the gearbox and it seems that the protective coating had been holding the bronze bushes in place, but after washing it is apparent that they are a sliding fit in the gears. I can easily push them out with my fingers. With the original gears the bushes are in tight, is the sliding fit intentional? Is it something I should be concerned about? I don't think the bush in the sleeve gear is a sliding fit, but I didn't wash that because of the roller bearing in there.
ANSWER
The mainshaft second and layshaft third are designed as a floating bush and always have been but as you have found they often stick, the sleeve gear is a definite interference fit, the layshaft first would normally be interference but can vary and is much lighter than the sleeve gear.

QUESTION GEARBOX
Has anybody heard of fitting a Norton gearbox to an OHC Velocette engine? I have a couple of KSS Velo’s which oddly have had their gearbox external linkage stripped off. I have to try to select the gear with nothing more than an extended bolt out of the back of the gearbox. Both my ES2 and Model 7 have a bog standard selector direct to the gearbox type of mechanism which works day in day out. One plan is to fit a spare Norton box I have or try your dry clutch & belt conversion, but I thought I would see if you have any ideas first.
ANSWER
As it happens I have a Velocette, a 55 Venom and as it was nice and sunny for a change I took it for a little run out after work today and as I was sitting outside a nice country pub enjoying a pint of Wainrights I had a look at it. I have no idea what's inside, I have had it twenty years and hardly laid a spanner on it. I also have no idea how similar or otherwise it is to your model but looking at this one first thing I noticed was how narrow the gearbox bosses are, Norton is much wider but of course this will help to align it properly once you mill the shell bosses. The other major problem I noticed was the final drive sprocket appears to run outboard of the clutch so it would seem that you would have to mount the clutch on what on the Norton box is the sleeve gear, Mainshaft fourth, and the final drive sprocket on the mainshaft. It all seems a bit difficult but of course anything can be done with a little ingenuity. On the other hand of course you could replace the linkage on the box you have. Neither clutch nor gearbox on mine have ever given the slightest bother, (it was built by Geoff Dodkin) Of course the Norton box is very good and I do like the belt drives. So at the end of the day you pays your money and makes your choice, as they say.

QUESTION GEARBOX
Dear Sirs, Back in July 1982 you supplied me with some gears for a 4 speed Quaife Norton box and also kindly sent an exploded drawing of the box with part numbers. I now need parts and a drawing for a 5 speed Quaife Norton box and parts to follow. Can you help ?
ANSWER
Hello well that’s a while ago, and unfortunately whilst we can do complete four speed close ratio kits we do not have parts for the five, I never did much with them as there are several people already doing them, Summerfield engineering or Mick Hemmings are two that spring to mind. Any other gearbox or general Norton parts we should be able to help with.

QUESTION GEARBOX
I bought a close ratio gear cluster from you some time ago and fitted it to my own bike, I was sixes and sevens as to weather it suited me, so took it out to try the standard again, laziness got the better of me and with out thinking too much about it I left the sleeve gear from the CR cluster on board to save the extra effort required to remove it. It subsequently occurred to me that while, like, the standard sleeve gear it is 23 tooth, it, having to interact with a different size gear on the lay shaft, will be a different radius and pitch.
ANSWER
Hello, yes you are quite correct the close sleeve gear will have a different tooth profile, you will not have full tooth engagement and it will wear out or possibly break a tooth off but it would work for steady away use for a while. I prefer the close ratio but we have lots of twist and bendy roads, gently test it then make your mind up is all I could advise.

QUESTION TRANSMISION/GEARBOX
Can you supply a mainshaft for a norton laydown gearbox. The gearbox is in a norton dominator model 7.
ANSWER
Morning, thank you for your enquiry, yes I am sure we will be able to supply this part, we stock seven different Norton mainshafts, we can just work from part numbers but if it is convenient for you it would be good if you could quote the overall length, from the end of the shaft inside the gearbox to the end of the spline at the clutch end, not the very end of the shaft, just the spline there is a small nose after this which is not important and can vary slightly, quote us both if you can otherwise its not a problem we can work with part numbers but things changed/have subsequently been changed and if what you have works best stick to that spec.

QUESTION GEARBOX
Hi I am hoping you can help me again. I am running a 20 tooth rear gearbox sprocket against a standard box and final sprocket on my 74 Commando. At 100 kph I am pulling 4000 rpm and would like to drop these revs to around 3600 rpm. What toothed sprocket would I need to go up to to achieve this. Thanks again
ANSWER
Hello, that would be about 22 teeth you are looking for.

QUESTION GEARBOX/CLOSE RATIO
I am a sometime customer of yours now seeking gearbox parts. Its a Norton Box, NA series. It seems to have been set up for racing and has 5 speeds. However, I want to use it for the road with a kickstart mechanism. The layshaft 1st is 25 teeth and the mainshaft 1st 15 teeth. The layshaft gear is not cut to receive a kickstart pawl. Do you have a 25t layshaft 1st to accept a kickstart please? Or how do I proceed?
ANSWER
Well its an expensive bit of kit you have there but I will not be able to help, first you need to identify the make, several firms have produced 5 speed conversions over the years, it could be one of two quaife sets, a shaftliner, a summerfields, even some triumph conversions, have a look at the gears and see what numbers are on them, when you have them I may recognize them but I do not stock them, I concentrate on the four speeds, any more is a bit pointless on a Commando.