Simply put it was ALWAYS weak because of the design, there wasn`t much meat on it in places and hardening `may` mean it`ll be embrittled too and more prone to stress fractures. I had both a Lightning and a MkIV Spitfire, 66 model with twin GP carbs. The Spitfire broke it`s cam plate but I was pretty hard on it back then to be honest, it didn`t get an easy life.
I could not find any reference to a five speed cluster for the A65 on the Nova site. I would be really interested in how they fit a drum in place of the camplate. Even if the drum were offset from the fork guide rod it could only be about 1/2" diameter which would make for extremely steep and narrow tracks. Then the selection mechanism would have to completely change. The stock camplate was too soft which wore the points of the tracks and they had to add the stiffener plate on the backside to keep the tracks from spreading. They could have fixed that by making the camplate thicker and making the tracks blind if they had the tooling.
The cam plate is thicker than standard and heat treated, the selectors are also heat treated. As the dogs are back cut the gear keep themselves engaged thus taking the load off both the selectors and cam plate. The heat treatment has been developed over the years by PES who have years of experience in manufacturing gear clusters for their big bore motocross engines.
The original BSA system had straight cut dogs on their gears, which when loaded push back against the selectors (ever wondered why their blue when you strip the box down), which then needs the cam plate to hold them in position.
Dave, Nova mount the selector drum in a new bearing plate and it replaces all the selector parts except the foot lever, only the front of the drum seems supported. I expect it would work well as does the set up on John's cluster. I also expect the number of new bits would add expense to change a whole system that I doubt needs changing.
Nova retain the taper and key to mount the clutch. The ease of removing the splined hub which comes with John's cluster is a real improvement. It's good to have that hub new as many are bent by prying off causing clutch wobble or shafts and hubs are damaged in the taper from shearing keys, which damage the tapers and again promote clutch wobble and less grip of the taper.
I decided to join the forum after finding a renewed interest in British bikes. I`ve recently found and been reading through an old C11G workshop manual amongst my fathers stuff, Dad passed away in 2009 and it`s stuff I had meant to look at and deal with that`s re-surfaced from the loft. I`ve been reading a few magazines that have also rekindled my interest, so with a few bikes in my garage, none British, I`ve also been considering selling a couple to fund another A65. I would love another MkIV Spitfire, mine went to Robertsbridge Motorcycles when mortgage rates went through the roof! I`ve never regretted getting rid of any bike more than that one. I was up at 05:45 this morning, reading through threads on here, got the British bike bug bad again...........
Originally the post was about my 5 speed gear cluster for the A65, however as various people are posting information about the Nova cluster under various aliases.
I have below added the benefits and information on my BSA A65 5 Speed Gear Cluster, as mentioned earlier the first 12 cluster kits are all sold and I'm taking names of those interested with the view to having another batch manufactured, anyone interested can contact me via the Brit-Bike site or my contact details below.
Based on original gear cluster technology, this new gear cluster system is being manufactured for me by “Performance Engineering Services Ltd” http://www.ccm-britain.co.uk and has also been further enhanced to incorporate many of the design benefits gained by their experience in the world of international moto-cross with BSA large bore single cylinders engines.
Along with suitable spaced ratios of 1st 2.222:1, 2nd 1.597:1, 3rd 1.296:1, 4th 1.111:1 and 5th 1:1. Other benefits include: a) Splined mainshaft with a clutch center adapter to suit the BSA clutch. No longer will you need to worry about the key shearing or having to torque the clutch center nut up to 75 ft lbs. b) All meshing gear dogs are back cut for positive engagement, and no longer rely on the cam plate and selectors to maintain engagement. c) The kit includes a new bearing mounted back plate to support the final drive sprocket on both sides with bearings, while the final drive gear also runs on needle roller bearings. d) All spinning gears run on needle roller bearing, no longer are gears running on brass bushes.
Total cost per 5-speed cluster kit is 1850.00 GBP plus postage.
The 5-speed cluster kit is built to the same high quality as my A65 big bore Nikasil coated alloy barrel.
For further information contact John Hill on 07802 500325 or e-mail firstname.lastname@example.org
Well we now have three name down for a 5 speed gear cluster, more the better. Between Gavin Eisler's post in the "members Bike Projects" along with Mark Parkers comments I'll be surprised if there is any other new products get so publicly commented on, wart's and all.
I don't know what the Nova cluster costs as I've not seen it advertised any place with a price, they will charge what they feel they need to.
When I started the project it was to make a 5 speed cluster which could be swapped out for the old 4 speed with minimum work. Plus as listed a few posts above, incorporating upgrades developed by PES in their motocross engines. The Idea was to also try and keep the cost down to where people more people could afford the 5 speed cluster.
Its the same with my Alloy barrel, there made at a good price, I'm certainly not going to get rich on them.
You certainly will not get rich making parts for BSA cycles, Some times we do things just because we need to for our own satisfaction. A few years ago I commissioned a company in India to make steel replacement gas tanks to replace the fiberglass tanks. What I received was 10 sub standard tanks. I was trying to fill a need. Now they are selling this same garbage on eBay. Now I have found a young man here in the US who can make aluminum tanks. We'll see how things turn out this time.
I don't know what the warts are John, the thing works, and you got the ratios exactly right. It's a much more performance orientated box than the Triumph 5 speed. It doesn't get a big rpm drop between 4th and 5th. It would be ideal for racing and it's fantastic on the road.
Damm, I knew I should have left all the explanation stuff alone. I bow to all you others knowledge on this subject. I'm certainly not a historian. Thus bow to your your all superior historical knowledge.
Its been a couple of months since the last update. I now have four names on the list who are interested in one of my 5 speed clusters. I still really need a few more to make the commitment to do another batch. Anyone interested can contact me on here or by my contact detail earlier in the post.
Update the number of names has now increased to 5, I'll contact those who showed an interests to see if their still interested and take it from there. Should any other be interested then please email me or PM me on here and I'll add your name to the list. Should you require detail, then just move back the post a little.
I need to do a batch of ten to make it worth while, so still short of a few names. So anyone whose interested should get in touch with me, either via the post/ PM or my other contact details are earlier in the post.
I notice on another post today that the Nova 5 speed cluster sale price is 2970 GBP (inc VAT), while the sale price for my 5 speed cluster is 1850 GBP, admittedly it doesn't have a barrel selector, but its a vast improvement on the original 4 speed cluster at considerably less cost against the Nova one.