New 5 speed gear cluster for the BSA A65. Based on original gear cluster technology, xxxxxxxxx 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 an 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)Final drive sprocket is supported on both sides by bearing, while the drive gear is running on needle roller bearings. d)All rolling gears run on needle roller bearing, no longer are gears running on brass bushes.
The new 5 speed gear cluster and selector system comes complete with clutch center adapter and new bearing mounted clutch back plate to support both sides of the final drive sprocket. xxxxxx
To go with a 5 speed cluster. xxxxxxx Ltd are also developing a new light weight clutch. That will offer a more effective clutch, with lighter action and superior chain alignment.
If any one can get this off the ground its John, more power to your elbow sir. As one of the first recipients of the alloy barrel conversion I can vouch for Johns high quality and well thought through approach to engineering solutions for these old twins. I may even be the first to get one of the big bores up and running but thats a different thread.
Now I need to think up an excuse to get one of those conversions. My 71 OIF has a very sweet box which works so well I can select neutral at standstill when warm. However the NorBSA has issues with the clutch. hmmm.
Ive had some interesting chats with John over the phone around this topic, I know how much thought and research he has done already, for most of us A65 owners this is too good an opportunity to be missed, I imagine this would be a boon to any would be classic racers out there.
Best of luck with this for the future John.
71 Devimead A65 750 56 Norbsa 68 Longstroke A65 Cagiva Raptor 650 MZ TS 250 The poster formerly known as Pod
I'd love one of these. What excellent ratios, this sounds such a great thing for A65 owners. It makes such a difference when a gearbox is helping a motor stay in its good rpm zone. Like Gavin, I have C/R 1st and 2nd in my A65 which makes a big improvement, but this sort of 5speed would be, yea, what Nick says. An 80 x 74 744 A65 with these ratios could be such a sweet and potent thing.
5-speed cluster; why these ratios would be so nice. I did a little calculating. This is using 20t 38t final drive sprockets with an envisaged 744 A65 hotrod(the final drive ratio we have used with a 650cc 90deg A65 engine in an RGV chassis.) The effect is the same with a different final drive ratio. Using a theoretical motor that makes peak power at 7800 or above. This example uses 7800 as a change point, changing at lower RPM the effect is still much the same. Its important to realize the faster you go the more HP you use to maintain the speed. So the first to second change can be the widest because the thing will not be using much HP to maintain 70MPH and hitting second at 5606RPM will be in good HP with lots to spare even if it has an extra twenty or thirty HP beyond 7000. By 4th gear though speed is up and the extra HP left over to accelerate the thing will be getting more scarce, (riders notice the gap between 2nd and 3rd on the std box because at lower RPM it can drop you out of the power)however going into 5th with the 5speed only drops RPM back to 7020, into an area closer to where the most power is produced and where the best chance is to have some extra HP available to accelerate the thing a bit more. If it went into top and revs dropped to 5606RPM it may not even have sufficient power to maintain the speed.
Gear ratio MPH at 7800RPM in gears 1st Gear 2.222 From 1st @ 7800 68.98 2nd Gear 1.597 Into 2nd @5606 95.98 3rd Gear 1.296 Into 3rd @6330 118.26 4th Gear 1.111 Into 4th @6686 137.97 5th Gear 1.000 Into 5th @ 7020 153.30
Original A65 ratios for 4-speed cluster Ratio MPH at 7800 in gears 2.513 From 1st 7800 61.01 1.599 Into 2nd 4964 95.87 1.145 Into 3rd 5585 133.91 1.000 Into 4th 6813 153.30
DD - ? Direct gearboxes drive through two sets of gears for everything except top gear which locks the high gear to the input shaft. It could be rearranged so 4th is 1:1 and 5th overdrive. Mark, I have the standard 4 speed 2nd as 23/36 (1.5294) which gives 100.23 MPH.
One thing I forgot to mention in the original post. Is that this system is only good for the later models with the speedo drive working from the rear wheel. It can't work on the early models where the speedo drive is off the gearbox.
The 5 speed cluster fits the cases, its just that I have shortened the layshaft, this was where the early speedo drive was attached to. As you said you can use a bicycle speedo and just blank off the casing.
In answer to the first question, hopefully the first batch will be ready by end of this month. Running a little later than first projected but that's how proto stuff goes. While we've not encountered any major issues, were trying to concentrate ensuring its right rather than fast and flawed.
In answer to Irish Swede. There will only be one cam plate, to do a reverse cam plate is a whole different ball game. If you want to change the shift pattern there are a few more simpler way to achieve that rather than change the cam plate and all that would entail.
If you have several bikes that shift "one down, three up," for safety reasons it would be good to have the option of the reversed cam plate for the rear-set shift lever, so down-shifting in an emergency can be done without having to think about it.
I have seen pictures of the aftermarket linkage to do this, and all look crude and "tacky."
For what this five-speed gear conversion will cost, It can't be that complicated to engineer a reversed shifter camplate for it. A conventional one has to be made, anyway.
Thank you for your comments Jon, much appreciated.
Irish. What about going from right to left change as well! There are a number of well made linkages on the market, or you can simple build your own to change it to one up. I'm trying to keep the costs down, building in a reverse pattern change is not just as simple as you might think and certainly for the time being one down four up is the way it shall be sold.
What it's like. Not the best video. Although its just short shifting into 3rd 4th and 5th, if you keep power on through all the gears the excellent ratios put you right on the power and rocket you forward. 4th to 5th is closer than the old 3rd to 4th, I wondered about that, but its perfect, if 4th is not low enough just below it is 3rd. The beautifully made cluster:
Hells bells there is not much mest between those slots. Considering the problems with the early A 65 boxes requiring strengthening to prevent the slots separating I hope they got their metallurgy spot on.
In answer to Anne's question. Sorry I missed your post. I'm fairly sure that an adaptor could be made to suite the Newby clutch, it would be a matter of talking to Newby, as this would possibly require new clutch centre, although I'm not to failure with the Newby clutch.
To answer trevor's question. There are a number of differences between the original selector plate and the 5 speed one. a) thickness b) heat treated c) the dogs are back cut, therefore the gears keep themselves engaged, unlike the original which relied on the selectors and selector plate to keep the gears engaged.
No, it's constant mesh, the gears are always in mesh and slide to engage dogs to connect or disconnect them, determining which gears drive the output. On this cluster those engagement dogs are robust and dovetailed so when they are engaged they tend to hold themselves engaged.
I'll take names of those interested now. The earlier I have enough names to run a batch the earlier I can get a production slot with PES, who are always very busy. Its would probably be towards the end of the year before they would be ready, but I'd have a better Idea once I have some interest and can make a commitment.
I can send anyone wanting more information on the cluster if they email me on email@example.com.
Your name goes to the top of the list. Yes you can swap the clusters out with the engine in the frame. Look forward to seeing how the clutch centre works on the Newby clutch. I know the Hayward clutch system uses the standard BSA centre, so that would just be a straight swap.
40th anniversary this year and a Rick Strange memorial. Could not think of a better reason to go. So the A65 I have been seeing there in the same frame you are using is not you ? Did you do this a coupe of times or are there other great minds out there ?
They are advertising an A65 gearbox and show an image of it in their advert, it`s a cassette type box and had me interested enough to give them a ring. Turns out it`s a 5 speed unit that uses a selector drum instead of the old style selector cam plate design with it`s inherent weaknesses. Apparently they have some prototypes out there being tested, interesting stuff they do if you take some time looking through their website.
I have the std primary with 21 front and 36 rear sprockets for final drive. So the gearing is very tall. The thing probably sounds a lot slower than it actually is. I think this illustrates just how nice these ratios are. Definitely made my BSA much more effective.
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.
It's mid winter here at the moment but today was lovely and sunny. I spent an hour or so taking the A65 for a run, I haven't used it much since fixing an oil leak at the head/cyl joint. And re-adjusting the compression ratio to get it back to 11-1 with this oval port head.
And I just want to reiterate just what a brilliant thing John's C/ratio 5 speed is. Close ratio is really what it is, all ratios are closer to each other, and 1st is lower than BSA's C/ratio version I used before, so right from the start, pickup is improved.
One of the good things about the std BSA 4 speed was that 3rd gear is relatively close to top, superior to the Triumph 5 speed in this respect. People racing with the std Triumph 5 speed will notice and suffer because of the big gap between 4th and 5th. Even on a road bike this is an unnecessary disadvantage and a mistake Triumph made.
John's 5speed puts the 4th-5th change closer than even the BSAs 3rd-4th, meaning that at that change point John's 5speed, spun by equal HP, will pull away. As it will right through all the gear changes. As it keeps the engine spinning and hitting each higher gear with more rpm and more HP. This effect happens at whatever rpm you choose to change at, even just pottering along.
Shifting is good, upshifts with or without the clutch. Tapping the lever from 1st to 2nd always hits 2nd, never neutral. Finding neutral itself takes some practice/getting used to, as the detent is shallower than the detents for 1st and 2nd, tending to let the camplate turn to a gear rather than have it stop at the neutral position when you don't want it.
Anyone road racing or land speed racing an A65 would love this gear cluster.
It's certainly transformed my 883 and made it a real rocket ship.
I'm trying to drum up enough interest in my A65 5 speed clusters to run another batch, the minimum batch I can run is 10, at the moment 5 people have shown interest and need a few more to show interest before I could commit to having a batch made.
I'm still also doing my Nikasil coated alloy barrels, most common is the big-bore, but can make these to suit up to a maximum bore size of 80mm and suit most common stroke upgrades.
Either PM me or contact me on email@example.com or call 07802500325 and I'll email all the detail.
That's 465 views in a week and not even one question. I would have thought somebody would have had at least one question, either on the 5 speed gear cluster or my nikasil coated alloy barrel which is 6kg lighter than the standard cast iron unit.
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Not a question, but more of a pocket urinating caper, if there was such a thing as reincarnation, I would like to come back as a toolmaker, and be able to create stuff like that and then build a bike like Mark Parker's to put it in/on ! But, of course, this would be on the understanding that I would have head injuries much more severe to have a BSA twin anyway !
A significant part of the challenge of selling upgrades for older bikes is that they will inevitably be quite costly due to design time and small batch production. For example there are other upgrades that are being offered, such as the aluminium big bore barrel to increase the capacity; and I know of two such sources for this.
Interesting that the BSA Rocket 3 as well as the earlier 4-speed Triumphs (T120 and T150) have a relatively easy route to a 5-speed gearbox upgrade because they became factory standard and hence can be bought second hand as well as new, or like most I suspect, a combination of both, with new parts replacing worn ones on a s/h unit. And because these parts are 'standard' there is a perception that they will always be available from specialist suppliers.
The original A65 had a production run in the order of 100,000, although exactly how many survive is not known with any accuracy. For a long time they have been underrated compared with their Triumph stablemate too.
My final thought is that the continued interest in and growing value of our older bikes does mean that new parts are actually becoming easier to source as well as there being more people prepared to spend money on an asset (their bike) that has been performing pretty well compared to cash in the bank.
Anne, I already have a 5-speed gearbox for my A65 - just waiting for the camshaft/followers to be sorted and it will then get the engine put back together.
In the meantime, I have been experimenting with a ball bearing tipped gear quadrant plunger for my Triumph gearboxes and will have one soon that will fit the A65. It makes the gear changes a bit smoother by reducing the friction between the quadrant and the plunger.
Its three weeks since I reposted this and there have been 1500 views but no emails phone calls or PM's, I would have thought some people might have been a bit more inquisitive and at least wanted more information!
Another video, showing 2nd and 3rd with the 5speed. The thing is very high geared, but with the C/Ratio box you always have a gear. I was trying to get a video with the new fairing so used some stills because the video doesn't show it so well.
I have just gone past about 2,000 miles since fitting the 5 speed cluster. Marks opinions are similar to my own. I use 21 / 47 gearing, the gears are beautifully spaced, 1st is very handy in town, there are no nasty gaps and the change is seamless, I can cruise through the 30 limits in 3rd at just over 2k , then wind it up for a very rapid return to cruising. On the open road one down change 5th to 4th will drop around 500 rpms , a bit like the old BSA CR Daytona 3rd gear, if a longer traffic snarl, dropping 2 gears gives excellent acceleration. As you go down the box the RPM change widens, its nigh perfect. Neutral is really only available from 2nd as you slow down, once stopped with the motor idling in first it is not an option. I had some self inflicted selection probs to begin with , leaving out the kickstart ratchet thrust washer was to blame, once corrected all was sweetness and light. The 5 speed box adds a lot of fun to a ride, always the right gear for any circumstance, no more clutch torture when pulling away with the high 1st in the CR 4 speed box.Overtakes are much easier. Lovely crisp change, and not a plain bush in sight. A pleasure to fit and use. This box would give a racer a big advantage, theres a bloke doing very well with one in the North of England somewhere, I am tempted to try my own set up at East Fortune, maybe next year.
71 Devimead A65 750 56 Norbsa 68 Longstroke A65 Cagiva Raptor 650 MZ TS 250 The poster formerly known as Pod