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 firstname.lastname@example.org 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.
Joined: Aug 2014 Posts: 1,225Triless
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Joined: Aug 2014
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