1950? 500cc BSA project

[rustycase]

I like that Jefferson a lot!
lol
very simple and straight forward... no clutch, no gears, a quill setup for the pedals.
Get some help to push start it and win or lose!
...I haven't seen where any of the BTRs used rear footpegs... wonder why not?

The new tranny looks quite a bit more robust, Harry.
Isn't there some way you could license it for road use as an antique vehicle???
Best
rc

 

[Ibedayank]

standard hardtail frame

to license it for road use as an antique vehicle you would need a frame with a valid vin and title. build the bike to look like the year/make of that vin
I can not say what hoops you would need to go through as Tennessee is pretty lax of stuff over 20 years old as far as getting it titled my laws on that won't be the same

 

[harry76]

We have way stricter laws here in Queensland, Australia. I may look more into it, but i was just planning and happy enough to have an unregistered boardtrack bike.

Ive always wanted a boardtrack style bike, very minimal and clean, if you look at my bike builds and cars thats what i always aim for. I would need to make concessions to road register it, im not sure im willing to do that.

Whwn the time comes i planned on using an XS650 or similar bike to use as a base for my road bike. That way id keep up with a couple of mates of mine, one has a Harley and the other a Triumph Bonneville.

In saying that those frames Ibedayank showed do look very nice, if i could get something like that cheap enough over here id consider it.

We arent called the land down under for nothing, its a different world. You guys in the U.S are very lucky

 

[harry76]

I havent had a chance to do too much but i had a quick clean of the box looking for numbers..... I found "66-3141 PBM" written underneath the box, which led me to this page http://www.wdbsa.nl/BSA M type gearbox.htm

It also has an extremely small "R.18" on it, not sure if that helps.

There is also either "I.C.I.5294 BSA" or "I.C.15294 BSA" written on the top inspection cover.

I have put up this info on a BSA website so hopefully they can help me out as to where to find a suitable clutch, otherwise ill be asking around at the swap meet im going to this weekend.

 

[rustycase]

de Harry...
"Whwn the time comes i planned on using an XS650 or similar bike to use as a base for my road bike. That way id keep up with a couple of mates of mine, one has a Harley and the other a Triumph Bonneville."

OK, I'm long winded... here's a tale of Tres Amigos.

Three young bucks in the trucking business bought motorcycles in the 70's to play in the Kalifornia sun and, well, bar hop.
Mike and Rocky were bucks up owner operators and bought harley sportsters which they customized to their satisfaction.
Nice bikes.

Gary didn't have the resources they had.
He bought a Yamaha xs650 and customized it, after the fashion of his friends bikes.

It became obvious the xs650 was a faster bike.

They spent a fortune improving performance of the sporties, Gary would make one less expensive improvement, and beat them!

In the end, the sporties were faster, but the xs650 was always able to run with them at a far lower cost.

I never had a xs650, and only had a sportster long enough to trade it off for a 4x4 Ford we needed for the logging crew.

There's quite a bit of information on the xs650 out there, including something I found interesting, called re-phasing???

Good luck
rc

 

[harry76]

Besides the sound of the Harley VTwin I've never really been a fan of the modern Harley's, their performance or their price tag.... So I have little choice but to go with something like an XS650, which I'm sure I can get looking just as good if not better then my friends rides for a fraction of the cost, and most certainly have a better handling and faster ride.

Harley's do have good resale value but you need the cash in the first place, and I don't.

Hopefully I will have Gary's luck, I'll have to look up rephasing...... I'm quite fond at what some of the Japanese are doing to XS650, they manage to keep the rear suspension while still be very pleasing to my eye. I'm not really into the chopper look which is what a lot of xs650's end up turning into.

*EDIT* RUSTYCASE, I just added this page if you are interested, its of a fair few Japanese XS650 builds that i very much like and would like to some day aim for.... more of the Bobber style builds rather then the Cafe Racer style ones

http://www.returnofthecaferacers.com/2009/01/awesome-flickr-photostream-japanese.html

 

[Ibedayank]

That transmission is a post war M20/B31/B33 transmission for the telescopic forked rigid or plunger framed singles, unfortunately, that is about the most abysmal motorcycle transmission that was ever made. Slow shifting, hard to find gears and is rumored to go from first to fourth or fourth to first in one shift if you boot the shifter hard enough. Also the stock M20 clutch is a miserable pile of ____, the later 6 spring BSA clutches are not much better, the 4 spring clutch is the one to use but as it is a Triumph preunit item, an $85.00 adapter is needed to adapt it to the BSA mainshaft.

 

[harry76]

That transmission is a post war M20/B31/B33 transmission for the telescopic forked rigid or plunger framed singles, unfortunately, that is about the most abysmal motorcycle transmission that was ever made. Slow shifting, hard to find gears and is rumored to go from first to fourth or fourth to first in one shift if you boot the shifter hard enough. Also the stock M20 clutch is a miserable pile of ____, the later 6 spring BSA clutches are not much better, the 4 spring clutch is the one to use but as it is a Triumph preunit item, an $85.00 adapter is needed to adapt it to the BSA mainshaft.

So I can get an adaptor for a good clutch but will still have shifting problems if I use this box? That doesn't sound very promising, I wonder if I should try and sell this box (ive seen these boxes go for more then what i paid for mine over here) and try and recoup my money and buy something else. I found a guy who specializes in BSA's in England and is meant to have a lot of parts, I might shoot him an email and get his opinion about alternative boxes, do you have any idea of a better box to look out for? Or is the adaptor the way to go?

 

[Ibedayank]

In this application I would suggest using either a pre unit swing arm frame Triumph transmission, a pre unit swing arm frame BSa transmission with the 4 spring clutch, or if finances are adaquate a Norton or Matchless transmission

 

[harry76]

In this application I would suggest using either a pre unit swing arm frame Triumph transmission, a pre unit swing arm frame BSa transmission with the 4 spring clutch, or if finances are adaquate a Norton or Matchless transmission

Thanks Ibedayank, I will keep an eye out for these boxes. Finances may allow, just may take me a little longer, no biggie. Thanks for the headsup

 

[GearNut]

Why not use a 50's - 70's Harley transmission?
Every part imaginable is still made in great quantities, easy to get, very strong, 4 speed, kick start.
Shoot, even if you come across a first year '36 tranny they are all basically the same until late '79 when the shifter design was drastically changed (which I find a bad design).

 

[harry76]

Why not use a 50's - 70's Harley transmission?
Every part imaginable is still made in great quantities, easy to get, very strong, 4 speed, kick start.
Shoot, even if you come across a first year '36 tranny they are all basically the same until late '79 when the shifter design was drastically changed (which I find a bad design).

Thanks Gearnut, I havent considered Harley boxes as they seem to be 2 to 3 times dearer, and seem to be in less supply, at least at this end. Id be looking at upwards of $250 just for postage from the U.S. Ive searched "Harley gearbox" and "Harley transmission" with very little success. And the ones ive seen have been around $1000 with postage. I like to build my bikes on a tight budget and thats a lot more then id like to spend. Especially for a bike ill likely rarely ever ride.

For that sort of money i could almost buy a complete Yamaha XS650. This motor was an impulse buy because i saw it, loved it, and thought it was extremely cheap. I would have liked to keep it a low budget build but learning that may be harder then i thought.

I will keep looking and consider the Harley boxes, maybe im not looking in the right places?

 

[rustycase]

I kinda gotta go against GN's harley trans idea... sry

they are just too big and the clutch is massive for this application.
pretty clunky shifting transmissions, too.

a british pre-unit would be much nicer all around.
I also think the clutch from almost any british twin would suffice for this application.

There's really not much that shifts as nicely as the jap bikes... maybe you could gather up some sort of 350cc or larger blown motor and saw the tranny off it???
...Just run the clutch dry???

some fellows use small mc trannies, cut off like that, on their band saws...

Good luck
rc

 

[harry76]

That sounds like a cool idea RC, I'd never heard of this. But i fear that would be beyond my capabilities. I'm rather confident with my fabrication skills but my mechanical knowledge/skills are probably below average I'm afraid. But I'm willing to learn so hopefully I'll get there.

 

[fasteddy]

Harry,
Here are two more words that you will never see used together in the same sentence.

Harley and cheap.

Steve.

 

[GearNut]

Ok, ok... sorry I suggested it... Sheesh!
I know them inside and out and yes, they are clunky the clutch is rather large, but they are bulletproof if built right and also used in many non motorcycle applications because of this trait.
They also will never shift from 1st to 4th with one fell tap of the gear selector either.

I am backing off now, sorry folks.....

 

[fasteddy]

Keep your hands where we can see them and back away very slowly from that Harley transmission Sir. Right now. LOL

Steve.

 

[harry76]

Ok, ok... sorry I suggested it... Sheesh!
I know them inside and out and yes, they are clunky the clutch is rather large, but they are bulletproof if built right and also used in many non motorcycle applications because of this trait.
They also will never shift from 1st to 4th with one fell tap of the gear selector either.

I am backing off now, sorry folks.....

I did appreciate your advice Gearnut, hope you didn't think that I didnt. Unfortunately budget is high on my priorities, I've got more projects then I do money.

 

[Ibedayank]

I did appreciate your advice Gearnut, hope you didn't think that I didnt. Unfortunately budget is high on my priorities, I've got more projects then I do money.

Don't we all.

 

[harry76]

Haha my girlfriend tells me im a hoarder but its good to see im not the only one here.

Ibedayank, you said Norton gearboxes were good, what do you think of this one? It has a while to go and is already at $300 Australian, so it may move away from my budget, but would this be a better box? it has the kicksarter and shifter which is a plus.

http://www.ebay.com.au/itm/251015277081?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Maybe someone can tell me why very few. if any at all of these old boxes have clutches with them?........ Is it because theyve had problems with the box and kept that clutch for a replacement box, if so that may cause me trouble as they must have been removed for a reason, or possibly just updated to a more modern box?