1950? 500cc BSA project

[harry76]

I may just look at putting a pulley on the engine, a sheave on the rear wheel and a hand tensioner like my Villiers, that would work, would look damn cool and best of all be cheap to do...... Providing I could get the correct reduction

 

[harry76]

Albion gearboxes arent cheap here in OZ, and since this bike isnt planned on being registered or ridden much id like to keep the costs as LOW as possible. This would be a big saving i would think and i just love belt drives

http://www.google.com.au/imgres?q=b...9&tbnw=172&start=0&ndsp=18&ved=1t:429,r:4,s:0

http://www.google.com.au/imgres?q=b...nw=185&start=138&ndsp=25&ved=1t:429,r:8,s:138

I guess i would add pedals (which would also be cooler) which is how i would start the engine, providing i could start it that way. And the lack of a gearbox would add to the boardtrack look. Any thoughts?????

 

[wayne z]

I would consider using the gearbox. looks to have a hefty kickstart shaft. How many speeds does it have. Only 2 or 3 speeds will make the physical size small.

That is a low compression low performance flathead engine, prolly about 12 hp or so. I think that box would do fine with moderate use unless you tried burnouts or crunching gears and speedshifting. The clutch is a great stress damper and would tend to slip before twisting anything apart in there.
That box only uses the single dry clutch plate with buttons, The multidisc clutches are for more powerful engines. The bolts and springs can easily be sourced. Could start with experimenting with small engine valve springs or other modern motorcycle clutch springs.
Sure would be nice to have kickstart and gears.

 

[harry76]

Yeah i think its a 2 or 3 speed but the seller didnt speak English so im not sure. Havent looked inside yet.

That would be awesome if i could use this box, because its so small it would really help the boardtrack look, the usual BSA box would look out of place being so large. This would look more like a jackshaft then a gearbox. And it doesnt owe me much so i guess i could try, and as you said i wont be doing burnouts or speed shifting. And wont be doing all that much riding. Just at car shows and stuff.

Sorry for all the newbie questions, but did you mean i just need to find 4 springs and bolts like i said.... will the wrong tension/size spring mean the clutch wouldnt activate or release properly?????

 

[wayne z]

If you're familiar with shifting a motorcycle, you can figure out the gears by rolling the clutch wheel by hand while shifting and watching the output shaft. Be good to see if it shifts OK . If it does, has no internal corrosion and the bearings feel good, you could prolly get away without complete dissassembly before use.

 

[harry76]

Cool thanks Wayne, much appreciated.

More newbie questions.... sorry guys LOL

It doesnt say Albion anywhere on the box, is it in fact an Albion box? If it helps the serial number is 227447.

The gear selector seems to have 3 clicks/selections. Im no expert but it appear to be a 2 speed, with neutral in the middle.... would that be right?

Also the clutch arm doesnt seem to feel like its doing anything, i think i need to do a little study on how this works.

Im imagining the box would be mounted with the 4 mounting bolts pointing upwards, so the drain plug would be on the bottom. If so there is no filler, im guessing the box would need to be removed and filled while upside down????

Sorry again for all these questions

 

[harry76]

It seems im always in awe of some of the shows you guys attend outside of Australia, and the museums you guys visit with pictures of boardtrackers and antique bikes. Ive never seen any antique motorcycles in person, the oldest bikes ive seen in person are from the 50's.

Well finally i found a show about 2 hrs drive from me thats right up my alley. It is called motors in motion and includes lots of different things planes, boats, cars, trucks, but more importantly stationary engines and antique motorcycles. Its towards the end of the year so something to aim for, would love to take this and my Villiers and my other bikes if finished. Its made my day This show may not get you guys excited if it were in your neck of the woods, but these sort of shows are rare in my parts (at least to my knowledge).

Heres some pics i found from last year

http://clivelowephotography.com.au/galleries/events-of-2011/motors-in-motion-kingaroy-airport/

 

[Ibedayank]

...........................................

 

[harry76]

Ibedayank, what you are saying sounds right, youre more knowledgable on these engines then me, but it seems you deal more with original M20's. So what you are saying may indeed be correct for daily riders of the heavier original bike, but maybe i could get away with it. Im certainly not dismissing your comments but id like to be certain either way whether i use it or not on this project, sure you can understand.

Ive seen a couple of similar engines (not sure of HP and torque of these engines admitedly) that use very small gearboxes like mine so who knows.

Scroll to the bottom of this page that Mr.B showed me

http://redmaxmonowheel.co.uk/boardtracker.html

Or this guys bike that offered me advice over at Jockey Journal

http://www.youtube.com/watch?v=tw0Vhxc1irc

 

[fasteddy]

Harry,
As Ibedayank said that motor is not 4.5 HP and it is not geared for an engine that size. It's gears are made to move you with a 98cc to maybe 150cc tops and the 150cc is my guess.
If you had an engine that was 200cc I'd have made you a deal on the transmission I have but that is the size of motor that it is built for.

As Ibedayank said it has a lot of torque but not huge on top end. To put this in prospective I asked my Dad how fast the army lorries were. As he said speed wasn't the worry since they were towing howitzers or were loaded with men and material. They needed pulling power and not top end and he added with a bit of a smile that you couldn't outrun a bullet anyway.

These bike were indeed made for rough roads and cart paths. Low compression since the gas wasn't what it is today or even the mid fifties when refining was improved greatly.
You will indeed need the transmission that matches the engine even though they don't match the board track look and as far as the belt drive, you will be putting an engine with that horse power and torque in place of an engine that had from 1.5 to 2.5 horse power and not a huge amount of torque. Chances are great that you will just sit there and smoke the belt with out the bike moving first.
This is why they all went to chains as horse power increased.

Steve.

 

[harry76]

All that sounds true, but arent many Harleys reverting to belt drive? And they are high HP engines.

If this is the case, and it sounds right this gearbox would be perfect for my 160cc Victa engine. Im not really liking the idea of a full size gearbox as far as looks on this project, and id have to find one and im guessing they arent cheap. Maybe i need to reconsider this project if thats the case. Did i bite off more then i can chew? Possibly......Im sure id get my money back on the engine and maybe make a little profit. The engine with the workshop manuals i bought owe me a little over $200.

I guess i have some decisions to make regarding this project

 

[Lurker]

You know harry some of the other guys might be right about that gearbox not being able to hold the torque and power of that engine.

I'm no engineer but I would venture to say that if the engine and sprocket and transmission sprocket use the same size chain you should be ok for the minimal amount of use you say this bike will see.

Another option like you said would be belt drive. Or you could look at later model board track racers and tt racers post 1923 sort of the same time period as my v-twin build. Some of those bikes had 3speed gear boxes. Heres one for example http://www.youtube.com/watch?v=KWFe3d6JpKg&feature=related

I think setting yourself a period of years (example 1923-1926) will help with the overall look and continuity of the bike. Have you already done this or are you still trying to figure everything out still?

If I were you I would buy a ton of books on vintage bikes just to see what was out there at the time. You might be surprised at what you find. I had no idea a cvt (well at least a version of it) was a invention from the 20's until I bought the "antique motorcycle construction and repair" book

 

[harry76]

If possible id like to do a teens bike but this would be very hard to replicate with the bigger standard gearbox. I like the style of bikes less and less as they get into the later models. This project came about only because i saw the engine and thought it was cheap. Im not really keen on spending much money on a bike ill barely ride so if it needs a standard gearbox im not sure im willing to invest that amount of money.

Thats why i considered the direct belt drive with tensioner, but i am also a long way from an engineer so my ideas may not always pan out.

Maybe i should try and find the origin of this box, that would help me make a decision. Like ive said i doubt this will be much more then a bike for shows, so id just like to be able to start it and putt around, but at the same time i dont wanna unecessarily blowing up the box.

I have a little thinking to do, in the meantime i welcome any thoughts from you guys...... Dont worry if the gearbox blows up im not about to come back and say "but you said itd work".

 

[Mr.B.]

If you go with a direct drive slip belt I’d recommend having a good & long adjustable travel path for the idler pulley.

And a adjustment system that can easily done roadside and a very long gate for the clutch lever travel.

The belts will stretch and leather in particular is subject to outside forces such as humidity.

-Kirk

 

[harry76]

Yeah I made the idler pulley on my Villiers adjustable. It's adjustable but is rigidly fixed to the lever, I've seen on the bigger bikes they have play in them via a spring connected to the lever if you know what I mean.

I like your ratchet system on your bike, I drew plans for a similar setup on my Villiers but ended up with the design I currently have.

I had a couple of people who doubted my clutch system on my Villiers would work but has performed perfectly with no complaints.

Still not sure what to do with this project, but I'm in no hurry so I'm sure I'll get there eventually.

 

[harry76]

Let's pretend for a moment that I do the direct belt drive and have working pedals..... Do you think I'd be able to put the bike on the stand and pedal start it or would it have too much compression? Anyone have an idea?

 

[Mr.B.]

Without a compression release it would be impossible, I can’t do it even with my comparatively small 4HP.

In fact your engine is large enough it likely would be pretty hard to pedal start even with a c-release. :-(

Kirk

 

[harry76]

Oh dear, this isn't looking good. If that's the case there's no point doing a belt drive.

I guess my options would be to try this gearbox, or search for a stronger box. But they ain't cheap here in OZ. in fact I'd say they would sell for what I'd like my entire build cost to be.

Do I try this box or maybe look at selling this engine and using this box with my 160cc Victa engine. The sale of this engine would pay for the electronic ignition I want for it, and probably pay for the rest of the build. Oh dear!!!!!!!!
LOL

 

[wayne z]

I would try the box.
I have been around many type vehicles over the years that either have larger engines mated to the stock drivetrain or their stock engines severely souped up. I have seen plenty trannys trashed, but it was always from dumping the clutch at full throttle or speedshifting under full power.

Show us a pic with the engine and tranny together. What dia. is the input and output shafts? how wide are the gears. More stuff to speculate with.

 

[harry76]

Thanks Wayne Z, ill post some pics tommorrow, i know you made your own variable transmission so im happy to take advice from you.

Just to be clear do you want the diam of the output shaft (you mean the engine shaft right?) and input shaft (shaft on the gearbox?).... and what do you mean by how wide are the gears, do you mean the ratio or actual size of the gears inside the box.

I apologise for the newbie questions but as i stated i have little experience with the inside workings of motors but willing to learn.... if you guys are nice enough to bear with me and i am very appreciative of the help ive already received. Thanks again