1950? 500cc BSA project

[harry76]

Ok but if I run a belt drive what will happen Ibedayank, are you saying it will break the belt? Or just spin on the pulleys. I would think it would still work (providing I found a strong enough belt). I would just have to be careful with the throttle, I don't plan on doing race starts, I just want to get in motion

 

[harry76]

Running a toothed belt like Harley's may prove difficult because of the teeth, I would need a sheave to suit

 

[Ibedayank]

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[wayne z]

I like that second transmisson. I would use it if I was in your shoes and could get it. It's a 3 speed from an old low rpm motorcycle engine so the ratios are prolly wide spaced and perfect for your type engine.You realy need an easy way to start the engine too, can't beat a kickstart.

Some of the naysayer posters here seem to think this engine has the higher performance, and torque of a more modern OHV 500cc engines, and requires a lot of meat in the drivetrain.

This is a very low compresson(4:1?) low horsepower (10-12?) low rpm (4200?) flathead engine. I don't think you will have trouble with needing such a beefy tranny as some suggest.

 

[Ibedayank]

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[harry76]

I don't see why I HAVE to have a trans and not get away with a direct belt drive providing the belt didn't break.

Did you say "a HD belt is not a sheave". I do realize that. A sheave is the rim type/pulley that bolts to the rear wheel.

Did you see my carb, and butterfly valve? What's your thoughts?

 

[harry76]

Thanks Wayne Z, that's what I thought.

Please don't take offence Ibedayank but Wayne Z has made his own CVT and as far as I know you are knowledgable in stock BSA's but I haven't seen any builds from you???? I'm not being smart or put you down, but I need to consider all options.

 

[Ibedayank]

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[Ibedayank]

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[harry76]

Are they restorations or customs of his own designs?

 

[harry76]

I think I might look at buying that box. At least get measurements from the seller.

If and when it blows up I can replace it with a bigger box, and then you can say "I told you so"..... We all win then

 

[Ibedayank]

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[harry76]

Welcome to the bin? I tried being polite but it seems I can't listen to anyone's advice but yours????

What you are saying could in fact be true, but on the flip side if you only build what you know 100% will work you will have a bike that is exactly the same as everyone's else and you will never have a unique ride.

I notice your only build is from a zombie cycles plan. I want something unique. If the box isn't up to it, it won't damage the engine and I'll only be out the price of a box. Not the end of the world.

But if it works I'll have a one of a kind bike, I think it's worth the risk.

It sounds like you're a little annoyed I didn't take your advice as gospel. Sorry mate but I wanna hear from more then one person

 

[harry76]

I actually appreciate your help Ibedayank but if that's your attitude you have a nice day as well mate. And I'll get back on that road, doomed to failure...... Either way I genuinely thank you for the help you've provided

 

[Mr.B.]

Harry if it’s any help historically for the most part belts were abandoned about the time engines were getting into the 6.5 to 7 hp range...

And of course these old engines were long stroke, high torque like yours.

However that doesn’t mean it wouldn’t work, it may just be a coincidence of technical advances?

Perhaps the best philosophy would be:

This is what I want, (you decide)

What do I have to do to make it work.

You seem to have good instincts.

-Kirk

 

[harry76]

Thanks MrB, always willing to take advice from the builder of my favorite bike. If I can get my bike half as nice as yours I'll be ecstatic.

I will go with my initial plan of a small gearbox, that way providing the box is up to the job, I'll be able to start it, I'll have more then one gear. The only reason I deviated from that plan is some said it wouldn't work, but providing I don't pay much for the box what have I got to lose.

So I will contact the seller and ask him to measure the diameter of the clutch sprocket as well as the thickness of it to see if it uses a similar chain. That should eliminate me buying another box too small.

And if I blow the box or it simply won't function it shouldn't be too much hassle to change. Just a little more time.

 

[harry76]

I'm extremely annoyed at myself at the moment, I was watching on EBay a 40 spoke 21" wheel with a brakelss front hub, all good quality and a Avon Speedmaster tyre as well. I was the highest bidder at $200, but thought to myself considering the Avon tyre alone is worth around $150 over here I should bid more close to the end of the auction.

Well I got sidetracked at work and missed the end of the auction and it went for $202.50....... I could cry right now.

Maybe I should take this as a sign and look for options on bigger diameter wheels :-(

 

[monark]

hello harry! progress being made i see,nice! hmmm, recognize your dilemma with tech backup but enjoy your attitude about it.There is allways some knowledge coming out of just doing it! still looking for info about that engine of yours but i would just try to get it going first without a total teardown,a lot of things can get wrong dissmanteling a engine without the right info.put the most work effort on the rest of the bike since there is allways the posibilety to fit another engine,especially with a separate gearbox.in the case of bigger wheels remember that it takes more tourqe to get you moving and with the size of the gearbox ill try to get the right (small)tires. plans looking really good so far and keep it coming

 

[harry76]

Thanks Monark, youre thinking is much in line with mine.

I was planning a total teardown, i have bought the manuals, but my only experience with engine rebuilding is the top ends of the 2 stroke motocross bikes i used to own. A LOT different to this complex 4 banger. The exploded view in the manual made me soil my pants LOL. It seems a stretch for my abilities so im considering just trying to get it going.... it wont be used much anyway.

When i said bigger diameter wheels i really meant bigger diamter rims. The overall diamter would only change very slightly but makes a huge difference visually.

The 21" motorcycle rim is probably my cheapest bet, would make the strongest wheel and have many tyres available at a reasonable price, and i already have a 21" rim.

Theres always the worksman rim, but may not be strong enough and would cost me a bit to get here to Australia, i would use Simplex tyres like Cobrafreak uses..... the cyclone replica with Briggs VTwin uses worksman rims

Then theres the 23" Honda XR rims, they are hard to come by and from what i can gather the tyres are even harder.

Then theres the original style 28" rims, im not sure where i would find them and tyres look the best but WAY out of my price range.

Im thinking of contacting Timeless Bikes to see if they can help me out.

Progress is extrememly slow but im OK with that. Im still just planning at this stage.

 

[Ibedayank]

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