RAZOR CHOPPER WITH 54cc CHAINSAW MOTOR

[MrSkater943]

i was going 2 use the original razor sprocket and use a bike front sprocket should i or no

[hairyalien]

@MrSkater943

The Razor chain and the bike chain isn't the same size if that's what you mean...?

Look at the pics between 0:07 and 0:12 in the video.

The way I did it there was bike sprocket/chain between the motor and jackshaft, then the original Razor sprockets and chain between jackshaft and rear wheel.

That wasn't enough gear reduction though and later on I had a different setup with more reduction which worked better.

[MrSkater943]

i have this chopper and a chainsaw motor with a built in clutch can you tell me what i need

[MrSkater943]

how fast does it go?

[hairyalien]

@MrSkater943

Dunno mate never checked it.

It felt a lot faster than it was though, sitting that close to the ground.

With better gearing it could have gone a lot faster.

.

This chopper is long gone now, only ran it a few times.

.

[14cichlid]

did you use the original sprocket from the razor

[hairyalien]

Yes I did.

On this version I put a bicycle sprocket on the motor and one on the jackshaft.

Then I put the original 9 tooth sprocket on there and used the original 55 tooth on the rear wheel.

It didn't give a low enough gearing though and the clutch kept slipping.

In the second version I put a smaller sprocket on the motor, and different ones on the jackshaft.

This gave me a gearing of about 7.5:1 which meant great acceleration but lower top speed.

[rrjhs199516]

dude thats fukin sick

[shinyfuzzy]

saw u on tzi world. place is fricken dead :(

[hairyalien]

Yeah it is indeed.

Shame really, it seems like it used to be quite an active forum.

Check out my RC car videos.

[lolyouwanker]

nice design i lik it..... practice ur welding more im not baggin u out but u dnt want that thing comin apart when ur doin 50 down the road .... especially the engine vibrations .. theres lots of good vidoes on here that teach u how to stick weld... nice bike

[northeast13eric]

your welds look like bubble gum.

[hairyalien]

Yeah I'm crap at welding.

Still learning

It's strong enough though which is the main thing.

[northeast13eric]

no doubt.

[geoff390]

Cool build. I would have loved to hear the engine but anyway.

[hairyalien]

Yeah unfortunately it was very windy that day and all the footage had too much wind noise.

Am going to make a new vid soon

.

[coshyno]

did you used a welder ??

what kind ??

[hairyalien]

Yeah.

A stick welder.

[hairyalien]

It's now geared at 7.5:1.

Standing start no problem and good acceleration, but not very good top speed.....

The search for the optimal gear ratio continues.

New video soon hopefully.

[hairyalien]

Today I got hold of some better sprockets and hope to have it all set up in the next couple of days.

This should bring the gearing down to around 7:1

[doesnowork]

Have you run it flat out yet?

[hairyalien]

Yeah we took it out to the industrial area last weekend for a spin.

Really picks up speed over 500 metres or so and gets a bit scary actually.

Am still tossing up between rebuilding the whole gear setup and putting on a different clutch setup on the motor....

....or just leaving it as is until I get hold of a different motor.

Maybe something like yours.

Wouldn't mind using this motor for an RC car as it is pretty powerful.

As for now though it just sits in my workshop looking awesome

[doesnowork]

Nice skull. The mounts for the gearing are better than mine too.

[hairyalien]

Thanks.

Yours worked out ok though didn't it?

Seemed to run pretty good.

One thing I wondered about was why did you put the chain tensioner pushing the chain out instead of in?

[doesnowork]

The gearing that side goes from 7 tooth to 11 tooth. Pulling it outwards keeps the chain away from itself, and makes it easier to take up the slack. Also it was easier to mount the spring that way!

[hairyalien]

As long as it works it's all good.

It's just that when you put it that way round you minimize the amount of chain that's in contact with the sprocket.

So what's the final gear ratio on that thing anyway?

[doesnowork]

The chain around the sprocket is no worse than on the original donor bike. Final gear ratio is about 14:1, but it was never intended to be fast, just reliable.

See my vid of it running at Cheddar Kart track to compare it's speed with my own minimoto.

[hairyalien]

14:1 eh.

Cool.

Probably won't gear mine that low but it definitely needs to be geared down a bit.

It does pick up speed pretty good over a long straight run, and I'm hoping to take it out to the industrial area this weekend with a mate and camera to try and get a couple of videos of it going flat out.

[AussieTimberWolf]

That shit is sic man..how long did it take you to make the bastard??

[hairyalien]

Hey.

Not too long actually as I had most of the bits laying around in the shed.

Probably a week of afternoons and evenings.

Worked out really well.

[drewcrew6]

Hey Alien looks good yeah a different ratio looks like is needed that clutch will toast before long.

[hairyalien]

Yo Drew.

Yip the clutch gets a bit hos as you can see....

Once it gets going though it engages fully and it's a pretty fast and scary ride.

Gonna take it for a longer run over the weekend.