Chainsaw in frame build

[fasteddy]

leaded 50,
I think if you could see all of us looking over your shoulder at this wonderful build you would need thousands of seats.

I'd have to agree with the thought that it is fun to take what you find around you and use it to make something beautifull. Silverbear is an expert at that and we have a lot of fun every summer following that idea with the truely great things that he has found before I get there.

I'm pulling up a seat to watch.

Steve.

 

[silverbear]

silverbear this is actually my second chainsaw build. I used a Poulan for my first build. My brother has laid claim to that bike however. You can check it out at the Poulan chainsaw build thread. Too lazy to post a link. I will be glad to post info on this build and photos too. Although this build is going to be just a bit different. My avatar is a picture of that bike as well.
Trust me when i say when the engines hit mid to top end they really are awesome. I have found that most saws need the piston rings replaced every couple seasons and carb kit. Other than that the darn things last forever.

NormO,
Do you have a link to that thread?
SB

 

[silverbear]

NormO,
Do you have a link to that thread?
SB

Found it...
http://motorbicycling.com/f36/poulan-chainsaw-build-34341.html
SB

 

[NormO]

Sorry about not giving the link. Most people weren't interested in it because i didn't keep the pedals. Or it wasn't friction drive. What you see is what you get now. I'm not changing anything. If my brother wants to he can do just whatever he wants.

 

[5-7HEAVEN]

Sorry about not giving the link. Most people weren't interested in it because i didn't keep the pedals. Or it wasn't friction drive. What you see is what you get now. I'm not changing anything. If my brother wants to he can do just whatever he wants.

I really enjoyed your chainsaw build, NormO.

I'll be watching this one too!

 

[NormO]

Thanks 5-7HEAVEN you also gave me lots of ideas on how to make the new build much better. leaded50 you may be able to get some extra width on the pedals by using a torch and bending them. I don't know if you have access to one or not but it's an idea.

 

[cannonball2]

I just bent a crank set on my current build, first one I have done. Wasnt hard but took a couple of trys to get it exactly right. Use a long crank as you loose diameter as its bent outward. Will do it this way from now on instead of paying for wide crank conversions. A torch is mandatory though.

 

[leaded50]

I planned to do it, but got trouble to loosen one of the "pedalpins"..and also the main sprocket, they are quite STUCK!!! I´ve got torches, but 50years do something with connected metall.... and i dont wanna ruin it, so i try to keep it as it is....

 

[happyvalley]

If you don't have to bend the crank arms, so much the better. That means the engine and drive train are narrow enough for the bike to still pedal well and not skew pedal tread.
http://sheldonbrown.com/images/stronglight-q-diagram.jpg

 

[5-7HEAVEN]

Thanks 5-7HEAVEN you also gave me lots of ideas on how to make the new build much better. leaded50 you may be able to get some extra width on the pedals by using a torch and bending them. I don't know if you have access to one or not but it's an idea.

Thanks for props, NormO. I'm glad you realize that chainsaw engines have awesome midrange/top ends.

My gears ratios are extremely stiff, with 46.32:1 first gear. With low gears, your engine would literally push your butt right off your seat!

JMO, chainsaw engines are the dark horses. Geared correctly, they have the power to motorvate bikes easily into the 40mph+ range.

 

[NormO]

At least my butt is 15lbs lighter than it was. Easier to get it pushed off the seat

 

[leaded50]

But trouble would be to make a correct gearing? 12500rpm, 26" wheel......does a lot of changes in sizes of the driving pulley/sprockets....at least to 46.32:1 ?

 

[5-7HEAVEN]

But trouble would be to make a correct gearing? 12500rpm, 26" wheel......does a lot of changes in sizes of the driving pulley/sprockets....at least to 46.32:1 ?

Oh yes.

With this granny gear, my heavy bike climbs the path along the steep, gridlocked hill like a dirt bike. Eighth gear is 15:1, which is VERY usable on the highway.

Ya just gotta experiment. I can help you with calculating gear ratios. Sprockets and rear cassettes are cheap.

 

[leaded50]

Yeah..but no space for cassettes, and dont wanna have the modern newstyle!

plan to use a 1,5" vbelt pulley at engine, 8" pulley at jackshaft, and from there 8-10 chainsprocket......and then to.....rear 26" wheel,( got a possibility for a 92teeth sprocket..) Or, just forget the last chain, and just make more vbelt pulleys.... if i can find the needed items....

 

[5-7HEAVEN]

Yeah..but no space for cassettes, and dont wanna have the modern newstyle!

plan to use a 1,5" vbelt pulley at engine, 8" pulley at jackshaft, and from there 8-10 chainsprocket......and then to.....rear 26" wheel,( got a possibility for a 92teeth sprocket..) Or, just forget the last chain, and just make more vbelt pulleys.... if i can find the needed items....

8"/1.5" = 5.33333:1
92/10 = 9.2:1

5.33333 x 9.2 = 49.07:1

Super granny gear.

What's your pleasure? 20mph? 30mph? 40mph?

If you're only having a single gear, shoot for 20:1 ratio.

6" pulley/1.5" pulley = 4:1

50t sprocket/10t sprocket = 5:1.

4:1 x 5:1 = 20:1 gear ratio

 

[leaded50]

Thanks 5-7 heaven, when i´m checking and put in the sizes in a ratio app, it came out with approx 50mph....and i dont this cycle would be so fun to go with in that speed, at least if/at something bad road........
if its reach in the 20-30´s i´ll be satisfied, at least the police........even if 40´s will be fun to, at least for now!
are you shure on your calculations? remember the sawengine have the best rpm about the 10.000, and tops 12500 at max.... and its gonna be a single gear,yes!

 

[5-7HEAVEN]

Thanks 5-7 heaven, when i´m checking and put in the sizes in a ratio app, it came out with approx 50mph....and i dont this cycle would be so fun to go with in that speed, at least if/at something bad road........
if its reach in the 20-30´s i´ll be satisfied, at least the police........even if 40´s will be fun to, at least for now!
are you shure on your calculations? remember the sawengine have the best rpm about the 10.000, and tops 12500 at max....

Guesstimating.....

20mph @ 12,500rpm w/26" wheel = 49.06:1 gear ratio

30mph = 32.2:1
6"/1.5 = 4:1
64t/8t = 8:1
4 x 8 = 32:1 gear ratio

40mph = 24.2:1
6"/1.5" = 4:1
48t/8t = 6:1
4:1 x 6:1 = 24:1 gear ratio

That's at 12,500 rpm.

 

[leaded50]

double posted..

 

[leaded50]

GREAT, and a big thanks....checked the faq on J.S. calculator...and put in right stuff on right places, and got some changes, and YOURE RIGHT!!
Then it gets more easy, the motor> jackshaft is already done, and then it seems that a normal "crank"sprocket, 40-50 teeth will be okay to get my goals! Just out for a check tomorrow, and pick up some parts! (did throw away a cassette gear bike yesterday, after just picking of some small stuff......but no sprckets! GRRR)

 

[5-7HEAVEN]

20.1 mph @ 10,000rpm

6"/1.5" = 4"1
77t/8t = 9.625:1
4:1 x 9.625:1 = 38.5:1

30.2 mph
6"/1.5" = 4:1
64t/10t = 6.4:1
4 x 6.4:1 = 25.6:1

40.3 mph
6"/1.5" = 4:1
48t/10t = 4.8:1
4:1 x 4.8:1 =19.2:1


http://www.motoredbikes.com/showthread.php?t=18102