Commando with a single sided swingarm idea.

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SOME chopper builders are excellent welders and fabricators, typically know how to read blueprints, and have the best equipment and facilities you can find.

Not ALL, not MOST, but SOME of them, anyway...

(I'm personally not a chopper kind of guy, but I know better than to criticise an entire group of people)
 
Sometimes it isn't what you do, but just how well you do it.

http://www.motorcycletuned.com/wp-conte ... ScorchFigh

Commando with a single sided swingarm idea.
 
grandpaul said:
SOME chopper builders are excellent welders and fabricators, typically know how to read blueprints, and have the best equipment and facilities you can find.

Not ALL, not MOST, but SOME of them, anyway...

(I'm personally not a chopper kind of guy, but I know better than to criticise an entire group of people)
Click to expand...


Lol.................not so sure about that, most of those I have seen on the biker build off type TV shows seem like badly trained apes, who are just about able to bolt together mass produced parts they have delivered to them by courier!

One of these people actually built a chopper frame out of anchor chain, and he got killed riding the bike when it failed............ he didnt seem like much of an engineer to me!
 
Fullauto said:
Powereng03 said:
Sorry for posting and not responding sooner. I guess I stirred up the bee's nest a bit. I chatted with the mech at the shop here and he doesn't think the iso's are going to be a problem. Probably have to mount the mono shock clost to a 45 deg angle. he thinks it could work. I was also looking at the JS motorsports monoshock frame plans for $10. they might be worth looking at. I'm checking an old buddy I went to school with that builds Russel Mitchel bikes here in Canada to see what he may be able to do for me. I may just break down and buy the SS swingarm on ebay to check things out for now. I'm waiting for my motor to get finished for my 850 Roadster, so I have another week or 2 until I get to do some more work on it, so dreaming it is!!
Click to expand...

If you have to ask a chopper guy for chassis advice, you're in BIG trouble.
Click to expand...

And if you chose a chassis made of anchor chain, you may well also end up dead!
 
The builder that you are refering to also liked to stand up on the seat and ride down the highway on his bikes, so it was just a matter of time before his ticket was punched. Indian Larry was his name I think!!
 
Riding a poorly built death trap standing on the seat seems like playing Russian roulette with a machine gun..............are all the chopper guys brain dead?
 
Carbonfibre said:
Riding a poorly built death trap standing on the seat seems like playing Russian roulette with a machine gun..............are all the chopper guys brain dead?
Click to expand...


nope. Just the dead ones!!!
 
Carbonfibre said:
One of these people actually built a chopper frame out of anchor chain, and he got killed riding the bike when it failed............ he didnt seem like much of an engineer to me!
Click to expand...
Dude, you sound like a broken record, we have been over this, do we have to do it again.
 
Powereng03 said:
Sorry for posting and not responding sooner. I guess I stirred up the bee's nest a bit. I chatted with the mech at the shop here and he doesn't think the iso's are going to be a problem. Probably have to mount the mono shock clost to a 45 deg angle. he thinks it could work. I was also looking at the JS motorsports monoshock frame plans for $10. they might be worth looking at. I'm checking an old buddy I went to school with that builds Russel Mitchel bikes here in Canada to see what he may be able to do for me. I may just break down and buy the SS swingarm on ebay to check things out for now. I'm waiting for my motor to get finished for my 850 Roadster, so I have another week or 2 until I get to do some more work on it, so dreaming it is!!
Click to expand...

Um back on subject, Here are some closer shots of my SSswingarm project...Ill measure the angle of the shock and report back.
Mind, this setup hasnt been "proven" yet.

This is a KOWA shock with the stock VFR bottom mount and a real basic setup on top, I think it may have been stock also and we just made the frame fit

Commando with a single sided swingarm idea.


And from the rear wheel looking forward

Commando with a single sided swingarm idea.
 
How does the frame behave with the fat tyre?
Have you altered the rake or trail?
What angle does the swing arm have at full extension?
graeme
 
GRM 450 said:
How does the frame behave with the fat tyre?
Have you altered the rake or trail?
What angle does the swing arm have at full extension?
graeme
Click to expand...


1. Do not know yet, but the massive amount of gusseting should help maintain

2. Rake...No
Trail..Yes, because the wheel Diameter has change...so I think the trail has increased.
Wheelbase...just FYI has also increased

3. I will have to check, and report back
 
motoalchemist said:
Powereng03 said:
Sorry for posting and not responding sooner. I guess I stirred up the bee's nest a bit. I chatted with the mech at the shop here and he doesn't think the iso's are going to be a problem. Probably have to mount the mono shock clost to a 45 deg angle. he thinks it could work. I was also looking at the JS motorsports monoshock frame plans for $10. they might be worth looking at. I'm checking an old buddy I went to school with that builds Russel Mitchel bikes here in Canada to see what he may be able to do for me. I may just break down and buy the SS swingarm on ebay to check things out for now. I'm waiting for my motor to get finished for my 850 Roadster, so I have another week or 2 until I get to do some more work on it, so dreaming it is!!
Click to expand...

Um back on subject, Here are some closer shots of my SSswingarm project...Ill measure the angle of the shock and report back.
Mind, this setup hasnt been "proven" yet.

This is a KOWA shock with the stock VFR bottom mount and a real basic setup on top, I think it may have been stock also and we just made the frame fit

Commando with a single sided swingarm idea.


And from the rear wheel looking forward



I wonder do you feel that increasing the wheelbase by probably 20%, is likely to improve handling? How did you calculate the correct rear spring rate, and work out what changes were needed to the damper internally?

In general modern machines have a much steeper head angle than old twin-shocks, with the motors mounted much further forward, and this linked to the fact that the distance from the front wheel spindle to the gearbox sprocket is a lot less than a TS bike due to much more compact motor being fitted, means the swinging arm is in most cases about 100-125mm longer than the TS one.


Commando with a single sided swingarm idea.
Click to expand...
 
Carbonfibre said:
I wonder do you feel that increasing the wheelbase by probably 20%, is likely to improve handling? How did you calculate the correct rear spring rate, and work out what changes were needed to the damper internally?
Click to expand...

I'm guessing he doesn't care as much about damping rates and precision handling, he just wanted a unique bike. Same goes for the Original Poster of this thread.

In the case of my monoshockers built with standard swingarms, the relative wheelbase is the same; the shocks I use are all 3 way adjustable, so ALMOST any combination can be dialed in. As far as the modern inverted forks, yes, the handling is altered; the happy consequence is that it has resulted in quite nice handling, certainly way nicer than my 75 I'state plod!
 
Grandpaul and carbon fiber.

Well, Grandpaul...youve hit pretty close to home on this whole project. The rear shock has only bee n modified with a heavier rear spring to deal with my 220 pounds. My process for this wholeset up is the front end is stock off a cbr900, and is installed exactly how it was on the original bike...except the steering angle is off (less steep) by 1 degree. the swingarm is giving the bike a tad more wheelbase which I am intending on getting some stability. But the rear shock is in the exact attitude as it was on the VFR.
if you look on the RH side of the bike I have installed a steering damper to deal with any headshaking if it becomes an issue.

I havent mathmatically proven any of the dynamics of this setup, yet. But trust me, i dream of the day I take this bad boy on the road.

Commando with a single sided swingarm idea.
 
Powereng03 said:
http://cgi.ebay.ca/ws/eBayISAPI.dll?VISuperSize&item=170701094269

Found this swing arm as my base to start.
Click to expand...

That look great, I originally wanted to do ducati swingarm...but back when this project began they were still really expensive. Thats a good proce, but see if you can find one that includes a few more parts...its that stuff that will cost so much. rotor, spindle, wheel, pivot, sproket.

I got lucky with my VFR rear end, I found it at a wrecking yard and just removed the whole thing wheel and all. (pre- ebay)
 
Well it's time to post again on this topic. Got a few more items for the rear assembly so I have almost all of the required parts for the rear of the bike. Question for you moto, what tire/rim are you using?? Do you have a problem with the fat tire overhanging the rear sproket for chain alignment?? The owner of the norton shop that I go to figures this could be an issue. What are you using for yours??

Also, if anyone knows of a shop that machines custom rims, that may help out this issue. Since this is not going to be a quick project, I may look at a set of custom rims to keep the rear rim more in the 4 in size so it will be just like the nortons. It won't be cheap, but I can always save my pennies to pay for them. Any ideas or people you have used in the past?? Thanks again.

On another note, the 74 is progressing nicely. It's probably 90% back together and will be ready for spring riding up here in Canada. I've got the motor, gearbox, and almost finished the primary. Still waiting for my black crome exhaust to come in from the UK. The motorcycle show is this weekend here in Edmonton, and I hear a rumour that there could be a new commando on display!!! Drool time. I need to take some new photo's to post with the wifes camera cause it takes way better pictures than my dive camera.
 
Will you be running the oil in the swingarm? I think some Triumphs do that and some Buells.
 
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