design for front shocks

[robbie]

Do any of you have any clever ideas for making an effective but simple front shock absorber system on a bike? There's a Honda motorcycle at the junk yard that I could buy parts from, but I'm planning to use a very fat ATV tire, so I'd have to spread the forks a lot wider. Is there a simple way to set something up using standard steel tubing and ATV shock absorbers? The advantage to that would be that I wouldn't be dependent on more expensive old motorcycle parts for future maintenance.

Also, for off-road riding up to 25 mph or so, how important is it to add shock absorbing suspension to the front end with a big soft tire? Should I just forget it and build it with a rigid front end?

 

[mrfreyguy]

You could try to use a Honda atc front end. I've also seen where people bend their forks backwards and have a mini swingarm for the wheel on it. I'll try to get some pics of it.

 

[mrfreyguy]

I couldnt find any pis so I made one using doodle on my ipod so its noth the best. The black is where the fork would be bent and the red would be the sswingarm. You would put the shocks on the swingarm and attach them to the fork.

Heres the link to the pic:

http://s603.photobucket.com/albums/tt120/mrfreyguy54321/?action=view&current=photo1.jpg

 

[robbie]

That's a neat idea. So, the shock absorbers would be the third side of the triangle where the other two sides are your black and red lines, right? That could work, although it might look funny. I'd have to use really small shocks.


I actually have a Honda ATC for parts. I'm going to use the front wheel and fork as the back end with a swing arm pointing backwards from the bottom of the frame. The reason I want to use the ATC front for the back is because it's a BIG tire, with brakes already built in, whereas my other tire is a little bit smaller. It should go on the front just to keep it from looking funny. They have some other ATCs at the junk yard, but one of them is so old it has a solid front fork, one of them has no front end, and the other has a bunch of welds and repairs on the front shock assembly. The motorcycle looks really good, but it occurs to me that even if I spread the fork wider the shocks will still be extra tall.

By the way, that's a really nice little bike in your photo. I like it.

 

[Kaptain Krunch]

I couldnt find any pis so I made one using doodle on my ipod so its noth the best. The black is where the fork would be bent and the red would be the sswingarm. You would put the shocks on the swingarm and attach them to the fork.

Heres the link to the pic:

http://s603.photobucket.com/albums/tt120/mrfreyguy54321/?action=view&current=photo1.jpg

Called a springer front end, google it.

 

[robbie]

Hey, I like that. I found a link to a youtube video where a guy explains the geometry of a springer suspension. Looks pretty easy to build. I could get the no-spring front end off the ATC at the junk yard and attach the swing arms to it where the axle would normally be.

 

[mrfreyguy]

That's a neat idea. So, the shock absorbers would be the third side of the triangle where the other two sides are your black and red lines, right? That could work, although it might look funny. I'd have to use really small shocks.
By the way, that's a really nice little bike in your photo. I like it.

I thought it was pretty neat when I first saw it. It seams easy and simple to build and it looks like it would work very well. I might try it on my bike sometime. Your right about the triangle thing where the shocks complete the triangle. If you have big enough wheels you could probibly use some normal sized shocks. Thanks for the compliment about my bike. I'm not sure I'm following you on the front fork for the rear end. Any way you could draw up what you'd like to do?

 

[robbie]

The front tire on the ATC is really wide, so the fork is shaped like a big letter U. My idea is to cut the handle bar and steering swivel off the top of it and mount the back edge of the seat on top instead. In the diagram, the red vertical line going up from the back wheel is the ATC front fork with shocks.

The green line is a swing arm with the same axis as the drive sprocket. I could make this from the front fork of an older ATC with no shocks, or I could make it out of tube steel.

The red line on the front wheel is where the ATV shocks would be mounted.

Thanks for the great ideas, both of you guys.

 

[porsche930dude]

heres some ideas

 

[robbie]

Wow, that's a lot of ideas....

 

[porsche930dude]

yup I think the black and white scooter with the pull spring would be the easiest and cheapest if your limited with tools and stuff. Because you can use your unsuspended forks as is and just add a rockers and a springs