Motorized Bicycle OVERSIZED TUBING solved

[2door]

That's the way to do it, tooljunkie. Fab up the mount and make it fit the engine and frame then install the engine using the rear mount on the seat tube. When everything is square and right, drag out the welder and tack things together. Remove the engine and weld it up right.
I like to use a MIG for tacking then go back in and TIG things up to finish. The prime rule? Keep it simple.

Tom

 

[crmachineman]

LiveFast has a clamp for oversized tube for $15.00...Live Fast Motors: Bike Motors, Bike Motor Accessories, Bike Motor Kits, Instructions for Assembling Bicycle Motors

Hey, I like that someone is selling a product to deal with that front tube problem, I'm not sure if my eyes are fooling me, but it looks like the wires are getting pinched; is that the case?

Thanks

 

[alvelez61]

i purchased a common conduit from home depot for $1.05

 

[culvercityclassic]

That clamp is not strong enough, It may work for the time being but its going to move and cause all the stress on the back mount.

 

[2door]

i purchased a common conduit from home depot for $1.05

Won't hold. That clamp is made of a material much too thin to hold the engine in place. It will probably crack and fail very quickly.

Find an alternative before you ride. If the mount fails under load there's a good chance you'll break the rear mount as well as locking up the rear wheel and causing you injury.

Tom

 

[alvelez61]

thanks, i kind of figured that, i just needed to hear it.....

 

[jauguston]

Sick Bike Parts has mounts for oversize front tubes. I have one on my bike.

Jim

 

[bigbutterbean]

my engine fits my oversized down tube with no modification. its a 66cc i bought from mgf on ebay a little over a year ago.

 

[happycheapskate]

Hahha. I know that feeling from going to lawnmower shops looking for gaskets or filters. The clerk was exasperated with my description of a rubber fuel line grommet, so he finally brought me a few boxes and let me select one.

Which is one of the things that caught my interest... not that I really need it - but you wouldn't happen to know the part number or specific application for that bushing wouldja Tom? It's no big deal as ofc I can just bring in measurements, but the guys at the part stores around here tend to crazyeye if you don't have exact year/make/model when yer tryin' to buy stuff...

It only gets worse if I actually dare tell 'em what I need the widget for

 

[Chopperz]

I used U-Bolts on my install and they work well. I also used automotive fuel line, which comes in various diamiters, to kind of shroud the bolt

Is this a Giant Stiletto? That was going to be my build, but I ended up having to scrap it because I couldn't figure out how to effectively mount the engine

 

[2door]

It's a Macargi, the bike in the banner at the top of the forum page.
By the way, that frame cracked, like so many Macargi frames have.

Tom

 

[donb4103]

That is a good clean look. I will try to remember it on the next one I build.

 

[jauguston]

Sickbikeparts.com has brackets for oversized tubes. I have one for my front mount and it works fine.

Jim

 

[Chopperz]

The problem is my frame is considerably over-sized. How would you recommend mounting the engine, now that you can see the bike

 

[2door]

If it was mine I'd fabricate mounts and weld them to the frame. Of course that would require repainting but hey, if you're gonna make an omelet............

Tom

 

[dracothered]

If it was mine I'd fabricate mounts and weld them to the frame. Of course that would require repainting but hey, if you're gonna make an omelet............

Tom

I agree on the welded mounts, it is the only safe bet. As far as repainting goes, if you do it right you could create a two tone look and not have to repaint the whole bike.

 

[happycheapskate]

Wow. Who made that? I like that bike.

The problem is my frame is considerably over-sized. How would you recommend mounting the engine, now that you can see the bike

http://i46.tinypic.com/21ju7bc.jpg[/IMG
[IMG]http://i47.tinypic.com/21iip.jpg[/IMG
[IMG]http://i47.tinypic.com/29mn4wg.jpg[/IMG[/QUOTE]

 

[Chopperz]

Its a Giant Stiletto

 

[jauguston]

Looks like you will need to add a vertical tube behind the pedal crank for the rear engine mount.

Jim

 

[fatdaddy]

Looks like you will need to add a vertical tube behind the pedal crank for the rear engine mount.

Jim

Or weld a vertical plate straight up to the rear stud holes. Drill two holes in the plate to mount it to where the rear mount usually goes. I think it would just look cleaner that way.
I've been using the u-bolts for years now. When I first started out I drilled a couple frames. Looking back I can't believe how dumb I was. I'm pretty sure those frames are in the scrap pile now.
I use the single u-bolt on a lot of customer builds. I wanted something a little firmer on my personal bike, so I went with the double u-bolt. The pic of it on my bike is not a GOOD pic, but you can kinda see it.
fatdaddy