New Build, 5 sp Chopper @ over 40+ mph

[Byron]

Fairly new to the forum, and have asked for a little assistance, but no response, so I went at it cold turkey. Now I've been building Mustangs and Cushman's for some time, so fabrication is not new, and I thought it would be fun to build a wild motor bike. So here is what I've come up with. It is an original OCC Chopper, w/ RAW 80cc(??) ported engine. It is built up with a aftermarket clutch actuator from a gentlemen in Florida I found on this list. It also has a SBC shifter kit that I had them make for a 'center' mount along with their expansion chamber exhaust. The bike is set up with a rear 5sp gear
freewheel w/ an axle mount derailleur and a custom mounted 200mm disc and Apex (I think) disc caliper. I could not figure out a way to mount a disc on the front wheel because of it's shallow disc and being to close to the forks for a caliper to fit. So I found an old bike frame that had a squeezer type of single point caliper that I mounted to the Chopper frame with a welded on mount that I made. Using a dual line hand lever I was able to adjust the brake bias to be as perfect as I could have hoped for. I still have some bits & pieces to attach like mirrors, maybe a stop light etc. I have clocked this Chopper at a whisker over 40 mph wound out in 4th gear. I think I'll just use 5th gear for cruising as I don't bounce anymore, I just splat......Byron

[azbill]

nice looking OCC !!!
watch the tank mounts, they tend to crack where bolted/screwed to frame

[Zev0]

All I can say is SWEEEEEEEEEET!!

[echotraveler]

oh my! you've done a great job! how long have you been doing this?

[Pablo]

Nice build! One of the only chopper Shift Kit bikes out there. I think you have done excellent work, taking your time and doing things right. I also think you are in "unexplored" territory, so maybe that's why people havn't poured in a ton of "help".

For example, I would need to see the disc brake set-up up close and personal to comment.

As for the Shift Kit install two things I can comment on (again can't see everything in photos):

Your driven BMX chain is loose (obviously), and it seems like there is little you can do to tension it, have you tried a half link? Tensioner? Just a thought.

Also, since it appears you didn't/couldn't use the supplied rear mount, there is nothing tieing the right mount for added rigidity. Has this caused any problems? We could come up with some ideas.

Anyway - one word: SWEET!!!

[butch27]

That is just NICE!

[Byron]

Hi Pablo:
I'll try to address your queries as time allows. Here's the first installation. As the pictures show, I felt that if the method of chain ring mounting (spoke sandwich using heavy belting material) was strong enough to apply engine torque to the wheel, then it would work to 'stop' the wheel. I cut out the center of a chain ring used on the 'flex mount' and used it as a basis for mounting the disc. It wasn't to much trouble to true the disc with the wheel, and it seems to be holding. Once the disc was mounted, and the wheel on the bike frame, I just had to mount the caliper, find an appropriate location and back spacing, fabricate a mount and attach it to the frame. Out of time for now.......Byron

[NunyaBidness]

While I'm not an expert on disc brakes, I think you may have problems breaking spokes with the way you have the disc mounted. Other than that you have built a great looking motor bike.

[Byron]

As I said before, I gave a lot of thought to this. I figured that if this type of mounting (same as used on the original style drive sprocket), could be used to drive the wheel, then it should be strong enough to stop the wheel, seeing as how there is only a 3 sq. in. friction patch on the tire. Now if the situation was different, ie gobs sticky tire rubber, monster (wide) rear tire, then there might be a problem. During the process of balancing the front/rear brake bias, so as not to land on my tush, I've locked up the rear disc many times with no hint of spoke problems, things working loose etc. None-the-less, all of this creative stuff gets a thorough going over every time I crawl on this thing. Good brakes were the most important criteria in this build. I've had to much road 'rash' over the years to come up with another 'case'.

[Zomby Builder]

I feel your pain. And you are my friend in pretty much uncharted water. I have found that whatever you have to do to make the disks work - is worth the effort. I have only had success with a hub that has the rotor mount. If you check out this hub from US Choppers it would probably lace right into your rim.

http://www.choppersus.com/store/prod...heel-Disc-BLK/