68 Spokes? No Problem, kinda.

Discussion in 'Performance Mods' started by Johnny C., Jun 12, 2008.

  1. Johnny C.

    Johnny C. New Member

    I wanted to build a motored bike out of a Micargi Royal with 68 spoke rims. It was a bit of an engineering nightmare, but well worth it. Blaze helped me build this bike as well as my electric, but on this bike, I mean help as in, he drank beer and watched me build the bike. When I first showed him a picture of the bike online he said, "Wow, that's a nice bike. Have fun trying to make it work." Not exactly the glowing endorsement I was looking for when I asked for his opinion on building this bike.

    The bike ended up being a perfect platform for the Chinese motor. The bottom bar runs below the crank, so it keeps the motor nice and low to the ground (hopefully out of the eye of John Q. Law, so I don't have to deal with the nebulous laws surrounding the operation of motorized bicycles in California). It also keeps the center of gravity low on the bike; making it easier to take corners (I hope you English majors enjoyed my use of the semicolon there). The bike drives as great as it looks and was well worth the effort it took to get it running.

    Here are some of the modifications I had to make in order to make this thing work:

    Brakes - Since this bike ships with a coaster brake, and there aren't any companies that make a 68 spoke freewheel or front disk hub, I had to take apart the rear hub to make it freewheel, and I had to drill holes in the front hub to bolt a disk brake onto the bike.

    Power - I couldn't use the rear sprocket mount that shipped with my kit (due to having 68 spokes) so I just drilled into the rear hub to mount the rear sprocket. For the front and back I just drilled holes in line with the holes of the items I wanted to mount, then I used nuts as spacers on each bolt.

    Gas Tank - I wanted a rear mount gas tank so my bike doesn't scream "Gas-Powered bike here!" Luckily, I was able to order one from Jordon (he posts as SkyHawkCanada). He was a pleasure to deal with. I will definitely order more stuff from him, and if you are looking for some good deals from a solid person, then I would recommend asking him first. The gas cap that ships with the rear mount tank sucks, so I used the cap that shipped with my original fuel tank, and it works great. I had to bang some dents into my rear fender to make room for the shape of the tank and I also had to bang out a slot for the nozzle that runs from the tank to the fuel line.

    Stealth - I painted my motor, gas tank, and exhaust pipe flat black to match the bike. You can see that the angle of the motor forces the exhaust directly under the bike; just a lucky break on the road to making this bike as stealthy as possible (look I used another semicolon). The exhaust reaches just far enough to clear the back tire.

    Nip Tuck - I had to shave my right crank arm down to clear the motor, but I believe it is better to do that than to bend the crank. I had to cut a couple of cooling fins off the motor to let the peddle chain pass. I also had to drill some holes in the base of the saddle to mount the gas tank, drill some holes in the frame to mount the rear rack, bend the chain guard to gain the correct tension on the peddle chain, and add several spacers to the rear end to make room for the drive chain. Chain tensioners on the rear axle are a must in order to keep both chains clear of the rear tire. You only get about 1/8 of an inch of clearance on each side.

    I hope you all enjoy the pics. If you decide to build one of these, please feel free to let me know if you have any questions.

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    Last edited by a moderator: Dec 15, 2015

  2. KiDD

    KiDD Member

    I like how it sits so low.
  3. Zev0

    Zev0 Member

    Looks pretty stealthy.
  4. wheelsy

    wheelsy New Member

    nice bike mate
  5. eljefino

    eljefino Member

  6. Sianelle

    Sianelle Guest

    That's a really nice looking conversion.
  7. fredie

    fredie Member

    cool bike dude
  8. srdavo

    srdavo Active Member


    I like it!!
  9. SirJakesus

    SirJakesus Guest

    Great job! I love how large the tires are and how well the whole bike comes together. Looks like a comfy ride for sure.
  10. Johnny C.

    Johnny C. New Member

    I wanted to thank everyone for the kind remarks and post some more detailed build info for those of you that expressed interest in building your own. I am going to do one post for each portion of the bike.

    This is how I mounted the headlight. It was easy. I just had to bend the mount at the end to get it to work.

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  11. Johnny C.

    Johnny C. New Member

    The front disc brake was fairly easy. I used 24, 8mm, standard thread, hex nuts; 6, 8mm bolts; and 6, 8mm nylon locking nuts for mounting the disk to the front hub. 8 mm is the size of the head, not the shaft. I believe the shafts are 5 mm. I used the 8 mm, nylon, locking nuts for the "lug nuts".

    Make Lug Bolts - All you have to do is take your disc and lay it centered on the front rim. Drill one hole in the hub of the front rim that will match the disc brake's mounting hole. Put the 8 mm bolt (now your lug bolt) through the hole in the hub from the inside out (so the disk brake goes over the threaded end of the bolt, like car tires). Put 4 nuts on the lug bolt to act as spacers between your bike's hub and the disc. Put your disc brake over your first lug bolt.

    Center the disc brake on the hub and drill a hole through the hub using the mounting hole on the disc brake directly opposite of your original hole. Take the disc off and put your next lug bolt through the bicycle hub and add 4 nuts as spacers.

    Put your disc on and bolt it to your 2 lug bolts using nylon, locking nuts. Drill the remaining holes and remove your disc. Repeat the process for installing the "lug bolts".

    Keep the spacer nuts a little loose until you get the disc on. The holes will be a little off (since nobody can drill holes perfectly). Once you get all 6 lug bolts through the mounting holes, hand tighten the nylon lug bolts, then take an 8mm wrench and tighten every spacer nut. Start with the ones that are closest to the hub, then move to the 2nd, the 3rd, and finally the 4th. Once all of the spacer nuts are snug, tighten down your nylon nuts, then cut off the excess bolt.

    Mount your caliper to the forks. You may have to bend the support for your front fender to make room for the caliper to move.

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    Last edited: Jun 26, 2008
  12. Johnny C.

    Johnny C. New Member

    Drive Train. I used 1/8" rubber gasket material to act as a vibration absorber between the motor mounts and the frame of my bike. It really cuts down on the vibration, but you have to make sure to tighten your mounts after a couple of hours of ride time.

    I had to shave a few cooling fins off the right side of the motor so the pedal chain would clear the top of the motor. Luckily, the bottom of the pedal chain runs right between the auto clutch and the motor.

    I bent the pedal chain guard straight up to accomodate the angle that the tensioner puts on the pedal chain. I did the same thing to the drive chain guard. It helps conceil the motor and eliminates any chance of the chain hitting the guard.

    I cut the drive chain guard so it would stop right at the rear support post of the bike. I drilled a couple of holes and used zip ties to attach it to the rear post.

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  13. ozzyu812

    ozzyu812 Member

    Nice bike! Its tied for 1st on my list of best bikes!
  14. Johnny C.

    Johnny C. New Member

    Now, the nightmare (a.k.a. the rear drive sprocket and freewheel). Hopefully, you are far enough into your build that you can't give up now. If I would've know that this part was going to be so difficult, I probably woulda went with a different bike, but I refused to admit defeat.

    I used this link to convert the rear wheel to freewheel http://www.wtlw.net/ff/suntour/ They call in an "unbreak", but I call it freewheel.

    While you have the rear axle apart, you will have to re-thread the rear axle so it sticks out about 1/2 - 2/3 of an inch to the left. You are going to have to add washers to the left side of the rear axle to make room for the drive chain. You have to move the axle to get enough thread on either side of the frame to bolt down the axle correctly.

    After you follow the freewheel instructions, you just have to make sure that you bend the 2 prongs that stick out of the retainer in the bike's rear guts down, so they don't catch in the breaking arm's slots.

    Then you have to cut the coaster break arm off so that the center piece (the circular part) can be used as a washer/spacer. You will also have to trim the dust cover that goes over the top of the bearings so it clears the lug bolts that you installed. It will seem a little rough when you first start to pedal backwards, but will work itself out nicely after a couple of hours of riding.

    I mounted the rear sprocket the same way that I mounted the front disk brake, but I had to drill my own holes in the sprocket because the holes that were pre-drilled in the sprocket were set too far out to drill into the rear hub. I just drilled my own holes half-way between the existing holes and about half-way closer to the center of the sprocket.

    I used 36, 8mm nuts (4 per stud); 9, 8mm bolts (as lug bolts); and 9, 8mm nylon locking nuts (as lug nuts). The next step is to drill holes in the rear bike hub to match the holes you drilled in the sprocket. I put a mark on the sprocket where it lined up with the air nozzle on the rim, so I could match it back up if the sprocket was dropped or I just spaced out.

    There will not be a lot of thread for each of the rear bolts when you finally mount the rear tire. Each side should have enough bolt to go about 3/4 of the way through each nut. Luckily, they make chain tensioners that slip over the rear axles and can be tightened from the back (like a motorcycle) so you don't have to worry too much about how much tension is applied on on the actual nuts. I got mine here http://bikeparts.com/search_results.asp?ID=BPC104772 they are 10mm chain tensioners.

    You are going to have to remove a few links from the drive chain, but after you get that ideal length, it is easy to use the chain tensioner that comes with your motor to adjust the pedal chain. Just make sure that you use the rear tensioners to align your tire to miss both chains and apply the correct amount of tension to the drive chain before you adjust the tensioner on the pedal chain.

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  15. graucho

    graucho Active Member

    Nice ride man.
    I can feel your pain about the 68 spokes delema. It was the most time consuming part of my build. It looks cool, but I dont think i'll do it again.
    Have fun riding...

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  16. Johnny C.

    Johnny C. New Member

    I had to cut the clutch arm because the grips on the handle bars are so thick. If I didn't cut the clutch handle, I couldn't get the clutch to engage where I wanted it to. You could set the clutch farther away, or at an odd angle, but I wanted mine straight on. It is a little tougher to pull, but that just makes it less likely for anyone else to ride it.

    The grips will barely fit over the throttle that comes with the kit, so you have to be very careful not to bust the little plastic ends like I did. Either I am stronger than I think, or the plastic ends are very delicate. (I am leaning towards delicate plastic ends). Nothing a little super glue can't fix.

    I used the speedometer made by Bell. I highly recommend them. We have used them on 6 bikes now, and they work wonderfully. You just set it for a 26" total tire width and you are off and running. It's a 24" rim, but with the big tires, it comes out to almost exactly 26" across the center of the tire.

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    Last edited: Jun 26, 2008
  17. Johnny C.

    Johnny C. New Member

    The gas tank required a little bit of modification to the fender, frame, and seat. I had to pound down a little of the fender to accomodate the shape of the tank, then I had to pound in the right side of the fender to allow room for the tank valve.

    I painted the valve flat black and used black gas line to run to the carb instead of the usual clear tubing.

    I had to drill holes on either side of the frame to bolt in the bottom of the rack posts, and I had to drill a couple of holes in the bottom of the seat to mount the front of the tank.

    I hope these instructions have helped. If you have any other questions, please let me know. Enjoy your build.

    I got my rear mount gas tank from skyhawkcanada (Jordon). He was great to work with and you can email him at dj_ooze@hotmail.com

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    Last edited: Jun 26, 2008
  18. Johnny C.

    Johnny C. New Member

    Some odds and ends. Remember that you are still going to have to shave your pedal arm and shave a little off the outside of the motor (all of the stuff that I mentioned in my original post). You are also going to go through about a can and a half of flat black spray paint, so buy 2 cans of the high temp when you are at the store.

    I mounted my kill switch under my seat just to be original, but I keep my idle so low that the engine will die as soon as I pull the clutch (that way the engine dies exactly when I want it to).

    The tires say to inflate to 40 psi, but I just went with 35. It makes the ride very smooth and does not take away from the top end of the bike.

    You will have to adjust the float a little because of the angle of the engine. If you aren't that mechanically enclined, then don't worry about it, but I got an extra 2 mph after I adjusted the float.
  19. meme405

    meme405 Guest

    I didnt even see the engine at first had to go back and look for it...
  20. Johnny C.

    Johnny C. New Member

    Here are some close ups of the engine. I had to buy longer bolts to mount the engine because of the diameter of the frame. I also had to reenforce the drive chain guard because the tab on the original (that mounted to the motor) snapped off due to vibration. I just used a small piece of steel and drilled a couple of holes in it.

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