04 October 2011

50cc Pushbike Motor Kit. Part 2.

Below are some photos of my second afternoon installing the 50cc motor kit to my spare bicycle. Day 1 and more pics are here.
Day 3 (pedals only) can be found here:



Rear sprocket installed and back on the bike.



The chain needed to be shortened. This was really close to the correct size. I had to take out one link. :(



Multi speed bikes have no position adjustment on the rear wheel to take up chain slack as that function is performed by the rear derailer. My new power-chain will need this issue dealt with.



The kit comes with a chain tensioner. I'm not keen on these things when they're not spring loaded but I have no choice in this situation.



It's on a proper bearing, not just a bushing, so it spins really nicely.



I did need to make a small hammer-adjustment to the mount bracket though...



The trailing arms to the rear wheel on the bike aren't parallel to the chain, so this little twist in the chain tensioner bracket should compensate for that.



The hammer-adjustment seems to have worked out ok.



Cool little exhaust.



I was curious if the exhaust was just a simple expansion chamber, or if it had real baffles in there. Turns out it was the real deal.



Totally SWEET idea for the exhaust bolts from the dude who made the installation video. The slightly-longer-than-needed bolts are threaded in by finger ALL the way, so you get a complete thread-engagement. Then you crank down the nuts to pull the exhaust in tight. I've stripped numerous bolts and studs in the past when tightening down into cast-iron components. This solution was brilliant and very easy. I'll be doing this for all future bolts where over tightening or stripping is common. (cast iron...always...)



The bike is starting to look like a 1930's motorbike. Exhaust bracket added to support the baffle end against the bike frame.



Tank and fuel valve with screen-filter built into it. Later I found I should have washed out the tank first...there is black powder residue running through the clear fuel tube to the motor. I'm just gonna run it through 'cus I'm a barbarian.



Tank on the bike. Geez if I painted this thing khaki you'd just think it was a WW1 motorcycle.



Bits left over after completion. Couldn't be bothered with the 2nd handgrip, as I prefer the rubber grip to the aluminium feel anyhow. Also don't think I'll put the chain guard on. The gearbox does a good job of keeping your leg clear of the chain.

edit: Oh I forgot to take shots of the throttle installation. It's a cool aluminium twist-grip throttle like you'd expect on a motorcycle.



Everyone knows that American Mustard makes engines run better. Oil in the motor makes them last longer too. ;-)


Some shots of the beast.







You can see the aluminium twist throttle on the right handle grip. (left in the photo) I didn't put the matching grip on the other side as I prefer the original rubber grips.





I kid you not, I pulled the pull-cord ONCE to start it the first time. Didn't make any effort to bleed the lines or any other kind of stuffing around. This thing starts more easily than my mower which has some sales-pitch "ezy-start" gimmick going on with it. I've had a bit of a hoon around this evening up and down our side street. It's completely awesome and made me smile like a little kid. Heaps of power. Good speed.

I'll need to buy some pedal extensions to get them about an inch further from the crank arms. I can pedal, but it's awkward and a little tedious. I may just hit Bunnings and make something up.

I'm already considering putting a larger pinion gear on to give a higher top speed. It has plenty of power, and the centrifugal clutch should give some leeway here.

Other thoughts are that I would like this kit on a full on Mountain Bike, not my hybrid. My body weight is fully on my butt on the seat, instead of offset by pedaling, and I want a more comfortable ride. Thick mountain bike tyres and some suspension would be perfect. I may drop into KMart at some point and just grab whatever $80 bike they've got going on the day...we'll see.

But I digress. This kit is awesome. Get one. Thumbs up. Very happy. :-)