50cc Pushbike Motor Kit. Part 3

I needed to make some modifications to the motor-pushbike. Previous build info is here (day 1) and here (day 2).


You can see here the clearance for your foot is pretty lean. The gearbox sticks out a ways, and the other side is similar.



The vertical clearance is somewhat lacking...



I'd like to extend the pedal about "this much". You can import pedal-extender-bars, but they're a specialist product, cost about $25-$40 a pair, and only extend about 2cm.



I had a spare set of pedals kicking around (why? because I'm awesome, that's why.) so decided I could modify them to make some sort of super-pedal.



Aluminium cuts like cake. I really need a larger vice. The drill vice isn't really meant for this.



So I broke my last blade. Blargh Bunnings trips in the middle of a build are a pain in the bum.



With any luck I can just bend the leaves around the existing pedal, bolt it, and be done with it.



No such luck, cast-aluminium. Snapped in my hands, didn't even needs tools to break this. :(



So I cut the remaining leaves off, and got started on the other pedal.



Bunnings forced me against my will to buy das-uber-vice. It's a sweeet 150mm bar with who knows how long an extension, with offset clamp. I've actually never used a clamp this beefy before. It weighs 17kgs on its own. For scale, the hacksaw next to it has a 30cm (1 foot) blade.



The clamp is offset, so you can drop large pieces of product down to the floor while locked in the vice, with a full grip unlike most clamps. It has whacky MONSTROUS fins on both jaws to prevent any flex due to the offset grip. The jaw depth is much deeper than a standard vice also. It's huge.



Shelf-brackets have served me well for steel-strip requirements in the past. I'm going to cut these down and use them as splints to extend the modified pedal off cuts.



Aluminium drills so nicely!! I wish every metal work job was like this.



So this pretty much completes the picture of what I'm trying to do. A few bolts should have this job complete in no time.



This whole job was eye-balled. Yep, that looks about right...



They don't look too bad.



Plenty of foot room now.



Left and right, looks fine. Another victory to ad-lib workmanship. Also...I scored a new vice, so it's a double win. :-)

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. :-)

50cc Pushbike Motor Kit. Part 1.

A friend from my study group mentioned he was thinking about grabbing a pushbike motor kit for a bit of fun. He had a few questions for me that I had no information on. I started looking around during the week...and decided to get one myself. ;-)

edit: there are rules regarding motorised pushbikes in Vic that you need to familiarise yourself with before pouncing on an ebay purchase. In summary, the 70cc two stroke engines that are everywhere online are TOO POWERFUL to match our local requirements. Also: two stroke engines are rubbish. Do the homework yourself first.



My old bike. It's the one I got very cheaply when paying for the 2006 Great Victorian Bike Ride. It's actually a pretty good bike. (cheap) Shimano derailers, a reasonably light weight steel frame. Nice hybrid setup. No rubbish bike. So anyway...it's getting a motor. The bike ready for its operation, mounted in the car-bike-rack which is clamped up against the work bench.





My "new" bike. A mate went overseas so I got it from him on the cheap before he left. It's actually a pretty sweet machine.



A 50cc 4 stroke pushbike motor kit.



Seems pretty nicely packed.



Quite nicely packed in fact. The engine mount bracket is seen in the bottom right corner of this image. The entire kit was designed around standard 26inch frames. The bracket is fully adjustable, however I have a 27 inch frame, and I had to modify this bracket somewhat later.

edit: I didn't actually "have" to, but I wanted to for a variety of reasons I can't be bothered justifying here :-D



It's like Christmas in here :)



Normally surgery on the engine bracket isn't needed, but I'm a compulsive Gizmologist. :-P



Again I couldn't help myself. As a result of the change to the engine bracket, I had to make my own frame strap with a wider reach between the holes. Used some standard builders strapping for this. Can't believe how many uses I've gotten out of this junk.



Engine mount plate is nice n snug.



My home made strap should be fine. (this is hardly high end engineering...)



A schwoit little 50cc four stroke engine with gearbox already fitted.








You can see a little carbon on the exhaust heatshield plate. These engines are supposed to have been pre tested, with the carburetor idle and throttle settings already done. I'm really glad 'cus I hate setting that stuff up.




So I modified the engine plate, and forgot to add new mount holes for the engine itself. Doh gotta pull this off and fix that.




I fixed the engine hole problem, but realised I'd intersected too closely to the previous holes I'd drilled to make the plate fit the bike. THIS IS SO TYPICAL !! New hole...














Engine sitting in the frame. Looks quite beastly in a pushbike to be honest.



Fitting the new rear sprocket to the rear hub. An interesting little press fitting design with rubber gaskets directly against the spokes right up against the hub. Very tidy.






I'll put some more pics up tomorrow when I finish the job. :)

Day 2 and more pics can be found here.
Day 3 (pedals only) can be found here: