gearing question

[feelinright]

Man I'm excited. For 30 years I have been riding bikes competitively but mostly just for fun,bmx freestyle jumping, flatland,road etc. and for all those years I wanted small engine on my bike. I just ordered a kit and then lot's of stuff to make it work good.

I'm getting a 47 cc engine kit. I can see I would'nt like the whole bolt the huge steel sprocket to the spokes hub flange thing so I got a stanton LHD hub. I never ride bikes unless the are sealed cartride bearing so I got a front hub to match.

I realized that now this thing won't start with both sides of the hubs freewheeling so I found a recoil starter and saw a 36 tooth sprocket there that threads onto a LHD threaded freewheel. Perfect, less rotating mass and more speed. I also did'nt like the chain tensioner so I'm getting a 1 speed kit so I can rig the springed arm with a metal chain pulley with sealed cartridge bearing in it.

Thanks to this forum I picked up alot of ideas to get this thing running smooth. Now I just have to get the bike to put it on. I think I am going to get a hardtail Iron Horse(a cheap $200 one) because I am way over budget on this one.

Anyways I weigh 145lbs. and my bike is will probably be 45lbs. gassed up with the kit on it. Is 36 a good gear or should I figure out the how to attach the 44 or 48t to a freewheel?????

All my life I rode bikes fast downhill but never uphill!! I can't wait to get this project running.

 

[azbill]

please post an intro
it's forum policy

 

[feelinright]

Sir yes sir!!!

Posted an intro and got the Iron Horse mountain bike today for this project. As an amatuer framebuilder/wheelbuilder/bicycle builder/rider I am happy that two hundred bucks buys alot of bicycle thanks to our hard working friends in China. Man, here in America I could'nt even buy a good aluminum tubeset for $200. let alone make a fairly decent complete bike.

 

[feelinright]

Got the 36tooh freewheel/sprocket today. It seems odd and I think it will work. The freewheel is threaded inside and out. Hoping it mates up with the stanton hub I ordered for lhd. Check out the pics I painted the sprocket with color shifting paint so it looks good!!

Is it green purple or blue??? or all the above. I am going to do the hubs and maybe some other stuff this color(s)

 

[azbill]

the paint does look cool
with this kind of attention to detail, I can't wait to see the finished ride !!!

 

[feelinright]

Oh yeah finally got this thing running. The build goes like this. I got an Iron Horse hardtail mtb. I installed the starfire 2k 47cc kit on it. I changed the rear hub to a stanton lhd/rhd drive. I used a 36tooth freewheel/sprocket combo and put together a custom chain spring loaded tensioner with aluminum gear with sealed bearing. I changed the front hub to a poverty sealed bearing hub. While I had the wheels apart for relacing I painted the rim, hubs and 36t sprocket with color shifting paint. I filed the engine drive gear to use a bmx 1/2 link chain. I made the front crank sprocket single gear, those small sprockets are useless anyway and used the shifter for the clutch which is easy to get to. I mounted the gas tank to the rear with a Schwinn rack. I painted the engine etc. high temp black to not atract the wrong kind of attention(5 oh). I put a champion plug in it and auto grade fuel line. I had to make a custom front engine mount which I bronze brazed a t shaped braket and steel bars and bolted it to the water bosses.

It's been alot of work but it finally paid off today. Rode for 4 miles at 25mph and can't wipe this grin off my face. I can't seem to rev out the gear yet. Thinking about an upgraded carb to tune the high end unless someone figures out how to mount a mini turbo on one of these!!! As for the gears I do have a 16 tooth left hand freewheel sitting around but I think it would bog too much unless I get more power!! any Ideas?? I want to keep it under 50cc's for legal reasons.

Thank guys for all the ideas!!!

 

[cooltoy]

Great looking bike. Thats how I have my tank but it's in a little zippered pouch for driving under the radar. Also ,love the way you mounted your ignition.
Other than that I did not understand one word of your post (ha ha ha ). Just goes to show that I should spend more time reading, looking at the pics here and going to real bike shops instead of "Canadian Tire"!
Sounds like you know your stuff and look forward to more pics from you. I have so many issues with my rear tire. Ball bearings, grease washing out and today, my peddles would not "lock". In other words, I can't peddle my bike to start it, it just spins. Boy, it may have been the coldest day yet and am thinking it froze up on me.

 

[Alaskavan]

From what I read, I understand the HT's gain power after break-in. So you might not want to get into too many modifications untill you get a couple hundred on it.
Oh yeah, good looking build. With my habit of running into bumps I'd be a little nervous about the tank hanging out back there. But maybe you're a better driver than me.

 

[Large Filipino]

I LOVE that tensioner. That really cleans up the whole bike. It's a sprocket too!

When you get a chance,could you post the other side? I liked too how you cleared the pedals.

Nice build,man.

 

[feelinright]

Sure thing. Here is the other side and a close up of the tensioner I put together. Luckily the chain stretched a bit today, just enough to take out a 1/2 link and take the tensioner off. The bike is much dirtier now I've been test riding it in the slushy messed up roads here in Spokane.If there was more light you could see the color shifting parts I painted. I clear the cranks fine and they are standard length 170mm.

I just ordered a boost bottle, hopefully get some low/mid power from it. I passed on the nitrous. Looking back I should have got the 80/70cc engine as that seems to be the best power upgrade available. I don't understand why pocketbike motor have the same cc and way more power from what I read.

Live and learn, no replacement for displacement, unless someone made a wankel engine this size!!