All things mtb

deacon

deacon

minor bike philosopher
I finally used a mtb frame for a build. I have explained on another thread all I did but going to move the new stuff here.

OKay here are the pics of the bike before I go wreck it. It is a virgin configuration never ridden. Never even started yet.

the bike
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engine gas tank kill switch and suicide clutch.
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Engine and mount
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New gas tank (goodwill 3bucks)
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evaluation of the mtb

ILOVEIT...

Joe tried to tell me the engine in the front didn't effect the bike's performance but he was wrong. IT MAKES THE BIKE BETTER.

The bike runs like it is being chased by a Harley with rape on it's mind. I'm not kidding you I hardly had to pedal at all. The bike is loud as ****. I drilled holes in the muffler. To be honest I didn't have the nerve to open it up. Not so much the fear of speed it is the fear of that one hand brake on the rear.

I am going to have to get a coaster rear wheel so I can let it out and see what it will do. That 31cc engine hums on the front end. I don't know why but it rocks.

What do I really think of it, anybody wanna buy a china girl bike. Just kidding, I haven't tested this bike thoroughly yet, but it does seem to do good. I wish I had better brakes I would love to test this out hard today. I just don't trust myself with that one rinky dink hand brake. It will make a nice emergency brake so I'm going to keep it.

the small amount of pedaling I did was really easy since it is set up on pretty low gears. The middle of the front ring and the smallest of the rear ones.

THIS BIKE IS A KEEPER.
 
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So what is the cost breakdown on this bike...

bolen weedwacker engine $75
mtb junked out $6 (Reused the cables as controls for the engine.
maybe $20 for hardware in the frame and bolts ect probably a little less.

Gas tank $3
gas lines to reroute $6 (I know I paid more for gas lines than the bike.)
The 24" wheel I used because I had it on the china bike and wanted to change it out anyway. $0

approx $110....

Now I'm satisfied that I can build a bike for about a hundred bucks that you can ride to work. I don't have to have the coaster wheel. I can get used to that brake but with this engine I don't know that I could stop without better brakes.
 
deacon said:
evaluation of the mtb

ILOVEIT...

Joe tried to tell me the engine in the front didn't effect the bike's performance but he was wrong. IT MAKES THE BIKE BETTER.

The bike runs like it is being chased by a Harley with rape on it's mind. I'm not kidding you I hardly had to pedal at all. The bike is loud as ****. I drilled holes in the muffler. To be honest I didn't have the nerve to open it up. Not so much the fear of speed it is the fear of that one hand brake on the rear.

I am going to have to get a coaster rear wheel so I can let it out and see what it will do. That 31cc engine hums on the front end. I don't know why but it rocks.

What do I really think of it, anybody wanna buy a china girl bike. Just kidding, I haven't tested this bike thoroughly yet, but it does seem to do good. I wish I had better brakes I would love to test this out hard today. I just don't trust myself with that one rinky dink hand brake. It will make a nice emergency brake so I'm going to keep it.

the small amount of pedaling I did was really easy since it is set up on pretty low gears. The middle of the front ring and the smallest of the rear ones.

THIS BIKE IS A KEEPER.
Click to expand...

Ok - I thought I was supposed to be the mad one around here rotfl

flat out a 31cc motor might be expected to hit anything upto 30-35 depending on gearing etc and output

pull is always better than push regarding motor vehicles - I am honestly not sure why but it seems to be that way all the time.

A cop in the UK would have kittens if he saw that gas tank! But its great - just make sure some homeless guy doesnt think he wants a drink - talk about firewater lol

Let us know how she goes :)

Jemma xx

PS. a run in HT would be great for a 'sasha's run' basis for the trike.. :D
 
Looks great deacon. I used to have a 'gas tank' that looked exactly like that when I was a kid, lol.

Is that a cantilever brake on the back? That's probably why it doesn't brake to well. I'd say upgrade the brake on the back, and add one to the front and you'll be good to go. No need for a coaster on this one.

Glad to hear it works well.
 
I have no idea what kind of brake it is except not very good. I probably am going to change it out for a ordinary old lever brake, but I dont have room for a front one the bike's engine took the bold on hold. I guess I could use a longer bolt but I am using the lever as a clutch lever.

I rode it again just before the rain. I LOVE THIS BIKE... It didn't try to kill me and it runs. I had to modify the mount back to my regular style but on the front it works just fine. The throttle works better now as well. I can throttle it down as long as I remember which way the throttle works.

I can't get it past half throttle... The wheel starts skipping on the terrain here. If I had a long flat I could run this thing like nobody's business. It climbed all the hills on my test track without any pedaling. The bike is terrific. I just need better grip on the drive wheel. I ran a smooth one this time.

I'm still going to try jb and fiberglass screen wire. I think I will ride up to the home depot and see if I can buy a foot of it.

Did I tell you I'm really pleased with this one.
 
One of the things that made this weed whacker better on the bike is that I drilled five holes in the muffler. I know there are differing opinions on whether this helps but it sure did a number on this bike. Of course it sounds awful. I'm sure one day the local constable is going to stop me. I can see the heads turning miles away.

I might need to get a set of those ear things that make me look like mickey mouse or a jet engine plane parker at the airport
 
Deacon it's hard to tell from the pics..is your brake the type where the wire splits into 2 and each piece runs to it's own side? If yes, it is a cantilever brake and I can see why you don't like it (I am extremely prejudice against cantilever brakes.) :)

This may be a bit advanced or even a nutty idea, but here goes my brain working in overdrive again....for the drive wheel:

Basically what you would do is make your drive wheel have the reverse tread of the bike tire. So to do this you would need an identical spare tire that you can cut up...Put a clay like material on the drive peg, all the way around. Then take your spare tire piece and wrap it around the peg, imprinting the tread, only once. Then take it off and let it dry. Then, coat with a very strong resin - polyester resin (for fiberglass) would work, as would most any other epoxy product that's not too thick. You could just dip the peg a few times.

When it's dry, you would have a peg that "locks" in with the tread of the tire.

I guess another way would be to coat in the clay like previously stated, but then lower the engine to contact the tire, and slowly rotate the tire to imprint the tread on the peg.

dunno, just a crazy rambling thought. Excuse me if I'm a little too "mad scientist" for your thread :)
 
No it actually sounds like how we used to make paster tire casts from tire prints. You did give me a thought. I wonder how a ceramic drive wheel like the tiles on a space shuttle would do, wear wise.

Oh wait I remember one of those exploded. never mind. I think your idea might work. But I'm not that ambitious I think I'm looking for something much easier. Too bad I can't find something to cut a deep pattern in the galvanized pipe. Of I only had the right tool and knew how to use it, I could cut in that pattern that is on the factory drives.

Yes it has the two wires that each go to a pad. I am not happy and of course it is old anyway. I probably will change it out god knows I have enough laying around. I will have to take a look to see how to mount a rear one. It has the factory holders welded on. not sure how the rear wishbone is made on the bike.
 
The holders for the pads is pretty standard, most brakes should mount right up. I am a big fan of "linear pull" or "v-brakes" as Shimano calls them. See if you have something like this, I find they work well and are my favorite.

SHIMANO DEORE M530 V-BRAKE at JensonUSA.com

What factory drive pattern are you referring to?
 
My brakes look like that with a cable to each one that goes to a round blob that the main cable goes into as well.

I once bought a drive wheel on ebay. The guy had a box of them from a bike motor company that was going out. It was kind of a rasp looking design. Not random or file cut more like a rasp cut. It worked really well except I had to have it welded to a gear.

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kinda like this
 
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Well I rode the bike three times and it isn't even noon. It went around the block while I made some adjustments. I had to cross tie the engine. It is the way I usually mount them in the rear I thought I might not need to do that but I did. I did it yesterday but I had to change the way I did it today.

I rode the bike down to the store where I buy my auto parts, then later I rode it up the nastiest hill I have on the way to the home improvement store. It pulled that hill just fine.

It is proving to be a very nice little bike.

I met a policeman and was very glad that I had on a helmet. I pulled my bike over and let him go by. Now I need to buy rear view mirror so I can be at least a little safe on the bike.
 
I had a pretty miserable time with the 25cc bike today so I cranked the mtb 31cc up and rode it a couple of miles. That thing is the best bike I have ever built on my own.

The kit bike is really not my own build. It was mostly a bolt on and ride thing. This one I designed the mount such as it is, the gas tank such as it is, the engine tie down system such as it is, the friction wheel such as it is, and of course the control adaptations. I feel like I built a bike this time. Of course it would be nice if I could build an engine as well but alas one has to recognize their limits.

Anyway I'm very proud of the performance of the bike. I am truly surprised by it to be honest.
 
After a really trying ride on Sunday, I replaced all the missing nuts and redid the drop cable. I tightened everything then went for a few rides. I still love this bike. When it is right it is really right. I think I am going to try to lower the size of the drive wheel tomorrow. Just for an experiment.

But the bike performs very well for what it is. I have less money in this bike than most guys spend for just the platform to build a china bike. This bike is a lot of fun as well. I ran a real life errand in it and the bike did great.

Later I almost bit off more than I could chew. I started up a steep hill from a dead stop. I pedaled like made. I might not have had to but I was afraid the bike would burn up trying to do that hill alone.

Even the china bike makes strange sounds on really big hills.
 
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Does the weight on the front of the bike have any ill-affect on the steering of the bike? I bought an old 3-speed Huffy from the town librarian thinking I would like to put a friction motor on it for my sister. She has severe arthritis in her knees. We use to ride (pedal) 20-40 miles a day before her knees went bad. Anyway, I thought the ladies frame would make it easy for her to get on and off and with the pull start she would not have to pedal. Here is a pic of the bike. Tell me if you think it will work or if I should look for another bike. Any input would be helpful.
 
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the steering once you are moving even a small mount is negligible. It is noticeable while the bike is being rolled around is about all. Some of those smaller engines if the area is flat would probably do better for that bike.
 
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