1" Friction Roller/Blow Engine??

A

Albula vulpes

Member
My 1.25 Friction drive roller is about shot/worn out so I threw on the 1 inch extra roller that came with my kit. It slowed my bike down to max speed of 25mph. and it sounds like I'm riding on the interstate in a car in 3rd gear. My muffler also is getting very hot driving under normal conditions (15-20mph). I was just wondering if anyone has ever blown an engine from having it undergeared or using a 1" friction roller? I've got a harbor freight 52cc waterpump engine. Playing it better to be safe than sorry. Anyone know or have experience? Thanks,
 
The change in spindle size is in effect a gearing change like changing the rear sprocket size on a chain drive. The smaller spindle will give more hill climbing or may be better for a heavier rider but will offer less top speed. If you rev the engine higher to get the same top speed or feel you had with the larger spindle, you're likely winding it out at the higher rpm range for the engine. Sounds like you'll have to choose between a lower top speed or replacing the 1.25" spindle.
 
Sounds like you need the BIG 1.5" roller!
big ROLLERDIAMETERS2x.jpg
 
The 1.25 roller size is excellent for Florida Flat ground with the engine I have. I made a new roller out of wood, but not having success mating it up to shaft collars to mount to clutch bell drum shaft.
 
Using a saw blade, maybe you could cut a 'cross' or plus sign into the wood at both ends, and fasten it there with a hose clamp, kinda like what fastens the NT carb to the manifold, I hope you can picture it in your mind, or another way to say it, is give the wood some room to be able to squeeze onto the shaft using the cuts for some 'give'. You will probably need to space the worm gear of the clamps 180 degrees apart to try to balance the shaft.
 
Thanks for the idea. The roller I made is too short now to do what I think you are saying. I was thinking about drilling some real small holes in the shaft collars, and then screwing the shaft collars onto the sides of the wooden roller. I haven't got there yet, and contemplating doing it because I think the wood would split under a load.
 
Had another idea that might be better than the one I previously posted but it would cause a change in the stock/standard kit and if it didn't work might render the original setup useless.

Was thinking..............................


Drilling a hole in the clutch bell drum shaft in 2 places where the ends of wooden roller would be at. Then inserting a metal pin/cotter pin.(kinda like a shear pin on a prop on an boat engine) then cutting 2 circular steel pieces to attach to the ends of the wooden roller that would have a groove in them to nestle the steel pin. Thus the shaft would be turning the steel and not the wood, but then again attaching the steel circular plates to the wood might be an issue.

Right now I lack the courage to try.
 
Yesterday I bought some sanding screen from the hardware store and rolled it around the 1" roller and then zippy tied the ends of it to increase the diameter of the 1" roller and give it some bite. It didn't work.....................
 
Today I bought some athletic fabric tape and increased the diameter of the 1" roller to about 1.25" It worked well for a short while and the engine sounded like it should cruising with the larger roller, however the fabric tape melted and it didn't work out.


The 1.25" roller I had got shot on my thatsdax kit. I was jumping around from bonefish flat-to-bonefish flat in the florida keys on it, and the coral rock that makes up the Florida keys took its toll on the roller. The coral ate the metal roller and made it smooth.

I've got another 1.25 roller on my BMP kit, but it will not fit the thatsdax kit. I think I'm going to do an engine channel swap, but my BMP clutch bell drum makes noise.....

Better than blowing an engine........................................
 
moravcik said:
Now that BMP is out of business is there anywhere to buy a kit at a reasonable price?
Click to expand...

Well, there's Staton, which is made in The USA and then theres Dax, which is not. When you added the cost of a throttle, cable and kill switch to the Bmp kit at their last price it came within a few dollars of the Staton kit, which BTW the other two are copies of.
 
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