Building another friction drive

The one with a pair are my favorite FD rear tire, that's cheap. When aired up the surface of the tire is flat, good tread depth too. The single tire is a good one for FD, but aired up the tire surface is rounded.

 
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The 43cc 2stroke that came with the FD had no problem with the 1.5” and was quite fast. Was just too noisy
for my area.
What tires are you running? I normally run the common 2.125 cruiser tires. The best I have found are Hookworms. The roller settles into them nicely at 25-30psi but they are pricey.
This bike won't run a hookworm. it has a kenda 2.125" puncture-resistant hybrid tire, with a 3/4" wide smooth center strip I just installed, what a difference from that 1.95 stubby gravel tire.

Hmmm, I got a 27cc full-crank motor, and a diamondback with a hookworm. But the bike's too heavy, I really like that featherweight motorbike.

Shoulda kept it.
🤣🤣🤣🤪😈
 
The one with a pair are my favorite FD rear tire, that's cheap. When aired up the surface of the tire is flat, good tread depth too. The single tire is a good one for FD, but aired up the tire surface is rounded.

I have looked at these tires, and thought about them. They seem at least in the pics to be a bit crowned in the center?
Hard to tell until they are inflated. Thanks for the links!
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
This bike won't run a hookworm. it has a kenda 2.125" puncture-resistant hybrid tire, with a 3/4" wide smooth center strip I just installed, what a difference from that 1.95 stubby gravel tire.

Hmmm, I got a 27cc full-crank motor, and a diamondback with a hookworm. But the bike's too heavy, I really like that featherweight motorbike.

Shoulda kept it.
🤣🤣🤣🤪😈
Heres a pic of my lightweight fun bike. I like 24s, they are so flickable. Great for dodging pot holes on our roads. Scoots pretty good with the 49cc and a 1.30 roller. Found it in a dumpster. Got it mainly for the fenders it had. Hung on the wall a long time as a frame, until I scrounged the parts to build it. Somehow my wife named it Hello Kitty, why I dont know.
 

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Heres a pic of my lightweight fun bike. I like 24s, they are so flickable. Great for dodging pot holes on our roads. Scoots pretty good with the 49cc and a 1.30 roller. Found it in a dumpster. Got it mainly for the fenders it had. Hung on the wall a long time as a frame, until I scrounged the parts to build it. Somehow my wife named it Hello Kitty, why I dont know.
Where did you ever get that handlebar stem plus the bolt to lock it down? Has to be an extra 6" into the neck.
 
They are on ebay. I have been buying them lately to get bars up to a comfortable level. Im too old to be riding low
bars leaning on my wrists. Did enough of that riding MCs in younger days.
My full suspension bike has them also.
Biking is a lot more fun when it's comfortable.
 
I brought it back yesterday for a few more upgrades, front tire basket, light mounts, a second bottle holder for spare gas, matching front and rear lights and reflectors.

Took it back, then out for a hard run, it’s definitely running low 20s for top speed, not bad. New tire grips better, new dual brake lever to make it right.
He’s of course already did a couple of runs, it’s climbing small grades no problem.
H e thinks it’s a bit fast. Heh, it’s just cruising.

Looking at a 1” spline roller to replace the 1.17” roller, that’ll give it a little more grunt. Little less speed won’t hurt it any.

I’ll get more pics next trip.
 
I brought it back yesterday for a few more upgrades, front tire basket, light mounts, a second bottle holder for spare gas, matching front and rear lights and reflectors.

Took it back, then out for a hard run, it’s definitely running low 20s for top speed, not bad. New tire grips better, new dual brake lever to make it right.
He’s of course already did a couple of runs, it’s climbing small grades no problem.
H e thinks it’s a bit fast. Heh, it’s just cruising.

Looking at a 1” spline roller to replace the 1.17” roller, that’ll give it a little more grunt. Little less speed won’t hurt it any.

I’ll get more pics next trip.
Look for older Lawnboy rollers I believe there were some around 1” to maybe 1.15. They are double knurled. They are on ebay sometimes. I have a few somewhere.

On the roller/ratio thing, think of the roller as a displacement drive. It moves a wheel, any size wheel the distance of its circumference. A 1” roller moves 3.14” per revolution put it on a 10” wheel or a 100” wheel and it going to move the same distance. So for any given number of revolutions they both will move the same distance. 3.14 x the diameter determines the distance a roller will travel per rev.

Now ad that to a time interval and you can determine speed. ie how many revs in a minute times the rollers circumference turns. Divide that by 12 gets feet traveled. Divide that by 5280 get miles, multiply by 60 gets speed.

2”roller at 4000: 6.28”x4000=25,120”
divide by 12=2093.3’
divide by 5280=.396 mi
.396x60=23.76 mph.

Now you can figure your rollers speed.
 
I just got a text, my brother finished his first dollar store run, good 10 miles.

I'm seeing this at 9:00 and thinking oh crap. Then he says 'smooth ride'.
Asked him did he need a headlight?
"Wore a headlamp."

Damn fool, but hey its doing what I built it for.
😁
 
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