recumpence
1 GW
Hey Guys,
Here is a simple item (of course, I say "Simple" as a relative term. This darn thing took me an entire day to make). This is a 10 tooth freewheel. The story behind this item is;
My Catrike has a 26 inch rear wheel. I have been running a Astro 10 turn 3210. However, it is a bit anemic for someone like myself who is used to more power. So, I wanted to gain a bit, but without spending a fortune, or going to another reduction stage. I had a 6 turn 3210 on the bench. However, in order to retain the same 33 mph top speed (perfect for a 3210), I would have to gain some serious increase in reduction. I was, previously, running a 16 tooth freewheel and a 56 tooth rear chainring. Also, I was running a 20 tooth motor pulley. Well, the math showed a 18 tooth motor pulley, 62 tooth rear chainring (the largest chainring that is reasonably priced at $52. Going to a 75 tooth would cost $190!). That leaves a freewheel tooth count of 10. Hmm, how to do that? Well, a sprague would never hold the torque, besides I have always wanted to try this. So, to that end, I made this part.
It consists of a machined (narrowed) #40 sprocket. I bored it out and added a needle bearing for freewheeling. Then I machined an adaptor to mesh with the 16 tooth freewheel. I purposely used a ACS freewheel because of their very ow resistance freewheeling. A White Industries freewheel has alot of drag if spun too fast. This freewheel allows me to pedal without too much drag from the tiny sprocket spinning a large freewheel.
How does it perform? AWESOME! This thing pulls really hard, now. It used to be kind of a pooch to say the least. I mean, it was fun to ride and very efficient. But, it was not torquey. Now, this thing pulls HARD! If I get hard on the throttle in mid corner, it will spin the tire a bit. I am very surprised. Also, my efficiency is only 19wh per mile at 20mph without any pedalling. Also, that WH only goes up a small amount if I am really hard on it.
This is my favorite setup so far, per dollar. There is some chain noise with that tiny sprocket. But, it is not too bad.
Anyway, enjoy the pictures.
Matt
Here is a simple item (of course, I say "Simple" as a relative term. This darn thing took me an entire day to make). This is a 10 tooth freewheel. The story behind this item is;
My Catrike has a 26 inch rear wheel. I have been running a Astro 10 turn 3210. However, it is a bit anemic for someone like myself who is used to more power. So, I wanted to gain a bit, but without spending a fortune, or going to another reduction stage. I had a 6 turn 3210 on the bench. However, in order to retain the same 33 mph top speed (perfect for a 3210), I would have to gain some serious increase in reduction. I was, previously, running a 16 tooth freewheel and a 56 tooth rear chainring. Also, I was running a 20 tooth motor pulley. Well, the math showed a 18 tooth motor pulley, 62 tooth rear chainring (the largest chainring that is reasonably priced at $52. Going to a 75 tooth would cost $190!). That leaves a freewheel tooth count of 10. Hmm, how to do that? Well, a sprague would never hold the torque, besides I have always wanted to try this. So, to that end, I made this part.
It consists of a machined (narrowed) #40 sprocket. I bored it out and added a needle bearing for freewheeling. Then I machined an adaptor to mesh with the 16 tooth freewheel. I purposely used a ACS freewheel because of their very ow resistance freewheeling. A White Industries freewheel has alot of drag if spun too fast. This freewheel allows me to pedal without too much drag from the tiny sprocket spinning a large freewheel.
How does it perform? AWESOME! This thing pulls really hard, now. It used to be kind of a pooch to say the least. I mean, it was fun to ride and very efficient. But, it was not torquey. Now, this thing pulls HARD! If I get hard on the throttle in mid corner, it will spin the tire a bit. I am very surprised. Also, my efficiency is only 19wh per mile at 20mph without any pedalling. Also, that WH only goes up a small amount if I am really hard on it.
This is my favorite setup so far, per dollar. There is some chain noise with that tiny sprocket. But, it is not too bad.
Anyway, enjoy the pictures.
Matt