Felt Fat Tire Ale build 99cc predator

I swapped to a 2.5" pulley on the jackshaft and gained 10mph top speed. This give me proof that the math is right about my speed estimates and shows that going with the variable pitch pulley will be perfect for my needs. 12.5:1 for take offs and 8.3:1 for top end (doubt I'll ever need those speeds anyway). With this setup I'm at 10:1 which is down from 12.5:1 I was running. With this setup I feel I need to pedal a little to help on takeoffs (not mandatory but I'm sure the clutch likes that I do) but top end much better and the bike is overall much smoother thanks to the lower rpms at my preferred 30mph cruising speed.

The variable ratios will really improve this bike.

I also picked up a tach today, it looks like the predator is idling at 1650 rpm roughly, clutch engages at around 2000rpm, although I admit I need to check it more to be sure since its raining and I only tested the new tach out very briefly.
 
Turned out great! I went with a rear mount tank as well on my 1903 although the top tube has a bit more volume. If you want to give the bike more of a vintage look you can find plenty of used old mower or minibike gas tanks. I started with a Briggs tank and felt that it looked like a mailbox so I just kept an eye on eBay for a while.

I also have the same fork with those loosening jam nuts. I find that just using two wrenches to get the second nut tight against the first is plenty. You might want to keep an eye on the nylon insert locking nuts considering you used loctite on the acorn jam nuts. Loctite is typically not compatible with plastics. A product called Vibratite works pretty good in those applications but you are still better off just getting a two wrenches for good torque.

Anyway, I really like the build.
 
Thanks for those pulley size so you swapped the 5'' with a 2.5 pulley. And you put the variable pulley on the clutch or the jackshaft going back to the wheel ( Torque Transmissions ) nice web site has veriable pulley.I'm not shure how to add gear size for pulley's I could figure it out if it was a jeep
 
buggy064 said:
Thanks for those pulley size so you swapped the 5'' with a 2.5 pulley. And you put the variable pulley on the clutch or the jackshaft going back to the wheel ( Torque Transmissions ) nice web site has veriable pulley.I'm not shure how to add gear size for pulley's I could figure it out if it was a jeep
Click to expand...

It is the same math, just one uses number of teeth and the other use the pulley diameter.
 
Thanks Harold. I used the nyloc nuts dry and put loctite on the acorn nuts then tightened them together using 2 wrenches, I doubt their going anywhere. :)

The clutch is still 3" running to a 5" pulley on jackshaft then a new 2.5" pulley running to the 15" whizzer pulley.

You divide the driven pulley by the drive pulley. So take 5 divided by 3 giving you 1.66
Then take 15/2.5=6
Then take your 1.66 and multiply by the 6
1.66*6= 9.96

Or a 10:1 ratio
 
Yes from max torque pulley is 3". I think the roller bearing was a worth while upgrade over the bushing. I will eventually install a standard pulley and try a manual clutch setup to see how I like it, I have a few things I want to play with on a manual clutch setup.
 
Thanks for that I figured it out how to figure out final gear ratio anyone ever put two pulley size's going back to the rear wheel make like a hi lo rang just pull up on the belt and move it over to the next pulley
 
Went out to put a few miles on the bike this nice 68* sunny day and had a problem. About 4 miles from home the I lost one of the retaining collars on the jackshaft (have since drilled the shaft to sink the set screws into it), even though everything on the bike has lactite that one collar managed to come loose allowing the shaft to slide sideways and mess with belt alignment and chewing my rear belt a bit. I was able to fix it quickly get it back home and save the parts (except now my idler pulley is warped so I need a new one).

I got it all put back together and noticed that my rear coaster brake seems to be toast. The rear wheel seems to be very tight and sometimes even locks up completely. When I can make the push the bike a few feet you can see the rear sprocket move back and forth (clockwise/ counter clockwise) roughly 1/8"-3/16" with the chain removed, not sure if this is normal or not but I don't think its normal.

Either way I'm pretty sure the coaster brake is toast and needs rebuilt or replaced. I'm not sure if there is an adjustment that can be made or if I have to replacement or if it can be rebuilt.

Anyone have any advice? The bike stops fine for my needs so I will be rebuilding or replacing with another coaster brake so I don't have to add another brake handle.

I am going to call the local bike shop tomorrow to check my options.
 
Try putting that spacer you have on the axel on the other side of the nut , that is the nut that keeps your coaster adjusted and where it should be.
BTW ...Your bike is very cool!!! Belt drives are just so nice to ride ( quiet )
 
Thanks, yes I do enjoy he belt drive, nice and quiet, no grease to fly around, less maintenance, etc.

Not sure what you mean. I have the 2 washers (spacers) on the outside of the nut touching the frame.
 
Got it fixed it was a bearing, the local bike shop fixed it for me for free right on the spot, great group of guys.

Played with a few things and saw a max speed of 49mph today, fun for a minute but definitely not my cruising speed, no thanks.

Its amazing how much easier these predators start with a different carb thats tuned, no need for the choke anymore and fires on the first pull every time.
 
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