Has anyone bought one of these?

[Sidewinder Jerry]

Ahhh, so your bike bears the "Mark of the Beast" then Jerry...lol.

Not my bike but a 4 speed freewheel I once built does.

4 Speed Freewheel

It has been some time since I've last built a 4 speed freewheel. Several on here have complained about the gear ratios being too close together on their shifter builds. The 4 speed freewheel is an easy and affordable way to widen the range between the ratios. It'll also helps to reduce cross...

motoredbikes.com

 

[Sidewinder Jerry]

I'm not sure gears would be worth the trouble. Could be that has enough power without. I just fear the chain being a weak link with a cassette. The drive chain on our china doll engines is bigger than a 1 speed chain for a reason.

If you'll read the thread I posted I address that issue as well. I personally use a Shimano HG-71 chain that was designed for ebikes. It's held up great for over 2 years now. So then, what becomes your biggest chain issue would be cross-chaining. By reducing the number of cogs you're using it'll reduce the lateral cross-chaining affect.

Bicycle's have the jumps between cogs close because even the best of human legs can't generate but about 1/3 hp. This is another reason I tell shift kit builders with higher hp engines to make the jumps larger between the gear ratios.

Just so you'll know the Late KC Vale built several china doll shifters. If you have a china doll that produces around 3 hp or so run it through an IGH. If it's one of those engines producing more than 5 hp run it through the bicycle gears and reduce the number of cogs as well as making the jumps between the cogs bigger.

 

[cloakedvillain]

If you'll read the thread I posted I address that issue as well. I personally use a Shimano HG-71 chain that was designed for ebikes. It's held up great for over 2 years now. So then, what becomes your biggest chain issue would be cross-chaining. By reducing the number of cogs you're using it'll reduce the lateral cross-chaining affect.

Bicycle's have the jumps between cogs close because even the best of human legs can't generate but about 1/3 hp. This is another reason I tell shift kit builders with higher hp engines to make the jumps larger between the gear ratios.

Just so you'll know the Late KC Vale built several china doll shifters. If you have a china doll that produces around 3 hp or so run it through an IGH. If it's one of those engines producing more than 5 hp run it through the bicycle gears and reduce the number of cogs as well as making the jumps between the cogs bigger.

View attachment 196593

There somewhat of a collectors item but suntour made 14 to 38 tooth 5 speed freewheels. Rivendale had Sensah make 12-55 tooth cassettes but you can really tinker with the tooth counts, number of speeds and so on with a cassette.

 

[Sidewinder Jerry]

There somewhat of a collectors item but suntour made 14 to 38 tooth 5 speed freewheels. Rivendale had Sensah make 12-55 tooth cassettes but you can really tinker with the tooth counts, number of speeds and so on with a cassette.

I've found about the biggest jumps a derailleur can make is 6 teeth between cogs. I know some 7 speed freewheels do (34,24,22,20,18,16,14) but the 34 is riveted to the 24 it also makes the 34 prone to bending. With the smaller cogs a tooth count higher than 6 causes the chain to want to jump completely over the next cog when shifting to a higher gear.

I've actually tested the 4 speed freewheel (34,28,22,16) out I built and found it worked perfectly; shifting up or down.

4 Speed Freewheel

It has been some time since I've last built a 4 speed freewheel. Several on here have complained about the gear ratios being too close together on their shifter builds. The 4 speed freewheel is an easy and affordable way to widen the range between the ratios. It'll also helps to reduce cross...

motoredbikes.com

Using a shift kit with a 44t drive sprocket and 34 chainring the reduction range for the 4 speed freewheel would be 30.67-14.32\1.
Using this freewheel with a 6 hp engine that could at least hit 8000 rpm on 29" wheels would give you a top speed of 48 mph. With the 30.67\1 first gear you'd be able to go up any hill with no problem at least 17 mph starting from a complete stop.