Sprocket Size

[DAMIEN1307]

I just don't want to get a 44t and end up carboning everything up at like 3000rpm lol.

Thats very dependant on the type of oil your gonna use after breakin period, you already told me your gonna use Royal Purple synthetic 2 stroke so I don't think too much carbon build up is a real scenario here at all.

 

[Lassic]

Thats very dependant on the type of oil your gonna use after breakin period, you already told me your gonna use Royal Purple synthetic 2 stroke so I don't think too much carbon build up is a real scenario here at all.

Hm... I guess running at a lower RPM will get me much better fuel economy too, be much quieter, and keep the engine cooler then...

 

[Sidewinder Jerry]

Mr Jerry, with a Stock Zeda 80, about what rpm would I be at with a 44t sprocket at 20-25 mph? That is the real question I guess.

With the 44t around 6000 rpm will get you 25 mph and around 4665 will get you 20 mph. If you're a large person (200+ lbs) and have really steep hills (20%+ grade) you're going to need a lot of pedal assist to get up the hills when entering them at a slow speed.

If this is your situation then go with the 48t.

 

[Lassic]

With the 44t around 6000 rpm will get you 25 mph and around 4665 will get you 20 mph. If you're a large person (200+ lbs) and have really steep hills (20%+ grade) you're going to need a lot of pedal assist to get up the hills when entering them at a slow speed.

This actually sounds significantly better... I only weigh 150, and there are lots of hills but they aren't crazy steep. Thanks math wizard, I think I'll have to contact them to change my order.

 

[Lassic]

This actually sounds significantly better... I only weigh 150, and there are lots of hills but they aren't crazy steep. Thanks math wizard, I think I'll have to contact them to change my order.

I feel that at around 4500 rpm is most likely the absolute best possible cruising rpm... So I think this will work.

 

[Sidewinder Jerry]

I feel that at around 4500 rpm is most likely the absolute best possible cruising rpm... So I think this will work.

I weigh 240 lbs, my bike weighs 100 lbs, and I live in the mountains of Tennessee. Up to 30% grade hills are common here. I have a shifter bike and use a 33cc 4-stroke engine. I may hit downhill speeds of 45+ mph but may only be doing 8 mph going up some of them when having to enter them from a slow speed. My average speed is around 15 mph at wot on many of the roads I ride on. Average speed isn't cruising speed.

 

[Lassic]

I feel that at around 4500 rpm is most likely the absolute best possible cruising rpm... So I think this will work.

Alright friends, I submitted a request to change the sprocket to a 44t. Thanks for not giving up on me, you guys are the best.

 

[Lassic]

I weigh 240 lbs, my bike weighs 100 lbs, and I live in the mountains of Tennessee. Up to 30% grade hills are common here. I have a shifter bike and use a 33cc 4-stroke engine. I may hit downhill speeds of 45+ mph but may only be doing 8 mph going up some of them when having to enter them from a slow speed. My average speed is around 15 mph at wot on many of the roads I ride on.

One thing I've never heard people talk about before. Is engine braking going down hill safe? Does it wear out these little China Girls?

 

[Lassic]

One thing I've never heard people talk about before. Is engine braking going down hill safe? Does it wear out these little China Girls?

And I don't mean anything crazy, just practical.

 

[Sidewinder Jerry]

One thing I've never heard people talk about before. Is engine braking going downhill safe? Does it wear out these little China Girls?

I have a centrifugal clutch on my bike. For steep downhills where you may need to stop at the bottom do bump braking. This way you can keep yourself at a controlled speed that your brakes can stop you. When you're going downhill gravity and/or tailwind assist increases acceleration thus also increasing stopping distance.

This is where a good bicycle computer speedometer comes in handy. I prefer wired ones over wireless ones. Going downhill and/or having a strong tailwind at 30 mph can increase stopping distance by as much as 50-100+% compared to 30 mph on level ground with no wind.