Best gear for speed 24inch tire

[NARLEY PEDALSON]

I am putting togetter a happy time kit on a 24inch bike and i want to cruise at a low rpm at desent speed and be able to try for 50mph on those emtpy dark roads at night

the engeine will be blueprinted from the get go so it will have a bit more then stock power to turn a lower geared set up

so what would be the best T rear sprocket for my bike

 

[max350]

I am putting togetter a happy time kit on a 24inch bike and i want to cruise at a low rpm at desent speed and be able to try for 50mph on those emtpy dark roads at night

the engeine will be blueprinted from the get go so it will have a bit more then stock power to turn a lower geared set up

so what would be the best T rear sprocket for my bike

Which engine? a china engine can not run 50mph with just a blueprint!

 

[motorpsycho]

if you gear it lower,l you will get more bottom end torque, not top speed.
If you want top speed ypu need to gear it higher (smaller rear sprocket)
a 36 tooth woudl give you some pretty decent top speed, but your take off power will suffer.
a 36 tooth may get you close to 40 mph (MAYBE ON A GOOD DAY), but it may take a long time to get there. think of taking off in a car from a dead stop with a manual transmission in 3rd gear. sure, it'll go but you have to feather the clutch, rev the engine and it will take awhile before the car will get up to speed.

you can get smaller than 36 tooth rear sprockets but they are expensive.
the smaller the rear sprocket, the more top speed / less bottom end power you will get.
the bigger the rear sprocket, the more bottom end take off power / less top speed you will get.

if you want to TRY to get to 50 mph with a china engine, you will need to port and polish the head, shave the head for more compression, add a hi-perf carb, high flow air filter, expansion chamber, better plug and plug wire and a shift kit with at least a 7 speed rear hub.

 

[Neon]

a shift kit with at least a 7 speed rear hub.

I agree with you there, but it has to be a megadrive cassette or something along that line. The standard rear cassette gear spread has not changed since the 5 speed. The tooth count has been 28t-14t for years, at least any that i have run across. They fiddled with the in between gears to get the extra speeds. So it doesn't matter if it's a 5,6 or 7 the end result will be the same.
Might consider larger wheels instead of the 24. Even 26 would be better for top speed than 24. But again acceleration will suffer slightly. What happened to the CR85 project?

 

[NARLEY PEDALSON]

I agree with you there, but it has to be a megadrive cassette or something along that line. The standard rear cassette gear spread has not changed since the 5 speed. The tooth count has been 28t-14t for years, at least any that i have run across. They fiddled with the in between gears to get the extra speeds. So it doesn't matter if it's a 5,6 or 7 the end result will be the same.
Might consider larger wheels instead of the 24. Even 26 would be better for top speed than 24. But again acceleration will suffer slightly. What happened to the CR85 project?

well um in testing the rear driver broke so i replaced the whole weel set then i was driving across grass and tryed the to rip a roster tail but found a geat way of de spoking a rime by dropping the cluch in 2ed gear so new rim again but this time from the garbage and i cold not get the chain to say on whats so ever and it took me about 10days to figer out that the frame was out of true

all in all it was a ton of fun for maybe 2 miles and i never toped her out

 

[NARLEY PEDALSON]

please answer this at least

sorry its a 25inch tire so its not normal

anyways with what rear spocket chould i use to do 50mph if my engine had the power to crank over that kind of gearing

 

[Neon]

Use jpilots gear ratio calculator and figure it out for yourself. It's a sticky near the top of this thread "Wild In The Streets" that is.

 

[Easy Rider]

Here's my bike with 24" tires. I ran a 52 tooth rear sprocket at the Grange race and I was radared at 41mph.

 

[5-7HEAVEN]

Here's my bike with 24" tires. I ran a 52 tooth rear sprocket at the Grange race and I was radared at 41mph.

The boy is asking advice about a Happy time's performance w/a 24" tire, not a Morini.

 

[Easy Rider]

The boy is asking advice about a Happy time's performance w/a 24" tire, not a Morini.

Well since your the resident "know it all" I mean "expert", throw in your two cents. People usually use a smaller tire for low end reasons. More pop off the line or coming out of the corners. A HT motor using a 24" tire and if he wants to hit 50mph probably can't be done. Your closest bet would be using a SBP shift kit. The problem is the lack of power to maintain the speed unless you're going downhill.