40 Tooth Sproket Vs. 36 Tooth

[bairdco]

i don't really care about all that, i had a vintage stewart warner speedo that i played with and figured out it was off about 100' less in a mile, an was 4-5 mph faster than reality.

then it broke.

what i think is cool, though, is the guy a few posts up with the dyno'd motor RPMs at 14500.

that's like twice as many as normal.

if mine revved that fast, i'd go backward in time...

 

[stv1jzgte]

there is no way someone could be that far off if they do the roll out method.
if they are that far off then i'm sure they wouldn't be able to figure out how to mix oil in the gas either.

lol do a search on oil mixture!

When i first got into these lil motors i to went and got 1 of the cycle comps measured my wheel to the mm over and over to be sure 63kph was what it said on the flats screaming along. i hit a bump 1 day and the damn thing fell off the clip it sits in and i lost it.
So for a month or so after i figured well flat out screamin im doin 63.
borrowed a mates gps, again flatout on the flats 55kph so a 5 mph difference and i was bang on with my measurements.
Humbly im goin with the satellite!

 

[troyboy]

Im debating between purchasing a 40T or 36T for my bike.
Can anyone tell me the speed increase for each sprocket?
Were maxing like 29mph with the Stock 44T.
I live in Florida so no hills, and Id still like to have pretty good Pickup, so which should I chose?
Thanks

bradentonmotorbikes,

Back to the sprocket question......
40 tooth sprockets are the Cream of the Crop. Not to much of a sacrifice on the lower end. Anything less you should have some mods on your motor to help pull it along.
Better top speed with less vibrations are achieved with the 40 sprocket. If you go from a 44 tooth to a 36 tooth you may not get what you were looking to achieve. It will slow the heck out of your bike off the line.


Hope this helps.

Justin

 

[pauliedata]

to all ,i,ve readjusted my previous statement with an apology to all ,my mph was a wrong claim ,i was radar gun shot by my sheriff buddy today to verify my claim and stand corrected, sorry but i'm only doing 39 mph on 3 passes and that was my best pass ,so once again i apologize to all i was mistaken and will verify all claims before posting again. i am however correct on my rpms because i'm using a matco tools tach thank you and keep the wheels turning

 

[FileStyle]

bradentonmotorbikes,

Back to the sprocket question......
40 tooth sprockets are the Cream of the Crop. Not to much of a sacrifice on the lower end. Anything less you should have some mods on your motor to help pull it along.
Better top speed with less vibrations are achieved with the 40 sprocket. If you go from a 44 tooth to a 36 tooth you may not get what you were looking to achieve. It will slow the heck out of your bike off the line.


Hope this helps.

Justin

on my last build the "Happy Wahoo" I installed a 39t sprocket and compared to my 35t on my other ride. the 39t has good tourqe to pull ahead quickly but lacks on top end such as the 35t. but still less vibrations and low RPM's. but I agree ,anywhere from 40t to 35t is nice. just consider your environment! top speed "80cc",3500miles+,custom intake and exhaust,35t sprocket-41mph and I was tucked in a fetal position to reduce wind resistance! it was a good day,good humidity,little wind and that was pushing it! and my speedo is correct as it matches GPS within a tenth! any other such claims with a 44t and 35mph is unreal! the motor would sound like its at 14,000 rpm!

 

[Riding Rich]

I run a 36T and spin my motor about 12000 RPM.
Highly modified though.
Pulls good off the start PK80-J Ported and Piped.

 

[ken murphy]

sproket choice

Yes i do agree with you on that 100 percent.

A person on a bicycle has about as much or more wind resistance as a Tractor Trailer.

Check Out
Thunder Products - Performance carburetor and clutching for snowmobiles, motorcycles and ATVs.

Affordable Accurate tacometer that reads the spark.

No way to cheat it and make it read higher or lower.

This spring i'll get one and see what kinda RPM i really get.

With accurate RPM it is possible to calculate accurate speeds.
carburation is key

I'd really like to know my true speed.

Too much snow here now to even attempt it.

the 36 tooth is ok if u dont mind the slow start I haven't tried the 40 it sounds to me to be optimum but carb n pipe is key u have to let the motor breath.

 

[theblueboy]

bradentonmotorbikes,

Back to the sprocket question......
40 tooth sprockets are the Cream of the Crop. Not to much of a sacrifice on the lower end. Anything less you should have some mods on your motor to help pull it along.
Better top speed with less vibrations are achieved with the 40 sprocket. If you go from a 44 tooth to a 36 tooth you may not get what you were looking to achieve. It will slow the heck out of your bike off the line.


Hope this helps.

Justin

Hey Justin,
I just bought a 36t off of ebay and I'm waiting to receive it but I currently have a 44t on the bike.
I only get up to 26mph on flat and up hills at 16-19mph like this http://tinyurl.com/38ppv57.
I wanted to go faster like somewhere in between 30-40mph so I bought the 36t sprocket.
But you said something about it won't pull or go faster. I weigh about 116 and I'm 15yrs old.
I've done about 112 miles on the bike and I'm using 25:1 ratio in oil mixture. Here what type of bike
I bought. UPGRADED 80CC BICYCLE MOTOR ENGINE KIT MOTORIZED BIKE: eBay Motors (item 190374281365 end time Jun-18-10 17:52:17 PDT). So tell me if I should install it or not.

Thanks!
Andrew

 

[insomniacshotrods]

The 36 tooth lacks low end power but lets you go 35mph without reving the crap out of the happy time. I went from a 44 to a 36 and didnt like it at all so i bought a 41 but dont have my chain done yet..Ive ported the intake and exhaust ,cut the muffler ,cut open air cleaner, ngk sparkplug,after market coil wire.. If you want top speed put on the 36

 

[theblueboy]

The 36 tooth lacks low end power but lets you go 35mph without reving the crap out of the happy time. I went from a 44 to a 36 and didnt like it at all so i bought a 41 but dont have my chain done yet..Ive ported the intake and exhaust ,cut the muffler ,cut open air cleaner, ngk sparkplug,after market coil wire.. If you want top speed put on the 36

I just put on the 36t sprocket and I was a little disappointed to find out that it only gained 3mph faster. I went from a 44t to a 36t (which I currently have installed). With the 44t on I went 26mph on flat
and 16-19mph up hills. With the 36t I go 29 flat and about the same as when I had the 44t up hills which makes no sense. Probably because I weigh under 120 lbs is why there is no effect in power. But I was hoping to get up to 33-40mph on flat. I don't think I have broken in the motor yet so could that have something to do with it? Iv'e done about 116 miles on it and I use 25:1 Oil ratio. And what can I
buy to make it go faster. People keep talking about moded mufflers and carburators? Could anyone
fill me in and where can I buy them for cheap?

Andrew

 

[jauguston]

Using a Garmin GPS and a Tiny Tach with a 26" tire I got 30 mph at 7500 rpm with the stock single speed setup. I now have a Sick Bike Parts shifter kit with a 7 speed chain ring on the rear with the big first gear also from Sick Bike Parts as well as a 30t (36t comes with the shifter kit) front freewheeler sprocket. 6th gear 5100 rpm at 30 mph and 4300 rpm in 7th. My stock angle plug HT won't pull 7th gear on the flat ground. I'm 250 pounds.

Jim

 

[Alson]

I found out by lodting the intake and opening the gasket open more and porting the exaust open more I got 4mph more slso, they say with the expansion chamber the 36t is no problem on take off

 

[jauguston]

Alson,

The tuned pipe will have NO effect on your ability to start out from a stop. A SBP shifter kit will. I have a SBP shifter kit with a 30t front sprocket for the rear chain and a SBP 7 chain ring rear sprocket with a oversized first gear chain ring-Sweet!! No pedaling except to start the engine. First gear is great for going slow and 6th gear is 30 mph at 5100 rpm. It won't pull my 250# in 7th gear. Stock Grubee 66 slant plug motor.

Jim

 

[peeduh]

So what was the verdict brandon?

 

[solokumba]

I just switched over from my 44 to a 36. I also live in Florida so there are no hills. I've noticed a slight speed increase, but the best part is being able to cruise at a comfortable speed without feeling top end vibrations. It's a BIG difference. Smooth baby! Now I'm thinking what a 40 tooth would be like. Hmmmm...

 

[peeduh]

My roommate and I switched to a 36t sprocket and it made a def difference. Not only are we able to cruise without feeling bad vibrations but a def speed increase.

 

[Alson]

If you get the new style NT carb foe 66cc/80cc engine, some times they call it tne speed carb, itll give ya a little more speed, abd open the intake gasket more. I bought a aluminum intake and filed it open more with a rat tale file and opened the gasket opened more with the rat tale file by putting the gasket on the flange of the intake and file slow so I dont tare it. Carb cost about 30, then if you want more power get a expansipn chamber at SBP there about 67 bucks. But just the intake, qnd if you have a stock muffler, open it up more also with u should get about 4 more mphdthe file. Yo

 

[ferball]

One question I would ask before recommending a sprocket size is How much do you weigh? This makes a huge difference. I am a heavy guy and a 50t has the best performance for me as it allows the engine to stay in the power band for my weight. I hardly ever go full throttle as it gets scary at those speeds on these bikes (I am not a speed freak, and I did lay a motor bike down once would hate to do it again on a bike.) Even a 50t has plenty of top end for the likes of me and I love the low end as most of my driving is around town.

 

[Alson333]

Well if you fine with your speed and all stick with it, I was thinking a 44 tooth might be ok with you also. Anyway I got a 36 tooth and I get 38 mph. When I got 150 miles on it it seemed to rev higher, its just starting to break in I guess, but now my speedometer is messing up, it gets up to 35 mph then goes to 17, 24, 30 crazy I dont know the right speed now, but I can here it rev, and rev and rev alot more, dont know what to do about the speedometer

 

[Predator303]

I got from 44 to 34 also living on the coast and I still dont have to paddle to take off, so take the smaller one, you wont regret it. Just in case, order clutch pads for 5 bucks too.