motorized bicycle 44 to 36 tooth sprocket swap

TANGO said:

Mapbike I am a Die Hard Gear Head . So I want some off the Line response . Sure I know it's not a Motorcycle . That's why I was thinking of going with the 40 Tooth . But you know how these Gears work out and I thank you for sharing this info with me . I will be using a 66cc Super Rat yes Marked as a 49cc Ha-Ha being a Larger Engine if I run the 36 Tooth Gear how well will it take off from a standing start or will it buck and Lug ?

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If you want a sprocket that will let you take off from a stand still you may need to look into soemwhere in the 50T - 60T range, even with a 44T sprocket unless you way about 75lbs and slip the clutch a bit you can't take off from a stand still.

maybe a 20MPH top speed with that big of a sprocket and a cruise speed of about 15MPH would be my guess....no good at all IMHO!

these engine dont have that kind of power or the kinda gearing for taking off like that.

Now you could get a shift kit from SBP and that would get you to where you could likely slip the clutch a little and easily take off without peddling, but like I said these engines dont have the power or the gearing for taking off like a motorcycle.

I would leave the "Super Rat Engine "alone if it were me, just get a standard 66cc engine that you can mod to run the way you want it too, the many of the parts that will get a standard 66cc engine running and pulling pretty good wont work on that "Super Rat Engine", until we have a good selection of spare parts and some upgrades for the rat engine I wouldn't mess with it myself.

Plan on peddling your bike for a few feet before you engage the clutch TANGO, 99.?% of us do.

Peace

Built a diy 4 stroke titan 50cc shifter bike. The motor is mounted on the top tube near the handle bars. The handle bars are above the motor for turning.
It is a dual suspension bicycle, my back does not like hard tail frames!

Uncle Ron weighs near 300 #. I have a different cassette on the rear wheel, low gear is 34 tooth for starting, it is a 7 speed cassette. (have since bought a cassette with a 38 tooth low gear = 5 speed)

Have more gear ratio in the system for power. The little motor makes me laugh when riding and going thru the gears. In the power band the little motor pulls like a small horse.

In fifth gear it is about 18:1 final ratio pullin me at 32 or 34 mph with gps = very accurate. The chains rub each other in 6th gear = would be nice for crusing on the flats or slight down grade.

Ron never has to pedal starting out even in the grass, but usually pedals for one or two pedal turns. The 38 tooth rear sprocket would be better for mud or the woods. This fall/winter I would like to put a hf eng and a comet cvt in my stretch cruiser. That would be near the ultimate build for me. And closer to the ground!! Yes!

Ron .

No offense intended her eat all but what you are talking about here with that 4 stroke set up is an entirely different ball game then the 2 smokers and there is actually no comparisons that can be made in the gearing set up between the two for the most part, you have a centrifical clutch......big difference in the manual clutched 2 stroke China Girls in the gearing department...... if soemone wnats to be able to take off without peddling

I said all of this to eliminate any confusion this might cause TANGO if he is not aware of the differences in what he is looking to do verses what you just described.

Peace

NEAT TIMES said:

Built a diy 4 stroke titan 50cc shifter bike. The motor is mounted on the top tube near the handle bars. The handle bars are above the motor for turning.
It is a dual suspension bicycle, my back does not like hard tail frames!

Uncle Ron weighs near 300 #. I have a different cassette on the rear wheel, low gear is 34 tooth for starting, it is a 7 speed cassette. (have since bought a cassette with a 38 tooth low gear = 5 speed)

Have more gear ratio in the system for power. The little motor makes me laugh when riding and going thru the gears. In the power band the little motor pulls like a small horse.

In fifth gear it is about 18:1 final ratio pullin me at 32 or 34 mph with gps = very accurate. The chains rub each other in 6th gear = would be nice for crusing on the flats or slight down grade.

Ron never has to pedal starting out even in the grass, but usually pedals for one or two pedal turns. The 38 tooth rear sprocket would be better for mud or the woods. This fall/winter I would like to put a hf eng and a comet cvt in my stretch cruiser. That would be near the ultimate build for me. And closer to the ground!! Yes!

Ron .

Click to expand...

mapbike said:

If you want a sprocket that will let you take off from a stand still you may need to look into soemwhere in the 50T - 60T range, even with a 44T sprocket unless you way about 75lbs and slip the clutch a bit you can't take off from a stand still.

maybe a 20MPH top speed with that big of a sprocket and a cruise speed of about 15MPH would be my guess....no good at all IMHO!

these engine dont have that kind of power or the kinda gearing for taking off like that.

Now you could get a shift kit from SBP and that would get you to where you could likely slip the clutch a little and easily take off without peddling, but like I said these engines dont have the power or the gearing for taking off like a motorcycle.

I would leave the "Super Rat Engine "alone if it were me, just get a standard 66cc engine that you can mod to run the way you want it too, the many of the parts that will get a standard 66cc engine running and pulling pretty good wont work on that "Super Rat Engine", until we have a good selection of spare parts and some upgrades for the rat engine I wouldn't mess with it myself.

Plan on peddling your bike for a few feet before you engage the clutch TANGO, 99.?% of us do.

Peace

Click to expand...

hello Mbs ---Awsome read cheers
i have the 66 superrat and can confirm with an expansion chamber those engines change alot in the torque department.....the power down low to mid range increases by an impressive 20%. im still running the standard 44 tooth and im a big guy 100kg and take off is no probs with a push off the road.....
I was also contimplating the smaller sprocket but have decided to keep the 44 as i am having way too much fun on the hills...

mapbike

That is a good point about manual clutch vs centrifical clutch when starting from dead stop.

I actually did not consider that!! duh, my bad.

Ron..............

ratrod said:

hello Mbs ---Awsome read cheers
i have the 66 superrat and can confirm with an expansion chamber those engines change alot in the torque department.....the power down low to mid range increases by an impressive 20%. im still running the standard 44 tooth and im a big guy 100kg and take off is no probs with a push off the road.....
I was also contimplating the smaller sprocket but have decided to keep the 44 as i am having way too much fun on the hills...

Click to expand...

Good deal..........I have no experience with the superrat engines, might try one some day if we get a good selection of parts on the market and some good mod parts.

yep 44 tooth is good for not having to peddle much or for a push off and a little slip of the clutch for just a second, good on hills also, but with a well tuned and slightly mod-ed engine a 36T does pretty good on the hills around here, we dont have mountains but we do have some fairly good hills and I never have to peddle up a hill, but then again if some of them were twice as long I probably would have to help it a bit at the top.

Good to hear your have such a good time with the superrat, keep us all posted on how it works out long term......

Peace

NEAT TIMES said:

mapbike

That is a good point about manual clutch vs centrifical clutch when starting from dead stop.

I actually did not consider that!! duh, my bad.

Ron..............

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Hey Ron,

Was not trying to be a butt head about things in my post, I hope you understand..........

And by the way Uncle Ron..... get us a pic of those bikes up on here........ sounds like a real beast you got thre with that 38T and the shift kit set up.....

Peace

Well I got Burned on that Super Rat Engine Order . Maybe it's Better off that way . So Now the Build changed to a 4 Stroke 2.8 H.P / Will be mod-ed to near 4 H.P . I will be running a #41 10 Tooth Centrifugal Torque Clutch with #415 Chain . The Question I have Now what Sprocket Gear would be best to run ? On the Mini Bike that Engine came off of it had a Large Sprocket Something over 60 Teeth . Sure it has way smaller Tires then a Bike . I am thinking of going with a 44 Tooth Sprocket with this 4 Stroke . What are your thought's on this ?

Here is the Engine -> http://motorbicycling.com/f37/97cc-4-stroke-26-bike-30534.html

mapbike

That was an appropreate post about the clutch`s from a dead start. I was not "paying" enough attention ! lol

I posted pic`s of the diy shifter bike somewhere, won`t let me post them again. Difficult to take more pics now the way it is packed in the garage. Should do a build thread of it this winter. It works great and only require`s a few shift kit parts, sort of a economy build. Any motor with the 76mm clutch bolts up nicely.

Tango, what kind of gear reduction are you using. Guess I could read back thru all the posts!! That 4 stroke should be aw-sum.

Mapbike, will send you some pics with the others .

Ron

Ron you can repost the pics if you will follow these simple instructions.

Just go to the folder that the pic is in, then right click on it, then in the multiple choices that appear click edit, at this point you should be taken straight into MS Paint program with your pic showing, now at the top of that window in Paint, click ( image ) now when you do this another multiple choice drop down will appear now click stretch/skew, you should now be looking at a window that will have 4 resizing options, dont pay any attension to the 2 lower ones only look at the 2 upper areas the first one should be highlighted so just type in 99 and tab down and type 99 in the next one as well then click OK.

the pic will be very slightly reduced in size but not enough to even be noticable.

Now go up to the top of the paint page and click the FILE button and then click on SAVE......NOT SAVE TO.........Just ( Save )

Now close the Paint window and the picture folder and go through the normal steps on the forum for posting the pic and you should get it right back up her eagain this way, I do this all the time when posting the same pic multiple times, and if you want to ever post it again just go through the same steps but instead of putting 99 in those 2 boxes put 101 and that will keep the pic in it's desired size as you toggle back and forth between 99 & 101 each time you post that same pic.

I hope I explained this clearly, I'm not very technical an there may be a better way but this is the way I figured out to make it work so thats how I do it.

There is one other way that works also, if you have any trouble with doing it like described above.

Hope this helps ya bud

Peace

NEAT TIMES said:

mapbike

That was an appropreate post about the clutch`s from a dead start. I was not "paying" enough attention ! lol

I posted pic`s of the diy shifter bike somewhere, won`t let me post them again. Difficult to take more pics now the way it is packed in the garage. Should do a build thread of it this winter. It works great and only require`s a few shift kit parts, sort of a economy build. Any motor with the 76mm clutch bolts up nicely.

Tango, what kind of gear reduction are you using. Guess I could read back thru all the posts!! That 4 stroke should be aw-sum.

Mapbike, will send you some pics with the others .

Ron

Click to expand...

For re-posting pics, cant you just go into userCP (control panel)at the top of each page, and down the bottom left there is an attachments tag, click that, find your pic, and re-use it.

I could be wrong, but that works on most vbulletin boards

Find the picture you want to use, then right click and copy the shortcut, start a new post, and right click and paste into the new post
http://motorbicycling.com/attachments/f42/35504d1303551385-first-build-mongoose-ht66-sdc10954.jpg..OK, the pic doesn't come up a thumbnail preview, but it is the same picture.

And back on topic, I'm waiting for a 36t sprocket, it should have come yesterday. I'm very happy to hear that it can still pull a MB up hills, because that is my favourite place to ride.

Now dont expect much pull on really steep or long hills with a 36T, but yes it does pretty good on what I would call moderate hills if there are a few other mods done to boost the torque of the engine a bit more than it is stock.

Peace

Dr. Dognuts said:

For re-posting pics, cant you just go into userCP (control panel)at the top of each page, and down the bottom left there is an attachments tag, click that, find your pic, and re-use it.

I could be wrong, but that works on most vbulletin boards

Find the picture you want to use, then right click and copy the shortcut, start a new post, and right click and paste into the new post
http://motorbicycling.com/attachments/f42/35504d1303551385-first-build-mongoose-ht66-sdc10954.jpg..OK, the pic doesn't come up a thumbnail preview, but it is the same picture.

And back on topic, I'm waiting for a 36t sprocket, it should have come yesterday. I'm very happy to hear that it can still pull a MB up hills, because that is my favourite place to ride.

Click to expand...

quote:" Now dont expect much pull on really steep or long hills with a 36T, but yes it does pretty good on what I would call moderate hills if there are a few other mods done to boost the torque of the engine a bit more than it is stock".

Peace

Today I went up a pretty long step hill with my 36 tooth cog. it did a surprising job. I do have a SBP tuned pipe and that helps it go quite a bit better. I went all the way across town and back over some pretty steep hills with my little skyhawk and a 36 cog. There were only two spots where I actually had to pedal. the rest of the ride I just hung on, smiling all the way.

It looks like my gas mileage also has increased. For the trip there and back I used about a quarter tank of gas and I'm thinking that that was over 20 miles. Going at a pretty good clip. I didn't do any checking with my Iphone so I don't have the direct data but I think I did it in really good time.

I think that if you are going to go with a 36 its a good Idea to have a tuned pipe or a stronger motor (like a morri)

mike

My comment about not "expecting to much pull" was refering to the fact that if a hill is fairly steep and very long you may have to peddle up the last bit of it, but yes you are right, with a good tune and good exhaust the 36T does work well, I have a 36T on one bike a 34T on another and a 41T on another.

I dont have to peddle any of mine up the hills around me because of the mods I've done to my engines, so they pull pretty good, but I have been on some hills that my 41T sprocketed bike will do better than the ones with the smaller sprockets.I consider " Pulling Good " as never having to peddle accept for taking off, i want mine to start a hill at say 30-32mph and finish at the top doing 20-25mph, i get this done around here most of the time.

A good free flowing exhaust and a well tuned carb along with correct chain tension and good free rolling wheel bearing, brakes not dragging ect... is the key to getting the most of the bike with any gearing used but these things start making a bigger difference when the ratio gets higher. (Smaller Driven Sprocket)

I've even got a 32T I plan to be putting on one of my bikes in the future but I know it will have to be pulled by a very well tuned engine with the right mods or the negine just simply wont pull it good, if I get it right I will have a very nice cruising speed on the flat on the not so windy days, I'm hoping for a comfortable cruise speed of 35-36mph and a top in the 43-45mph range.


Peace

retromike3 said:

quote:" Now dont expect much pull on really steep or long hills with a 36T, but yes it does pretty good on what I would call moderate hills if there are a few other mods done to boost the torque of the engine a bit more than it is stock".

Peace

Today I went up a pretty long step hill with my 36 tooth cog. it did a surprising job. I do have a SBP tuned pipe and that helps it go quite a bit better. I went all the way across town and back over some pretty steep hills with my little skyhawk and a 36 cog. There were only two spots where I actually had to pedal. the rest of the ride I just hung on, smiling all the way.

It looks like my gas mileage also has increased. For the trip there and back I used about a quarter tank of gas and I'm thinking that that was over 20 miles. Going at a pretty good clip. I didn't do any checking with my Iphone so I don't have the direct data but I think I did it in really good time.

I think that if you are going to go with a 36 its a good Idea to have a tuned pipe or a stronger motor (like a morri)

mike

Click to expand...

Hi,

I put together my friends Raleigh singe speed together using the grubee 66cc kit. I used the stock kit sprocket. I believe a 44tooth. It tops out on a flat surface at 40mph wide open. It has the cbs carbon I tuned and a modded stock exhaust. We are looking for a higher cruising speed, I would assume a larger rear sprocket would get a higer top speed but I've been reading that a smaller rear sprocket gets a higher top speed. What can be done gearing wise to better my top speed?

so how fast can you go with the 36t sprocket? cause i have a 44 and am considering swapping mine to a 36 to get a higher top speed? how is accelration? and top speed with the 36?

The difference between a 44 and a 36 is about 20% or around 5-6mph. So just think, you gain a 20% top speed if your motor can pull it, but you lose 20% of your climbing power.

I put a 38 on my bike, and it starts a lot easier! (wheel turns engine less times per revolution). It is a 48cc and runs about 35mph. Good enough for me. I am not bothered that I have to pedal away from stoplights and pedal assist up some really steep hills. I get around well.

I read that for every too lost or gained it is a 1mph difference in top speed. My friends bike im working on tops of at 40mph and that's engine at recline. I will be building one when I move closer to work in a few month hopefully. I want a 30+mph cruising speed. I plan to portmatch intake/exhaust and get a boost bottle with a 36T sprocket that way I can avoid a shiftkit because it's $200.

Just a word to the wise. The wheel bearings in most of these bikes are cheap! The grease they use is cheap! It gets hot at speed and will sling out of the race! Put high speed greese in your wheels before you get hurt! Don't use Wal Mart stuff! I've crashed hard, it's no fun

That is true, but almost every bike I've ever had (unless it had sealed bearings) had a little dab of cheap brown grease that looked like earwax. I habitually go over all the bolts, bearings, and bushings of any bike.