trailmaster mb200-2

#1
im getting my trailmaster monday and see there is a 60 tooth rear sprocket that adds huge backend/torque. i was gonna buy that but see there is also a 72 tooth sprocket. i saw people saying they pop wheelies on this with a 60 tooth. how much difference would a 72 tooth be? is it worth it? will i die? lol will 5 feet of chain be enough? thanks.
 
#3
IIRC, the stock rear sprocket is 38T, so even the 60T should make quite a difference. I assume (never wise) that the torque converter sprocket is 10T. Also assuming that the torque converter is basically the same as other Chinese series 30 type knockoffs, it should have a theoretical ratio range of 2.7:1 to 0.9:1. You can calculate overall ratio by multiplying the primary drive ratio (torque converter) by the final drive ratio (sprockets).

38/10=3.8 (3.8::1 ratio) 2.7x3.8=10.26 (10.26:1 overall ratio) 0.9x3.8=3.42 (3.42:1 overall ratio, the torque converter would never reach the 0.9:1 overdrive though, which is why I used the word "theoretical" previously)

60/10=6 (6:1) 2.7x6=16.2 (16.2:1) 0.9x6=5.4 (5.4:1) Calculated top speed at 3600 rpm, CVT in 0.9:1 OD: 38 mph

72/10=7.2 (7.2:1) 2.7x7.2=19.44 (19.44:1) 0.9x7.2=6.48 (6.48:1) Calculated top speed at 3600 rpm, CVT in 0.9:1 OD: 31 mph

Because the MB200-2 has 19" OD tires (tire OD makes a difference, search "effective gear ratio" if not familiar with it), I don't think the 72T would be too large, ratio-wise, especially if you intend to ride rough terrain, steep hills; your chain/sprocket should be around 3.5" off the ground. @Rapidrob rides a torque converter equipped Hawg Ty on mountain trails, he could better advise you on this. @noseoil is another member who could advise you on torque converter equipped big tire bike gearing. The 60T might be a better choice for most riding conditions and should provide close to an inch of additional ground clearance compared to the 72T. Link to sprocket size chart below.

Yes, you will die, that is certain.

https://www.rollerchain4less.com/sprocket-diameters
 
Last edited:

SAS289

Active Member
#4
IIRC, the stock rear sprocket is 38T, so even the 60T should make quite a difference. I assume (never wise) that the torque converter sprocket is 10T. Also assuming that the torque converter is basically the same as other Chinese series 30 type knockoffs, it should have a theoretical ratio range of 2.7:1 to 0.9:1. You can calculate overall ratio by multiplying the primary drive ratio (torque converter) by the final drive ratio (sprockets).

38/10=3.8 (3.8::1 ratio) 2.7x3.8=10.26 (10.26:1 overall ratio) 0.9x3.8=3.42 (3.42:1 overall ratio, the torque converter would never reach the 0.9:1 overdrive though, which is why I used the word "theoretical" previously)

60/10=6 (6:1) 2.7x6=16.2 (16.2:1) 0.9x6=5.4 (5.4:1)

72/10=7.2 (7.2:1) 2.7x7.2=19.44 (19.44:1) 0.9x7.2=6.48 (6.48:1)

Because the MB200-2 has 19" OD tires (tire OD makes a difference, search "effective gear ratio" if not familiar with it), I don't think the 72T would be too large, ratio-wise, especially if you intend to ride rough terrain, steep hills; your chain/sprocket should be around 3.5" off the ground. @Rapidrob rides a torque converter equipped Hawg Ty on mountain trails, he could better advise you on this. @noseoil is another member who could advise you on torque converter equipped big tire bike gearing. The 60T might be a better choice for most riding conditions and should provide close to an inch of additional ground clearance compared to the 72T. Link to sprocket size chart below.

Yes, you will die, that is certain.

https://www.rollerchain4less.com/sprocket-diameters
38 tooth? As soon as the belt shifts it's over for the engine. Yeah I would be getting a 60 before the first ride. Maybe that's their way of restricting top speed. The bike is rated for 25 mph top speed. Governed Coleman 200's get 35+ with a torque converter and a 50 tooth.
 
#5
38 tooth? As soon as the belt shifts it's over for the engine. Yeah I would be getting a 60 before the first ride. Maybe that's their way of restricting top speed. The bike is rated for 25 mph top speed. Governed Coleman 200's get 35+ with a torque converter and a 50 tooth.
I just looked at a parts list that says it's 38T, which is what I remembered from some old threads. Yeah, that was a ridiculous choice that some "engineer" made.
 
#6
thanks. thats what i was looking for, more torque with the 72t for hills etc. i might get the 60 and then try a 72 later if its not enough. dont care too much about top speed. ive seen videos of stock mb200-2 going 45mph. i think it was cars and cameras on youtube. only engine "mod" ill be doing for now is removing the throttle stop screw, or grind it off if its welded. eventually ill get a stage 1 and 2 kit. the bike is for my 11 year old son. he has a chinese 125cc quad right now that runs good after 3 months lol. but i wanted him to have something thats probably gonna last him till his teens with proper maintenance.
 
#8
ive seen more than one site list the mb200-2 with a 46 tooth sprocket. i think the mb200-1 has a 38 tooth. either way im ordering the 60t tonight. along with new chain.
 
#9
bike will be here tomorrow. i ended up buying the 72t and 5 feet of chain. i may have to remove or modify chain guard from what ive read. the sprocket and chain wont arrive till next week maybe. but ill post a review on a complete stock after i get it put together after work tomorrow. then later swap the sprocket and review again.
 

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