2 stroke vs 4 stroke on hills

Thunderlipz

New Member
Joined
Jul 12, 2019
Messages
2
Just made my first motorized bicycle out of a bike that's been sitting for over 2 years used a 50cc 2 stroke eBay kit and it it's a lot of fun but can't handle hills just wondering if I bought a 50cc 4 stroke with a belt drive would it be enough? or should I go for a 80cc 2 stroke?
 


extremeodd

Active Member
Joined
Mar 30, 2019
Messages
287
If you want to make the bike handle hills better but not spend too much money, look into higher tooth count sprockets.

Your kit more than likely came with a 44t which is a decent all-around sprocket but it can fall kinda flat when it comes to a stock motor and hills. I would suggest maybe a 48 if you only need a little more torque or 50+ for way more torque.

Do keep in mind that increasing the tooth count will increase torque at the expense of top speed.

Assuming 8k rpm, 26in wheels:
36t - 42 mph
40t - 38 mph
44t - 34 mph
48t - 31 mph
50t - 30 mph
52t - 29 mph
54t - 28 mph
56t - 27 mph
60t - 25 mph
64t - 24 mph
66t - 23 mph

Now keep in mind these numbers are rounded and will vary from bike to bike, but that is the rough breakdown of speed vs sprocket size.
 

Old Busted Hotness

Active Member
Joined
Jul 2, 2018
Messages
328
Can't say how a 2-stroke would do, but my 4-stroke pulls 320 lbs of fat bike and fat rider up a 6% grade at 15 mph. No pedalling.

Huasheng 49cc, Grubee 5:1 belt drive, 44t sprocket, 24x3 tires. Tops out at 35 mph on level ground.
 

Thunderlipz

New Member
Joined
Jul 12, 2019
Messages
2
im from the uk most websites wont ship parts to me so my options are slightly more limited here is the set i've been looking at HERE hopefully that will work with stock belt drive
 
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