How fast does your mini dirt bike go?

[roost]

that sprocket wont fit as it has 16mm hole and Lifan use 20mm hole and it is 420 pitch Lifan is 428. I ave been looking every where for a 17 for Lifan with no luck including ebay , i'm just wondering if any one knows of any other model bike that will fit?

 

[tysons_201]

maybe a ct or xr sprocket will fit? Going to take my sprocket into the local dealers tomorrow and see if they have one.
How much do sprockets cost from a motorcycle dealer usually?

 

[mason1]

Usually about $20.

 

[Mack]

yep about that

 

[tysons_201]

anyone know of any sprockets that fit off other engines like a honda engine or something?

 

[roost]

yep Honda CB125 comes in 14 , 15 , 16 , 17 made by JT sprockets , all you have to do is hone it out about 1mm on the inside i have got one on its way cost $20

 

[tysons_201]

yeah i reckon ag175 will fit. only 1mm needs to be taken off to make it fit and everything should be right.

 

[FLICK]

Ducars max out at about 70km/h on 14/37 sprockets with a 12" wheel.

60km/h is comfortable, 70km/h is screaming (but not hitting the rev limiter).

Taking this a step further....

I haven't been able to find the primary drive ratio or gear ratios for the Ducar so I just removed spark plug and magneto cover, put it in 4th gear and counted the crank revs per front sprocket rev, which was 3.9:1 (+/- 0.05) ..

so:
primary drive x 4th gear = 3.9:1
14 front, 37 rear sprocket = 2.64286:1
12" rear wheel circ. = 1465mm

1000rpm (in 4th) = 97rpm of the rear wheel = 0.1421Kpm = 8.5263kmh

so:
in 4th
1000rpm = 8.5263 km/h
2000rpm = 17.05 km/h
3000rpm = 25.6 km/h
4000rpm = 34.1 km/h
5000rpm = 42.6 km/h
6000rpm = 51.2 km/h
7000rpm = 59.7 km/h
8000rpm = 68.2 km/h
9000rpm = 76.7 km/h
10000rpm = 85.3 km/h

Looks about right, but I don't guarantee my calcs...

 

[tysons_201]

someones done their homework! lol good work.