Is it okay to take off in second gear on a mini bike (Ducar 125cc Atomik Pro X aka AGB29). I dont see the need for first gear unless your going down a steep hill so you dont stall the engine, or going very slow trough thick high grass or something. My bike goes nowhere in first anyway, and that way I can avoid higher revs at run in.
Taking off in second
- Thread starter throtl
- Start date
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eichkay
Well-Known Member
Yeah , starting in second is fine... my advise would be to get a bigger gear for the front so you can use first ,.... thats what i did ive got a 17t on the front and i use 1st all the time now.
cranga
Well-Known Member
I wouldnt recommend it if you are concerned with running the motor in. As starting in a higher gear will put more stress on your engine when taking off.
There are plenty of suppliers around now that can get you the correct sprocket combo for your AGB. Go the front sprocket first as the rear hub has different spacing than most bikes.
There are plenty of suppliers around now that can get you the correct sprocket combo for your AGB. Go the front sprocket first as the rear hub has different spacing than most bikes.
eichkay
Well-Known Member
Call a shop like Boxy's or Oz50's $15-$17 each... if its a honda should be easy , if its a china based bike it'll be running the same sprokets as the older z50's
I did some calcs a while back for 14/37 sprockets, with a Ducar engine and 12" rear wheel ...
http://www.miniriders.com.au/forum/showthread.php?p=45629#post45629
Hey flick, I meant to post up for that thread, but forgot. Speed is actually directly proportional to power not revs. My dremel does 35,000 revs but it ain't gonna propel me nowhere. Basically an engine must overcome every opposing force to move you. These can all be measured as resistance in lb's. Rolling resistance remains relatively constant over all speeds and comprises weight of rider and machine, the road surface, tyre inflation etc. But the biggy is air resistance and drag. It increases greatly as the speed increases. There is a formula for calculating resistance. The frontal area of rider and machine in square feet x the velocity squared x the drag + the rolling resistance. This will give you the horsepower required for any given speed. Gearing is negligible except for keeping the engine within its greatest power producing range or if you still have power but run out of revs.
For example, some guys in the states are making 90 mph with heavily worked motors and are trying to hit 100. But what is standing between them and 100 mph is about 5 hp.
For example, some guys in the states are making 90 mph with heavily worked motors and are trying to hit 100. But what is standing between them and 100 mph is about 5 hp.
speed is not directly proportional to revs, well unless your changing your sprockets while your riding along then we'll assume it is.
as for starting in second, i do every time, the problem with gearing up and using first is that the ratio gap from first to second is quite large, where as 2-3-4 are close ratios and much better when your having a go.
