Rotary Transmission

[shaundtsl]

Hi Guys,

I am new to this forum and to biking.

I just picked up a lifan 125 scrambler for pretty cheap. Its in good running condition etc and would like to start using it for commuting and maybe some trail type stuff.

The only thing I dont like is it has a rotary transmission, which means I could easily pop it into 1st from 5th which I dont like.

So, my question is this, can I modify it to only go up and down? Or, if I want to replace it, do I need to replace the whole engine or just the gear box?

I also read that some honda parts might work. If I was trying to source second hand parts, could I use honda?

Thanks in advance!

[Martay]

Yes you could, but it would be like trying to ram a car box into 1st from 5th. Its technically possible but fucking difficult!! Even if you try, its really hard to do.
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[shaundtsl]

Thanks, I did manage to do something though, I was riding around 40-ishkm/h and I am not sure which gear I changed to and the bike revved really high slowed down all most throwing me over.

I would like the peace of mind that all the way up until it doesnt go anymore is 1st and all the way down is 5th (or 1st prize would be the normal way).

Can this easily be done?

[MarJay]

[shaundtsl]

[Teflon-Mike]

[Frost]

Chinky bikes often have a N-1-2-3-4-5 gearbox. Some of the older ones have a C90 clone engine in them with rotary gearbox. I managed to get one of those into 1st from 5th but i could feel everything tighten up and my speed drop as i let the clutch out so i whipped it in and came to a halt sharpish to investigate. everything seemed fine until i set off and realised i was already in 1st

[Dan_Davies]

good luck if its a lifan (Y)
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current ride: 07 suzuki sv650s
ex rides : lifan mirage 125

[shaundtsl]

I dunno guys. I just tried it out on purpose, got into 5th, pulled the clutch in pushed the gear down into neutral and again into 1st. Slowly released the clutch and the revs shot up and bike slowed down as expected.

I dont feel confortable riding like this...

Is there anything I can do to remedy it or should I just look at selling the bike?

[herulach]

I'mnot quite sure what you're asking.

You start in neutral, then go through the gears to 5, then push down once and you end up in neutral, then a second time for first?

Something is really wrong there I reckon.
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YBR 125>FZS600

[shaundtsl]

[herulach]

Must be annoying, how do you change down from say 5 to 4?
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YBR 125>FZS600

[binge]

If it's an all up (or all down) box, then how are you going from 5th to 1st by accident?
You'll have to go into neutral first surely?

As it'd go-

N 1 2 3 4 5 (Then down again would be back to N)



I think you need to learn how to ride your bike properly.
You should just know what gear you are in from the speed and RPM of the engine. It's about paying attention to your bike.



Ben

[Frost]

For a start all bikes will go into 1st when they are still moving, otherwise that would be a hell of a pointless gear. An R1 does 100mph+ in 1st so it's a very useful gear.

As said above the Honda C90 uses this type of gearbox and is the best selling bike of all time. There are more of them in use throughout the world than any other type of bike. They all seem to have survived riding them so shall you.

A gearbox cannot simply be swapped over. You can't just unscrew the old one and bolt a new one on. You have to take engine out, the cylinder off, engine covers, fly wheel must be pulled using a special tool, the engine cases split and the gearbox internals changed. I was once quoted £1000 for a gearbox rebuild and you'd need a part that may or may not exist. I could buy 4 or 5 chinky bikes for that.

[Frost]

[shaundtsl]