Busted 5 speed Transmissions from Takegawa

[KK32]

Hi there,

I'm building a Honda Nice TJR 59x66 180cc engine with 5 speed gearbox, superhead +R and clutch from Takegawa. The gearbox is a super street for 4SM engine and broke after a few kicks :

I have ordered a TAF super street instead but I'm afraid this will not solve the kickstarting issues with big displacement/high comp engines. After a few researches, it appears that the last takegawa 148 and 158 engines and all the newer 125 to 160cc chinese engines

have the kickstart connected to the primary gearbox shaft, which allows starting in any gears when clutch is disengaged. you can have a look here : 148-TAKEGAWA

The takegawa CSM type HD crankcases and matching TAF gearbox haven't been released yet but it would be great having your hands on it to use same design in your CNC crankcases ?

We bought 3 set of TAF gearbox for our own bikes with the Taky 138cc motor. Currently 2 set of the TAF exploded after a few ride and 1 set is still ok since the bike is not being ridden.....

For our own SMR motors, we are developing an auto decompression system when the bike is being kick started. This auto decompression system will be available for both our 180cc DOHC water-cool motor and the 200cc air-cool motor. We will be using the Nice 4 SP gearbox for our own SMR motors that we are developing. The 5 SP gearbox are not strong enough for our motors, from our research and testing of the gearboxs.

[PlanetMinis.com]

[50race]

The taf 5 speed looks like they just removed the true trochoid form from the root of the gear and maximized the root thickness. lower efficiency gear meaning more energy/stress is put into gear almost negating the added gear root tooth thickness.

Like first two replies from 2010 5 speed+high horsepower=hard to hold together.

No free lunch out their maybe be able to fudge the tooth design a little and use some really pricey material and get one set to come out on all the good side of the tolerances and it might hold together

[steera]

Hi all I have been reading this thread and can't believe u all having so many problems I'm running a tjr 62mm crank with 56mm piston 152cc on takegawa super clutch with sport touring 5 speed but I have auto decomp cam I have done about 3000 miles on it with no gearbox issues the bike makes 20bhp on the dyno I find the nice 4 speed no good as I'm on 8inch wheels cheers steera

[fatcaaat]

Hi all I have been reading this thread and can't believe u all having so many problems I'm running a tjr 62mm crank with 56mm piston 152cc on takegawa super clutch with sport touring 5 speed but I have auto decomp cam I have done about 3000 miles on it with no gearbox issues the bike makes 20bhp on the dyno I find the nice 4 speed no good as I'm on 8inch wheels cheers steera

You'd need a 19t front sprocket and about a 25 rear and then you'd be fine with a Nice tranny on 8" wheels. I run a 19 front and 29 rear on 10" wheels on my TRP build...for flats it great. For full mountain pass riding, I swap in an 18 up front. The nice transmissions are virtually indestructible.

[steera]

You'd need a 19t front sprocket and about a 25 rear and then you'd be fine with a Nice tranny on 8" wheels. I run a 19 front and 29 rear on 10" wheels on my TRP build...for flats it great. For full mountain pass riding, I swap in an 18 up front. The nice transmissions are virtually indestructible.

Yeah my problem is a small rear fouls my rear set mounts so smallest I can go is 30 on rear I'm running 19 on front

[vintageguy]

I have the ahp 4 speed in two of my 124 motors and they work great in dirt and on the street ratios are very good

[natek]

At what power levels are these 5 speeds braking and which unit is better? What do these transmissions cost? I skimmed through this thread so I might have overlooked the answers.

Edit- nevermind. Flawed design for that kind of coin is ridiculous.