fitting a motorcycle fork onto a bike?

[Yungyakz]

I have used Pit bike forks on a pair of my builds for the extra braking power and cause i am cheap. You should just go to the junk yard with some measuring tools and see what will work, i managed to get both forks for around $100 each including some shitty 21" wheels that i reused the hubs and spokes from the 21" moto rim to lace a wide aero 26" bike rim too(Almost perfect fit, spokes were a fraction short so i drilled out the spoke holder on the hub by 5mm giving me enough to get the right amount of threads engaged). Also came with the full brake setup, had to space out the brakes to fit the larger 21" wheel avaliable disc sizes. The other i left as a 17" moto wheel.

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Hi, im interested in doing this, did the forks fit into the bike headtube or where there any adapters you had to make etc.

 

[stan.distortion]

Some of the 50cc forks might be worth looking at but I doubt it, more or less all put cost before quality, heavy for what they are and poor damping. Girder forks are worth considering, kind of surprised they're not more common tbh, light, relatively simple, MTB rear shocks should work well with them... Worth having a look at BMW motorcycle front suspension, they did a re-think on girder forks for their high spec models that works very well and their telelever suspension has to be tried to be believed, miles ahead of conventional forks imo.

 

[Olds C0ol]

Why bother? You can buy new "triple tree bicycle forks", for $80- 150, made for your bike, that dont have the Excess weight, of a motorcycle set-up. Also they're disc ready. Go shoppig; Olds C0ol

 

[markz]

I had to go look up what the girder forks were, close enough to a springer fork. Those do look like something anyone can build. I was thinking of building one, and using coil springs that had a wide variety of compression rates so you can play around with rates.

Sunlite and the other ones you can buy for $100 on ebay are useless and a waste of money.

https://www.custom-choppers-guide.com/girder-forks.html#gallery[pageGallery]/3/

Girder forks are worth considering.

 

[MadRhino]

Nothing comes close to a modern DH racing fork. Their action, tuning options and weight, is making pro motorcycle custom builders replace motorcycle forks with bicycle forks in many fields of competition. In Trial motorcycle world cup notably, all bikes are mounted with bicycle forks for quite some time.

The pit bike forks that some are mounting on ebikes, are absolute crap. Good motorcycle forks are heavier than a whole touring bicycle plus the equipment that an average cyclist is wearing.

Apart of some, very few and very expansive, girder forks made with carbon fiber and designed with modern tuning options, the usual springers and girders are heavy with poor action control. Fancy looks to build a show chopper, is all that they have.

Motorcycle components may be good to build e-motorcycles, on ebike they are poor choices. After your power beats 40hp, you can start looking at motorcycle components.

 

[GypsyWolf]

I am currently working on a build that involves using the triple tree suspension forks off a Kawasaki ninja ZX 600r. This build is using an all aluminum gas tank frame for a motorized bicycle. So far I have had to cut the steering stem out and shorten it by 3 inches and machine the bottom 3 inches down to 25mm to accept the same bearing that is on the top since the bottom one was too big to fit in the bikes steer tube but the top fits perfect. Oh yeah had to reweld the steering stem back to the lower fork bracket. This build is a work in progress. The motor is a china 66cc motor that I have upgraded to a 49mm piston and cylinder. I am installing a jackshaft setup so that the motor chain will work off the normal right side of the bike. Tried it on the left and it rubs the 90/100 - 21 MC tire. The jackshaft us a custom deal that instead of the freewheel being on the pedal crank it is in the 5/8 shaft. So the shaft has 3 cogs on it. A 15T at the motor side then a 10T that had it's chain going to the rear wheel, then a 20T that is attached to a HD freewheel and adapter for the shaft that chain goes to a 40 toot pedal sprocket. The rear wheel sprocket setup is custom built by me. It will involves 3 gears. Kinda like taking a triple freewheel chainring setup and screwing it onto the rear hub. I'm considering using a 48t, a 40t and a 32t and then possibly a 24t as well. Eventually I'm planing on installing the luna cycle mid drive 3000Watt cyclone motor. That way at times I can just run on electric power but when on a long run I can pop the clutch and let the gas engine take over shutting off the electric motor. I'm hoping that part is possible since I'm not familiar with electric motors I was hoping you all might be able to tell me in that aspect what is possible and what's not. I will update my post about the motorcycle forks and any other modification I additionally have to do to for them to work on this specific build.