1979 GS425 Inverted Forks

[Guest]

So as I mentioned in my engine tuning thread over in the 2cylinder section, me and a buddy are building a cafe race bike out of a GS425. Something we would like to do is run inverted front forks.

So, this being both of our first custom build we're a little lost on how to do this. Is there a common front end that swaps onto these? If you have done it what front end did you use and how does it mount?

[Big Rich]

I wouldn't say there's a "common" USD fork swap. But Suzuki used the same steering bearing sizes for a long time, on a lot of their bikes. Google around for a steering stem chart (I think Allsballs has one on their site too) and see what would be close to compatible. Then you have to figure out if the steering stems are the same length as your current one. Speaking of length : watch for fork lengths too. I can't speak for the 425, but my 450 has fairly short forks (compared to some bikes anyways).

Are you looking at running the stock wheels, or updating them to 17" mags as well?

[dude99]

We haven't really gotten as far as what wheels we'll be running. I think I have that stem chart saved somwhere already. I was just curious if there was a "standard" swap so to speak.

[posplayr]

Havering gone through many of the gsxr's combinations , unless you are willing to have to fambricate everything custom decide on what wheels first the pickup forks that work with those wheels.

It is much easier to fit almost any fork to the frame than to mix all combinations of forks wheels, brakes rotors

[dude99]

Good advice... wheels first it is..

[Big Rich]

Dude99, if you go with 17" mags look around on the thread for my GS450. I mounted up a Bandit 400 rear wheel and listed a bunch of the problems that came up.

The B4 rear has the same pattern as quite a few bikes, so a matching front wheel is easy to find (regardless of forks / axle / etc).