Triple trees that are "known to work" for swapping to a USD front end.

[Guest]

Considering a USD front end on my GS400. I dont see too many USD swaps on these little bikes.

Any triple trees that are known to work with with the GS400 neck?

IS the GS400 neck similar to ther GS`s?

what about other GS`s ?

[Billy Ricks]

A good place to start is looking at bearing sizes on the steering stem. If those match up you shouldn't have any more trouble than people doing it on bigger bikes. I know it's been done of 550s and a 400 probably isn't too different when it comes to the neck area. Sometimes the upper bearing needs a conversion piece that the SV650 guys use to convert to newer GSX-R forks.

[boontonmike]

I sent you a PM, by the way i will look for that bearing chart, it is in my shop somewhere.

[spacepirates]

https://www.allballsracing.com/index.php/forkconversion

up to date chart. Takes into account triple trees that will work with new bearings (sold by All Balls Racing, of course). does *not* take stem length into account.

[jfman]

Well it's official, I have to make this work on my GS because... I bought it.

Just picked this up along with the calipers and full master cylinder.



This is going to be a winter prohject once the riding season is over.

Gotta make this thing fit my 1980 GS400.

The bolt that goes thru the neck on the 636 is huge (hollow aluminum) I think I may have to have an adaptor machined to be able to press a smaller bolt ton the bottom triple tree then another adaptor up top....


Now shopping for a matching ninja 250 rear wheel...

[Billy Ricks]

You'll most likely need the same upper bearing the SV guys use to adapt GSX-R forks to their bikes. The lower bearing will probably be the same.

Nice buy and it's going to make your 400 handle like it's on rails. Might do a a little frame bracing to go with it.

[jfman]

The process has been started

[jfman]

I have to remount the cluster and the headlight then I will move to the rear of the bike to do the swingarm. I will use the kawasaki keyset and I will rig some risers to remount the factory handlebar.

[steve murdoch]

That didn't take long.
Have you got the steering stops sorted out. It does not look like a lot of tank clearance.
btw...love the indoor workshop.

[jwhelan65]

What are the plans for the rear? I assume 17" wheel..

[pete]

There have been two 450's on here with USD front ends on them.

One was a direct swap and I'm pretty sure the other was close...

Unfortunately I can't find either with searching at the moment.

One was by scottychop who is no longer a registered user so I can't search by his username, and the other I can't remember the user... that's so frustrating!

[Tukn20s]

What year is that zx6 front end from? I have an 03 that I'm hoping to put on a GS750 frame. I just ran into the same problem with the stem on the triple. It's too large in diameter to fit through the neck. What did you end up doing to fit yours?

[jfman]

Mine is from a 2005 but its the same stem size from 2003 up IIRC.

On mine I bought some custom bearings to make it all work.

[Tukn20s]

Were you able to use the stem then? On mine its actually larger than the neck so it it wont even fit through. I figured I would just need bearings....but not the case.

[jfman]

The zx6r stem works with no mods but you cannot use taper roller bearings on top. You need to use two regular bearings one on top of the other.

The bottom bearing can be sourced from all balls part number 99-3525-5 costs 22$

Up top you have to use two of these - 35x47x7 Sealed part number 6807-2RS costs 20$ each on ebay.

The bearings are very thight in the neck. I put them in the freezer to get the to shrink a bit and they went into the frame w/o too much hassle.

The GS steering neck is a bit taller than the ninja neck so when you mount the triple, you can only use one of the castle/slotted nuts that come with the 636 front end. (usualy you use two and theres is a little washers with ears on it)

But hey it works! You can even use the kawasaki ignition and if you welds a stop on you steering neck, you can still have the use of the steering lock.