Front steering/suspension parts compatible with '78 GS400

[Angerhouse]

Hi guys. Doesn't matter what I do, I can't get the front wheel of my '78 GS400 to line up with the handlebar. So I am in market for replacement triple trees and forks. However, I am having difficulties in find (quality used) parts for a GS400 and thought I'd need to expand my search to cover other similar models, such as the GS450 and GS550.

Are the upper and lower fork tubes, top and bottom triple trees and the steering stem all compatible between these models?

Thanks.

[Chuck78]

If the tubes are 35mm diameter, then you can search up to most GS650's and 750's, but there are slight ride height differences between some models (650 dual disc forks dropped my GS750 3/8" lower in front). If the 400 forks were smaller than 35mm diameter, you could still swap a common GS550/650/750 triple and fork setup as long as you had the right bearings. I believe a lot of the bikes starting in the late 70's started using needle bearings instead of ball bearings, so that could require an AllBalls bearing upgrade kit if you were stuck needing to convert. My neighbor buddy has a 7,000mi GS425 project, if I'm over there I'll measure the forks. GS425's are rare though, 79 only. but basically a bored out 76-78 GS400.

[tkent02]

Hi guys. Doesn't matter what I do, I can't get the front wheel of my '78 GS400 to line up with the handlebar.

Thanks.

What have you done so far, and what part is bent?

[slayer61]

What have you done so far, and what part is bent?

That is a good point. If the frame is bent, no amount of parts changing will fix it until you straighten or swap frames.

[Angerhouse]

What have you done so far, and what part is bent?

When my handlebar is straight, the front wheel points to the left. To ride straight on the bike, I'd have to turn the handlebar to the right a little. I guess it is about 5 degrees out. There's no wobble or anything, but bugs the crap out of me.

I've loosened up everything holding my forks, as well as front axle's pinch bolts and tried to line up the wheel to the handlebar by bouncing up and down on the forks.. pushing the wheel.. kicking the wheel.. I may very well try again by pushing it against a wall but all my attempts thus far are fruitless.

People tell me something must be bent, that's why I am looking for parts to replace with. Because the misalignment of the wheel in relation to the handlebar is quite apparent, I did not dwell on the possibility the frame could be bent...

[Angerhouse]

you could still swap a common GS550/650/750 triple and fork setup as long as you had the right bearings. I believe a lot of the bikes starting in the late 70's started using needle bearings instead of ball bearings, so that could require an AllBalls bearing upgrade kit

Thanks, Chuck. It sounds like I won't have to worry about the steering stem diameter? Steering stems from all models should slide right in (provided I have the right bearing)?

I don't believe the forks I have on the bike right now came from a GS400.. probably a GS550 but I haven't met anyone with these small GS's in my area.

[mrbill5491]

When my handlebar is straight, the front wheel points to the left. To ride straight on the bike, I'd have to turn the handlebar to the right a little. I guess it is about 5 degrees out. There's no wobble or anything, but bugs the crap out of me.

I've loosened up everything holding my forks, as well as front axle's pinch bolts and tried to line up the wheel to the handlebar by bouncing up and down on the forks.. pushing the wheel.. kicking the wheel.. I may very well try again by pushing it against a wall but all my attempts thus far are fruitless.

People tell me something must be bent, that's why I am looking for parts to replace with. Because the misalignment of the wheel in relation to the handlebar is quite apparent, I did not dwell on the possibility the frame could be bent...

Only two areas that could be bent, the area around the steering head including the down tubes and/or the lower triple tree mount. I had a similar problem with my bike when it was first wrecked. We replaced everything on the front end (forks, fender, wheel, axle and handle bars) with the exception of the triple trees. My front wheel would be pointing one way and the handle bars another (was about 5 degrees as well). It would not align up no matter what we did. We installed a new set of triples and cured the problem.