Fork brace and wheel wobbles.

[user11235813]

If I hit a dip in the road like a smooth shallow pot hole or even a bit of a rutted road, the front wheel wants to wobble as if it's about to go off on a tank slapper, it's not a big problem but I was wondering if this is the sort of thing that a wheel brace is meant to fix.

[kapiteinkoek]

Sounds like a worn steering head bearing or like one that needs adjustment (too much play on the bearing).

[Bluesmudge]

Or a bad wheel bearing. The bike should not act like that, even with that scrawny stock fork brace.

[user11235813]

The wheel bearings feel rock solid I cannot induce any play or detect any movement at all in any direction, same with the steering head bearings no play nice smooth movement with no ratchety feeling. I might have to investigate a brace then.

[Knuttzz]

Unless you are riding your bike at near racetrack speed I doubt very seriously it is the lack of a brace.

Several things can cause what you are experiencing. Bearing like we're already mentioned, tire pressure, tire wear, suspension , geometry etc etc......

I'm not telling you to not buy a brace just that I doubt that is it.
Before I bought a brace I would check all of the above. Make sure the suspension is in good shape and sprung for my weight. Check fork position in the triples. Etc etc etc

[user11235813]

@Knuttzz, I suppose you are right because this is only a low speed thing, but especially annoying going around corners, and if this was normal you'd think it would have been fixed by now. On the other hand it may be considered a minor problem.

I'm confident that it's not either of the bearings. I'm not very heavy, 60kg, and I have recently had the fork oil changed with the seals. The rear shock looks in good condition and I be willing to bet there's nothing wrong with it. The number that lines up with the bolt above the chain is 4. I'm not sure what setting that means it's on but I'd guess whatever it is on is the standard setting it comes with. It does wallow a bit sometimes but then that's what this bike does.

I think I'll put a fork brace on anyway because it looks like a pretty flimsy piece of plastic that's currently on it and it's an easy mod.

Do you think progressive fork springs would make a difference to this sort of problem, I'm thinking of doing that in the distant future.

[Endopotential]

Did you notice this problem only after the recent fork rebuild?  There's a chance things didn't bolt up perfectly straight afterwards. 

After I did mine, I noticed the forks sticking.  Loosened everything, even took front wheel off and put it back on. Solved it very easily. If axle is not perfectly straight, that'll definitely cause problems.

Somewhere on this forum, someone stated that with the GS's relatively short fork length there's not enough room to make full use of the benefits of progressive springs.

So I just went with straight Sonic springs, and it feels great.  0.80 for my 70kg weight.

[gregjet]

A too high transient on top out will make the forks wobble as well. Make sure you have put your top out springs back in if you have had the forks apart.
Too high preload on the back and front will give you a preload wobble. That's usually more of a weave than a wobble. If you have too preload the springs too much to get the right ride height, you need to go to heavier springs so you can preload them less)
Possibly increase rebound damping (heavier rate fork oil).
Head bearings most likely, then wheel bearings.
Bent fork/s or head stem bearings too tight will do it too.
Work rear swingarm bearings or loose REAR axle or wheel bearings. It is not unusual for the problems in suspension to feel like there are at the opposite end of the cause.

Sometimes a transverse imbalance in the tyre ( heavier on one side). Pretty rare on good modern tyres.

[user11235813]

I had new seals put on by a shop as I didn't fancy working on the forks myself. I'll check the weight oil they put in I think it was 10 though. I was going to preload them more but in the end I decided to leave them standard. Just went for a 400km ride today and it feels like there's no problems on the motorway. So I think I'll put in some new constant rate springs before anything else I was thinking .75 as my gf just got a bike so I won't be doubling very often any longer.

thanks for all the feedback, I will have a closer look at the rear end too. But my gut feeling is that it's just a bit sloppy in the susupension.