$40 Steering stabilizer DIY xj750

For those who are handy enough and have access to a welder, this will run you around $40
I did this to minimize/eliminate speed wobbles. Yes many of you have told me this bike doesn't need a stabilizer but yet I have had more tank slappers than I can count. Maybe it's just the crappy way they fix the roads here.
Now the previous owner of my bike did a 650 front end swap, I put lower handle bars on since I bought the bike with a tall harley style bar, and I mounted aftermarket led spot lights to my handle bar which was hitting the tank so I welded about 1/8th" onto my steering lock... So things might work out differently for you.

As usual, I'm happy to help but I am not responsible for your actions.

I'm sure there are other ways to mount a stabilizer, but I didn't trust any cheap ebay stabilizer and didn't want to spend hundreds. GSXR has always come with a stabilizer from the factory, and being one of the better sport bikes around means a lot of guys upgrade to ohlins stabilizers instead.

Used GSXR steering stabilizer (prior to the ones with electronic plug in)
15 weight fork oil (personal preference really)
Fasteners
Metal
Grinder, vice, welder, and basic tools. Torch or other ways to help bend metal would save a lot of time and effort.

The stabilizer has a tiny screw. Unscrew it. Get rid of all the nasty oil. Cut up a windshield washer bottle or something that'll allow you to submerge the unit in fork oil while cycling it. Alternatively find a syringe which fits nicely into that small hole and creates a decent seal. The syringe I used fit well enough to get the job done but did leave a few drops on the ground. the upside to this is it requires very little oil so you can use it for other stuff.

I used a sheet of aluminum about 1/16" thick and 1" wide to build a bracket for the ball join end of the stabilizer. Take off the trim covering the top fork crown (at least that's what I know it to be called since I'm a mountain biker). Cut, drill, grind, then install. I mounted the outside end with the bolt on the clutch lever bracket. The inside end will mount to the left bolt which held the trim in place. You will have to grind the bracket to have it clear the handle bar mount and the centre nut on the crown. You will also have to cut the bottom left of the trim to clear this bracket.

Next is fabricating a bracket which will then be welded to the frame. I used 1/8" x 2" steel for this. The design is up to you. 3 things to think about: strength, clearing the tank (a bit of a gap would make tank removal easier), and clearing the trim as the steering goes lock to lock. The bottom of the bracket should be right up against the steering column and grinded to maximize area touching the frame. The bracket is going to point up and back, then a bend forward of slightly over 90 degrees.

Now sort out the nuts and bolts you are using to mount the stabilizer to the brackets. I put a nut between the stabilizer and my frame bracket to allow the spherical bearing to have some movement, and also between the ball joint and the aluminum bracket to help level things. Simulate the way everything will mount and decide if you need to make any adjustments to the frame bracket. If you are happy, then take the tank off, grab some water, grind the frame to prep it, and weld away. I kept the frame as cool as possible just so I don't do any damage to the head bearings. That's what the water is for.

I chose to drill my brackets after so that should things be off by a bit (welding = heat = metal expanding = imperfection) I can drill the hole exactly where it needs to go for things to square up. Once you've decided where to begin drilling, do the frame bracket first. Then mount the stabilizer. You want to then turn all the way to one side, push the stabilizer rod all the way in/out, then draw a mark on the aluminum bracket. Next, turn all the way to the other side and do the same thing. Now you know that you have to mount the stabilizer ball joint end somewhere between those two marks. So once you're happy, drill away. Then paint the frame and bracket to prevent rust, and mount everything into place.

What I also noticed after this is the left side of the handle has more vibrations now. Enough to be uncomfortable for long rides. I didn't have any bar ends on and I know that weighed bar ends help dampen vibrations. My grip has a chrome piece on the end and I kinda like it so I decided not to get weighed bar ends. I just so happen to have a damaged crank bolt from a car I worked on and it fits nicely into the bar. So I cut off the head of the bolt, put some electric tape around her so she fits in there snug, then put my grip back on. Now the vibration is the same on both sides and same as before.

So far, I've put on 1500km. Not a single issue. Done city, highway, and road trip through mountains. The stabilizer requires just a bit more strength to turn the bar but it's not something you'd notice if you've never ridden this bike before. It has made the bike A LOT more stable, otherwise I wouldn't be sitting here sharing my work with you. The bike used to wobble on me when a semi comes from the on coming and we're both doing 120km/h separated by a dotted yellow line. So far no wobbles from that at all. Not even the tiny wobbles you get from flying down the highway on a windy day.

Let me know if anyone has any questions

 

Without going into a bunch of physics about why motorcycles do what they do, here's the simple version
Steep steering angles (rake) turn quicker but are prone to head shake and as angle becomes steeper head shake becomes more prominent

Longer steering angle(think chopper) is much more stable but very difficult to steer.
In simplest terms if it raises the steering head bike SHOULD gain stability.
If it lowers the steering head, bike should steer quicker with less effort but is more prone to head shake.
Add to this rake vs trail. If a line is drawn parallel to the fork tube all the way to the ground the amount the contact patch is behind the intersection of the fork parallel line with the ground is "trail" this helps to re-center the steering. So changes in this ratio can result in head shake. Tires also have different profile when viewed head on. Most are designed for specific parameters, lastly even mixing front and rear types and brands can cause handling problems

 

That's one way to do it, and not a bad way at all. A body could also make brackets to fit the factory mounting holes that are on the frame, and use a fork collar at the other end.

 

did you ever check the steering head bearings or the wheel bearings or swingarm bearings or wheel alignment. maybe you put a real nice band-aid on a broken bone. the original stabilizer came with the big heavy tour package and there's a lot of secas riding around without a stabilizer that have no head shake problems

 

That's exactly what I was gonna type as I read through that---- You best me to it.....
Yup, steering stem bearings .

 

I don't have the tour package, and do have new head bearings (new bearings all around), but will occasionally have a bit of head shake at...let's say highly enthusiastic...speeds. It's not an issue most of the time, but does happen more often when the rear tire has squared off, and near the end of its useful life. The tendency for some (manageable) headshake at high speeds was mentioned in a few of the magazine articles when the 750 Seca was new.

Having said that: the 650 fork legs (assuming they are from a Seca) put the wheel directly in-line with the fork leg, changing trail from what the bike has with the stock 750 fork. That could be causing the problem.

 

I've checked everything twice. I race with a litre CBR and used to daily that but had it impounded a month ago ( gone for 2 months) so I do ride hard and fast. If anything I'd want the front end lower as I want more weight on the front wheels from the natural weight rather than always having to brake into the corner or the front end will wash out, so raising the front end is never going to happen for me. And yes I am aware our bikes have loads of stake and I've been riding/racing bicycles since I was 9, from downhill, to trial, to endurance, to road, and I build race cars for a living, so I am fully aware of suspension geometries.

And maybe it's just that I wrap up about 40000km a year, and over 25000 of them are on my motorcycles, so maybe it's just one of those things where if you ride enough, it'll eventually happen. I don't know anyone else but me who rides day or night, rain or shine, 40 celcius to -15 celcius, heck even when theres half an inch of snow on the ground.

 

WOW !