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Discussion Starter #1
Took my '93 900SS out for a spin this morning before the tourists came out in force on one of my regular coast routes that's full of twisties. Thought I heard the sound of plastic on pavement through one corner and sure enough, a visual check at the end of the ride revealed I'd tagged the right rear lower corner of the fairing, scraping some paint off.
I also noticed a fresh rash on the opposite side exhaust pipe right at that 90 degree bend where the pipe comes out from under the bike.

I'm assuming this is a regular issue for many, what are some ways I can improve clearance?
I recall reading here somewhere that an SSie rear shock is a cheap way to bring the rear end up a little bit, both improving turn in and ground clearance. The expensive way being an Ohlins shock.



 

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Different bike, so fwiw. Had similar issue with my 98 VFR at the track. Added a shim / washer on top the shock to raise the height a bit, probably adjusted the shock too (it's been a long time). Problem solved for cheap. Good luck, you don't want to grind a hole in that header pipe.
 

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Discussion Starter #5
Get your butt off the seat more.
I'm already getting off the seat. In those hard corners, there's nothing but air between my butt and the ground. I'm 6'3", so my long legs allow me to really hang into the turn.

,... and keep rolling on the throttle midturn - don't chop it. Might be able to take another turn increasing the rear shock preload too.
I never ease off the throttle mid turn, always slowly roll on the power.

Increasing pre-load would definitely help. I'll put that on my to-do list before I take it out again.
 

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If you are dragging those parts on a SS, you either have it lowered, or you are cornering like Marquez. Otherwise you are doing something wrong.
 

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some of the ssie shocks may be longer, but none of the ones i've measured have been. eric may know more on that.

if yours has the right spring and preload for you already then a longer shock is the answer.
 

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Discussion Starter #8
If you are dragging those parts on a SS, you either have it lowered, or you are cornering like Marquez. Otherwise you are doing something wrong.
The prior owner was on the shorter side, but he kept the stock rear shock and the swingarm is stock, so it certainly hasn't been lowered. Tire is the funky-by-today's-standard stock 170/60, so no undersized tire to lose any clearance. I suppose the real tell tale is actually measuring my clearance.

some of the ssie shocks may be longer, but none of the ones i've measured have been. eric may know more on that.

if yours has the right spring and preload for you already then a longer shock is the answer.
Rear shock assembly is bone stock. Just eyeballed it and the pre-load is set right in the middle, which makes sense as the prior owner was a small guy.
I installed Racetech .90kg springs last fall, I suppose it's time to match the rear with the front. I'll try setting the pre-load a bit stiffer, but I will probably wind up buying a better shock in the near future.
 

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It doesn’t sound as if you’ve ever set the sag. I’d start there.
+1 on making sure your sag is correct
Make sure your spring rate matches your weight. Turns with bumps and dips compresses the suspension, which loses ground clearance.

If your sag and springs are in spec, I'd do a revalve on both ends. Improved/increased compression dampening can alleviate clearance issues at lean.

Good luck,
Scott
 

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If you are dragging those parts on a SS, you either have it lowered, or you are cornering like Marquez. Otherwise you are doing something wrong.
Well, I guess we are both like Marquez because I had the same problem with my 1997 SS/SP. At the track, I started rubbing the headers, foot pegs and brake and shift levers (not good!). I solved the problem with a Penske shock from ca-cycleworks (1/2" longer than stock, plus ride height adjustable). I initially lowered my forks in the triple clamps and that helped cornering clearance, but made the bike turn even slower than already. With the Penske I could raise the forks to help quicken the steering and still have enough clearance.

Hanging off helps, but at least for me at the track, cornering clearance was still a real problem. You probably need stiffer springs if you are 6' 3". How much do you weigh? Stiffer springs and more rear preload may help, but they won't solve the problem. Those bikes weren't designed to lean as far as good tires will allow them to.
 

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I noticed my race fiberglass cut 3" off that "tail" piece on the side fairings, right where it dragged in your picture, ...
 

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When I started racing my 900 I was dragging those items too. An interim solution for the exhaust [before I replaced it] was to cut the pipes off at the X and trim off about 1/2" to pull the pipes in. It does take a bit of welding but it is cheaper than an aftermarket pipe. I also replaced the shock which raised the ride height, but that was more to quicken the steering than add ground clearance. A 180/55 or 180/60 would also give a bit more height as their O.D. is greater than the 170.
 

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Discussion Starter #15
Thanks all. Setting rear sag is going to be first on the list. However, I believe that at 185 pounds before gear, I'm going to be a bit heavier than what the stock spring rate is ideal for, so a Penske, Fox or Ohlins may be in my future. Pricey, but I can afford it.

As for the tire, the thought did cross my mind of going with the wider, and more common, 180/60 to get that little bit of increase in clearance.

I do have access to a welder, so I could cut, tuck and weld the exhaust bits I'm hitting, but I'll leave that as a last resort. I'm banking on the bolt in parts solving this.

I'm curious what will happen when I finally do get around to taking the SS out for my first track day. One of these days I'll find out, after I dial in the rear of course.
 

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I'm almost the same weight as you, and I believe (as my butt dyno tells me) that the stock rear spring is actually on the stiff side. If you enter the information into racetechs spring rate calculator it will suggest a ~8kg/mm spring, and I'm pretty sure the stock springs are stiffer than that.

I've also had the occasional spark from the header touching the ground, although I try to avoid this on public roads. But it is a problem, and potentially not only expensive but dangerous, especially when hitting an unexpected bump mid turn.

Check your sag for sure, but i think you will arrive at the same conclusion: you need a longer or length adjustable shock.
 

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It doesn’t sound as if you’ve ever set the sag.
I finally did this last month and wow, what a difference. When I bought it I had set the susp. to stock settings and played with it from there, but without setting the sag it was mostly a waste of time.
 

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Setting sag is VERY important, as is having the correct spring for your rider (plus gear) weight. If correct sag cannot be achieved by preload, then a different spring is required.

Having correct sag allows the suspension to operate in its optimum design range. Not only that but if the suspension is not operating in the optimum design range, the bike’s geometry is also altered (think rake, trail, and even wheel base). It also means the tyre is doing some of the work of the suspension and it will eventually show itself in unusual wear patterns on your tyres. It is more obvious if you ride on the track due to increased wear rate of the tyre - the harder riding exacerbating the problem and makes wear patterns more obvious.

Here is a very good video showing how to set up sag. A much more modern bike, but the principle is the same.

Notice how they give the forks a bounce to align them before tightening the pinch bolts after a wheel change. Something our manuals (factory and Hayne’s) don’t mention, but a “cardinal sin” according to the Ohlins race technicians.

(Robert Taylor is a very experienced motorcycle technician and suspension specialist in NZ. He used to be the Technical Manager for Yamaha in NZ)

 

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I'm almost the same weight as you, and I believe (as my butt dyno tells me) that the stock rear spring is actually on the stiff side. If you enter the information into racetechs spring rate calculator it will suggest a ~8kg/mm spring, and I'm pretty sure the stock springs are stiffer than that.
The stock springs are progressive rate, (rear 8.5Kg/mm, front 0.65Kg/mm.) Racetech’s springs are linear. It’s therefore not an exact comparison. That’s where it gets tricky on our machines.

I agree though, my “butt dyno” also finds the stock rear to be quite stiff.
 

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the pre-load is set right in the middle, which makes sense as the prior owner was a small guy.

I'll try setting the pre-load a bit stiffer ...
Preload doesn't change the spring stiffness, it only changes ride height.

Add some preload, that's all you need to do.
 
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