Rear suspension upgrade

It's widely known that the SV650's stock suspension has 3 drawbacks:

1) the components are budget pieces
2) only preload is adjustable (no compression or rebound damping)
3) too soft for anyone over 150 lbs.

Upgrading suspension can make an old bike feel like new, and a not-so-old bike feel a whole lot better. This post deals only with my rear suspension because I haven't decided what I'll do with the front. Last year, I changed the fork oil (from 5W to 15W) and I added a 12 mm spacer on top of the springs. This made a noticeable improvement up front, but I should really think about chainging the stock 0.67 Kg/mm springs for 0.85 Kg/mm. I don't think I would bother adding cartridge emulators to these cheap forks. If I was going to put that much effort into the front suspension, I'd probably just consider doing a GSX-R front end swap.

I'd been reading about all of the rear shock swaps for the SV650. People inevitably replace the crappy OEM unit with something that offers adjustability, plus most people are after something a little stiffer. All types of swaps have been done: shocks from various GSX-R models will bolt right into the SV frame but they all seem to require some amount of cutting/modifying the battery box. Some people have even opted for a shorter battery (ex: à la Honda CBR). The Kawasaki ZX-6R (a.k.a. Kawi 636) shock is also a popular swap, and I bought one of these in very good condition last summer. These are among the stiffest shocks around and are perfect for someone over 200 lbs. However, it too, would require altering the battery box (less so than a Gixxer shock). Then I learned that the ZX-10R shock can be installed without cutting the battery box, but only if you can get a hold of one from the 2007 or 2008 model years. The ZX-10R shock is also perfect for someone weighing 175-190 lbs. Finally, I learned that the ZX-14R shock is nearly identical to the '07-'08 ZX-10 shock, but sprung a little heavier. I generally tip the scales at 195 lbs, so add another 10 lbs or so when my gear is on. With that then, either the ZX-10 or ZX-14 shocks would suit me, and neither would require major surgery to install. I'd been on the lookout for a while, and I managed to sell the 636 shock I had sitting in the basement for 8 months. By the time you pay shipping, expect to pay $75-$125 for a decent used shock.

Here is the OEM shock I removed from my bike
(after 9,500 Km on the odometer).
The spring is quite soft, rated at 7.7 kg/mm (430 lb/in).

Here is a shock from a 2008 Kawasaki ZX-6R (a.k.a. 636) which I had initially intended to install. Notice the reservoir sticks out, above the upper bolt hole. This is where it would contact the battery box. Spring is 9.2 kg/mm (515 lb/in).

This is the shock I bought from a 2007 Kawasaki ZX-14. The spring is even stiffer than that of the 636 shock. The reservoir is angled lower than the 636 unit and doesn't intrude on the battery. A perfect fit. Spring is 9.7 kg/mm (542 lbs./in).

After about an hour, installed.

I loosened the upper and lower bolts on the shock, and also the bolts which secure the dogbones. Then I attached a couple of ratchet straps from the rear subframe to an overhead support joist. I raised the front end with my steering tube stand and I used a small floor jack to take the main weight of the bike (the ratchet straps were just in case something went wrong). With all of the bolts loosened before raising the bike, the removal was rather easy. With the shock removed, I used Nevr Dull to polish the rear-facing cylinder's exhaust pipe. Then the new ZX-14 shock went into place.

Finally, it was time for the test ride: I blasted up and down the canal for a few miles, crossed over to the other side, repeated. Twenty minutes was all, but it was enough to notice a big improvement. Familiar bumps (little ones and big ones) in my neighbourhood are better, and the whole bike feels planted much more firmly when you get on it hard around curves. I'll need to make a few adjustments but for now, I'm very pleased with this upgrade. The increased stiffness is welcomed given the bike needs to haul my ~200 pound ass. And the adjustability means that I'll be able to tweak it just the way I like it once I get used to it.