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Rear Shock Options, Including Budget

90683 Views 81 Replies 30 Participants Last post by  urbane
Hopefully this summary will help to group a bunch of scattered replies on the topic. Obviously, it's all JMO. :)

I found just a re-springing of the stock shock to be a very adequate economy answer to the wallowing and general lousy handling experienced on these as you start to push them, ESPECIALLY for just street use. It's NOT a Penske but is still a dramatic improvement. If you're not experiencing those wallowing problems, not pushing it a bit, or just a cruising type rider, ignore this post. ;)

I took the time honored approach that on a budget, the best bang for the buck is get the spring right. These are so soft that that approach made even more sense the more I thought about it. I took the measurements, figured the linkage ratios, drew up some cups, sourced a used spring, and proceeded. I was AMAZED with the improvement and easily recommend it to anyone who wants to improve the suspension but hasn't the money to do it "right" (translation: Penske, translation: $). ;)

I've used this on the track and will again, finding it totally rideable, but the shock absorber's weakness really shows there, cold tearing tires. Inflating a couple of extra pounds over typical track pressures will help, but not totally cure that. If you're a rider who track rides and can push that hard you could probably justify the cost of a Penske just with a season's tire wear savings alone and could realize the benefits of a nice, tuneable shock.

But if you're a street rider, possibly a novice track rider just getting into it, you won't have the tire tearing problem and will LOVE the dramatic improvement in handling if you're riding twisties even a little hard. On the street, even experienced riders won't be able to push so hard as to have the cold tear issues and will find that it's rideable at a pretty good pace, certainly FAR better than a stock set-up. Not a Penske, but not so bad. :)

It requires a spring for your weight, a set of special machined spring cups and, not necessary but highly recommended, a set of links (often called dog bones) to raise it.

The spring is a 2" X 6" series from Hypercoil and is the same spring used on Penske's shock. They are available in 50# increments. The range most likely to be used on these is 400, 450, or 500#, and for the really husky ones, maybe a 550#. New cost, about $100.

The spring cups are machined from 6061 aluminum and should cost no more than $100. I can make them for that, shipped. That price may be better depending on material costs.

The links to raise the rear and built with a minor outward step in them to clear the spring's slightly larger diameter should cost no more than $65. If you weren't raising the rear the stock links can be used but a washer should be added to each side to afford just a little more clearance. The addition of the washers then requires a longer set of bolts to maintain the engagement of the locking feature on the stock nuts. The spring will just fit between the links either with this mod or a purchased Penske, but even the slightest shift of it on the spring cups or the smallest variation in diameter will cause it to rub. Not good. The additional 1/16" per side assures clearance.

Summary: The cost for the shock mods alone is about $200.
Add the links for a truly complete package and the total is $265.

Shopping for a used spring from a racer who has had occasion to change his Penske shock's spring could be as little as $25 shipped (that's what mine cost) so you could conceivably complete the whole deal for under $200. If you have access to a machine shop and can figure out the parts, maybe way less than $200.

Next lowest cost package to my awares is a basic Works Performance shock, ordered and sprung for your weight, at about $400. That's an old price and from memory so it may be more, not likely less. It would still need the links if raising the rear was to be done so add the $65 for those to complete the package. That makes a total of about $465.

The ultimate, the Penske, sprung for your weight, is around $875. It has everything including adjustable ride height. (For those not familiar, ride height adjustment is NOT the same as spring adjustment. All of these, including your original, have spring adjustment, but not ride height.) At its lowest setting it already raises the rear 7/8" but can then be adjusted up from there. It should have washers added to the stock links to assure spring clearance and then longer bolts to assure the locking nut engagement. Those longer bolts will not be hardware store stock in that size and length so will have to be ordered from a fastener supplier. Expect between $10 at best and $20 at worst by the time you cover shipping and handling, getting that package up to just under $900.

So, there you go. A good list of the options... for the rear. ;D If you're going to do the rear you should really consider doing the front, too. The best handling is when you keep the front and rear working similar. With a spring change at the rear that will be at least a one third increase for anybody but the lightest rider (the stock rear is 300#) and it will underscore the front's soft springing. :(

At the front expect to spend $150 for parts to do the springs alone. That would include the springs, fork oil, and a little for miscellaneous. Add another $150 for cartridge emulators and you'll have all of the parts for the front, as good as it gets. No high dollar Penske options here, thank goodness. ;) The works for $300, the minimum for $150, or maybe shop the racers again for used.

Additional Notes:
This list is from my experience with my bike over about 10,000 miles riding as modded, riding it on both street and track, about equal amounts of each. (I use it coaching novice sometimes.) The total list of mods is:

1. re-sprung rear.
2. links to raise rear (started at 7/8", now at 1 1/2").
3. re-sprung front.
4. cartridge emulators front.
5. front raised 1/2" by sliding tubes in triple tree clamps.
6. radial tires.
7. lowered stock bars (approx. 2") using old 600 risers.
8. carburetor pilot screws out 2 1/2 turns.
9. EBC front brake pads.
10. EBC floating front rotor. (Just installed, warped two stockers beyond hope.) :(

That's the TOTAL list. And in that configuration it can be ridden quite fast without doing scary things. :) If I were racing it or running against my lap timer at track days, going for the track record, ;) I'd certainly want a Penske. If one comes my way at a steal, I'll buy it and put it in. Other than that, I'm content with the bike as it is.
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It's been done look in FYI for this:
Setting your Sag
A freebe to better handling
One of the most often overlooked adjustments to your Ex is the Sag setting This is the amount the bike's springs colapse when you sit on it. Both front and rear are adjustable, Here's how.

Measure first: Put a piece of tape or a mark of some kind on the body near the rear. with the bike on it's wheels held vertically by a friend your going to measure from the ground to this mark like this.
Have your friend:
1 lift the tail as much as he can and let it down slowly, measure

2 push down on the tail and let it rise slowly, measure

3 average those two measurments. thats the top point

4 Have both your friends try to bottom out the travel to get the
bottom measurments.

4 sit on the bike and repeat the process, have a 2nd friend measure for you (you do have 2 friends don't you?)

The diffrence should be about a third of the total rear wheel travel.

If you get too little you spring is too stiff, strong , hard, back off the adjusting collar around the top of the shock. Theres a lock nut you must release first. a long screw driver and a hammer are your tools.

If your sag is too much tighten the spring collars. Same process as above.

The process is the same as the rear, but the adjustment is tougher
to make adjustments you must remove and change the leghtn of the spacer above the springs.

To do this:
Prop the front wheel off the ground, remove the handle bar riser from the top triple clamp leave all the cables connected. With a small 2 legged wheel puller hold down the plug against the spring. fish out the lock ring. Release the wheel puller and the spring will push the plug out for you. (no it won't fly.........far). remove the spacer on top of the spring and fit a longer or shorter one according to wheather you want to stiffen (Longer) or soften the forks.
Reassemble and measure again. NOTE HERE: bend the end of the lock ring up and in for about 1/8 inch to make it easier to fish out the next time.

The next time is now if you didn't get what you want.

General notes: The ex is rather softly sprung and responds well the stiffining both ends. Unless you a 100 Lb. Girl (or ride like one).

Usually a stronger spring is required in front for 150 lb or more riders.

Stronger rears are also aavliable too but fitting one will most always overpower the shock and cancle any gain. General note more spring requires more dampining. In front you can thicken up the oil, in back your screwed (Penske, but still screwed $700+ ).

Have fun Kiddies and ride safe.
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Lucky#13 said:
I guess the head instructor at MMI in Florida doesn't know what he's talking about ???
Not if hes recomending 4 inches of sag.

That's a fatal assumption Eric, The rear suspension on many bikes has a progression too, and will change the amount of movement per unit of load per it's ratios.

You didn't signify the you were referring to the front only. Even there some variability is avaliable with a progressivlly wound spring. These have several coils on one end wound in a tighter spacing, This causes them to stack (coil bind) first thus shortening the remainder and creating a stiffer spring in the process.

No not at all. You are correct just not difinitave enough. If your going to teach you must learn your subject well. There are linier springs (most are) then there are Progressives, and a whole bunch of other variables too.

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