Rear Suspension

[radman]

Well then sporty, how much for a basic unit for Frank? I'm not chasin R1's, so I don't need 40 way adjustability, just a good quality replacement.

 

[sportryder]

Well then sporty, how much for a basic unit for Frank?  I'm not chasin R1's, so I don't need 40 way adjustability, just a good quality replacement.

radman - I do not recommend the basic Penske unit - Sport Shock - because it is an "emulsion" shock and does not have compression damping adjustment. It does not have a remote reservoir either. The valving is pretty good on it but an emulsion design allows the oil and nitrogen gas to mix together. Under moderate to hard use, this design is prone to fade over a period of extended use - as when used on spirited longer rides. The shock heats up, the nitrogen and oil mix and damping rates become less precise.

The Sport Shock has preload, rebound damping and ride height adjustments.

If you are a soft rider and do not feel it may be worth the extra money for the 8981, then $601 is our price delivered to your door in the lower 48 United States. This includes a 5% discount over MSRP, unlimited technical support, the proper spring for your weight and riding style, shipping and handling.

For an additional $167, you could have the Penske 8981 with remote reservoir, compression damping, rebound damping, preload and ride height adjustments. It would be $768 delivered to your door in the lower 48 United States.

With the remote reservoir (8981) and it's internal floating piston, the nitrogen and oil remain separated. The shock does not fade even under racetrack use. It has a very wide adjustment range on both damping circuits. It's external and internal parts are hard coat anodized to minimize oxidation which contaminates the oil. They hold up really well even under very hard use. I've serviced Penske shocks that were over 5 years old and other than changing the oil, disassembling the shock for a full inspection, polishing the shaft to remove any microscopic burrs that could damage a new shaft O-ring oil seal, nothing wears out on them. With a lot of miles and years, the shim stacks would eventually also need replacing during a service. All Penske shocks are quite easy to work on and are truely owner serviceable if you purchased a couple of tools to complete the disassembly/assembly. The owners manual by itself is a remarkable booklet. Everything you need to know about the shock is inside it. It's basically a Penske encyclopedia for that model of shock. They impress me quite a bit after working on most of the other big name brand shocks on the market. This isn't a sales person talking. It's a service tech sharing information with you.

Now, it's possible to upgrade a Sport Shock to turn it into an 8981. The drawback is the cost of the upgrade. The remote resi with associated additional components, revalving and other bits is nearly $400 not including labor. It's a very wise move to spend the extra money up front. You would not be dissatisfied I assure you.

 

[PapaUtah]

Sporty,

Some of us riders are a wee bit larger than the "average" 180lb riders the shocks are spring for. Does the Penske have an option for higher spring rates for us, umm, err, slightly larger(270) fellows? Is there additional cost for the option if available??? Inquiring minds want to know...

 

[sportryder]

Sporty,
Some of us riders are a wee bit larger than the "average" 180lb riders the shocks are spring for. Does the Penske have an option for higher spring rates for us, umm, err, slightly larger(270) fellows? Is there additional cost for the option if available??? Inquiring minds want to know...

There is no additional cost to have a spring that is proper for your weight.

Unless you weigh 400-500 lbs, we should be able to get pretty darn close. If we don't get it correct straight away, then we will work with you at no additional cost to you until you are satisfied.

Something I would like to point out here is this. The correct spring at the rear is going to make the unmodified front forks feel quite soft. I'll say it now because I experienced this on Sunday during my test ride with my wife. You won't care much for the handling with only "fixing" the rear of the bike. It's not the fault of the shock or spring selection. It's the fault of the soft progressive springs out front. They sag too much and cause the chassis to have a "nose-down" attitude. It doesn't feel balanced any longer. At least the OEM suspension had a very soft balanced feel to it.

Here is the caveat - in order to get that balanced feel back, an upgrade to the front will most likely be required. Springs stiff enough to bring it back to a good balance may require the valving to also be upgraded in order to control those stiffer springs.

We see it all the time and it's also what I've experienced when personally upgrading the suspension on my own motorcycles. If you upgrade one end or the other separately with the proper springs and good damping units for your weight and the bike, it magnifies the deficiencies on the end that was left unmodified.

There are some inexpensive options, but they all tend to be simple compromises.

Look at it this way - you've got a car that has old worn-out shocks and saggy springs on all 4 wheels. Would you even consider only replacing the front or the rear separately? And, if you did do them separately, would you expect the handling to be real good? Something to consider.

 

[radman]

Sthporty, we shall be talking further, I have a bonus coming, and this sounds like just the thing to blo......invest it in Oh, and the "inquiring mind" will need a XXL

Edit-I will be rear only (leave it alone ya sicko's) till the fund re-charges. Neccessity put a bullet into Mother Inventions sternum....

Edit#2-Are these prices/models compatible with ABS models? Both John and I have 'em.

 

[sportryder]

Yessir, they are compatible. The only change is a slight "clocking" difference on the 45 degree fitting that exits the shock body which is connecting the hose to the remote resi .

My FJR is a non-ABS model and Penske got the fitting clocked perfectly for it. I didn't have to make one change to it.

 

[Dangerous Dave]

Something to make a note of is this - when you get the correct springs for your weight, bike and "purpose" installed, there really is no need to make changes to the spring preload just because you add a passenger or gear.  Minor changes may be necessary if your passenger is real heavy or you pile on loads of gear though. 

WOW!! In all the tech articles I've read about suspension tuning (online and off), I have NEVER heard anyone make this statement! How can this be? Don't misunderstand what I'm saying here Lee. I'm not calling you a liar, you've just blown my mind with this piece of info. But if what you say is true, then where's the attraction in a remote hydraulic preload adjuster like the ones the svedish guys are selling like Chia pets?? Here I've been thinking that I really needed one of these remote preload adjusters to make life easy when going from solo to two-up...now you're telling me it's not necesary. This is like telling me that Jennifer Anniston looks like a homeless person until she gets her makeup on! I just don't know what to think.

Ok, trying to gather my thoughts now. Can you elaborate for me a little on this topic? Again, not calling you a liar, but I need more info to get a grasp on this, since it goes against everything I've learned about suspension to this point. Help?? :blink: :blink: :blink:

 

[sportryder]

DD - I'm speaking from my experiences regarding fiddling with the spring preload. I've upgraded the suspension on my FZ1 and with the correct springs both front and rear, the only change I make when riding with my wife is to add 1 click on the compression damping at the remote resi.

Now, if your passenger weighs as much as you, or is quite heavy, then adjusting the preload will most likely be necessary.

Here is the deal. Take a 600 lb bike, add a 220 or more rider. You have an 800 + lb bike/rider combo. Add a 125-150 lb passenger. The percentage of change with the passenger is minimal compared to the 1-up weight. Now, if you want to ride as fast with your passenger as you do by yourself, then by all means go ahead and adjust your preload to match the additional weight.

I ride at a slightly slower pace with my wife (with repeated punches in my ribs) as I do when by myself. With the correct springs as a starting point, there is only a small difference in the handling with my 125 lb wife aboard the FZ1.

What we get trained to do is accept OEM spring rates as "proper". Then we must constantly adjust preload at the rear to accomodate load changes. Stock OEM springs are too soft and they have too much preload already. If you add a load, increasing the preload only adds to the initial feel of the bike being stiffer. However, when you "g-load" the bike while cornering, you are still operating at that too soft spring rate. The rate has not changed at all. The rate scale has only been shifted upwards by the extra preload.

So, if you are starting with a spring rate that is already 30-50% stiffer than OEM, then the amount of preload fiddling is much less necessary.

My FZ1 had a 425 lb/inch spring as OEM. It now has a Penske with a 625 lb/inch spring. That's somewhere around a 45-50% change. The front springs went from .8-1.0 kg/mm progressive rate springs to 1.025 kg/mm straight rate. Adding a passenger hardly effected the handling at all.

I upgraded the rear suspension on the FJR and selected a 950 lb/inch spring. I have not tested the OEM spring yet because of lack of time at the shop this week. When my wife and I went for a test ride this past Sunday, I found it to be more than adequate for our needs. I may opt to upgrade the spring and go with a 1000 pounder but at this point, I consider it acceptable. The rear upgrade magnified the overly soft front OEM progressive springs. I'm confident when I upgrade the front springs and valving we will be more than happy with the handling characteristics while riding 2-up or 1-up and there will be no need to make preload changes.

The last point I will try to make is this - if you are riding with a passenger and wish to ride it at the same velocity or pace that you would by yourself, then by all means, tweak the preload adjuster slightly to get perfect handling. But, if you dial the pace back 1-2 10ths on a 1-10 scale you'll also find that changing preload is not necessary when you have the correct springs already under you. And, shame on you if you are riding with your passenger just as quickly as you would by yourself. :agent:

Have a happy holiday... I'm out of here for the weekend. Got to leave shortly for the airport and heading north to visit in-laws.