Fine tuning the Penske 8983

[BigOgre]

I run 220 lbs, ride 25% of the time with a 100 lb passenger, and I told GP that I am not an extremely aggressive rider that rides on some crappy/bumpy New England roadways. They recommended that I up my spring rate from the 800 that was on there to a 900. They said that will allow me to back off on the spring pre-load and the compression damping and give me a more compliant ride.
I haven't got the shock back from them yet with the new spring, but will report my impressions when I do.

We have a new Sheriff at GP Suspension and it sounds like he is recommending bigger springs than the old one.

My experience...........I'm in the same weight range and have a 15lb trunk that I transfer from bike to bike. My 800 spring (with 10mm of installed preload) is a tad firm with the saddelbags off but feels very good with the bags on and loaded. The spring felt a bit undersprung last summer when I had a 105 pound passenger and I had to add about 10mm of preload to maintain steering geometry.,,...but this is with a GEN2.

I think your 900lb spring on your 05 is going to feel pretty good loaded with your passenger but very stiff riding solo unless you are carrying a lot of weight in the trunk and bags (just like the LD riders who were using 900 lb springs in rally mode).

Similar situation here. Thinking I'm about 215 geared up and, while almost always solo, tend to pack heavy on overnighters. (Trying to break that habit.) After both talking with Barry at GP and looking here, ended up with the 900 lb. spring. As suggested have about 36mm preload. Also rebuilt forks all stock but adding 1.0 Race Tech springs.

One concern I had immediately was the inabilty to lower the ride height as the adjuster was almost all the way down. Barry explained that this was normal and as I can still flat-foot it, it's no longer an issue. After only about 150 miles now the bike definitely turns in quicker but not happy yet with the harsh ride. Slowly playing with the rear and it seems to be getting there but not quite. Haven't done much to the front yet either but know I have to. Related (maybe?? hopefully??) is a clunk in the bars upon hitting a low-speed bump or even while rocking the front while on the centerstand. All along I was thinking it was the steering head but now wondering if it has to do with the stiffer springs. (Both were done at the same time.) Gonna watch this thread closely and appreciate any advice and/or what others have done.

 

[Fred W]

I'm definitely saving my old 800 lb spring as a backup plan, as I really had no issues with it bottoming out (even fully loaded and two up) and was just looking to improve things.

PS - Try backing down on the preload (it sounds really high) and the compression damping, Mike. If you still can't get rid of the road-jangles then the spring is too stiff.

 

[TomInPA]

I know I have the 8983...here is the sale thread. Sure wish I would have had the chance to try this thing out before dropping a 4000 mile road trip on it.

I don't know your weight or much total weight you will be carrying but a 850 lb spring is a pretty hefty spring for a GEN1, if it feels too firm you may need to put the compression damping on or close to full soft. Either way it should be a huge improvement over a high mileage OEM shock.

I also have the Hyperco 850lb spring, shortened .25" so I can sit flat footed. Seems to work great.

I thought you said it worked great except for the harsh ride.....which is understandable for a 210 lb rider with a 850 lb spring on a GEN1 (GEN2s have a longer wheelbase and need about an extra 50lb in the spring rate). I'm surprised they gave you a 850 unless you indicated that you often have a passenger or a large trunk but you may still get a plush ride by backing off the compression damping.

Unfortunately I'm no lightweight at 260 and have a Givi E55 trunk. For the long trip, I'll carry moderate weight and the spring should be right at home. I still need to do upgrades on the forks in the Fall. The problem is I installed this right before moving and have zero ride-time on it, and will immediately take off cross-country.

 

[kamal]

I know I have the 8983...here is the sale thread. Sure wish I would have had the chance to try this thing out before dropping a 4000 mile road trip on it.

I don't know your weight or much total weight you will be carrying but a 850 lb spring is a pretty hefty spring for a GEN1, if it feels too firm you may need to put the compression damping on or close to full soft. Either way it should be a huge improvement over a high mileage OEM shock.

I also have the Hyperco 850lb spring, shortened .25" so I can sit flat footed. Seems to work great.

I thought you said it worked great except for the harsh ride.....which is understandable for a 210 lb rider with a 850 lb spring on a GEN1 (GEN2s have a longer wheelbase and need about an extra 50lb in the spring rate). I'm surprised they gave you a 850 unless you indicated that you often have a passenger or a large trunk but you may still get a plush ride by backing off the compression damping.

Unfortunately I'm no lightweight at 260 and have a Givi E55 trunk. For the long trip, I'll carry moderate weight and the spring should be right at home. I still need to do upgrades on the forks in the Fall. The problem is I installed this right before moving and have zero ride-time on it, and will immediately take off cross-country.

Tom, IMHO you won't have a problem. The shock came off an '06, has the Hyperco 850lb spring and was used for 1.5 years, so it should be close to where you want it.

I can't think of anything catastrophic that could happen on your ride (suspension'wise

) and it is simple to adjust if you need to.

Have a great trip.

Al.

 

[MCRIDER007]

Similar situation here. Thinking I'm about 215 geared up and, while almost always solo, tend to pack heavy on overnighters. (Trying to break that habit.) After both talking with Barry at GP and looking here, ended up with the 900 lb. spring. As suggested have about 36mm preload. Also rebuilt forks all stock but adding 1.0 Race Tech springs.

If you have 36mm of preload then you have a serious setup problem, I think you meant to say that you have 36mm of sag....which still seems a little high with a 900 lb spring. You should have around 10mm of preload and if backing off the compression doesn't get rid of the harsh ride then you probably need a lighter spring.

 

[BigOgre]

Similar situation here. Thinking I'm about 215 geared up and, while almost always solo, tend to pack heavy on overnighters. (Trying to break that habit.) After both talking with Barry at GP and looking here, ended up with the 900 lb. spring. As suggested have about 36mm preload. Also rebuilt forks all stock but adding 1.0 Race Tech springs.

If you have 36mm of preload then you have a serious setup problem, I think you meant to say that you have 36mm of sag....which still seems a little high with a 900 lb spring. You should have around 10mm of preload and if backing off the compression doesn't get rid of the harsh ride then you probably need a lighter spring.

Yup. My bad. Sag it was. And going to keep a positive outlook about the spring as even the few changes I've made so far have been noticeable so hopefully . . .

Then again, probably by the time I think I've got it figured out it'll be time to send it back for service.