Triumphrat

ventur4th · 01-01-2007, 03:23 PM

I like my Sprint. Actually, I love this bike. But the suspension, at best, is ***** and after 21k miles it was becoming a PITA to ride. Various mods to the forks helped to amplify the deficiencies of the stock shock that seemed to have become devoid of any dampning whatsoever, so I began looking for a shock. There isn't much aftermarket support for the Sprint, and after discussing the situation with my local independent shop they suggested contacting GP Suspension for a solution. After some phone calls and a few emails I recieved a beautiful Penske shock from them. Unfortunately, there was a mix up with the resevoir hose length and the shock had to go back to have this corrected. A few days later the shock was back and installed on the bike. Holiday obligations didn't allow for more than a quick around the block ride, but yesterday I broke free and took the bike up to Angeles Crest. What a difference! The bike feels composed, solid and confidence inspiring. The suspension now works - it's firm and compliant - it works so well that you stop thinking about it and just concentrate on the riding.
Some observations: The bike is suprisingly sensative to dampner and ride height adjustments. Small changes can be felt clearly. This really helps in setting up the shock. I haven't found the absolute best settings yet because the bike now has so much more potential to explore.
Installation was about the same as the stock shock except that there are a few more spacers involved to replicate the stock shock eye widths. I mounted the resevoir on the left subframe rail with the supplied mounting kit. I had them remove the 90* elbow from the resevoir, and found this to be a mistake. The hose would have run much better had I left the elbow in place. When I get time, I'll machine a bracket for the resevoir to replace the hose clamps that hold it to the subframe, or possibly fabricate a bracket that mounts the resevoir under the battery box in a transverse fashion.
And now a plug for the guys at GP Suspension: These guys were excellent. They came highly recomended, and I too pass along that recomendation. Nice people, good work and good customer service. Check out their web site.
As I get more miles on the shock I'll post a follow up.
Happy New Year to all!
Cheers,
Steve.
GP Suspension

womcat · 01-01-2007, 07:26 PM

Definitely keep us posted on how it works. I have been thinking about upgrading but not sure if I want to spend the money or not. What have you done to the forks? I might have missed your thread on it. I was going to change out fork oil this winter and switch to a heavier weight, maybe even thought about different springs.

ventur4th · 01-01-2007, 09:35 PM

womcat,
I had Race Tech install their Gold Valves and a heavier set of springs. It was a definite improvement, but felt that the springs were too stiff and not responsive over smaller surface irregularities and sharp edged bumps. I put in a set of Hyperpro progressive springs and found them to be too soft and require too much preload to set the sag and never was able to get the static sag correct either. I ended up cutting four coils out of the softer (tighter wound) end of the spring and installing them with spacers cut to the length of the removed coils + 1/8 inch. It works much better now!
I think that the springs make more of a difference than the Gold Valves did. As the rebound dampening is too heavy changing your fork oil to a heavier weight may amplify that problem. But try it, and let us know.

womcat · 01-01-2007, 11:16 PM

Thanks for the info. You are probably right about the heavier oil, and if I get stiffer springs that will probably cure the problem w/ excessive dive. I was thinking that w/ the heavier oil it would slow down the action some but I might be off in my thinking. I am far from a suspension expert, I always have my dirt bikes done by a pro for that very reason. I was thinking about trying to do the Sprint myself, though. I will post anything I do and might have to ask a few questions as I go from those who have already done it. Hopefully I will tackle it in a few months.

Thanks for the info

Stlakid · 01-02-2007, 03:50 AM

I've mentioned this to a couple others. I put the Race Tech springs in my bike and the dive was much better. I don't mind a firm front end so the recommended spring from them is what I have. I would probably go one step softer on the spring that Race Tech recommends because in my opinion they error on the SPORT side of things and tend to be a bit stiff for someone who is not going to do a track day even once in a while. If I were to do it over again, I think I would pick one the next step softer just so I use a bit more of the suspension during normal riding and enjoy a slightly plush ride. I can always crank in a little more preload if needed. JMHO

olgray1 · 01-02-2007, 09:05 AM

I had talked to Tim at Penske about sending them my shock and making a shock up for me. I have removed the shock and was going to mail it to them this week. The one thing I was not sure about is the length of the reservoir line and as you mentioned the angle of the fittings.
While Tim at Penske has been great, after looking at GP Suspension's website I may call them for a price. Penske was going to give me a discount from list for using my 2006 Sprint shock as a template. :???:

ventur4th · 01-03-2007, 01:43 AM

I would imagine that GP Suspension had to work with Penske to get the shock built, but there was no discount on my end... I don't feel bad about it because I know that they had to do a bunch of work to get it sorted out, and keeping independent shops alive is a good thing. Plus, they're nice folks.
I have to agree that Race Tech does set things up stiff! I ended up going two steps down from their initial recommendation. (1.0 to .90) The best compromise was the .95s. They helped a lot on the rebound, making the bike feel significantly more poised and planted in front but were at the same time were really stiff. That kind of setup is OK for the track, but on the road it's uncomfortable. I ended up with the Hyperpros, trimmed them to suit and they're much better. Most anything is better than the stock springs, particularly after you get some miles on them.
I'm currently looking into a fix for the rebound. If I get it right, it could be one of those cheap/easy fixes that really work well. I'll post the results.

gavinb · 01-03-2007, 11:57 PM

I have an Ohlins shock on my 00/01 Sprint and would like to fit a new mono shock on my 06 ST.
For some reason Ohlins no longer supply units for any Sprint other than the 99 model.
As I am thinking of selling my 00/01 ST I would, if possible swap the unit over to my new bike.
As some of you have had the suspension apart, do you know if they are inter changeable?
If you do not know the answer do you have the specs for original unit for your 06 available?
I will also swap over the springs and gold valves which should fit as I don't think the forks have changed.

ventur4th · 01-04-2007, 03:11 PM

gavinb,
I still have the stock shock. When I get home tonight I'll measure it for you and post the dimensions. The springs from the 01 forks may work, but the 05/06/07 have cartridge forks.

[ This message was edited by: ventur4th on 2007-01-04 13:14 ]

ventur4th · 01-04-2007, 10:44 PM

Hope this is of use!
2006 SRINT STOCK SHOCK DIMENSIONS
Eye to eye length: 350 mm
Top eye width: 30 mm
Bottom eye width: 40 mm
Bolt diameter: 10 mm (both)