Hyperpro Fork Spring Install

[Mr. Bean]

I decided to replace the fork springs in the Ballabio for something better matched to my weight and our wonderful NW roads.

 

After checking around, I settled on the Hyperpro forks springs from GuzziTech. Todd asked me if I wouldn’t mind writing up some instructions with some pictures…so here we go!

 

The Hyperpro springs are not drop-in replacements for the 43mm Marz forks. In fact, when they first arrived, I assumed they sent the wrong ones. The instructions referred to features and settings from the earlier 40mm Marz forks. Todd assured me they were correct and that they used the same springs for both the earlier and later models. They simply required a bit of additional work to install.

 

As you can see in the picture below, the new springs were not the same overall length as the stock spring with it’s stock spacer.

 

 

Also, the diameter of the new spring did not match that of the old one. The stock spring is tapered over it’s full length. From the bottom where it mates with the spacer it is 1.5 inches in outside diameter to the top where it nestles into a groove in the fork cap it is 1.3 inches.

 

The new Hyperpro springs were an even 1.4 inches outside diameter end to end. Because of this, they did not correctly match either the spacer at the bottom or the cap at the top.

 

 

I acquired some special 1.5 inch outside / 1 inch inside diameter washers from our friends at McMaster-Carr to provide a better mating surface for the spring to rest against the spacer.

 

 

 

For the top where the spring meets the fork cap, Todd recommended I place a 5/8 inch washer on the cap to provide a flat area for the spring to rest against. As you can see in the picture below, the stock spring is designed to fit on the flat surface just inside the outer lip.

 

 

The washer provides a flat surface for the spring to rest against.

 

 

Once I completed the build using the washer though, I discovered that I lost all but three turns of preload adjustability. As you turn the preload adjuster, it pushes the hexagonal spring mating surface down against the spring. With the washer in place, it could only go down until the washer hit the jamb nut holding the fork cap in place. The regular amount of adjustability for the preload on these forks is 15 turns. I was not willing to lose that much adjusting ability so I looked for another option.

 

I figured that if I could remove the “lip” around the outer edge of the preload adjuster the new spring would have flat surface to rest against…and…the adjuster would be able to slide down past the jamb nut as it is designed to do. The metal that it is made out of is a very light and soft aluminum. Some quick work with a metal file and then a parts washer had the lip filed down flush with the mating surface.

 

 

 

So with that information behind us…the actual steps involved are:

 

 

 

Steps:

 

1) Back both the Pre-Load and the Rebound adjusters fully.

 

2) Loosen the fork caps while the tubes were still in the triple tree.

 

3) Remove the brake calipers and hang them up from the oil cooler mounts using small bungee cords or similar.

 

4) Remove the mudguard.

 

5) Remove the wheel, noting where the spacer fits first.

 

6) Loosen the triple tree screws and slide the fork tubes out.

 

7) Block up the tubes from below and place a 19mm wrench on the jamb nut. Using the preload adjuster on the top of the fork cap, spin the cap off.

 

8) Pull out the rebound adjuster rod from the center of the assembly and set it aside.

 

9) Remove the stock spring.

 

10) Tip the tube over to pour out the old oil. Watch out, as the spacer that sits below the spring will slide out as well. Pump as much of the old oil out as you can by pumping the internal rod assembly as you keep the tube tipped over. I also left mine upside down in a pan while it was leaned in corner for a while to get more out.

 

11) Measure the length of the stock spring and spacer and compare with new spring. The difference is what you need to cut the old spacer down to. Be sure to include the thickness of the washer that goes between the spacer and spring in your calculation.

 

12) File down the lip flush to preload surface on the fork cap. Thoroughly clean the entire fork cap assembly afterward using a parts washer if you have access to one, or a lot of metal parts cleaner.

 

13) Hold the fork tube vertical in a vise and block up the bottom fully. Fill the tube with your choice of folk oil or synthetic. I just used the 10 weight oil that came with the springs. After putting few hundred ml of oil in the tube, be sure to purge all air out by pumping the internal rod until it moves smoothly through its full travel and no more air is bubbling out.

 

14) Top off the tube with oil using the air-gap method. For me, Todd recommended 125mm of air gap for my 180lb weight with full gear on. Others recommend 100mm for average build. Go with what you think…it’s easy to add more later if needed. One thing you do not want to do is use the Guzzi recommended 400 ml. Doing this will likely result in a different air-gap for each fork leg.

 

15) Once you have to correct amount of oil in the tube, slide the spacer down along with the washer on top of it.

 

16) Slide the new spring down into the tube with the progressive (close-ratio coils) toward the top.

 

17) Place the rebound adjuster rod back into the center of the tube.

 

 

18) Screw the fork cap back onto the assembly and tighten down against the jam nut.

 

 

19) Remove the tube from the vise and screw the fork cap back down onto the tube.

 

 

20) Repeat Steps 17 thru 19 with the other fork tube.

 

21) Insert both fork tubes back into the triple trees. Hyperpro recommends raising the tubes 10mm in the triple trees. On my bike keeping them at the stock 22mm above the triple trees kept the ride height exactly the same as before.

 

22) To keep from causing binding and increased stiction, you must assemble the forks in the proper order.

 

a. Lower Triple clamp

b. Upper Triple clamp

c. Axle Spindle nut

d. Bounce the suspension a few times to center everything.

e. Axle spindle pinch bolts

f. Fender assembly

g. Brake calipers.

 

23) Tighten the fork caps back up.

 

24) Set your sag to where you want it. I set mine to 32mm laden. (There is a ton of info on this site detailing the correct setting of laden and unladen suspension sag. I won't go into any detail here.)

 

Hopefully this will helpful to anyone looking to install these springs on the later forks. It is actually quite straightforward once I got past the early confusion. The benefits are definitely worth it! It is like a new bike now!

 

Randy

[richard100t]

On my 01 Rm the spacer goes on the top of the spring instead of the bottom. There is also a collar that sits atop the spacer & there is a blue nut that is used to adjust the preload. My fork caps also look a little different than yours on the inside, mine dont have that large nut on the inside.

I also had a devil of a time trying to get enough preload but I found that the spring was just too long. Out of frustration I just put the stock springs back in the bike & used slightly longer spacers to get more preload. Now the bike rides a lot smoother than it ever did. If anyone has put the hyperpro springs in an 01 model I'd like to hear how you did it. Like I said, getting them in is easy, getting enough preload for my 180lb riding weight is not easy.

[WitchCityBallabio]

I have to say, I have them on my '04 Ballabio as well and the bike never rode or handled as good as it does right now. It soaks up the small choppy bumps with ease, and never has the hard shock feel that it did.

 

Dive during braking is greatly reduced and cornering especially on imperfect surfaces is vastly improved. The HyperPro spring on the Sachs shock also did wonders for ride and handling.

 

Thanks too to Todd Eagan and Guzzitech for his suggestions and help selecting the proper springs for me. I could not be happier with the Ballabio's handling right now.

[WitchCityBallabio]

I have been considering a HyperPro spring for my Penske.

By chance did you measure sag?

Can you tell if it bottoms out?

Or did you compare inner and outer diameters of the Sachs Spring compared to the HyperPro spring.

Don't trouble yourself to measure. I may just give it a try for the heck of it.

I think I progressive spring on the rear should really help the front and rear stay better in balance.

 

 

Sadly, I didn't measure the sag. I had the springs installed and the sag set by the excellent mechanic at the shop I take the Ballabio to, so I'm unsure of the numbers before and after. I could call him and get them if you need them.

 

The HyperPro spring on the Sachs has yet to bottom out from what I can tell and I've been driving some pretty awful roads in and around Boston.

 

Sorry I couldn't be more helpful.

[Mr. Bean]

Randy:

 

1. Sorry for the thread piratage.

 

2. Does this mean that the Hyperpro progressive springs are installed with no spacer at all?

 

Not sure about the 2000 model forks...I believe those are different from my 04 model ones. Mine did require spacers. Originally I simply matched the same length as the spring / spacer combo that was stock. Since that time...and the above posting, I have added about 20 mm more to the spacers to get it just where I wanted it. I should add that to the steps above...if I get a few moments I will.

 

Randy

[richard100t]

On my 01 Rm the spacer goes on the top of the spring instead of the bottom. There is also a collar that sits atop the spacer & there is a blue nut that is used to adjust the preload. My fork caps also look a little different than yours on the inside, mine dont have that large nut on the inside.

I also had a devil of a time trying to get enough preload but I found that the spring was just too long. Out of frustration I just put the stock springs back in the bike & used slightly longer spacers to get more preload. Now the bike rides a lot smoother than it ever did. If anyone has put the hyperpro springs in an 01 model I'd like to hear how you did it. Like I said, getting them in is easy, getting enough preload for my 180lb riding weight is not easy.

After seeing the new posts here I got to thinking about how to make the hyperpro springs work for me. I took out some preload on the rear shock which is what I should have done all along. Now I can say that the sag up front is just fine & the bike rides very smoothly over bumps. I would say that the hyperpro springs offer a better ride than the stock ones once you get them set right.

[VR6Dave]

My instruction booklet recommended 150mm air gap. Is there some concensus as to what it needs to be based upon rider weight? I ended up with 110mm air gap but I'm on the heavy side. I think that was roughly a little over 400mL per leg. I shold have everything buttoned up and ready to test this week, just wanted to know what people felt with regard to the air gap?

 

I placed a pvc spacer in the groove on the fork cap so it was flush with the lip.

 

I noticed one of the stock spings was worn on one of the coils where it had rubbed with the tube. Is it possible the fork tube is tweaked?

 

Dave

[Greg Field]

If you are of the school that believes one size of spring does not fit all, there're Racetech springs that drop right in the late forks and can be ordered by spring rate.

[quazi-moto]

If you are of the school that believes one size of spring does not fit all, there're Racetech springs that drop right in the late forks and can be ordered by spring rate.

 

Does Racetech carry fork springs that will drop right in an '02 LeMans?

[Tom M]

Does Racetech carry fork springs that will drop right in an '02 LeMans?

I don't know about Racetech but Traxxion Dynamics and Sonic Springs both have drop-in straight rate springs for the 02. TD doesn't show them on their web page but they do have them. The HyperPros that Mr Bean installed are progressive rate springs. I have the TD springs and I'm very happy with them. The company was great to deal with too (they sent me extra springs to try at no charge).

[ALdad]

I installed the hyperpros in my 2ooo sport a few months ago. The springs are the same length as the stock+ the spacers, so no spacers are needed. The sag was too much at 46mm static. The ride was really supple but front was too low and quick. I put 8mm spacers which brought the sag up to 32mm static 44 loaded. I dropped the forks in the top clamp to 5mm they were at 10mm and I like it now. Front wheel sticks to ground better in corners than stock. ride is really nice. Rear is about 38mm loaded the bike seems pretty well ballanced now. I weigh 210lbs I hope this is of some help to somebody . Cheer!!

[arek]

Hi,

There is a YouTube video of a dude doing this, and although it is not the exact same fork, it is the same procedure. I thought it may be useful for someone who has neve done this, so here you go:

 

[P3GA]

I don't know about Racetech but Traxxion Dynamics and Sonic Springs both have drop-in straight rate springs for the 02. TD doesn't show them on their web page but they do have them. The HyperPros that Mr Bean installed are progressive rate springs. I have the TD springs and I'm very happy with them. The company was great to deal with too (they sent me extra springs to try at no charge).

 

 

I can vouch for the Traxxion Dynamics springs - they used my '02 LeMans some time ago to develop spring rates for the front forks & the rear shock. Best money I ever spent on the bike, especially the rear spring.

 

Hope this helps.

[Slavomir Musilek (R.I.P.)]

I have just received my set of Wirth (or wurth)? Progressive springs for my Marz 41mm. Does anybody know much oil should be in the each leg? In manual is written something like 420ml to each leg, but since the new springs are different size than the stock I'd preffer to know how many milimetres should be the oil from the top of fully compresed fork.

 

[Tom M]

When I replaced my fork springs I followed the advice from forum members here and set the oil height to 100mm, which is measured with the forks fully collapsed and the fork springs removed. Even though I pumped the damper cartridges a lot to get the air out, I still found the rebound side oil level was substantially lower when I went back into the forks a few weeks later to make oil height and preload spacer adjustments.

 

FWIW I ended up using 5wt oil on the compression side and settled on an air gap of 110mm or so to get what I consider a nice ride. Remember that my 40mm Marzocchi is different than yours...