ST1100 Hyperpro Fork Springs

[The Duke]

I recently bought a set of Hyperpro fork springs from Number9 (thanks Jason!), and I'm curious if anyone else has these springs in their 1100, and if anyone still has their installation instructions. I want to make sure that I get things setup correctly when I install the springs because I don't want to tear the forks apart again for a while.

I did read that Hyperpro recommends 20wt fork oil. This seems REALLY thick compared to stock. Has anyone run thinner oil with Hyperpro springs? I'm afraid if I run the thick stuff that I'll wind up with an unpleasant ride. I live in South Dakota so I have to ride a long way to get to a road with curves. I don't want to beat myself to death before I get there.

Any info and advice provided will be GREATLY appreciated.

Thanks,

Duke

 

[chesthing]

In my opinion the ST1100 stock damping is just too harsh for straight rate springs gauged for your weight and (less so) Progressive springs. Honda used .6 rate super soggy progressive style springs and 5 wt oil to offset this harsh (cheap) damping. Many seem to disagree with that, as I read all kinds of positive reports of Sonic or Hyperpro springs with 10 wt oil - maybe they ride on smoother roads or are less sensitive, but my experience with correct rate Sonics springs was very frustrating (jarring).
I've ordered the Race tech gold valve kit and springs in search of a smooth, stable ride. Btw 20 wt is just begging for a jackhammer ride.

 

[Mark]

I have them installed.
I will look for the instructions; but, don't hold your breath because it has been about 4 years and with my kids and wife nothing in the garage stays put!
That being said... there wasn't anything out of the ordinary in the instructions... except for that 20wt... In my opinion you are correct it made the ride too harsh.
I changed it to 15wt after a year. I have been running 15wt ever since.
I weigh about 175...

And all that being said: I really like them!

Good luck,
Mark

P.S.
Have you asked HyperPro for an electronic copy of the instructions?

 

[The Duke]

Thanks for the feedback!

As for oil, right now I'm running a mix of 5 & 10 wt. I'd say it's still a little less responsive than I want, so I may change to 10 wt the next time I drain the forks and I'll keep increasing the viscosity until I find what works for me. Of course I'll first have to see how the bike handles with the current oil and the new springs.

I did ask Hyperpro for an electronic copy of the instructions, but I haven't heard back from them.

Do either of you recall if you needed to add/remove/change the spacers, or did you just install with the stock spacers?

Thanks!

Duke

 

[Mark]

Do either of you recall if you needed to add/remove/change the spacers, or did you just install with the stock spacers?

Thanks!

Duke

Sorry... no memory of what I did... yeah... I followed the directions...
Which I guess means that you might want to call the US distributor and talk to a 'tech' rep.

 

[bdalameda]

Running progressively wound springs in the ST1100 really does not work very well. This is because it is not possible to control damping with a progressive wound spring. The softer portion of the spring collapses easily and the damping force needs to be very light for this but as the spring compresses and becomes stiffer the damping needs to increase. It is hard to balance the damping needs of both a light spring and stiff spring. It is easy to use up the first inch or two of travel before the fork begins to work effectively. If you use a straight rate springs the damping can be adjusted with the right weight fluid to work throughout the travel. It actually makes the fork seem like it has more travel than with the progressive wound spring because the actual working length of the travel is increased. I use a straight rate spring with 10 wt. fluid. The ride is very good and large bumps are absorbed much much better than stock. I also increased the height of the fluid in the forks by 10mm. It is interesting that the forks feel a lot stiffer just sitting on the bike but the ride and handling is very nice and you can feel the supension work.

Most bike manufacturers have stopped using progressively wound springs in the last few years because of these types of control issues with damping throughout the travel of the suspension.

FYI - the correct term is damping not dampening as most people think.

Dan

 

[chesthing]

I agree the medium/large bumps were taken better with the Sonics I tried, but all the little stuff was felt too. The handlebars would just chatter up and down through the whole ride, no matter what fork oil or level I tried. I'm hoping the gold valves work to reduce that, because I'm not spending $1400 with Traxxion for forks on a $3000 bike, that's for sure.

 

[Ken H]

I recently bought a set of Hyperpro fork springs from Number9 (thanks Jason!), and I'm curious if anyone else has these springs in their 1100, and if anyone still has their installation instructions. I want to make sure that I get things setup correctly when I install the springs because I don't want to tear the forks apart again for a while.

I did read that Hyperpro recommends 20wt fork oil. This seems REALLY thick compared to stock. Has anyone run thinner oil with Hyperpro springs? I'm afraid if I run the thick stuff that I'll wind up with an unpleasant ride. I live in South Dakota so I have to ride a long way to get to a road with curves. I don't want to beat myself to death before I get there.

Any info and advice provided will be GREATLY appreciated.

Thanks,

Duke

Duke-
Ive got Hyperpro's installed in my '99 ST and I have the instructions. They are pretty generic but they do point out to be sure and move the piston rod up and down 15 - 20 times in the cartridge fork to get the air out before filling and to adjust the oil level in the forks with the forks compressed. They also included a specification page for the ST1100 which includes the following info:

Mount the fork springs with the standard preload bushing.
Oil Level: 150 mm
Static sag: (+/- 5) 36mm

They do specify the 20w Hyperpro oil, but as mentioned previously you can adjust that to suit your preferences.

I have had the Hyperpro's for several years now and they have worked well for me. The Hyperpro 20w oil worked well for me for the initial installation but I am 6'1" and weigh about 245 so the viscosity of the 20w Hyperpro was probably fairly well suited for me considering my weight. I have used Silkolene 20w fork oil on subsequent changes because I could not find the Hyperpro oil locally but I have about decided it is a little too harsh for my liking and I think I am going to step down to the 15w Silkolene oil on my next change. I have learned that the same fork oil weight across different brands does not necessarily give the same performance across all brands. The 20w Silkolene was a noticeably firmer ride than the 20w Hyperpro oil. Good luck with your Hyperpros.

 

[bdalameda]

Many times the springs and or fluid weight is not the problem at all. Sometimes the problem is stiction which is caused from a slight binding or fork seals being new and tight. Make sure before you tighten the axle clamps or axle bolt you push your forks up and down to make sure they are not in a slight bind. Also make sure your fork tubes are even in the triple clamps as this can cause issues with binding as well. Some fork seals can be tighter than others and this can cause little bumps to be transmitted through. Even though they do not last very long I use the Leak-Proof Pro-Moly seals and wipers as they decrease stiction quite a bit and allow very free movement of the fork. Even though they are guaranteed for life I only get about 15K out of a set. I guess they would give me new ones if I sent them back but I usually just buy a new set.

Dan

 

[Ken H]

I get a huge amount of chatter on my bike rolling down the road, but I believe at 73,000 miles it's the original suspension. I know the rear is original. I'm hoping a fluid swap will help, but i don't even know what weight to consider. Probably 10, and see how that goes.

When you change out the rear shock dont be surprised if you have one of those 'why didnt I do this sooner?' moments. I changed my rear shock out with a Works Pro Series at around 65K miles. It made a world of difference.

 

[Mark]

When you change out the rear shock dont be surprised if you have one of those 'why didnt I do this sooner?' moments. I changed my rear shock out with a Works Pro Series at around 65K miles. It made a world of difference.

Same kind of moment when I did mine at 54k!

I think Smash should put out a call on all the ST1100 sites to find someone who has to total a bike, and find a used aftermarket rear shock!

might want to find out if Freestyle Don has an aftermarket too!

 

[The Duke]

Thanks for all the great feedback! This information makes me feel a lot more comfortable. I expected that I needed to use the standard preload bushing, and now I have confirmation. I still have a PM out to the guy I bought them from because he had some measurements written on the box and I wanted to find out what they meant. Somehow I expect he may have gone with a non-factory bushing to adjust the static sag.

I am sure I won't go with 20wt oil, if for no other reason than living in a colder climate. Somehow I think 20wt would be unbearable in the spring and fall. Regardless, now I need to get to work and get them installed.

Duke-
Ive got Hyperpro's installed in my '99 ST and I have the instructions. They are pretty generic but they do point out to be sure and move the piston rod up and down 15 - 20 times in the cartridge fork to get the air out before filling and to adjust the oil level in the forks with the forks compressed. They also included a specification page for the ST1100 which includes the following info:

Mount the fork springs with the standard preload bushing.
Oil Level: 150 mm
Static sag: (+/- 5) 36mm

They do specify the 20w Hyperpro oil, but as mentioned previously you can adjust that to suit your preferences.

I have had the Hyperpro's for several years now and they have worked well for me. The Hyperpro 20w oil worked well for me for the initial installation but I am 6'1" and weigh about 245 so the viscosity of the 20w Hyperpro was probably fairly well suited for me considering my weight. I have used Silkolene 20w fork oil on subsequent changes because I could not find the Hyperpro oil locally but I have about decided it is a little too harsh for my liking and I think I am going to step down to the 15w Silkolene oil on my next change. I have learned that the same fork oil weight across different brands does not necessarily give the same performance across all brands. The 20w Silkolene was a noticeably firmer ride than the 20w Hyperpro oil. Good luck with your Hyperpros.

 

[broc11]

Running progressively wound springs in the ST1100 really does not work very well. This is because it is not possible to control damping with a progressive wound spring. The softer portion of the spring collapses easily and the damping force needs to be very light for this but as the spring compresses and becomes stiffer the damping needs to increase. It is hard to balance the damping needs of both a light spring and stiff spring. It is easy to use up the first inch or two of travel before the fork begins to work effectively. If you use a straight rate springs the damping can be adjusted with the right weight fluid to work throughout the travel. It actually makes the fork seem like it has more travel than with the progressive wound spring because the actual working length of the travel is increased. I use a straight rate spring with 10 wt. fluid. The ride is very good and large bumps are absorbed much much better than stock. I also increased the height of the fluid in the forks by 10mm. It is interesting that the forks feel a lot stiffer just sitting on the bike but the ride and handling is very nice and you can feel the supension work.

Most bike manufacturers have stopped using progressively wound springs in the last few years because of these types of control issues with damping throughout the travel of the suspension.

FYI - the correct term is damping not dampening as most people think.

Dan

I am just updating the suspension on my 01 st1100 abs, I have a shock ordered but I am wondering should I also change the fork springs? what is the consensus on straight rate versus progressive springs?
Don't know which to go for or should I just leave the forks alone and just replace the fork oil with 10 wt?
thanks

 

[broc11]

In my opinion the ST1100 stock damping is just too harsh for straight rate springs gauged for your weight and (less so) Progressive springs. Honda used .6 rate super soggy progressive style springs and 5 wt oil to offset this harsh (cheap) damping. Many seem to disagree with that, as I read all kinds of positive reports of Sonic or Hyperpro springs with 10 wt oil - maybe they ride on smoother roads or are less sensitive, but my experience with correct rate Sonics springs was very frustrating (jarring).
I've ordered the Race tech gold valve kit and springs in search of a smooth, stable ride. Btw 20 wt is just begging for a jackhammer ride.

Hi, as stated in the above post I am just updating the suspension on my st1100, I wonder should I just leave the forks as they are with the oem springs and replace the fork oil?
or go with new springs too,either straight rate or progressive?
just looking for some wisdom from folks who have ben there and done that, Thanks

 

[DeanR]

New 10 wt oil (although that can vary between brands), then I'd definitely go with straight rate springs.

 

[ST1100Y]

I recently bought a set of Hyperpro fork springs from Number9 (thanks Jason!), and I'm curious if anyone else has these springs in their 1100, and if anyone still has their installation instructions.

I run Hyperpro linear-progressive(!) fork springs in my standard model since '03 now, and just love them (contrary to the previously tested 2-stage progressive springs made by Wilbers which were just awfully hard and bouncy...); the suggested 20W fork oil was definitely way to harsh on my wrists, after some testing I ended up with a 7W fork oil (BelRay) as my ideal setup (with the frost beaten, pretty patchworked alpine roads we've to cope with over here in mind); so IMHO is anything heavier then a 10W pretty harsh and wearing on long hauls, a 5W feels quite 'spongy' (especially under heavy breaking). I like a progressive working suspension, but I dislike sore wrists...

 

[broc11]

I run Hyperpro linear-progressive(!) fork springs in my standard model since '03 now, and just love them (contrary to the previously tested 2-stage progressive springs made by Wilbers which were just awfully hard and bouncy...); the suggested 20W fork oil was definitely way to harsh on my wrists, after some testing I ended up with a 7W fork oil (BelRay) as my ideal setup (with the frost beaten, pretty patchworked alpine roads we've to cope with over here in mind); so IMHO is anything heavier then a 10W pretty harsh and wearing on long hauls, a 5W feels quite 'spongy' (especially under heavy breaking). I like a progressive working suspension, but I dislike sore wrists...

Sorry hadn't seen this post before I replied to you on another thread,so you reckon the wilbers springs weren't great, ok then I will go for the same springs you use, isn't linear-progressive 2 different types of spring though, one being linear and the other being progressive type?
the roads here are similar to the alpine roads you describe,so I don't want suspension that's too harsh.

 

[ST1100Y]

Well, the Wilbers 2-stage progressive fork springs had a short soft/narrow wound part, and a longer hard/wider wound section. During use it felt as if the soft part was floating at nearly fully compressed and so I was constantly bouncing on the (obviously much harder) section of the springs, literally 'hammering' on my wrists and on mentioned patchworked roads the whole cowl/fairing started to rattle and clank (on cobblestone tooth fillings/crowns and kidney stones simply disintegrated...). No such thing on the linear progressive wound Hyperpro springs, totally smooth ride, whilst showing a fast increasing 'stiffness' on harsh braking action and/or pushing through the compression of a fast/narrow turn (or hitting a noticeable detent/crest in the road surface). I did give the Wilbers 2-stage springs a try, went from 20W (like having rods instead of springs...) over 15 (still way too harsh for our roads) and 10 even down to 5W oil, but no avail; the 'softer' the fork oil the more perceptible the difference between the 'soft' and the 'hard' part of the springs grew... the suspension guru then suggested the linear wound springs, and indeed do they have a seamless change in distance/angle between each winding over their entire length.

 

[broc11]

is this the springs? ebay item number 181181732931

thanks

 

[ST1100Y]

According to their site (http://www.hyperpro.com/hyperpro/en/node/21) yes