• IF YOU GET 404 ERROR: This may be due to using a link in a post from prior to the web migration. Content was brought over from the old forum as is, but the links may be in error. If the link contains "cog-online.org" it is an old link and will not work.
  • Can't post after logging to the forum for the first time... Try Again - If you can't post in the forum, sign out of both the membership site and the forum and log in again. Make sure your COG membership is active and your browser allow cookies. If you still can't post, contact the COG IT guy at IT@Concours.org.

Rear Shock Upgrade Questions

willard.e.williamson5632

willard.e.williamson5632

Member
Member
Greetings:
I have a 2002 C10 that I bought new and am in the process of restoring. It has been sitting in my garage for 18 years. Was interested in exploring a rear shock upgrade. I see in other posts that members have purchased Hagon and Wilburs shocks. Are these companies still accepting orders for C10 shocks? What do people think of these shocks as compared to stock if you have any experience with them. Which shock is better?

I was also wondering about a RaceTech G3-S shock. Is RaceTech able to make a GS-3 shock for the C10? Does anyone have any experience with this shock on the C10? This seems like the best option to me but I find no evidence of anyone using this shock on the C10.

I know a lot of people use C14 or ZZR shocks but I would prefer to get something that I don't have to modify the linkage or mounting hardware.

Are there any other options available not mentioned here?
 
I understand your thoughts but want to add some info.
If you use a ZZR Shock you don't have to modify the Linkage. {Because a ZZR Shock is "very" near the same length as a C-10 shock}.
(NOTE: A C-14 shock is longer than a C-10 shock and would require Linkage modification only if you're not tall e'nuff to ride with the increased height) (approx. 1")

All you need to do on either used shock is;
Make a bushing to install in the lower mount of the Shock and increase the size of the mounting hole at the other end.
No frame modifications are needed.

I agree; This is not as EZ as installing a new shock, but it is faaaaaar cheaper to do.

Ride safe, Ted



PS: This will help me understand your wants.
Have you changed the fork oil or set the sag on your bike previously?
 
Last edited:
How many miles? If the stock still holds air then changing the oil might be the cheapest option. That is if it didn't sit outside that whole time.
 
Thanks for the info - I have not set the sag recently. Is the ZZR shock rebuildable by a company like Racetech? If I do go with a used shock like that I would want to get it rebuilt. But then if I get it rebuilt it may make just as much sense to go with something like a Wilburs or a custom - would have to compare costs on that.
 
smithr said:
How many miles? If the stock still holds air then changing the oil might be the cheapest option. That is if it didn't sit outside that whole time.
Click to expand...
The bike has 34000 miles on it. It has always been stored inside my garage since it I bought it new in 2002. I live in Syracuse NY and it gets really cold in the winter and really hot in the summer so I'm sure that takes a toll on everything. It does appear to hold air ok. I recently bought a dedicated air shock pump to check it. It had 20 psi when I checked it and its been sitting for at least 18 years. I pumped it up to 30 and then checked it the next day and it was right at 30. The front fork is leaking oil - I was just going to take off the forks and send them into Race Tech for gold valves and a rebuild. I am the only one who has ever done service on the bike and the shock oil has never been changed.

Thoughts?
 
My next question is; are you able to do repairs yourself?
ie; If we give info, do you have a garage and tools, and could you rebuild the front forks and install the rear shock?
If you can do the mods yourself, you can repair {and improve} both ends the suspension for about $300.
Going the way you're planning, I think you're talking about $2500 or so.

I'll be out of town tomorrow. May be home in the afternoon to check the discussion.

Ride safe, Ted
 
connie_rider said:
My next question is; are you able to do repairs yourself?
ie; If we give info, do you have a garage and tools, and could you rebuild the front forks and install the rear shock?
If you can do the mods yourself, you can repair {and improve} both ends the suspension for about $300.
Going the way you're planning, I think you're talking about $2500 or so.

I'll be out of town tomorrow. May be home in the afternoon to check the discussion.

Ride safe, Ted
Click to expand...
I can definitely do the work myself. I have a heated garage, an extensive tool collection, and decades of wrenching experience. However, I don't currently own any specialty fork tools but I'm sure Motionpro would have everything I need. I have watched a few youtube videos of guys rebuilding C10 forks and it doesn't look too bad. However, the gold valve product offered by Racetech seemed like a nice upgrade.

As I understand it, the only thing you can do with the rear shock is replace a some of the oil through the schrader valve. Is that correct?
 
The forks on a C-10 are not very complicated. The manual has you use special tools. I am here to tell you that the simple items shown in the pic attached will do the job. The all thread and double nuts will hold the metering tube while you un-torque it. The PVC I used as the bushing and seal driver to reassemble it. They get attached to the inner shock and use it as a slide hammer. The small diameter to drive the bushing and the large to install the seal.

Last winter I did the fork upgrade to emulators with information found on the forum. The emulators were about $60 and I used my stock springs.

forum.concours.org

Re: What did You Do to your C-10 Today?

Put the wheels back on the bike after having new tires mounted at my local Cycle Gear. (They actually price matched the American MotoTire price I found so saved about $70 on the pair. Plus they mount and balance for $30 a tire if you buy from them.) Finally retired the Avon AM26 RoadRider I...
forum.concours.org forum.concours.org
 

Attachments

  • forktools1.jpeg
    forktools1.jpeg
    228 KB · Views: 4
  • fork tools.jpeg
    fork tools.jpeg
    143.4 KB · Views: 4
Ok, sounds like you can do it.
Here are 2 video's to watch.

We can offer more info when you're ready to discuss.
Adding an Emulator is DEFINITELY a nice Upgrade!
I've never done one, but I think the Oil is added to the stock C-10 shock thru the hole where the hose attaches to the Shock.

Ride safe, Ted

How to Rebuild Forks;
No special Fork tools needed. Simple tools can be built to do the job.
Important; Use Metric Allen for the bottom bolt. Many use a SAE Allen that can "and will" round out the head of the bolt.

mc garage - Search Videos

Watch videos instantly on Bing—enjoy direct playback, discover related clips, and dive into trending content all in one place.
www.bing.com www.bing.com

How to install Gold Valve Emulators.
(Works EXACTLY the same with the "Inexpensive ones" with a simple modification for about $150 less).

how to install gold valve emulators - Search Videos

Watch videos instantly on Bing—enjoy direct playback, discover related clips, and dive into trending content all in one place.
www.bing.com www.bing.com

Ride safe, Ted

NOTE: PM sent...
 
Last edited:
connie_rider said:
Ok, sounds like you can do it. Here are 2 video's to watch.
We can offer more info when you're ready to discuss.

Ride safe, Ted

How to Rebuild Forks;
No special Fork tools needed. Simple tools can be built to do the job.
Important; Use Metric Allen for the bottom bolt. Many use a SAE Allen that can "and will" round out the head of the bolt.

mc garage - Search Videos

Watch videos instantly on Bing—enjoy direct playback, discover related clips, and dive into trending content all in one place.
www.bing.com www.bing.com

How to install Gold Valve Emulators.
(Works EXACTLY the same with the "Inexpensive ones" with a simple modification for about $150 less).

how to install gold valve emulators - Search Videos

Watch videos instantly on Bing—enjoy direct playback, discover related clips, and dive into trending content all in one place.
www.bing.com www.bing.com

Ride safe, Ted
Click to expand...
 
Thanks for the info. I did watch the videos and found them very interesting / educational. I very much enjoyed the videos.

For my front forks, I think the only thing that I would gain by doing the work myself as opposed to sending them into RaceTech is the $225 labor fee (which is not insignificant) and shipping fees. I definitely want to upgrade the springs and get the gold valve kit as I am sure this will be a big suspension improvement. Since one fork is already leaking oil quite bad, it makes sense to just go ahead and rebuild them with new bushings, seals, washers, oil, etc. So I just need to watch the videos again a couple more times and decide if I want to do it myself or not.
 
I called RaceTech and confirmed that they can indeed make a G3-S shock for the zg1000 for $899, 4 to 6 week lead time. They said that they have made G3-S shocks for the zg1000 for customers in the past. I am posting this because I could not find any hard evidence on the internet that the G3-S shock was available for the zg1000. Even the RaceTech web site doesn't say anything about it. I think this is a good option because the other custom / aftermarket shocks that are available seem to come from Europe (Hagon, Wilburs) which could be more of a pain to deal with.

So if I was going to buy a used ZZR shock I would probably want to rebuild it anyway and that adds to the cost. The ZZR shock also changes the ride height (a little) which I'm not thrilled about. The way I understand it the ZZR shock is a little soft for the C10 anyway which would necessitate a different spring at the least.

The C14 shock is not an option for me because the ride height changes by a lot and I definitely don't want to deal with changing the linkage - would rather spend the $899 :).

So for anyone out there who needs a new rear shock, the RaceTech G3-S shock is a great option. Seems to be priced similar to the Hagon and Wilburs options.

Given that my forks are in significantly worse shape than the shock I am going to focus on rebuilding the fork right now.
 
willard.e.williamson5632 said:
For my front forks, I think the only thing that I would gain by doing the work myself as opposed to sending them into RaceTech is the $225 labor fee (which is not insignificant) and shipping fees.
Click to expand...
Is $225 the rate for std Fork rebuild or rebuild with Gold Valve etc?
I suspect Race Tech's labor fee for installing the Gold Valves, Springs, & spacers might be more. (as it requires OEM parts to be modified)

Ride safe, Ted
 
connie_rider said:
Is $225 the rate for std Fork rebuild or rebuild with Gold Valve etc?
I suspect Race Tech's labor fee for installing the Gold Valves, Springs, & spacers might be more. (as it requires OEM parts to be modified)

Ride safe, Ted
Click to expand...
The way I understand it the fee includes rebuild and gold valves. Their web page for the zg1000 says "Install Gold Valves and Rebuild Front Suspension (labor only)" -> $225.

Also note that RaceTech sells all of the rebuild components themselves. You can purchase all the seals, bushings, washers, snap rings, etc, right from RaceTech.

That being said I think I am going to do the fork rebuild myself. After watching the videos I'm confident I can do it. My daughter and I are working together on this restoration project and neither of us has ever cracked open a fork before. This is a great learning opportunity for both of us. I am looking into picking up a low cost drill press from Harbor Freight to assist with drilling the damper rod. Drilling the damper rod seems like the trickiest part of the job and having a drill press will make the job a lot easier. I'm sure I will save very little money doing the work myself as opposed to paying RaceTech but I am interested in gaining the experience of rebuilding the fork and also enjoying time working on it with my daughter. I have extensive motorcycle repair experience and I am passing it down to the next generation :).
 
I agree that drilling the damper Rod is more difficult with a hand drill, and a drill press is better/easier.
ie: The hole location/spacing is not important so it can be done with a hand drill. The Press is just easier/more precise.
The holes are only added to increase the flow area. (So that the holes no longer control the oil flow)
ie; By adding the extra holes you move the control of the oil flow from the holes in the tubes to the valves in the Emulators.

Go to this discussion. Great info from SethInIllinois.
Seth shows the hole drilling process, the pet numbers and he also compared the Gold Valves and the (inexpensive) Emulators.

forum.concours.org

emulator settings

About 30K miles ago my bike was in need of steering head bearings and so they were replaced. At about the same time a partial transformation to the front suspension was also done, this included race tech 1.0 springs and emulators (left at factory settings). The suspension compliance was great...
forum.concours.org forum.concours.org

Ride safe, Ted
 
Last edited:
Willard, really cool that you've owned it since new, and who is helping you with the work.
BTW, you can get some good deals on seal drivers. I bought a full set for about $45.
 
So the way I read that is labor only. $225 plus parts, valves, bushings, seals, and springs. (I didn't go to their web site for pricing)

I used the cheap emulator and drilled extra holes in it and the metering tube. I used my original progressive rate springs. You have to cut off at least the length of the emulator to get them to fit in the fork. Hi speed cutoff or Dremel and time will work.

Before you remove the fork. Loosen just the top triple tree bolts and break the top cap loose. The upper bolts can pinch the end of the tube making loosing of the cap harder. I used a 6 point socket on a speed handle. Look at your socket and see if the end is chanfered. I grind the chamfer off any socket that gets used on a fastener that is not very tall. You want full engagement to prevent damage to the cap. Hold down on the cap to prevent damage to the threads as it gets near the end of the tube. It's got some spring tension on it. Use care while installing also.
 
Jpd11958 said:
So the way I read that is labor only. $225 plus parts, valves, bushings, seals, and springs. (I didn't go to their web site for pricing)

I used the cheap emulator and drilled extra holes in it and the metering tube. I used my original progressive rate springs. You have to cut off at least the length of the emulator to get them to fit in the fork. Hi speed cutoff or Dremel and time will work.

Before you remove the fork. Loosen just the top triple tree bolts and break the top cap loose. The upper bolts can pinch the end of the tube making loosing of the cap harder. I used a 6 point socket on a speed handle. Look at your socket and see if the end is chanfered. I grind the chamfer off any socket that gets used on a fastener that is not very tall. You want full engagement to prevent damage to the cap. Hold down on the cap to prevent damage to the threads as it gets near the end of the tube. It's got some spring tension on it. Use care while installing also.
Click to expand...
Good disassembly advice!
 
I emailed Hagon (sales@hagon-shocks.co.uk) and they confirmed that they still make a zg1000 (gtr1000 in Europe) shock. They provided the following link: Hagon ZG1000 Shock. Chat GPT said that it thinks import tariffs would be 0. So for the more expensive version of the shock with the remote preload adjuster it sounds like it would be around $613 plus shipping. Is anyone familiar with Hagon shock performance and how it might compare to the RaceTech option? The RaceTech option is around $300 more expensive.

I'm not in any rush to replace my shock because it still does hold air. I'm actually surprised that it holds air after all these years! That being said I am thinking about upgrading the shock to a Hagon or RaceTech after I get the more pressing mechanical items sorted. I know that RaceTech is a well respected suspension company that makes high quality suspension but I am not familiar with Hagon.
 
Jpd11958 said:
So the way I read that is labor only. $225 plus parts, valves, bushings, seals, and springs. (I didn't go to their web site for pricing)

I used the cheap emulator and drilled extra holes in it and the metering tube. I used my original progressive rate springs. You have to cut off at least the length of the emulator to get them to fit in the fork. Hi speed cutoff or Dremel and time will work.

Before you remove the fork. Loosen just the top triple tree bolts and break the top cap loose. The upper bolts can pinch the end of the tube making loosing of the cap harder. I used a 6 point socket on a speed handle. Look at your socket and see if the end is chanfered. I grind the chamfer off any socket that gets used on a fastener that is not very tall. You want full engagement to prevent damage to the cap. Hold down on the cap to prevent damage to the threads as it gets near the end of the tube. It's got some spring tension on it. Use care while installing also.
Click to expand...
If you cut the stock springs does that change the spring rate given that the stock spring is a progressive spring. Also, does changing the length change any other spring properties? I was going to buy the RaceTech spring because the stock spring is pretty far off from the spring rate recommended by RaceTech for my weight (~200 lbs).
 
willard.e.williamson5632 said:
If you cut the stock springs does that change the spring rate given that the stock spring is a progressive spring. Also, does changing the length change any other spring properties? I was going to buy the RaceTech spring because the stock spring is pretty far off from the spring rate recommended by RaceTech for my weight (~200 lbs).
Click to expand...
I am sure it changes it some. The early year bikes had straight weight springs with air preload I have heard of people looking for them to replace the progressive springs. I still have the original rear shocks on both bikes. I run 2 up with full damping and air preload. I don't change it if I ride alone because it is probably only to work and back. I will top up the air preload in the spring and before a long trip.

I have 2 C-10's a 99 and an 05. The 99 I replaced the seals many years ago before I knew about the emulators. I just replaced the seals due to leakage. I don't remember what oil I used. We ride 2 up most of the time but not extremely hard.(both around 160lbs. plus gear) I am more concerned with comfort than performance. On the 05 (1 side was leaking also) I did the fork mods and I feel that the ride is better. I don't feel the small bumps up through my arms and the bigger hits are well controlled and not as jarring. I also added Hile-bars and a Rifle windshield at the same time. Both bikes still have the threaded preload adjusters in the fork caps so there is some adjustment there. From what I have read you can cut more off the spring and add a spacer to get a stiffer spring weight but I haven't felt I needed to. Without cutting the spring I don't think I would have been able to put the caps back on. The emulators can be adjusted for the transition from slow to high speed fork compression by tightening/ or replacing the spring on the emulator and oil weight. They are more adjustable than the stock, you just have to take the caps back off and mess with them.
 
willard.e.williamson5632 said:
If you cut the stock springs does that change the spring rate given that the stock spring is a progressive spring.
Click to expand...
Spring rate is determined by the size/stiffness of the wire that was used to build the spring, and the "number" of coils.

When the spring is compressed, each coil in the spring deflects. (assume 1" of compression for our discussion)
Cutting the spring reduces the number of coils.
So, when you compress the spring the same 1"; each of the remaining coils deflect more than they did previously.
The extra deflection of each coil "increases" the force that is required to compress the spring.
ie; You get a higher spring rate.

Ride safe, Ted
 
Last edited:
willard.e.williamson5632 said:
Also, does changing the length change any other spring properties?
Click to expand...
The only change will be the amount of force that is required to compress the spring.
NOTE: There is a maximum amount of spring that can be removed.
** Between each coil is an air gap. If you decrease the number of coils, you also reduce the amount of air gap.
So, Reducing the length of the spring also reduces the amount of area available for the spring to compress.
Bottom line; There is a maximum amount of spring that can be removed.

willard.e.williamson5632 said:
I was going to buy the RaceTech spring because the stock spring is pretty far off from the spring rate recommended by RaceTech for my weight (~200 lbs).
Click to expand...
Your weight is the same as mine, so removing 3"-4" should give you the spring force that you want. (see below)
* I opted to remove 4" from the tightly wound section of a Progressive wound spring. {This allowed me to set my sag at 35mm}
You may opt to remove the material from the other end of the spring to lessen the initial jolt when you hit a small bump.

A stiffer spring will increase the initial jolt you feel when you hit a bump.
BUT: The emulator makes it possible to soften that initial jolt and control the damping throughout the movement of the forks.
ie; After installation, you can adjust the Emulator to adjust for the ride you want.

*** Oil weights and oil level can be used to further adjust the ride.

Ride safe, Ted

PS: ** Did you read the PM I sent you?
That PM has the steps I used to stiffen my springs.

In the second phase of the PM: I explained shortening the spring spacer 3/4" for the installation of an Emulator and the mods that are required if you opt to use the Inexpensive Emulator.
 
Last edited:
Another trick is to increase the height of the oil in the tubes.
The tube caps are sealed, and the air at the top acts like an air spring. Increasing the oil height reduces the air, effectively increasing the spring rate of the "air spring". You don't want to increase it too much, because you want to leave ebough space, but it's another means of fine-tuning the spring rate.
 
willard.e.williamson5632 said:
I can definitely do the work myself. I have a heated garage, an extensive tool collection, and decades of wrenching experience. However, I don't currently own any specialty fork tools but I'm sure Motionpro would have everything I need. I have watched a few youtube videos of guys rebuilding C10 forks and it doesn't look too bad. However, the gold valve product offered by Racetech seemed like a nice upgrade.

As I understand it, the only thing you can do with the rear shock is replace a some of the oil through the schrader valve. Is that correct?
Click to expand...
Yes after bleeding off air pressure. REMOVE the shrader valve to drain oil. Helpful to warm up heat the shock for oil draining. Reported that the oil volume drained from the rear shock is 6 - 8 oz. It does help to have the oil replaced after 40k mi. 10 or 20W oil. Fork oil or suspension fluid recommended.
 
Thanks for the info everyone. I ended up ordering a RaceTech gold valve fork kit that had the 95K springs from Parts Giant at a good discount over the Race Tech site. T kit including springs and gold valves was $269.50 from parts giant and $350 from RaceTech. I ordered a full set of fork rebuild parts from RaceTech because it was a lot cheaper than Partzilla. I liked the idea of obtaining authentic RaceTech parts.

Just need to wait for the parts to come in and then work it into our Motorcycle Saturday schedule :).
 
When it arrives; please let us know what all that is in the "Race Tech gold valve fork kit."
If it comes with instructions for modifying the damper tubes.
If it has an oil level suggestion.

Ride safe, Ted
 
connie_rider said:
When it arrives; please let us know what all that is in the "Race Tech gold valve fork kit."
If it comes with instructions for modifying the damper tubes.
If it has an oil level suggestion.

Ride safe, Ted
Click to expand...
Actually the RaceTech calculator suggests oil level when you calculate your spring rate based on your weight and riding style. For my weight (200 lbs) and riding style (touring) it suggests 150mm oil level. I will get back to you on what the kit includes when it arrives.

As far as instructions go, even if the kit does not have printed instructions, I could just call RaceTech tech support. I have already spoken to "Louie" at RaceTech tech support a few times and they are more than willing to provide help.
 
One really interesting thing about their GS-3 rear shock is that (according to Louie at RaceTech) you can order one with up to 6mm of height adjustment. I want to do the Mean Streak rear wheel switch next winter and ordering a shock with 6 mm of adjustment would go a long way towards restoring the stock geometry.
 
When you do the fork level, be sure that the Emulator is installed in the Fork before setting the oil level. (as it sets below the oil)
If you find that the new springs are a bit harsh for you, you can increase the oil level, shorten the spacer, and/or crank in less turns on the emulator.

From my notes;
Oil Level;
"Racetech" recommends 150mm (5.9")
"Stock oil level" is 171mm (6 3/4")
I opted to set "my oil level" at 160mm (6 1/4")

"Raising the fluid level, makes the air pocket at the top of the fork Smaller.
That Smaller air pocket helps control brake dive because it compresses that the air in the pocket more quickly".

Ride safe, Ted
 
I did receive the RaceTech kit. I ordered the full kit with .95K springs. The kit includes paper instructions. Also includes 2 pair of .95K fork springs (one upper pair, one lower pair), 2 gold valves, and 2 color coded sets of gold valve springs (one set installed on the gold valves, another set with a different spring rate). A code is provided such that you can log into the RaceTech web site and, input data for your bike and riding style, and get specific tuning data for the dampers. Its like a software activation code that is only works once. The instructions say that if you enter the tuning data wrong that you need to call RaceTech to get it straightened out. They probably use the activation code to prevent people from buying knock off damper valves and then using RaceTech software to obtain tuning data - I can't think of any other reason to have an activation code to obtain tuning data.
 
You must log in or register to reply here.
Top