Affordable suspension work

Related:
Create New Tag

1/22/2019 12:01 PM
Edited Date/Time: 1/22/2019 2:43 PM

How many Socal riders have used mainstream suspension services and think they're too expensive and replace parts "just to CYA" during a basic service job? Would you use a friend instead to do the work at a much lower cost if you knew they had the competence/tools BUT you had to supply the parts/liquids? Besides a real good price, what other expectations would you have (besides doing what was contracted and things not falling apart)? Things like turn-around, support, availability, LIABILITY, etc. Not sure this is the proper forum, I'm just trying to gauge reaction.

Obviously, this would apply to the person without the time/knowledge/tools to do it themselves but informed enough to properly select springs and/or replacement parts (seals/wipers/bushings/valves, etc). This would also not apply to the guy wanting a major setup change (new valving baseline). Minor tweaks to existing setup (assuming the person can communicate the issue) would probably be included.

|

Retired Mechanical Engineer, published technical writer, mscperformance.com, Bisimotoengineering.com,

1/22/2019 12:17 PM

Honestly, best way is to service it yourself.

Call the shop, get a recommended spring rate and setup for what you are looking for, tear the assemblies apart and send them the assembled stacks on the rods, have them mail it back with springs to match what they did and reassemble everything back yourself and add the recommended oil height.

It requires very basic tools to do this. Only thing speciality you'll need is an inch pounds torque wrench and a spring holder.

|

A wise man once said nothing

1/22/2019 12:22 PM

Revalve - send to a good company
Service/oil change - do in your garage or have a friend do it.

|

1/22/2019 12:33 PM
Edited Date/Time: 1/22/2019 12:35 PM

I'm not from SoCal but I do all my own work and my friend's suspension needs. I'm an ME so I was always curious about it and took the time to learn. Yes, suspension companies are expensive. Some have fantastic products that are worth the money. But most of the time a revalve is rearranging shims or adding a few. Pennies compared to hundreds of $$$$ spent. You are paying for their knowledge, which can be learned if you do some research and do some of your own tinkering. I never could understand why the suspension business is such a hush hush thing. It isn't rocket science guys. All the tools and materials needed can be purchased on the net or your local dealer. Unless you are using a local shop, you need to include boxing and shipping. More cost to the equation. Support comes down to local guys also. They know who you are and the tracks you will ride. National chain companies usually have no clue who your are or what conditions you ride at your track. Turn around and availability is pretty good everywhere anymore. They have to keep inventory and get it done in reasonable time or loose business. Liability could be a concern. But to be honest. Any suspension company could claim that you messed with a fork or shock before installing them. Basically would be a he said, she said. If there is a contract between parties, it would have a liability clause in it to release any fault.

|

1/22/2019 2:29 PM

I do the pull it apart, send out internals for revalve to the pros. It helps save money on labor, and shipping. I think maybe your looking at the cost thing wrong. I use Enzo and the best thing about them is the vast amount of racers and riders that use them. You can't begin to put as much knowledge together as they have in a life time of doing your own. They have such a broad feed back from riders, that their base settings are so close. Maybe just a couple of clicks will make it great for the track/woods you ride. And if you become a regular with them, their knowledge is usually free for the asking. I'm sure I could change some shims around 10 or 12 times, and maybe come close. But how nice is it to just strap it on and go! And their Technica stuff is really good!! Good suspension is worth the money every time.


|

1/22/2019 5:23 PM
Edited Date/Time: 1/22/2019 5:24 PM

Enzo does excellent work!
About 10 years ago when I raced a lot a guy named George who has esp suspension used to do revalves fairly cheap.
Rees firestone at pro action used to do cheap revalves too.
This was just oil and revalving as I would have new bushings and seals already. This was awhile ago and I don’t know what these guys would charge now or if theyre still in business.

|

1/22/2019 6:08 PM

I help out at an accessory shop in Victorville. No service dept. , but one of the owners (former mechanic sx and shop) likes to get his hands dirty from time to time with suspension only. Straight oil changes 60 bucks. Anything else he will do and is very qualified and, of course, has all the proper tools.

|

1/23/2019 5:31 AM

Polishhammer wrote:

Enzo does excellent work!
About 10 years ago when I raced a lot a guy named George who has esp suspension used to do revalves fairly cheap.
Rees firestone at pro action used to do cheap revalves too.
This was just oil and revalving as I would have new bushings and seals already. This was awhile ago and I don’t know what these guys would charge now or if theyre still in business.

Wow. Reese Firestone. I haven't heard that name in years. He used to be all over D6 back in the day. Running around in his Pro Action van. He did a good job but I never understood his valving basis. He would use the same valving stack for everyone. Novice to pro. I think that is why he was affordable.

|

1/23/2019 6:30 AM

If you trust your " friend" then I would let them service them. Chances are you will be over at his house helping him so if hes competent your going to learn how to do them yourself and what tools are needed. I dont feel the best about letting even reputable dealers/ tuners work on my stuff for many reasons. Most of us dont need a revalve. We need to have properly sprung / serviced / adjusted components and the basic knowledge of how suspension works to make clicker/ sag/ oil adjustments to suit our riding style and discipline.

|

1/23/2019 6:49 AM

Started doing my own "revalves" using the racetech gold valves. I was lost the first 4 tries on myshock and forks. The 5th try i got it figured out. I had my suspension on multiple bikes done by several big shops. 90% good. Until I figured out how to fine tune even further doing them myself. Especially working with the restrictor stack.

|

1/23/2019 7:03 AM

Polishhammer wrote:

Enzo does excellent work!
About 10 years ago when I raced a lot a guy named George who has esp suspension used to do revalves fairly cheap.
Rees firestone at pro action used to do cheap revalves too.
This was just oil and revalving as I would have new bushings and seals already. This was awhile ago and I don’t know what these guys would charge now or if theyre still in business.

ama530 wrote:

Wow. Reese Firestone. I haven't heard that name in years. He used to be all over D6 back in the day. Running around in his Pro Action van. He did a good job but I never understood his valving basis. He would use the same valving stack for everyone. Novice to pro. I think that is why he was affordable.

Lol! Yeah he was always running around talking to riders at blue diamond.
Whatever he did it worked well for me! I think he’s in NJ now.
ESP was too soft on spring rates on the forks for me. I’d always put a heavier weight set in place of his recommendation.

|

1/23/2019 7:23 AM

My experience in the last 3 + decades in dealing with 3 local shops & about 7 reputable suspension companies is I don't mind paying for it. Before knowing & understanding that it was one of the top components in feeling / getting comfortable on a bike I didn't know any better.
Dealing with the local 3 tuners was a negative experience to say the least with 2 mediocre results after a couple of revavles. The 3rd tuner resulted in worse suspension feel than what the factory started with.
The 7 reputable tuners have been good experiences with FC having the best results for me.

I believe suspension is a science & not any ordinary Joe or backyard mechanic can achieve the results of many hrs. R&D put in by the reputable well known companies. That being said most on here including myself at this stage in my life would just benefit from having the right spring / sag set up.


Here is a good read on suspension for those that like to get into the intricacies & details of it. It sure appears to be a science & it shows it's more than just moving shims & oil heights around..

https://thumpertalk.com/forums/topic/1264005-baseline-suspension-setup/

|

Speak softly and carry a big stick.

1/23/2019 7:32 AM

Just want to put a plug in for Mark. He's a top bloke, has all the right tools and knows what he's doing. He even has engineering software that can model your bike on different terrains. If Mark's intending on doing suspension work on the side, he'll take good care of you.

|

1/23/2019 7:38 AM

theycallmeebryan wrote:

Just want to put a plug in for Mark. He's a top bloke, has all the right tools and knows what he's doing. He even has engineering software that can model your bike on different terrains. If Mark's intending on doing suspension work on the side, he'll take good care of you.

I was wondering if this was the direction he was heading with this thread.

|

1/26/2019 3:22 AM


Thanks for the nice words Bryan. As mentioned, I try to take a very scientific approach to a discipline seen as more art than science. I've tried all the typical approaches, including "re-stackor" and as an engineer was frustrated when the actual results didn't match the tool/theory. My current process is very time consuming and involves measuring the bike very accurately (within .005") using a portable CMM arm to determine the kinematics, and scales to determine the mass properties (both by component and in total). I then build a CAD model that mimics these.

Once I have a CAD model I import it into ANSYS, a very sophisticated simulation software. In ANSYS I assign initial damping curves to shock/fork (generated in re-stackor), spring rates to same (including the effects of fork air pressure and shock gas pressure and bottoming systems), preloads, friction tables for any moving part, chain torque table, tire data, and of course an articulated "rider" with proper kinematics and mass properties.

There's a whole process for determining the proper dynamic front/back spring rates (with no damping). After that I'll apply the damping and do more simulations while tweaking the damping curve. Finally, I'll put the entire COUPLED system (most math models do not couple front and rear) through some simulated track conditions where the rear tire is actually driving the system (traction coefficients added) through the chain.

There's literally hundreds of outputs calculated by ANSYS during a simulation of this type. From forces, to velocities, accelerations, elongations (travel), attitude, etc. The trick is identifying the ones that affect the two biggies, comfort and control. Damping changes are just one variable I can alter. Note, I'm currently using Re-Stackor to generate valve stacks required for desired damping curves. Since I can create ANY (ie, physically impossible to achieve) damping curve I want in ANSYS, Re-Stackor keeps me within the limits of current damping control technology, almost! My next level process step is to model the actual valving using CFD to validate damping curves.

Here's a slow motion clip showing shock velocities in one condition (low amplitude, high speed, high frequency).
https://www.instagram.com/p/BtFvLrIgX7I/
|

Retired Mechanical Engineer, published technical writer, mscperformance.com, Bisimotoengineering.com,

1/26/2019 4:09 AM

mark911 wrote:
Thanks for the nice words Bryan. As mentioned, I try to take a very scientific approach to a discipline seen as more art than science. I've tried all the typical approaches, including "re-stackor" and as an engineer was frustrated when the actual results didn't match the tool/theory. My current process is very time consuming and involves measuring the bike very accurately (within .005") using a portable CMM arm to determine the kinematics, and scales to determine the mass properties (both by component and in total). I then build a CAD model that mimics these.

Once I have a CAD model I import it into ANSYS, a very sophisticated simulation software. In ANSYS I assign initial damping curves to shock/fork (generated in re-stackor), spring rates to same (including the effects of fork air pressure and shock gas pressure and bottoming systems), preloads, friction tables for any moving part, chain torque table, tire data, and of course an articulated "rider" with proper kinematics and mass properties.

There's a whole process for determining the proper dynamic front/back spring rates (with no damping). After that I'll apply the damping and do more simulations while tweaking the damping curve. Finally, I'll put the entire COUPLED system (most math models do not couple front and rear) through some simulated track conditions where the rear tire is actually driving the system (traction coefficients added) through the chain.

There's literally hundreds of outputs calculated by ANSYS during a simulation of this type. From forces, to velocities, accelerations, elongations (travel), attitude, etc. The trick is identifying the ones that affect the two biggies, comfort and control. Damping changes are just one variable I can alter. Note, I'm currently using Re-Stackor to generate valve stacks required for desired damping curves. Since I can create ANY (ie, physically impossible to achieve) damping curve I want in ANSYS, Re-Stackor keeps me within the limits of current damping control technology, almost! My next level process step is to model the actual valving using CFD to validate damping curves.

Here's a slow motion clip showing shock velocities in one condition (low amplitude, high speed, high frequency).
https://www.instagram.com/p/BtFvLrIgX7I/

Dude, that's awesome.

|

1/26/2019 7:13 AM

Which shops will accept the valving only? I asked FC and the said no way, send complete shock/forks only.

|

1/26/2019 8:03 AM

Truckdriver wrote:

I do the pull it apart, send out internals for revalve to the pros. It helps save money on labor, and shipping. I think maybe your looking at the cost thing wrong. I use Enzo and the best thing about them is the vast amount of racers and riders that use them. You can't begin to put as much knowledge together as they have in a life time of doing your own. They have such a broad feed back from riders, that their base settings are so close. Maybe just a couple of clicks will make it great for the track/woods you ride. And if you become a regular with them, their knowledge is usually free for the asking. I'm sure I could change some shims around 10 or 12 times, and maybe come close. But how nice is it to just strap it on and go! And their Technica stuff is really good!! Good suspension is worth the money every time.


Enzo will do just the stacks if you send in the rods? That would be the way to go for someone that is a little intimidated by the shims.

But like others here, I have done the re-valve on my last few bikes and was really happy with how it came out. For sure it took some time reading up and taking notes but I enjoy that part.

What drives me nuts is in bike tests they say the cliche- "Sent the suspension to PC or whoever..." What I'd like to see is them take the stock stack apart and list it, then take the PC stack apart and list it.

|

1/26/2019 8:13 AM

swtwtwtw wrote:

I help out at an accessory shop in Victorville. No service dept. , but one of the owners (former mechanic sx and shop) likes to get his hands dirty from time to time with suspension only. Straight oil changes 60 bucks. Anything else he will do and is very qualified and, of course, has all the proper tools.

Avid Cyles?

|

1/26/2019 8:29 AM

FWYT wrote:

Enzo will do just the stacks if you send in the rods? That would be the way to go for someone that is a little intimidated by the shims.

But like others here, I have done the re-valve on my last few bikes and was really happy with how it came out. For sure it took some time reading up and taking notes but I enjoy that part.

What drives me nuts is in bike tests they say the cliche- "Sent the suspension to PC or whoever..." What I'd like to see is them take the stock stack apart and list it, then take the PC stack apart and list it.

That bugs me also. Suspension is this 'secret society' that nobody knows about but you can pay allot of money for it. My intent is not to call out the suspension companies and hurt their business, but this secrecy is a load of crap. Let the buying consumer know what you are doing and why it is better than your competition. Not this 'try our stuff, it is better'. Let the market drive the business. If you produce good parts and provide good performance, your products will sell. If not, the market will determine your fate. I have seen revalves from certain big companies. They add or remove a few 5 cent shims here and there and you owe them hundreds of dollars. Then they will nickle and dime you to death on oil and repair parts you supposedly need on a shock that has 10 hours on it. If you call them to ask them technical questions, you get the same 'send your stuff in' remark. That attitude needs to go by the wayside.

|

1/26/2019 8:31 AM
Edited Date/Time: 1/26/2019 8:34 AM

I understand that some of you think certain suspension shops are expensive: they are. However, in my case...it's always been worth it.

I've recently run FC on an RMZ & they did a REALLY super-good job. And that's on The Big Piston Super Blow-Thru shock! They've done miracles with Yamaha suspension for Rockstar/OTSFF in Canada, also.

I've had Enzo more than a few times and they're awesome...often asking to have it back if it's not quite right...this is after talking to me about what I feel the suspension is doing versus what they feel it SHOULD be doing. Boom! They take another swipe at it...no charge.

I've had PC KX-Fs and they've always worked better than expected and they make AMAZING PSF-1 parts that turn those forks into simply "unbelievably smooth".

There's a forum member, here, "SlipDog"...& he can just "service" your forks or shock for a pretty damn good deal and he has ALL the correct tools and parts.

Very recently...I tried a Murietta 'local', JBI...I was stoked on his ability to give me EXACTLY what I asked for and the dude was very reasonable on price. On KTM/Huksy...he's got ALL the good parts options to make your stock stuff stellar. I'll have a Bike Build with more info about his stuff VERY soon.

After that, I'm doing a KX450 with Race Tech stuff.

|

I ripped a start from Egypt and I was happy about that.

1/26/2019 8:43 AM

mark911 wrote:

How many Socal riders have used mainstream suspension services and think they're too expensive and replace parts "just to CYA" during a basic service job? Would you use a friend instead to do the work at a much lower cost if you knew they had the competence/tools BUT you had to supply the parts/liquids? Besides a real good price, what other expectations would you have (besides doing what was contracted and things not falling apart)? Things like turn-around, support, availability, LIABILITY, etc. Not sure this is the proper forum, I'm just trying to gauge reaction.

Obviously, this would apply to the person without the time/knowledge/tools to do it themselves but informed enough to properly select springs and/or replacement parts (seals/wipers/bushings/valves, etc). This would also not apply to the guy wanting a major setup change (new valving baseline). Minor tweaks to existing setup (assuming the person can communicate the issue) would probably be included.

Mark, I will say that there is Rudy at Pro-Prept http://www.propreptmotocross.com/ and he is one of those soul guys that will want to watch you ride BEFORE he touches your suspension. He is at Pala a lot and works with the rider to see what the bike is doing and then does the work. (very reasonable, too!) He will then assist in dialing in the clickers and such.

|

1/26/2019 8:56 AM
Edited Date/Time: 1/26/2019 8:58 AM

Ross Maeda works at ENZO and he used to work for KYB. I worked at Kawasaki Motors USA in the R & D department, and the Racing department was 50 feet away from me. I and the racing department would take shocks over to Ross at KYB which was only a mile away and he would revalve them as we asked. Ross is ridiculously knowledgeable and is one of the nicest, most easy going people I have ever met, and I would be more than happy to have ENZO work on my shocks. There are of course others that can do a good job, and it may be best to have someone near to you do it in case there is a problem etc, but besides Race Tech and Ross, I have no experience with any others.

.

|

1/26/2019 10:04 AM
Edited Date/Time: 1/26/2019 10:14 AM

In order to tune the valve stack for a specific condition you need to know the effective shaft/fork velocity "zone" generated. Here's only a few different conditions and the SHOCK SHAFT velocities resulting from a given shimstack. Obviously, the other variable is speed! The "shape" of the velocity trace (Time/Velocity integration) is important as well.

Photo
Photo
Photo
Photo

|

Retired Mechanical Engineer, published technical writer, mscperformance.com, Bisimotoengineering.com,

1/26/2019 1:36 PM

Has anyone tried the “shim stacker” program?

|

Don’t piss off the old people - the older they get the less “life in prison” is a deterrent for them!

2020.5 KTM 450 SXF FE
2006 KX250

1/26/2019 6:14 PM

mark911 wrote:

In order to tune the valve stack for a specific condition you need to know the effective shaft/fork velocity "zone" generated. Here's only a few different conditions and the SHOCK SHAFT velocities resulting from a given shimstack. Obviously, the other variable is speed! The "shape" of the velocity trace (Time/Velocity integration) is important as well.

Photo
Photo
Photo
Photo

We had an mts machine at kawasaki that we ran the shocks on, and we also had a mobile telemetry pack we would wear while doing some testing although I'm sure there are far more sophisticated telemetry devices these days that can be attached to a bike while it is being ridden.

We also did an enormous of testing and re-valving by seat of the pants riding and sometimes videoing the bike while it is being ridden.

.

|

1/26/2019 6:22 PM
Edited Date/Time: 1/26/2019 6:24 PM

frankly, most suspension shops are clueless...The top guys are knowledgeable but you need someone there that cares about YOU. And it takes a few swings at the bat. Plus what works at one track/trail won't work somewhere else. So you are constantly adjusting from area to area.... just a fact.

I know some of the top suspension design guys in the moto biz. A good friend of mine ran the power sports division for Fox Racing Shocks for over 20 years. After having my stuff serviced by a known local guy.... I went to visit my buddy at Fox and spent 15 mins in his office asking him a few questions about stacks. That's all it took.... haven't paid someone to touch my stuff since then.

It is NOT rocket science. You need some basic valve stack lessons (what does what), then you need to experiment from there. If you are mechanically inclined... go for it! It's not very difficult. It does take sometime but is rewarding. And once you learn what does what, and what you like, you'll be able to tune your stuff to do what YOU want it to do. Not what someone tells you it should.

My 3 cents..... )

|

1/26/2019 6:45 PM

PTshox wrote:

frankly, most suspension shops are clueless...The top guys are knowledgeable but you need someone there that cares about YOU. And it takes a few swings at the bat. Plus what works at one track/trail won't work somewhere else. So you are constantly adjusting from area to area.... just a fact.

I know some of the top suspension design guys in the moto biz. A good friend of mine ran the power sports division for Fox Racing Shocks for over 20 years. After having my stuff serviced by a known local guy.... I went to visit my buddy at Fox and spent 15 mins in his office asking him a few questions about stacks. That's all it took.... haven't paid someone to touch my stuff since then.

It is NOT rocket science. You need some basic valve stack lessons (what does what), then you need to experiment from there. If you are mechanically inclined... go for it! It's not very difficult. It does take sometime but is rewarding. And once you learn what does what, and what you like, you'll be able to tune your stuff to do what YOU want it to do. Not what someone tells you it should.

My 3 cents..... )

This is the approach i decided to take. After paying thousands to shops for several bikes I've owned, I decided to take a shot with my new bike. Granted cheating with racetech dvs to get me started. Still took several attempts to make it right for me. Now I can't imagine paying someone else to get me to 90%. Also it's helped me fine tune my buddies bikes with non valving changes.

|

1/26/2019 7:36 PM

PTshox wrote:

frankly, most suspension shops are clueless...The top guys are knowledgeable but you need someone there that cares about YOU. And it takes a few swings at the bat. Plus what works at one track/trail won't work somewhere else. So you are constantly adjusting from area to area.... just a fact.

I know some of the top suspension design guys in the moto biz. A good friend of mine ran the power sports division for Fox Racing Shocks for over 20 years. After having my stuff serviced by a known local guy.... I went to visit my buddy at Fox and spent 15 mins in his office asking him a few questions about stacks. That's all it took.... haven't paid someone to touch my stuff since then.

It is NOT rocket science. You need some basic valve stack lessons (what does what), then you need to experiment from there. If you are mechanically inclined... go for it! It's not very difficult. It does take sometime but is rewarding. And once you learn what does what, and what you like, you'll be able to tune your stuff to do what YOU want it to do. Not what someone tells you it should.

My 3 cents..... )

coastlinecascot wrote:

This is the approach i decided to take. After paying thousands to shops for several bikes I've owned, I decided to take a shot with my new bike. Granted cheating with racetech dvs to get me started. Still took several attempts to make it right for me. Now I can't imagine paying someone else to get me to 90%. Also it's helped me fine tune my buddies bikes with non valving changes.

Agree as well. If you have a setup that's reasonably close it's fairly easy to tweak the stack and get good results with only some basic knowledge (stiffer = more shims, etc). Assuming the mechanicals are done properly It's pretty hard to totally screw things up. I've done some pretty retarded things and the bike was still very ridable. On the other hand, like Paul Thede says (paraphrasing), the best you expect is only the best you've ever had.

Now, take a situation where you're swapping forks/shock from a totally different bike with no baseline. Simply using percentages or scaling probably wont be nearly as successful.

An interesting side note on PT and Racetech. His "claim to fame" was/is the gold valve and it's huge compression ports which allowed his shim stacks almost 100% control over the damping curve. Now that most mfgs have done the same he's switched back to ultimately restricting flow through a "virtual" fixed orifice. Funny how things just go round and round!

|

Retired Mechanical Engineer, published technical writer, mscperformance.com, Bisimotoengineering.com,

1/26/2019 7:40 PM

PTshox wrote:

frankly, most suspension shops are clueless...The top guys are knowledgeable but you need someone there that cares about YOU. And it takes a few swings at the bat. Plus what works at one track/trail won't work somewhere else. So you are constantly adjusting from area to area.... just a fact.

I know some of the top suspension design guys in the moto biz. A good friend of mine ran the power sports division for Fox Racing Shocks for over 20 years. After having my stuff serviced by a known local guy.... I went to visit my buddy at Fox and spent 15 mins in his office asking him a few questions about stacks. That's all it took.... haven't paid someone to touch my stuff since then.

It is NOT rocket science. You need some basic valve stack lessons (what does what), then you need to experiment from there. If you are mechanically inclined... go for it! It's not very difficult. It does take sometime but is rewarding. And once you learn what does what, and what you like, you'll be able to tune your stuff to do what YOU want it to do. Not what someone tells you it should.

My 3 cents..... )

coastlinecascot wrote:

This is the approach i decided to take. After paying thousands to shops for several bikes I've owned, I decided to take a shot with my new bike. Granted cheating with racetech dvs to get me started. Still took several attempts to make it right for me. Now I can't imagine paying someone else to get me to 90%. Also it's helped me fine tune my buddies bikes with non valving changes.

I'm so glad I'm not the only one! Excellent posts guys.

|