ReX
TY 4 Stroke God
Many of us, myself included, have ranted here at TY4stroke about how poorly the 07 RTX handles rough trails in stock form and there are 100's of posts on workarounds to try to get it to handle them better.
I finally got around to rebuilding my shocks last week and installed Mike Carver's custom valve stacks. The difference is absolutely incredible. The sled now handles bumps better than any sled I've ever ridden.
Before:
- Completely stock it would bottom out at any moderately sized bump and if pushed the sled bounced all over the place (bouncing off the bump stops), making it difficult to control at high speeds on rougher trails.
- To control the terrible bottoming out I installed anti-bottomers and then after that wasn't enough and to try to get 3" of sag I re-arched the torsion springs (I was seeing up to 8" of sag at the rear bumper once 50+ lbs of ice built up with my 240 lbs ready to ride on the seat and about 10 lbs in the trunk). I also tried the optional Yamaha "heavy duty" torsion springs which, while stiffer, actually lowered the ride height.
- With the clicker set to the 2nd from full hard, it would still bottom out fairly regularly but the biggest problem now was the uncontrollable "bounciness" and how the sled wanted to "spring" off every little bump. Off bigger bumps the sled would often launch several feet in the air when it should have only "just" made it off the ground.
I asked Mike Carver to send me a custom valve stack for both the center and main shock. Mike looks after the Yamaha snow cross sleds and the shocks on Yamahs's cross country race sleds. He has been setting up race sled shocks for many years and really knows what he's doing. I asked Mike for a setup for a very aggressive rider weighing 210 lbs or 240 lbs ready to ride who prefers to be able to ride sitting down - even on very rough trails (in other words setting up the shocks to handle all of my weight, not using my knees to reduce the suspension loads). I also asked him to consider 50 lbs of ice built up in the tunnel, 10 lbs of "stuff" in the trunk and another 50 lbs for saddle bags when we go on our saddle bag trips. I also told him I had the anti-bottomers installed (so I needed a little "extra" rebound damping control).
He sent me out a triple stage (4 stages if you include the piston ports) compression valve stack for each shock (stock is just a single stage so no wonder they bottom out easily and at the same time ride so harsh), a new center shock piston, a new custom rebound valve stack for each shock and two shock service kits (o-rings, etc.). He also rebuilds shocks in house if you don't have the tools to rebuild them yourself.
If you want to rebuild them yourself, Yamaha keeps the IFP depths a "secret" (and Mike Carver won't give them out either), but after a little research, advice from others, calculating and testing I decided to use an IFP depth of 124mm for the center and 5mm off the bottom for the remote reservoir on the main shock. These numbers should work well for anyone wanting to rebuild the skid shocks on an 07/08 Apex RTX. They take 300 psi of nitrogen for the final charge. I'm running the clicker pretty much all the way out to allow Mikes multi-stage valving to fully control the ride (the clicker affects mid speed compression damping the most due to the spring and ball design).
After:
I had asked for and was expecting a firm, well controlled ride and that is exactly what I got. Here is a rundown on the performance:
- Now when riding, smallish sized stutter bumps (3-4 inches) at medium speeds (25-40 mph), the ride is similar for harshness as stock with the clicker set on the 3rd from stiffest position. I added this note to give you a feel for how it compares to the stock ride. The ride is much more damped and solid feeling though.
- Smaller stutter bumps in the 1-2" range with a very close pitch (2-3 feet) at 20-60 mph now just totally disappear. The unnecessary harshness for this sort of thing is now gone (Mike’s first compression stage is softer than the stock single stage). Don't get me wrong, the ride is not plush (by far) in all conditions/speeds, but it isn't unnecessarily harsh on little tiny bumps either.
- As the bumps get bigger and the speeds increase, the shocks get stiffer and stiffer in compression. It is now VERY difficult to bottom out. Yesterday riding some rough, high speed trails only once did I bottom it out and that was probably at over 90mph (indicated) off a rise and into a fairly nasty G-out. Without the shock update, the suspension would not only have bottomed out hard, but it would have kicked me high in the air off the exit of the G-out. Instead the suspension soaked up the hit perfectly, just bottoming out, and then perfectly controlled the sled got about 1' off the ground followed by a smooth landing without any "bounce". The front end did bottom out a little, but not too badly either (floats were set at 70psi and have stock valving). To be honest I bottomed out so lightly in the rear at first I wasn’t sure it bottomed out at all. I stopped to have a look at the bump stops to check and found at the rear bump stops that the build up of ice had cracked away (I had been keeping tabs on this because I wanted to get a feel for how much it would take to bottom out). The front skid bump stops never did bottom out but I suspect they must have been very close too.
- Where the sled really shines now is absorbing bumps at high speeds and keeping the sled stable. Some of the trails we were on were high speed mogulled up trails. With the stock valving the sled would have been bouncing absolutely everywhere and very difficult to ride this sort of trail at speed. Now it is simply amazing. Skipping across the top of the moguls or even transitioning from lower speeds all the way through to "skipping" speeds, it is always perfectly controlled.
- One thing I was expecting, but was surprised see how much this changed, is how much harder it is to get the sled off the ground. With the stock valving it would tend to pop the sled high off the ground over almost anything. To give you a feel for this, there is one particular field access laneway in the ditch near my house with about a 1.5 foot rise and a fairly narrow top (maybe 9 feet wide). Even at 30-40 mph it would pop off the rise and get a good 1.5 feet in the air before missing the top of the narrow laneway and landing on the trail on the other side, followed by a couple of cyclic bounces upon landing (that I would absorb with my legs). Now off the same laneway at 30-40, the track hardly gets off the ground at all. Instead to get probably a foot off the ground I have to hit it at about 60 mph, now since I'm travelling faster it covers more distance in the air before a perfectly absorbed landing without any hint of even a single bounce. It is a very cool experience the way this thing lands so smoothly now. Its sort of a single continuous motion, the landing just gets absorbed away and the motion seems to just stop right there without any bounce back at all.
- Another impressive feature with the new valving is how much better braking and accelerating works on rough mogulled up trails. Instead of bouncing all over the place, the track now stays on the ground much more. Braking is further improved because with the stock valving it used to tend to kick the back end up very high off bumps when braking. Now the sled is level and stable when braking.
- With the stock setup I used to have to always be under power to some extend when hitting bigger bumps. If not, the sled wanted to nose dive. Now I can comfortably decelerate or even brake when travelling over the same sort of bumps and the sled stays level.
- One of my most important tests for how well my rear skid rides is how my back feels after riding rough trails. Even though this sled rides very firmly now and does have a much firmer ride compared to stock on high speed, bumpy trails, my back didn't once get jarred. Stock, if I didn't stand up before any bigger bumps I could get that sudden "bang" that would shoot up my back (I spent a lot of time using my knees to make sure that didn't happen). Now I can literally sit down all the time if I want. The ride is firmer, but the maximum loads that my back sees are within what my back can handle.
For a rough trail, aggressive setup I don't think I could ask for anything better. This sled is simply incredible now when pushed hard on rough trails. I probably could have got away with slightly less mid speed compression damping, but now I have the option of turning down the preload on the rear springs and lowering the sled to improve handling while still not likely to bottom out.
What the sled is not though is a luxurious smooth riding sled for when I want to slow down and take it easy (doesn't happen very often though...). I didn't ask for that and I didn't get it. I'll let you guys know if on higher mileage rides if I find it a little too firm (I only did about 500 km yesterday and have about 600 km in total on the revalve).
I finally got around to rebuilding my shocks last week and installed Mike Carver's custom valve stacks. The difference is absolutely incredible. The sled now handles bumps better than any sled I've ever ridden.
Before:
- Completely stock it would bottom out at any moderately sized bump and if pushed the sled bounced all over the place (bouncing off the bump stops), making it difficult to control at high speeds on rougher trails.
- To control the terrible bottoming out I installed anti-bottomers and then after that wasn't enough and to try to get 3" of sag I re-arched the torsion springs (I was seeing up to 8" of sag at the rear bumper once 50+ lbs of ice built up with my 240 lbs ready to ride on the seat and about 10 lbs in the trunk). I also tried the optional Yamaha "heavy duty" torsion springs which, while stiffer, actually lowered the ride height.
- With the clicker set to the 2nd from full hard, it would still bottom out fairly regularly but the biggest problem now was the uncontrollable "bounciness" and how the sled wanted to "spring" off every little bump. Off bigger bumps the sled would often launch several feet in the air when it should have only "just" made it off the ground.
I asked Mike Carver to send me a custom valve stack for both the center and main shock. Mike looks after the Yamaha snow cross sleds and the shocks on Yamahs's cross country race sleds. He has been setting up race sled shocks for many years and really knows what he's doing. I asked Mike for a setup for a very aggressive rider weighing 210 lbs or 240 lbs ready to ride who prefers to be able to ride sitting down - even on very rough trails (in other words setting up the shocks to handle all of my weight, not using my knees to reduce the suspension loads). I also asked him to consider 50 lbs of ice built up in the tunnel, 10 lbs of "stuff" in the trunk and another 50 lbs for saddle bags when we go on our saddle bag trips. I also told him I had the anti-bottomers installed (so I needed a little "extra" rebound damping control).
He sent me out a triple stage (4 stages if you include the piston ports) compression valve stack for each shock (stock is just a single stage so no wonder they bottom out easily and at the same time ride so harsh), a new center shock piston, a new custom rebound valve stack for each shock and two shock service kits (o-rings, etc.). He also rebuilds shocks in house if you don't have the tools to rebuild them yourself.
If you want to rebuild them yourself, Yamaha keeps the IFP depths a "secret" (and Mike Carver won't give them out either), but after a little research, advice from others, calculating and testing I decided to use an IFP depth of 124mm for the center and 5mm off the bottom for the remote reservoir on the main shock. These numbers should work well for anyone wanting to rebuild the skid shocks on an 07/08 Apex RTX. They take 300 psi of nitrogen for the final charge. I'm running the clicker pretty much all the way out to allow Mikes multi-stage valving to fully control the ride (the clicker affects mid speed compression damping the most due to the spring and ball design).
After:
I had asked for and was expecting a firm, well controlled ride and that is exactly what I got. Here is a rundown on the performance:
- Now when riding, smallish sized stutter bumps (3-4 inches) at medium speeds (25-40 mph), the ride is similar for harshness as stock with the clicker set on the 3rd from stiffest position. I added this note to give you a feel for how it compares to the stock ride. The ride is much more damped and solid feeling though.
- Smaller stutter bumps in the 1-2" range with a very close pitch (2-3 feet) at 20-60 mph now just totally disappear. The unnecessary harshness for this sort of thing is now gone (Mike’s first compression stage is softer than the stock single stage). Don't get me wrong, the ride is not plush (by far) in all conditions/speeds, but it isn't unnecessarily harsh on little tiny bumps either.
- As the bumps get bigger and the speeds increase, the shocks get stiffer and stiffer in compression. It is now VERY difficult to bottom out. Yesterday riding some rough, high speed trails only once did I bottom it out and that was probably at over 90mph (indicated) off a rise and into a fairly nasty G-out. Without the shock update, the suspension would not only have bottomed out hard, but it would have kicked me high in the air off the exit of the G-out. Instead the suspension soaked up the hit perfectly, just bottoming out, and then perfectly controlled the sled got about 1' off the ground followed by a smooth landing without any "bounce". The front end did bottom out a little, but not too badly either (floats were set at 70psi and have stock valving). To be honest I bottomed out so lightly in the rear at first I wasn’t sure it bottomed out at all. I stopped to have a look at the bump stops to check and found at the rear bump stops that the build up of ice had cracked away (I had been keeping tabs on this because I wanted to get a feel for how much it would take to bottom out). The front skid bump stops never did bottom out but I suspect they must have been very close too.
- Where the sled really shines now is absorbing bumps at high speeds and keeping the sled stable. Some of the trails we were on were high speed mogulled up trails. With the stock valving the sled would have been bouncing absolutely everywhere and very difficult to ride this sort of trail at speed. Now it is simply amazing. Skipping across the top of the moguls or even transitioning from lower speeds all the way through to "skipping" speeds, it is always perfectly controlled.
- One thing I was expecting, but was surprised see how much this changed, is how much harder it is to get the sled off the ground. With the stock valving it would tend to pop the sled high off the ground over almost anything. To give you a feel for this, there is one particular field access laneway in the ditch near my house with about a 1.5 foot rise and a fairly narrow top (maybe 9 feet wide). Even at 30-40 mph it would pop off the rise and get a good 1.5 feet in the air before missing the top of the narrow laneway and landing on the trail on the other side, followed by a couple of cyclic bounces upon landing (that I would absorb with my legs). Now off the same laneway at 30-40, the track hardly gets off the ground at all. Instead to get probably a foot off the ground I have to hit it at about 60 mph, now since I'm travelling faster it covers more distance in the air before a perfectly absorbed landing without any hint of even a single bounce. It is a very cool experience the way this thing lands so smoothly now. Its sort of a single continuous motion, the landing just gets absorbed away and the motion seems to just stop right there without any bounce back at all.
- Another impressive feature with the new valving is how much better braking and accelerating works on rough mogulled up trails. Instead of bouncing all over the place, the track now stays on the ground much more. Braking is further improved because with the stock valving it used to tend to kick the back end up very high off bumps when braking. Now the sled is level and stable when braking.
- With the stock setup I used to have to always be under power to some extend when hitting bigger bumps. If not, the sled wanted to nose dive. Now I can comfortably decelerate or even brake when travelling over the same sort of bumps and the sled stays level.
- One of my most important tests for how well my rear skid rides is how my back feels after riding rough trails. Even though this sled rides very firmly now and does have a much firmer ride compared to stock on high speed, bumpy trails, my back didn't once get jarred. Stock, if I didn't stand up before any bigger bumps I could get that sudden "bang" that would shoot up my back (I spent a lot of time using my knees to make sure that didn't happen). Now I can literally sit down all the time if I want. The ride is firmer, but the maximum loads that my back sees are within what my back can handle.
For a rough trail, aggressive setup I don't think I could ask for anything better. This sled is simply incredible now when pushed hard on rough trails. I probably could have got away with slightly less mid speed compression damping, but now I have the option of turning down the preload on the rear springs and lowering the sled to improve handling while still not likely to bottom out.
What the sled is not though is a luxurious smooth riding sled for when I want to slow down and take it easy (doesn't happen very often though...). I didn't ask for that and I didn't get it. I'll let you guys know if on higher mileage rides if I find it a little too firm (I only did about 500 km yesterday and have about 600 km in total on the revalve).
stumper
Extreme
Nice write-up! This sounds like exactly what I need for my 06 Nytro, so I may PM you for more detail on the "secret stuff", if that's OK. Thanks again.
GYTRules!!!
Extreme
REVALVE!!! 
berge75
Expert
Carver did a good job on my Mono on the GT. I may have given up a little small bump performance,but I find myself driving past some of these so-called big bump sleds in the nasty stuff with confidence.
number1kyster
TY 4 Stroke God
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How much is the setup?
ReX
TY 4 Stroke God
My setup was $138 shipped, but the price depends on what you want, weigh, if he rebuilds the shocks, you do it, etc.
If I recall correctly, the individual valve parts are $2.50 and $3.50 each (depending on the diameter and thickness), but depending on how many stages and how much you weigh, the price can add up quickly (he doesn't specifically talk about stages, but the more valves, the higher the price). The Yamaha piston's are fairly expensive too, but I don't think he always changes them. In my case I have my springs re-arched (adding additional pe-load) and have the anti-bottomers installed so he felt I needed a little extra rebound control.
His website has a page with valve prices for Fox shocks to give you an idea how this works (the Yamaha prices are basically the same):
http://www.carverperformance.com/valves.htm
The main web page is:
http://www.carverperformance.com/home.htm
It is a little hard to get ahold of Mike these days. He is very busy, on the road, looking after the Yamaha snow-cross sleds right now and his web site is also at least a year out of date. My understanding is he is Yamaha's head mechanic for snow cross this season. At the same time he is also looking after the Yamaha cross country race shocks as well as all of the other snow cross teams he builds shocks for (not to mention all of us snowmobile enthusiasts looking for custom shock valving).
It was probably 5 years ago that my buddies and I first bought valve stacks from him for our Polaris sleds and his valve stacks have always provided incredible performance, stability and resistance to bottoming out.
I have never asked him to provide a "soft Cadillac like ride that doesn't bottom out too easily" so I can't say know how well he would do if anyone is looking for this sort of thing. What I can confirm he does extremely well is aggressive and borderline "race ready" setups. Also based on how well Yamaha's snowcross team is doing this year its clear he knows how to setup shocks for all out snowcross too.
If I recall correctly, the individual valve parts are $2.50 and $3.50 each (depending on the diameter and thickness), but depending on how many stages and how much you weigh, the price can add up quickly (he doesn't specifically talk about stages, but the more valves, the higher the price). The Yamaha piston's are fairly expensive too, but I don't think he always changes them. In my case I have my springs re-arched (adding additional pe-load) and have the anti-bottomers installed so he felt I needed a little extra rebound control.
His website has a page with valve prices for Fox shocks to give you an idea how this works (the Yamaha prices are basically the same):
http://www.carverperformance.com/valves.htm
The main web page is:
http://www.carverperformance.com/home.htm
It is a little hard to get ahold of Mike these days. He is very busy, on the road, looking after the Yamaha snow-cross sleds right now and his web site is also at least a year out of date. My understanding is he is Yamaha's head mechanic for snow cross this season. At the same time he is also looking after the Yamaha cross country race shocks as well as all of the other snow cross teams he builds shocks for (not to mention all of us snowmobile enthusiasts looking for custom shock valving).
It was probably 5 years ago that my buddies and I first bought valve stacks from him for our Polaris sleds and his valve stacks have always provided incredible performance, stability and resistance to bottoming out.
I have never asked him to provide a "soft Cadillac like ride that doesn't bottom out too easily" so I can't say know how well he would do if anyone is looking for this sort of thing. What I can confirm he does extremely well is aggressive and borderline "race ready" setups. Also based on how well Yamaha's snowcross team is doing this year its clear he knows how to setup shocks for all out snowcross too.
number1kyster
TY 4 Stroke God
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- 2018 SW RTX SE
Sounds to me like you run the same setup I desire. I weigh 200 lbs and I love to ride aggressively. Maybe in the off season I'll get mine done.
TBay Sledhead
TY 4 Stroke Master
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01 SXR Long Track
What I've done in the past to find the IFP depth is
Release the gas from the shock
Remove the valve
Fill the gas side with shock oil with shock rod all the way in, re-install the valve (doing this will not allow the IFP to move on dis-assembly)
Disassemble the shock them you can measure the depth of the IFP.
When reassembling the shock set the IFP and fill the gas side with oil and then it can't move when assembling. Just remember to drain oil before recharging gas.
Release the gas from the shock
Remove the valve
Fill the gas side with shock oil with shock rod all the way in, re-install the valve (doing this will not allow the IFP to move on dis-assembly)
Disassemble the shock them you can measure the depth of the IFP.
When reassembling the shock set the IFP and fill the gas side with oil and then it can't move when assembling. Just remember to drain oil before recharging gas.
Ported Hornet
Expert
REX,
That is a good write up. Not exactly the set up I am looking for, but I would like to reduce some of the kickback in the rear skid and not have too harsh of a ride on the smooth trails.
That is a good write up. Not exactly the set up I am looking for, but I would like to reduce some of the kickback in the rear skid and not have too harsh of a ride on the smooth trails.
ReX
TY 4 Stroke God
Update - 07 RTX shock revalve review - Carver Performance
Now that I've put a good 1500 km on my sled since revalving the shocks and tweaked the suspension to optimize everything I thought I'd post an update:
- Every time I ride the sled now I can't get over how well this machine handles bumpy trails with such an incredible level of overall stability. The overall performance improvement is literally like night and day.
- With the extreme resistance to bottoming out, I have now lowered the rear torsion springs to the lowest setting, left the center shock preload at "just tight" with the shock fully extended, tightened the limiter by another hole (tightest hole), increased the weight transfer setting to about 2/3rds towards max and increased the float pressure to 75 psi. With just me on the sled, the floats are the first thing to bottom out, but it takes a lot before they do. The cornering performance on smooth trails is better than it was due to the lowered center of gravity and the increased down pressure on the skis keeping the sled planted.
- With just me on the sled in -30°C weather, at first the rear suspension is definitely on the firm side. Increasing the weight transfer (reduced coupling) softened the ride a little, but it is still firm. Once I have about 20 minutes to 1/2 an hour of aggressive riding on the sled, the shocks warm up, thinning the fluid a little. At this point it is absolutely perfect for very aggressive riding on everything from smooth to highly mogulled trails. Sitting down over the biggest bumps I don't hurt my back, but since it pretty much doesn't bottom out it could probably be a little softer (at this point) without any bottoming issues.
- Once I've been riding for a good 6 hours or so (or a second day without a thaw), the 50 lbs or so of ice that builds up in the tunnel helps to tune the suspension closer to perfection. This was exactly what I was looking for and Mike Carver managed to get it bang on. At this point the ride becomes quite comfortable, yet it is still very difficult to bottom out. A big hit can bottom it out, but it takes a very, very big bump at very high speeds. I do notice a bit of shock fade (softening up the ride) when ridden very aggressively on very rough trails for hours on end, but the shocks never loose control and always maintain excellent bottoming control. Basically the shocks are about as perfectly dialed in as they can be for my riding style.
- When I load the sled up with about 50 lbs of saddle bags and that 20 minute warm up period is over, the sled starts off riding exactly as above. It is a blast to ride very aggressively, loaded up with saddle bags without bottoming out hardly at all. Since the suspension isn't hitting a hard stop (bottoming out), the saddle bags don't get that sudden "bang" on a regular basis that tries to rip the saddle bag straps off. Even jumping and powering down very rough trails at high speeds, the suspension just handles it flawlessly.
- After a good 6 hours of saddle bag riding, more noticeable on a second or third day, the suspension now starts to ride noticeably lower. At this point there is a good 50+ lbs of ice built up in the tunnel (I suspect there is more than 50 lbs of ice), ~50 lbs of saddle bags, 10 lbs in the trunk, plus my 240 lbs ready to ride. Now the sled starts to ride plush, but amazingly it still doesn't bottom out easily and even with the suspension hitting the anti-bottomers there is not any noticeable kick back. I do find at this point it is a little on the soft side of things for aggressive riding plus I want to crank the torsion springs up to the medium setting (partly because the headlight is now out of alignment - pointing too high). I also find if I continue to push the sled very hard on very rough trails I now start to experience a noticeable amount of shock fade. The shocks don't fade away to nothing, but the damping is noticably reduced and it becomes easier to bottom out. Stopping the sled and putting my hand on the skid shocks, they both become quite hot to the touch (steam coming off the shocks as the snow dust evaporates too). After a short slowdown or stop, the suspension firms up fairly quickly again.
Overall I have to say I don't think the shock valving could be any better for my application. The sled now handles everything from extremely aggressive riding with just me on the sled to providing a comfortable ride when loaded up with saddle bags on a long trip.
As far as further improvements, I wouldn't mind a little more damping in the floats now - both additional high speed compression and additional rebound. Considering the floats are still valved stock, they do an excellent job as is. Dreaming of the absolutely perfect sled, larger diameter shocks that run cooler, bigger gas tank...
Now that I've put a good 1500 km on my sled since revalving the shocks and tweaked the suspension to optimize everything I thought I'd post an update:
- Every time I ride the sled now I can't get over how well this machine handles bumpy trails with such an incredible level of overall stability. The overall performance improvement is literally like night and day.
- With the extreme resistance to bottoming out, I have now lowered the rear torsion springs to the lowest setting, left the center shock preload at "just tight" with the shock fully extended, tightened the limiter by another hole (tightest hole), increased the weight transfer setting to about 2/3rds towards max and increased the float pressure to 75 psi. With just me on the sled, the floats are the first thing to bottom out, but it takes a lot before they do. The cornering performance on smooth trails is better than it was due to the lowered center of gravity and the increased down pressure on the skis keeping the sled planted.
- With just me on the sled in -30°C weather, at first the rear suspension is definitely on the firm side. Increasing the weight transfer (reduced coupling) softened the ride a little, but it is still firm. Once I have about 20 minutes to 1/2 an hour of aggressive riding on the sled, the shocks warm up, thinning the fluid a little. At this point it is absolutely perfect for very aggressive riding on everything from smooth to highly mogulled trails. Sitting down over the biggest bumps I don't hurt my back, but since it pretty much doesn't bottom out it could probably be a little softer (at this point) without any bottoming issues.
- Once I've been riding for a good 6 hours or so (or a second day without a thaw), the 50 lbs or so of ice that builds up in the tunnel helps to tune the suspension closer to perfection. This was exactly what I was looking for and Mike Carver managed to get it bang on. At this point the ride becomes quite comfortable, yet it is still very difficult to bottom out. A big hit can bottom it out, but it takes a very, very big bump at very high speeds. I do notice a bit of shock fade (softening up the ride) when ridden very aggressively on very rough trails for hours on end, but the shocks never loose control and always maintain excellent bottoming control. Basically the shocks are about as perfectly dialed in as they can be for my riding style.
- When I load the sled up with about 50 lbs of saddle bags and that 20 minute warm up period is over, the sled starts off riding exactly as above. It is a blast to ride very aggressively, loaded up with saddle bags without bottoming out hardly at all. Since the suspension isn't hitting a hard stop (bottoming out), the saddle bags don't get that sudden "bang" on a regular basis that tries to rip the saddle bag straps off. Even jumping and powering down very rough trails at high speeds, the suspension just handles it flawlessly.
- After a good 6 hours of saddle bag riding, more noticeable on a second or third day, the suspension now starts to ride noticeably lower. At this point there is a good 50+ lbs of ice built up in the tunnel (I suspect there is more than 50 lbs of ice), ~50 lbs of saddle bags, 10 lbs in the trunk, plus my 240 lbs ready to ride. Now the sled starts to ride plush, but amazingly it still doesn't bottom out easily and even with the suspension hitting the anti-bottomers there is not any noticeable kick back. I do find at this point it is a little on the soft side of things for aggressive riding plus I want to crank the torsion springs up to the medium setting (partly because the headlight is now out of alignment - pointing too high). I also find if I continue to push the sled very hard on very rough trails I now start to experience a noticeable amount of shock fade. The shocks don't fade away to nothing, but the damping is noticably reduced and it becomes easier to bottom out. Stopping the sled and putting my hand on the skid shocks, they both become quite hot to the touch (steam coming off the shocks as the snow dust evaporates too). After a short slowdown or stop, the suspension firms up fairly quickly again.
Overall I have to say I don't think the shock valving could be any better for my application. The sled now handles everything from extremely aggressive riding with just me on the sled to providing a comfortable ride when loaded up with saddle bags on a long trip.
As far as further improvements, I wouldn't mind a little more damping in the floats now - both additional high speed compression and additional rebound. Considering the floats are still valved stock, they do an excellent job as is. Dreaming of the absolutely perfect sled, larger diameter shocks that run cooler, bigger gas tank...
Ported Hornet
Expert
Thanks for the additional write up REX.
ReX
TY 4 Stroke God
I just thought I'd let everyone know that my sled now has a broken front pivot arm in the skid.
I can't be certain that it wasn't "just about to fail" before I installed Mike Carver's custom valve stacks, but I didn't notice any indication that it was about to go when I did the shocks (although during my inspection I didn't expect it to let go where it did so I wasn't really inspecting it in the right places).
The front pivot arm has a linkage that controls the position of the lower shock mount for the main (rear) shock. It is this linkage that has broken on the front pivot arm. It is a fatigue failure (crack) that has gone all the way through right beside this link (alowing the link to spin freely on the shaft).
My sled was still riding well, except I noticed a softer ride, it was a little easier to bottom out and the worst thing was I was getting kick back on big bumps. I couldn't see any structural problems with the suspension until I melted out the snow.
Now that I have the skid out I can see that the suspension can move up and down by a couple of inches now before there is any main shock motion (due to the broken link). This explains why the skid was riding with less damping.
I'm going to reinforce the pivot arm, hopefully making it so it won't fail again.
I can't be certain that it wasn't "just about to fail" before I installed Mike Carver's custom valve stacks, but I didn't notice any indication that it was about to go when I did the shocks (although during my inspection I didn't expect it to let go where it did so I wasn't really inspecting it in the right places).
The front pivot arm has a linkage that controls the position of the lower shock mount for the main (rear) shock. It is this linkage that has broken on the front pivot arm. It is a fatigue failure (crack) that has gone all the way through right beside this link (alowing the link to spin freely on the shaft).
My sled was still riding well, except I noticed a softer ride, it was a little easier to bottom out and the worst thing was I was getting kick back on big bumps. I couldn't see any structural problems with the suspension until I melted out the snow.
Now that I have the skid out I can see that the suspension can move up and down by a couple of inches now before there is any main shock motion (due to the broken link). This explains why the skid was riding with less damping.
I'm going to reinforce the pivot arm, hopefully making it so it won't fail again.
number1kyster
TY 4 Stroke God
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Does your sled sit up higher REX? I was overlooking my 07 the other day and noticed it is sitting on the transfer nuts. Does this mean my shocks are blown?
ReX
TY 4 Stroke God
number1kyster said:
It sits a little higher, but it rides much higher.
To be honest, I don't understand why it is sitting higher. The shocks shouldn't be providing any extra static lift so the "just sitting there" ride height should be about the same. I suppose the nitrogen pressure could have been low before, but even then the height shouldn't change much.
When riding though, since the ratio of compression damping vs rebound damping has increased, as I ride the sled on typical bumps (big or small), the suspension will tend to raise a little compared to stock. The amount it raised while riding was enough that I had to realign my headlight, even though I dropped the torsion spring preload from medium to low.
To answer your question - no, blown shocks shouldn't lower the sled much when the sled is not moving. When you ride it though, a blown shock can often make the sled ride lower, and especially make it bottom out more. If a shock looses its nitrogen pressure, the static height will drop a little, but not much.
If your sled has dropped a lot of ride height, there is likely a different problem - possibly the torsion springs have lost some preload, or there might be some sort of structural failure.
