Ricor Suspension Review – Long
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01-09-2010, 08:24 PM
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Ricor Suspension Review – Long
Thursday Greg Benner and I took a ride to Ricor’s manufacturing facility outside of Las Vegas to have a set of Intiminators installed in my 2009 Road Glide. While there Brian from Ricor offered to let me try a set of their prototype shocks as well. I thought I would write a review and also include some basic technical background for those that are interested. The technical section follows the results.
Goal
I’ve been interested lately in improving the suspension on my Road Glide. Overall the stock 2009 fork is pretty reasonable but it still feels harsh to me on sharp edged bumps and a bit unstable in fast sweepers. Even though brake dive is not excessive since I always use both the front and rear together, I felt a bit less dive would be an improvement. As for the rear, I’ve gone through the stock air shocks, Progressive 440s and am now running Works Steel Trackers and have Ohlins from Howard on the way.
Results
Simply put, the difference in the way the bike reacted to bumps with the Intiminators and Ricor shocks installed was nothing short of amazing! I’m usually pretty skeptical when it comes to after-market stuff but this is definitely an exception. Before the Intiminators and Ricor shocks I would find myself tensing up when I’d see a bump coming particularly if it was sharp edged and big like between two pieces of freeway slab. The hit would be severe and jolting. Now when I hit the exact same bump absolutely nothing happens. The bike just goes over it like it wasn’t there. Overall, bumps just don’t disturb the bike anywhere near like they did before. It actually seemed a bit eerie at first. Even though there wasn’t a lot of brake dive before there is even less now and, more importantly, what dive there is is so much slower. Instead of dropping down two inches or so quickly when hitting the front brakes it now drops down half that far and with more control. We have a mile long elevated ramp that is a transition between two freeways which is undulating with a high speed curve in it. I usually enter it at 80 mph and find myself backing off the gas about half way through the curve once the bike starts its slow weave. Thursday night on the way home from Ricor I took the same ramp at the same 80 mph and held it without any drama all the way to the end. No weave at all!
Does the bike ride like a Cadillac? No, but it does perform many times better than it did and particularly in regards to the forks. I'm very satisfied.
I’ve had Ohlins on other bikes in the past as well as on my GS currently so I’m curious to compare the Ohlins and Ricor on the Road Glide in the next couple of weeks. I’ll let you know how it goes.
Fork Background
Our bikes use what is referred to as a Damper Rod system. Simply described, a damper rod system has a hollowed out rod attached to the bottom of the fork. As the suspension moves up and down it draws oil through drilled holes in the rod which controls how fast the fork can move determined by the type of bump encountered. The problem with damper rod systems is that these fixed orifices necessitate a compromise in control when hitting undulating bumps (slow bumps) versus sharp edged bumps (fast bumps). The result, like most compromises, is that they don’t do a particularly good job in either case. Some applications include a relief valve in combination with the damper tube which offers more flexibility in how well the system can handle different types of bumps as well as brake dive. Race Tech’s emulators are an example. Harley also includes a similar valve in our Touring bikes that have fairings. Many higher end sport bikes have cartridge type forks that use gas pressurized self-contained mini-shocks fitted inside the forks that have more sophisticated control systems including separate valves for compression and rebound. Within all these different types of fork control there are even more variations based on the design of the valves, the types and number of springs used, etc. BTW, for those unfamiliar with suspension, compression refers to the dampening that comes into play when the fork reacts to a bump or the rider hits the front brakes and rebound refers to the dampening used to control the suspension as it recovers from a bump or when the wheel drops into a recess.
Observations
Regardless of the type of suspension being used, all of the above react in one way or another to movement between the bike and the wheel. On the compression side this means reacting to the wheel rising as a result of hitting a bump or of the bike sinking as result of hitting the brakes. On the rebound side the fork has to control how fast the wheel returns after hitting a bump as well as how fast the wheel is allowed to drop when encountering a dip or hole in the road and also how the bike reacts under acceleration. It does gets complicated! Not only do our forks have to do all of this but they also have to do it not knowing whether the movement was caused by the wheel hitting a bump or because the rider hit the front brakes causing the front end of the bike to dive. All the fork can react to is the fact that the relative distance between the wheel and the bike just got shorter. You might wonder why this matters… it does and here’s why. Let’s say we just hit a sharp edged bump in the road going 60 mph. The fork needs to compress quickly as we pass over the bump. If we exerted a lot of compression dampening the bump caused movement would transfer into the chassis of the bike and right into us. No fun. On the other hand if we had low compression dampening the bump could be absorbed by the spring so much less of the movement would get through to the chassis. It would seem that low compression dampening would be the way to go. But, what about brake dive? If we hit the brakes the front end is going to try and compress. One way to slow the front end down is to use a large amount of compression dampening. There‘s the conflict, brake dive requires high amounts of compression dampening while bump control often requires low amounts of compression dampening. How to handle both cases? With a simple damping rod like in a Road King as an example there is nothing except drilled holes to control how fast the fork oil can move when the fork is compressed. The size of the holes are a compromise, make them too small and when the fork has to move quickly like when hitting a bump the oil can’t get through fast enough and the bump is transferred to the rider. Make them too big and when the rider hits the brakes and the chassis starts to move down relatively slowly the oil passes right though the holes easily developing almost no dampening which causes excessive dive. The fairing models have it a bit better. The extra valve they have sitting on top of the damper rod works as a kind of a blow off valve supplying high speed relief and also contains a small metering hole through the center of it to help control slow speed dampening. When the suspension tries to move quickly the higher oil pressure created pushes against a spring loaded disk in the valve opening it which allows the oil to bypass easily. This is better of course. The problem inherent in this design is that the system is purely reactive. That means that the relief valve can’t react until enough pressure is built up to overcome the spring pressure holding it closed which also takes time. In other words, a certain amount of shock is going to get through to the rider regardless.
A Better Way
The best situation would be if the fork could react to a fast bump instantaneously with very little compression dampening while at the same time offering increased dampening to control brake dive. This is exactly what Ricor has come up with. Their valve assembly looks similar to the Harley valve but included in the design is an extra valve which makes all the difference. This extra piece is what they call their Inertia Valve. It floats within the valve assembly supported by a very light spring. When the wheel hits a bump the valve reacts to the movement of the wheel (rather than built up oil pressure) and instantly opens a large oil bypass allowing the wheel to react to the bump freely. Another advantage of having the Inertia Valve is that they can also include a separate shim controlled valve that offers the optimal amount of dampening to control brake dive.
This same Inertia Valve technology is used in Ricor’s shocks. In this application the valve is used to control rebound instead of compression dampening. When the rear wheel hits a bump it needs to return to the road as quickly as possible in order to maintain traction and security. This control is done with rebound dampening. At the same time the shock has to control how fast the bike chassis bounces back from a bump. Chassis movement requires high rebound dampening and wheel movement requires lower rebound dampening. The Inertia Valve senses when the chassis is moving and increases rebound dampening. This allows the shock to be designed with 30% lower rebound dampening than normal so the wheel can better follow the road surface while increasing rebound dampening when the valve senses that the bike chassis is moving. The effect is much better wheel and chassis control and increased compliance resulting in a more comfortable and stable ride.
Goal
I’ve been interested lately in improving the suspension on my Road Glide. Overall the stock 2009 fork is pretty reasonable but it still feels harsh to me on sharp edged bumps and a bit unstable in fast sweepers. Even though brake dive is not excessive since I always use both the front and rear together, I felt a bit less dive would be an improvement. As for the rear, I’ve gone through the stock air shocks, Progressive 440s and am now running Works Steel Trackers and have Ohlins from Howard on the way.
Results
Simply put, the difference in the way the bike reacted to bumps with the Intiminators and Ricor shocks installed was nothing short of amazing! I’m usually pretty skeptical when it comes to after-market stuff but this is definitely an exception. Before the Intiminators and Ricor shocks I would find myself tensing up when I’d see a bump coming particularly if it was sharp edged and big like between two pieces of freeway slab. The hit would be severe and jolting. Now when I hit the exact same bump absolutely nothing happens. The bike just goes over it like it wasn’t there. Overall, bumps just don’t disturb the bike anywhere near like they did before. It actually seemed a bit eerie at first. Even though there wasn’t a lot of brake dive before there is even less now and, more importantly, what dive there is is so much slower. Instead of dropping down two inches or so quickly when hitting the front brakes it now drops down half that far and with more control. We have a mile long elevated ramp that is a transition between two freeways which is undulating with a high speed curve in it. I usually enter it at 80 mph and find myself backing off the gas about half way through the curve once the bike starts its slow weave. Thursday night on the way home from Ricor I took the same ramp at the same 80 mph and held it without any drama all the way to the end. No weave at all!
Does the bike ride like a Cadillac? No, but it does perform many times better than it did and particularly in regards to the forks. I'm very satisfied.
I’ve had Ohlins on other bikes in the past as well as on my GS currently so I’m curious to compare the Ohlins and Ricor on the Road Glide in the next couple of weeks. I’ll let you know how it goes.
Fork Background
Our bikes use what is referred to as a Damper Rod system. Simply described, a damper rod system has a hollowed out rod attached to the bottom of the fork. As the suspension moves up and down it draws oil through drilled holes in the rod which controls how fast the fork can move determined by the type of bump encountered. The problem with damper rod systems is that these fixed orifices necessitate a compromise in control when hitting undulating bumps (slow bumps) versus sharp edged bumps (fast bumps). The result, like most compromises, is that they don’t do a particularly good job in either case. Some applications include a relief valve in combination with the damper tube which offers more flexibility in how well the system can handle different types of bumps as well as brake dive. Race Tech’s emulators are an example. Harley also includes a similar valve in our Touring bikes that have fairings. Many higher end sport bikes have cartridge type forks that use gas pressurized self-contained mini-shocks fitted inside the forks that have more sophisticated control systems including separate valves for compression and rebound. Within all these different types of fork control there are even more variations based on the design of the valves, the types and number of springs used, etc. BTW, for those unfamiliar with suspension, compression refers to the dampening that comes into play when the fork reacts to a bump or the rider hits the front brakes and rebound refers to the dampening used to control the suspension as it recovers from a bump or when the wheel drops into a recess.
Observations
Regardless of the type of suspension being used, all of the above react in one way or another to movement between the bike and the wheel. On the compression side this means reacting to the wheel rising as a result of hitting a bump or of the bike sinking as result of hitting the brakes. On the rebound side the fork has to control how fast the wheel returns after hitting a bump as well as how fast the wheel is allowed to drop when encountering a dip or hole in the road and also how the bike reacts under acceleration. It does gets complicated! Not only do our forks have to do all of this but they also have to do it not knowing whether the movement was caused by the wheel hitting a bump or because the rider hit the front brakes causing the front end of the bike to dive. All the fork can react to is the fact that the relative distance between the wheel and the bike just got shorter. You might wonder why this matters… it does and here’s why. Let’s say we just hit a sharp edged bump in the road going 60 mph. The fork needs to compress quickly as we pass over the bump. If we exerted a lot of compression dampening the bump caused movement would transfer into the chassis of the bike and right into us. No fun. On the other hand if we had low compression dampening the bump could be absorbed by the spring so much less of the movement would get through to the chassis. It would seem that low compression dampening would be the way to go. But, what about brake dive? If we hit the brakes the front end is going to try and compress. One way to slow the front end down is to use a large amount of compression dampening. There‘s the conflict, brake dive requires high amounts of compression dampening while bump control often requires low amounts of compression dampening. How to handle both cases? With a simple damping rod like in a Road King as an example there is nothing except drilled holes to control how fast the fork oil can move when the fork is compressed. The size of the holes are a compromise, make them too small and when the fork has to move quickly like when hitting a bump the oil can’t get through fast enough and the bump is transferred to the rider. Make them too big and when the rider hits the brakes and the chassis starts to move down relatively slowly the oil passes right though the holes easily developing almost no dampening which causes excessive dive. The fairing models have it a bit better. The extra valve they have sitting on top of the damper rod works as a kind of a blow off valve supplying high speed relief and also contains a small metering hole through the center of it to help control slow speed dampening. When the suspension tries to move quickly the higher oil pressure created pushes against a spring loaded disk in the valve opening it which allows the oil to bypass easily. This is better of course. The problem inherent in this design is that the system is purely reactive. That means that the relief valve can’t react until enough pressure is built up to overcome the spring pressure holding it closed which also takes time. In other words, a certain amount of shock is going to get through to the rider regardless.
A Better Way
The best situation would be if the fork could react to a fast bump instantaneously with very little compression dampening while at the same time offering increased dampening to control brake dive. This is exactly what Ricor has come up with. Their valve assembly looks similar to the Harley valve but included in the design is an extra valve which makes all the difference. This extra piece is what they call their Inertia Valve. It floats within the valve assembly supported by a very light spring. When the wheel hits a bump the valve reacts to the movement of the wheel (rather than built up oil pressure) and instantly opens a large oil bypass allowing the wheel to react to the bump freely. Another advantage of having the Inertia Valve is that they can also include a separate shim controlled valve that offers the optimal amount of dampening to control brake dive.
This same Inertia Valve technology is used in Ricor’s shocks. In this application the valve is used to control rebound instead of compression dampening. When the rear wheel hits a bump it needs to return to the road as quickly as possible in order to maintain traction and security. This control is done with rebound dampening. At the same time the shock has to control how fast the bike chassis bounces back from a bump. Chassis movement requires high rebound dampening and wheel movement requires lower rebound dampening. The Inertia Valve senses when the chassis is moving and increases rebound dampening. This allows the shock to be designed with 30% lower rebound dampening than normal so the wheel can better follow the road surface while increasing rebound dampening when the valve senses that the bike chassis is moving. The effect is much better wheel and chassis control and increased compliance resulting in a more comfortable and stable ride.
#3
01-09-2010, 08:45 PM
This afternoon. Mark installed the intiminators in my 07 RG. I rode it home 50 miles on LA freeways just a couple hours ago. Couldn't be more pleased.
As most of you know, the springs on an 07 are much weaker than on the 09. (33% or so). I had too much brake dive, but not anymore. Ride is really nice. Hard to believe.
When we intalled the Intiminators, I was shocked
at how weak the fork springs are compared to the stock springs on Mark's 09. However, they now seem to work great. I currently have Works Trackers in the rear...hopefully Mark, you will let me try the RICORs when your Ohlins arrive
Thx for the help,
greg
As most of you know, the springs on an 07 are much weaker than on the 09. (33% or so). I had too much brake dive, but not anymore. Ride is really nice. Hard to believe.
When we intalled the Intiminators, I was shocked
at how weak the fork springs are compared to the stock springs on Mark's 09. However, they now seem to work great. I currently have Works Trackers in the rear...hopefully Mark, you will let me try the RICORs when your Ohlins arriveThx for the help,
greg
Last edited by gregbenner; 01-09-2010 at 09:09 PM.
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