Pay Attention to your Suspension Air Pressure!

[V7Goose]

Let me tell you a story about a man named Jed .. . oh, wait, wrong story...

 

Let me tell you a story about suspension air pressure on an RSV...

 

Many of you may remember that I crashed my 05 last summer when brand new tires slid out from under me in a curve. I picked up a barely used 07, but my cornering has never felt quite as good as it did on the 05 - nothing really wrong, but I didn't seem to hold a solid line in the big sweepers, and I sometimes found myself fighting the bars in the tight ones. I just assumed that was still some residual nervousness from my crash that I had to work through. Not so.

 

I kept forgetting to to check the pressure in the forks, just assuming it was 0 (the way it comes from the factory. Even though I have my pump with me, I never think about it untill I am riding. Well, yesterday morning I finally remembered to check it before we went our riding - WHAT A DIFFERENCE!

 

Some background - I'm a fairly big guy - 6'5", 230 lbs, and my passenger is 130 lbs. I have Leveling Links installed to raise the rear and stock size Avon Venom tires.

 

I had the rear shock still set at 30 lbs (where I keep it when riding solo), so I pushed it up to 40. The front forks were at 8 and 8.5 lbs. Not only is that over the maximum, but not having them exactly equal is a BIG no-no. I dropped both of them to 6 lbs. These changes might not sound like much, but the difference in the handling is huge. The bike goes through sweepers like it is on rails now, and the twisties and ass-kisser turns are once again fun and comfortable. Just thought I'd pass on this experience for anyone who has not really checked thier suspension air pressures and found the right settings for their load and riding style -

Goose

[WIKD]

Hey Goose what type of pump are you using for the front? I can't seem to find one that brakes it down to increments smaller than 5 pounds so mine has a 5 pound setting and 10 and my gauge I used seems to lower it just by placing it on.

[oldandcrotchety]

you can get a digital gauge from "Roadgear" that reads from 5 to 99 pounds in 1/2 pound increments. mine cost about 25 dollars. when you use it you have to hold it on the valve a second or 2 before it gets the reading. excellnt gauge and has a 90 degree neck for those tight places.

[V7Goose]

Since those forks hold so little air, you cannot get them accurately filled if you lose ANY air when removing the pump or guage. The only real option is one of the Progressive or HD pump/gauge combos that have a zero-loss air chuck. I have the 0-60 one that makes it a little tough to read the very low pressure in the forks (lowest mark is 4 lbs, I think, in 2 lbs increments above that). I am going to buy one of the 0-15 pumps when I get around to it.

 

If you hear ANY psssss escaping air when you remove your gauge, your forks will NOT be equal. If you don't have the right gauge with a zero-loss chuck, your best option is to make sure both forks have NO air.

Goose

[SilvrT]

Since those forks hold so little air, you cannot get them accurately filled if you lose ANY air when removing the pump or guage. The only real option is one of the Progressive or HD pump/gauge combos that have a zero-loss air chuck. I have the 0-60 one that makes it a little tough to read the very low pressure in the forks (lowest mark is 4 lbs, I think, in 2 lbs increments above that). I am going to buy one of the 0-15 pumps when I get around to it.

 

If you hear ANY psssss escaping air when you remove your gauge, your forks will NOT be equal. If you don't have the right gauge with a zero-loss chuck, your best option is to make sure both forks have NO air.

Goose

 

OK, dumb question here ..... why is there separate air valves for each shock if ya don't want to have them uneven? Wouldn't it make sense to have a single air valve feeding both? Or am I understanding the info wrongly?

[V7Goose]

OK, dumb question here ..... why is there separate air valves for each shock if ya don't want to have them uneven? Wouldn't it make sense to have a single air valve feeding both? Or am I understanding the info wrongly?

Not a dumb question at all. Yamahaha just made a really STUPID design (IMHO) by saving $1.00 and not putting a connecting hose on them. Progressive used to make a connecting kit for a different bike (1st gen?) that some have used successfully on the RSV, but it does not really fit right and can be difficult to put on even if you can find one. I thought about making one of my own, but since I rarely ever change the pressure after getting it set right, it is just easier to leave it as is.

Goose

[Freebird]

They are a bit of a tight fit to put on but mine worked well once I DID get it on. Here is the article that I wrote for the tech library about it and there is also a link there to the kit at Dennis Kirk.

 

http://www.venturerider.org/forum/showthread.php?t=497

[BoomerCPO]

This is probably a stupid question but won't running the front shocks with 0 pressure effect the handling of the bike in tight turns?

[kbran]

I've got the same thing and it wasn't that hard to put on. Sure makes a difference in seting both forks equal.

 

They are a bit of a tight fit to put on but mine worked well once I DID get it on. Here is the article that I wrote for the tech library about it and there is also a link there to the kit at Dennis Kirk.

 

http://www.venturerider.org/forum/showthread.php?t=497

[V7Goose]

This is probably a stupid question but won't running the front shocks with 0 pressure effect the handling of the bike in tight turns?

Yes, I think it does affect the handling - less precise. But, Yamahaha ships it with 0 psi and says that is the standard setting. I played with different settings when I first got my 05, and found then how important it was to have them exactly equal. That is why I advise making sure they are both empty if you do not have the right gauge to verify they are equal.

Goose

[BoomerCPO]

Yes, I think it does affect the handling - less precise. But, Yamahaha ships it with 0 psi and says that is the standard setting. I played with different settings when I first got my 05, and found then how important it was to have them exactly equal. That is why I advise making sure they are both empty if you do not have the right gauge to verify they are equal.

Goose

 

Thanks for the response. There is so much info to learn about this bike it amazes me. This is my 1st full Touring bike and I'm really looking forward to the start of riding season here in the frozen Northeast.

 

Regards.....Boomer

[SilvrT]

Yamahaha ships it with 0 psi and says that is the standard setting.

 

Sounds kinda crazy... they ship it with 0 psi and say that's the standard setting (meaning ya can ride it that way), they don't link the 2 together in 1 valve ... why even bother with air .... just put progressive springs in to begin with...

[Midrsv]

Just a thought, would it be possible to dial the pressure regulator on the air compressor down to about 5 lbs and let it control the input pressure to the shock instead of using a guage? Will the regulator control that precisely?

 

DT

[halfwitt]

http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=282090&store=&catId=418&productId=p28236&leafCatId=41807&mmyId=

 

Is a Progressive 0-60 psi gauge

[KeithR]

The Kit that Don used is on sale at Cruiser Customizing for $20.88

 

http://www.cruisercustomizing.com/detail.cfm?Category_ID=79&manufacturer_ID=39&product_ID=5363&model_ID=0

 

Keith

[RoadKill]

Let me tell you a story about a man named Jed .. . oh, wait, wrong story...

 

Let me tell you a story about suspension air pressure on an RSV...

 

Many of you may remember that I crashed my 05 last summer when brand new tires slid out from under me in a curve. I picked up a barely used 07, but my cornering has never felt quite as good as it did on the 05 - nothing really wrong, but I didn't seem to hold a solid line in the big sweepers, and I sometimes found myself fighting the bars in the tight ones. I just assumed that was still some residual nervousness from my crash that I had to work through. Not so.

 

I kept forgetting to to check the pressure in the forks, just assuming it was 0 (the way it comes from the factory. Even though I have my pump with me, I never think about it untill I am riding. Well, yesterday morning I finally remembered to check it before we went our riding - WHAT A DIFFERENCE!

 

Some background - I'm a fairly big guy - 6'5", 230 lbs, and my passenger is 130 lbs. I have Leveling Links installed to raise the rear and stock size Avon Venom tires.

 

I had the rear shock still set at 30 lbs (where I keep it when riding solo), so I pushed it up to 40. The front forks were at 8 and 8.5 lbs. Not only is that over the maximum, but not having them exactly equal is a BIG no-no. I dropped both of them to 6 lbs. These changes might not sound like much, but the difference in the handling is huge. The bike goes through sweepers like it is on rails now, and the twisties and ass-kisser turns are once again fun and comfortable. Just thought I'd pass on this experience for anyone who has not really checked thier suspension air pressures and found the right settings for their load and riding style -

Goose

 

Great reminder Goose. Same is true with Tire pressure too. I like you forget to check the shocks as often as I should. I usually end up checking at at the first gas stop. It always amazes me what a difference it makes.

Thanks for the reminder.

Jay

[Roy Hoffman]

I got chrome valve extensions and put them on each side of fork. I also got a 0-30# pump with a check valve so I don't lose any pressure after pumping to 5#. I did the same on rear shock and use same pump on it, works for me.

[Rick Butler]

Goose,

 

You make some very good points, especially to have the forks equalized with each other. However for everyone's information all the air does in the rear shock or front forks is adjust the ride height. In other words it raises or lowers the bike based upon the overall fork or rear shock travel after the bike is loaded with rider and/or passenger.

 

The ride of the bike is really based upon the spring rate and the shock or fork dampening. And the controllable dampening is only available to the forks in the form of fork oil weight and amount of oil. If I remember right, the weight of the oil controlls the compression rate and the amount of oil controls the rebound rate. The spring rate really controls the basic part of the ride based upon the weight that is added to the bike.

 

The Japanese build these bikes for an average rider & passenger and the spring rate is set as cushy as they can for a comfortable touring bike. The specs for the RSV is a front spring rate of .90kg/mm. However for most of us, we need a spring rate of 1.20kg/mm to decrease the front end sag with the weight of the bike plus driver. This heavier spring also helps in front end dive under heavy front braking.

 

So if you are an average weight rider with an average weight passenger and ride primarily on the straighter interstates, the RSV is suitable as delivered. But if you ride two-up when riding alone and like to ride more aggressive and want the bike to handle better, I'd suggest that you at least consider changing out the fork springs with Progressive's or a constant rate spring from someone like Race Tech or Sonic Springs. A good time to do this would be when you decide it's time to change the fork oil. And then forget about running any air pressure because the springs now control the ride height based upon the spring rate, the available travel, and bike/rider weight.

 

Hope this clears up some questions,

 

Rick

[Guest KitCarson]

Goose,

 

You make some very good points, especially to have the forks equalized with each other. However for everyone's information all the air does in the rear shock or front forks is adjust the ride height. In other words it raises or lowers the bike based upon the overall fork or rear shock travel after the bike is loaded with rider and/or passenger.

 

The ride of the bike is really based upon the spring rate and the shock or fork dampening. And the controllable dampening is only available to the forks in the form of fork oil weight and amount of oil. If I remember right, the weight of the oil controlls the compression rate and the amount of oil controls the rebound rate. The spring rate really controls the basic part of the ride based upon the weight that is added to the bike.

 

The Japanese build these bikes for an average rider & passenger and the spring rate is set as cushy as they can for a comfortable touring bike. The specs for the RSV is a front spring rate of .90kg/mm. However for most of us, we need a spring rate of 1.20kg/mm to decrease the front end sag with the weight of the bike plus driver. This heavier spring also helps in front end dive under heavy front braking.

 

So if you are an average weight rider with an average weight passenger and ride primarily on the straighter interstates, the RSV is suitable as delivered. But if you ride two-up when riding alone and like to ride more aggressive and want the bike to handle better, I'd suggest that you at least consider changing out the fork springs with Progressive's or a constant rate spring from someone like Race Tech or Sonic Springs. A good time to do this would be when you decide it's time to change the fork oil. And then forget about running any air pressure because the springs now control the ride height based upon the spring rate, the available travel, and bike/rider weight.

 

Hope this clears up some questions,

 

Rick

Good Post Rick......hey you are like me!! You have stood in front of the bus!!:rotfl:.I also run with no air.......and listen to all the complaints about installing leveling links......and hey just let the air out!!......I experimented with all kinds of air levels and pressures.....did not make much difference to me....or did not seem to........This is my exact viewpoint on this air shock business with these bikes...exactly. Kit

[BEER30]

I for one will not run without air in the rear shock . Wife and I were riding and hit a spot once that cause us to bottom out . I hate to blow out a shock because of no air in the rear .

 

BEER30

[V7Goose]

However for everyone's information all the air does in the rear shock or front forks is adjust the ride height. In other words it raises or lowers the bike based upon the overall fork or rear shock travel after the bike is loaded with rider and/or passenger.

Rick

Sorry Rick, I don't agree with this. Based on my own testing, adding air to the suspension DEFINITELY changes the firmness of the ride and the handling on both of my RSVs. Too soft is worse than too hard. While doing a day ride in Fort Collins with my brother last summer, I decided to experiment and drop the rear pressure to 15 lbs. Not only did she wallow in the twisties, but after only a 250 mile day, I was miserable. The previous two days of riding we did 300 and 400 each day, and my rear shock was still set at 45 where I had it when riding up there fully loaded, and each day was a breeze (and the bike handled well too). I reset the shock to the right pressure for me the following day and again experienced no discomfort after all day in the saddle. Just this week while riding in the Smokies with my wife, the day after I raised the pressure in the rear shock, we both noticed several sections of the same road we had ridden the day before being much rougher.

 

In my opinion, increasing the pressure in the rear shock does not significantly raise the rear of the bike, but it certainly changes the softness of the ride. I suspect this is because I weigh quite a bit and manage to compress the shock back close to normal ride height when I sit on it even with 45 lbs pressure. Maybe if I weighed less than 200 lbs, by opinion would be different? I just want the other owners out there to keep an open mind and check out their machine for themselves instead of blindly going with whatever they read in the forum. Good luck all,

Goose

[Rick Butler]

Sorry Kent,

 

I guess I didn't make myself that clear and was really addressing the front forks, which was the issue I think you were pointing out.

 

Yeah, for most of us who are around 200 lbs or better, you need to have some fairly significant air in the shock. But this is still meant to establish the bike's rear ride height once the rider and especially the passenger (over the rear wheel) are on the bike. Yeah it really doesn't raise the bike per say, but it doesn't let the bike drop as much as it would with less air. I think in your case with 15lbs of air and your weight, you probably had the shock compressed pretty good. And it probably sat somewhat lower in the rear which caused the wallowing in the curve because you now have more rake & trail. But, I will suggest that a 150lb rider could have ridden your bike with 15lbs of air in the rear shock and it would handle just as well as it would with you on the bike with 45lbs of air?

 

Now in my case I'm running a Works shock so I don't have to deal with the OEM shock. And all I have is the proper spring rate for my weight and 500 lbs of nitrogen and oil to control the compression and rebound dampening, where I can adjust the rebound.

 

It's the front forks that really don't need that much or any air with the proper springs. But then again for a rider that is heavier, then yes they will need some air, but again to limit the sag (ride height) once the rider get's on the bike. I know from experience that this bike alone needs a heavier 1.20 kg/mm spring rather than the .90kg/mm. But, air is a poor medium for any shock and they are using it to provide the rider the option to set the ride height because of the broad range of rider/passenger weights. Why is it that in autos that air shocks are often referred to as load levelers?

 

But you are so correct that each rider needs to adjust their bike's suspension to fit thier riding style and comfort level based upon their weights being placed on the bike.

 

JMHO,

 

Rick

[Guest KitCarson]

There is an article on the web, where some riders from some magazine took three bikes for a 7000 mile ride, switching bikes each day and writing about their opinions. One of the big ones was the way the Venture handled under heavy load. Nothing they could do, add air....let out air......put in more air, could resolve the erratic behavior of the Venture under a touring load. With each different road condition encountered, the Bike would handle differently. The also state, and I fully agree, once unloaded, and normal weight riders were on the bike......its handling returned. Air is a compressible substance, and cannot be trusted to hold a steady even stability under various road conditions encountered. A proper weight spring, and maybe oil used as a medium in the shock , works very well.......oil, water......liquid, any hydraulic substance cannot be compressed.

I for one find the venture quite enjoyable for myself and my wife just stock, in fact putting air in the shocks seems to cause me to lose contact with the front wheel(at times) I do not like the extreme damping the fork goes through under heavy use of the front brake, and have found adding air to the extreme makes that even more erratic. The bike was designed for the proper weight load, do not remember exactly what,,,,,know it is somewhat low....400 pounds I think......with just myself and my wife on the bike and a few items the bike performs quite well, I love it. I have no desire to run the twisties at 70 to 85 mph. I will roll around the U-Turn corner in a calm easy manner and enjoy it, I have no desire to scrape the foot boards.

Now I see a lot of folks with the saddle bags stuffed to the brim, extra luggage racks put wherever you can put on. Tank bags...fork bags, windshield bags.........and hooked up to a trailer too!! Quite simply the Bike is totally overloaded way past its design capacity.

It does not take much to weigh 70 pounds.........I think my jacket with all the armor in it weighs 16 pounds........a first aid kit......tire kit....a few tools.....can of fix a flat........rain coats......two helmets........and a few extra clothes, does not take much to add up. Some of these bikes are stuffed with all the comforts of home...........and wallow around like a hippo too!!

So air does not solve the performance problems with overloading the bikes. Heavier springs do........I myself like Crickett just fine, I have never had a bike that rides so smooth and I think it is great........I do not overload it either......I may change the front fork springs......not for ride, but for braking.......do not know yet........still experimenting with the brakes. Respectfully Kit

[nelsonrl]

This one works well for me. Should be available locally, or online.

 

Normal price is about $35. You can find is a couple of bucks cheaper if you search on the part numberr (54630-03A).

[V7Goose]

This has been a great discussion, but I think it is one much better suited for a long afternoon over beers than taking turns posting messages . . .

 

Oh well, it is what it is. I find that the handling of my RSV is VERY good when fully loaded and set up correctly with the right shock pressure, tires, etc. For me, this requires raising the rear of the bike by changing the suspension links and NOT having to make the suspension overly stiff to try and mistakenly achieve the same result. So I won't be agreeing with anyone who is equally positive that it does not handle well.

 

I do agree that air is compressible, but I do NOT agree that it is a poor medium for use in suspension components when properly designed. Air is compressible, just like springs are, and the compression rate is adjustable by changing the pressure. The only way to change the compression rate of springs after they are manufactured is to change the preload - both methods work and both have their limitations. The DAMPING rate of a shock is controlled by oil and valves - completely unrelated to the compression mechanism (overly simplified, but I'm just trying to make a point).

 

Although most of Rick's comments are in line with my thinking, I still maintain that the air in the forks and the rear shock primarily serves to change the spring rate (firmness) and any change in height of the bike is an incidental change, just as changing the preload on a rear spring will raise the rear of a bike until an appropriate weight (rider's butt) is added to the seat to push it back down. My point here is that ANY change in the spring rate of a bike, no matter if it is by air or preload or something else, is intended to appropriately change the suspension characteristics of the bike and match the load weight and riding style. This is MAINTAINING the correct design height of the bike, NOT raising or lowering it. I liked Rick's reference to the auto "load levelers". These are correctly named, as the design is to MAINTAIN the correct height of the vehicle despite changing loads, not change the height of the vehicle. Other than that, their function is quite different than the air in a motorcycle shock, as those big land yachts are not designed to change the suspension rate and handling performance.

 

I think I'll stop here, but I could go on and on . . . You see, this is why this discussion would be so much better around a table after a great day of riding . . .

Goose