[ozpoker]

Hi all,

I have a 1999 Suzuki rf 900R, and I'd love to lower it, as its a high centre of gravity, and I aint tall.
I have bought links for the back and it seems straight forward enough, but I don't think I can lower the front, there is cowls on the handle bars that will stop the forks coming up.

Any one out there ever done one?

Cheers

 

[Unkle Krusty]

On my triumph, I backed of the pre-load on the rear shock, and lowered the front forks. I also took about one inch of foam from the forward part of the seat. I also lowered the forks on my Suzuki and one of the Yamahas. Saying lowered may be confusing, as it is the frame that gets lowered on the forks, and the forks stick up a bit. Usually the forks hit something. I will reread my book on suspension about this. On some bikes like my older Yamaha that has two rear shocks, the shocks can be changed for shorter one. There are a variety of shocks around 12 12.5 and 13 inches.
Keep in mind tho, when you lower the frame, it makes it harder to lift the bike on the center stand. On my Triumph I shortened the legs on the center stand. Sometimes altering the seat, can be the easiest way to get your feet closer to the ground.

UK

 

[hogcowboy]

Hi all,

I have a 1999 Suzuki rf 900R, and I'd love to lower it, as its a high centre of gravity, and I aint tall.
I have bought links for the back and it seems straight forward enough, but I don't think I can lower the front, there is cowls on the handle bars that will stop the forks coming up.

Any one out there ever done one?

Cheers

How much do you think you might want to lower it? If only an inch you might be okay with foam removed or different foam. Changing wheels can get you a little closer to the ground as well. As UK says, there are several other options.

 

[WintrSol]

Have a look under the body work, to see how much clearance you may have between the fork tops and plastic parts. Just 1/2" to 3/4" can make a big difference in the feel at a stop sign.

Keep in mind tho, when you lower the frame, it makes it harder to lift the bike on the center stand. On my Triumph I shortened the legs on the center stand. Sometimes altering the seat, can be the easiest way to get your feet closer to the ground.

Note that it also will make the bike more vertical when on the side stand, so you have to be careful to not let it tip over if you park on the side of a hill. I lowered my CB450 ~3/4" with shorter shocks and moving the forks up a like amount. To use the center stand, I use a 2" thick board with a mini-ramp under the rear wheel, with a small bump stop at the front to keep it from rolling off. Useful only at home, of course.

 

[Eagle Six]

I have a 1999 Suzuki rf 900R, and I'd love to lower it, as its a high centre of gravity, and I aint tall.
I have bought links for the back and it seems straight forward enough, but I don't think I can lower the front, there is cowls on the handle bars that will stop the forks coming up.

Hi oz, and Welcome,

I have never had a 1999 Suzuki rf 900R so I'm not familiar with this bike. However I did look it up online and it appears to be a typical sportbike type with fixed front fairings and therefore should be no way they are attached to the forks or triple tree that holds the forks. Of course, as others have pointed out there will still be a limit to how far you can raise or lower the forks in the triple tree before it starts to interfere with the fairings or some other parts. Assuming they are still set at the factory height that could be less than an inch or more than an inch.

In theory if you lower the rear 1" and the front 1", the original level designed for the bike would then be the same. In application, that is not exactly correct, but if you don't change it much (less than an inch), it might not matter to you depending on your riding style and experience level. Regardless, I suggest to proceed with caution.

We don't know your experience and/or knowledge level, but if you new to riding, and you happen to have a high performance bike shop in your area, if it were me that is where I would start. Any race shop is going to be familiar with your Suzuki and they can offer not only a quote but a recommendation and wealth of advice. Also we don't know how much the dog bones you have will lower the rear. Regardless of how much in the rear and/or the front, you are going to also reduce the ground clearance, something to consider!

I have adjusted the height of many bikes through the years. When I was young I wanted to be flat footed, and most bikes I have owned that is impossible for me. Instead of learning how to ride and handle a bike with the height I have I kept trying to modify bikes to fit, some of them came close but none of the adjustment were perfect and some I completely ruined the stability of the bike design. So, for me it was a matter of learning how to deal with a bike that had a long leg reach for my short legs. Again, as others have stated, there are various you can employ, including adding a bit of thickness to the soles and heels of your riding boots.

Your bike is 20 years old and if the shock and forks haven't been serviced for a while (or maybe never), I would start there. If you don't have the tools or the shop along with the expertise to do it yourself, maybe a nearby shop can assist you. Fork and shock oils are good for about 12,000 miles. The forks should be serviceable, the rear shock may not be, in which case should be replaced. It may also be time to replaces the fork seals and whippers while replacing the fork oil. Maybe I'm offering advise you didn't ask for and do not need, if so please ignore my post.

I will offer one more caution on adjusting the fork height. If you raise the triple tree (lowering the forks) (opposite of your question), without changing the rear height, you will increase the rake and trail. This will reduce the turn-in speed (that you will notice) and may add some straight line stability (most likely you will not notice). If you lower the triple tree (raising the forks) this will lower the front end and reduce the rake and trail. If you do this without lowering the rear (about an equal amount) you will increase the turn-in speed and reduce the straight line stability (and you will notice both!). Some bikes you can get away with doing this by a 1/2 inch or so and they like it. Other bikes are super sensitive to even small 2-3 mm changes and this can wreck havoc with the stability to the point they are not fun to ride and maybe even unsafe to ride.

Whenever I make changes to the fork height I proceed with caution, taking and keeping measurements, so if what I do makes things worse, I can then return things back to the starting point. With some of the older bikes (like yours) there are some real advantages to changing things sometimes on some of them (again, I'm not directly familiar with your model). On the newer (later model) high performance bikes, the designers have pretty much set the bikes up for optimum street performance and little is gained by changing things. I think I've said more than I should have and a lot more than you asked for or need. Good Luck with your project.

 

[WintrSol]

One issue not mentioned is, if you lower the front, the fender will be that much closer to everything above it. You don't want it bashing the underside of the headlamp housing, for example, when it reaches maximum compression. Something to ask about if you get the forks serviced.

 

[SemiFast]

Good post George. Lots of useful information there.
One other thing to think about is that if you lower both the front and rear the same amount then you have shortened the wheelbase. Doing so will alter the factory designed geometry of the vehicle and its weight distribution. A lot of riders have lowered their bikes with no ill effects that they can detect, but it will change things at least a little.
I would proceed with caution by first lowering the front a little less than what you lower the rear. Then go out and do some corners while trying to detect any odd twitches or quirks that were not present in stock form. If all is good, lower the front a little more then go at it again.
It's probably been around 10 ~ 15 years or so since I've even seen a 1999 RF900R so I don't know what parts might interfere with sliding the forks up some in the top tree. What are you seeing that is in the way?

S F