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The Making of a GSMAX-R
2001/8/20 12:00
From Mount Airy
Posts: 466
Level : 19; EXP : 97
HP : 0 / 474
MP : 155 / 29533
Forks wobbly? Rear shocks flabby? Does your baby do the bounce and shutter when you hit bumps in a corner') Friends on sportbikes leaving you for dead') Well we're gonna fix all that! One of the first things that many of us want to change about Mr Max is the lack of handling and poor suspension performance. The source of these problems is the antiquated front fork design, chopperesque steering head angle, and the pogo stick rear shocks. [n addition the wimpy 40mm forks on pre-93 maxes are subject to all sorts of flexing and carrying on. Overly soft front springs don't help things any more than that measly excuse for a fork brace. Let's start with the front end. The forks on the Vmax are traditional damping rod style and have many disadvantages over a modern cartridge fork. [n a damping rod fork the fluid is forced back and forth thru fixed sized holes in the damping rod. The disadvantage to this is that there is only one speed at which the fluid can travel thru these holes. If we attempt to go to thicker fluid in order to increase the damping effect of the forks over small dips and normal bumps (low speed damping) then we run. Into problems when the fork suddenly hits a sharp or square edge bump (high speed damping). What happens is that the fork needs to compress more quickly than the fluid can travel thru the holes. The jolt is transferred thru the suspension to you, the rider, and you don't like it very much. The rebound damping is also linked to the fluid viscosity. Therefore we are unable to change the speed at which the fork returns to its original position without affecting the compression damping as well. It was Hi-tech in 1968 but not now.

The slow heavy feel of the steering is caused by the fact that the steering head kicks out much further than on a quick handling sport bike. The more angle (Rake) that a bike has, the slower it will steer. You can feel the handlebars wobbling around in a turn and at low speeds because the forks are unable to deal with the weight and power of Mr Max and tend to flex and twist around on you. The cheap cast factory fork brace does nothing to help this problem. The Front fork springs are way too soft and allow the front end to dive under braking just in time to upset the steering geometry as you are about to tum. And then there is the dreaded wobble and headshake problem! Hidden in wait to spit you off at 120 plus when you least expect it! I think the rear shocks were used on Japanese pogo sticks and Yamaha bought them in mass and bolted them to Mr Max They are too stiff and at the same time have poor damping characteristics which allow the chassis to shake and carry on at the worst possible time.

All these are things I wanted to improve on my bike without spending the national debt in order to do it. Fortunately the aftermarket has come to our rescue. RaceTech Industries manufactures a product called the Gold Valve Emulator. This product fits inside your fork tubes and makes your old damping rod fork work like a modern cartridge fork. In order to make it work you drill the compression holes on your old damping rod out so that they are no longer effective as a damping tool. All the fluid is now forced to travel thru the emulator as the fork compresses. The emulator is spring loaded and has two ways for the fluid to get thru. The first way a very small hole that the fluid travels thru on those low speed impacts. When you hit a square edge or large bump however and the fluid tries to push them all at once, the spring is forced open, the fluid takes the route thru the larger hole, and like magic the impact is absorbed! Because the emulator is adjustable you can now tune the rebound damping with fluid viscosity the way you want it, and then dial in the compression damping with the adjustments on the emulator.

We can quicken up the steering on the V-max by changing the angle of the steering head. The way we do this is by lowering the front end upon reassembly. You can purchase a lowering kit from PCW Racing that will shorten the travel of the front end I 3/8". In addition on pre-93 models you can remove the rubber dampers directly below the top triple tree and slide the fork tubes up about 1/4" in their clamps. This lowering will change the angle of the steering head in relation to the ground and fool the Max into thinking it has less rake than it really does. The bike will respond much more quickly to rider input. Another use for this mod is that it will have a substantial anti-wheelie effect. The suspension will reach full extension sooner and it will be more difficult for the bike to lift the front end. In order to get rid of the wobble and fork flex, take off that cheap cast piece of junk holding your fork tubes together and bolt a milled aluminum Superbrace in its lace. When you reassemble the Front end do so using the steering head fix made famous by the infamous John Furbur. Instead of nut, rubber, nut put the two nuts on together and put the rubber under the top triple clamp. Throwaway those sacked out front springs and install a set of stiffer aftermarket front springs. Progressive makes a real nice set of front springs for Mr Max. Don’t worry about the ride as it will ride better than it did before even with the stiffer springs. A word of caution here. Don't forget that you have removed I-3/8" of travel from the front end. You must allow for this and the I Omm of the gold valve emulator when you make up your preload spacer. Use PVC pipe. it works good and it's easy to cut. Now go shock shopping. I used the billet bodied Progressive rear shocks 112" shorter than stock. These have adjustable rebound damping and preload. In addition the damping characteristics are worlds beyond the stockers. I recently performed all of these changes on my 88 Max. I must say that the entire bike is much improved over the stock arrangement. The fork is more supple over small bumps and doesn't stiffen up when hitting a square edged bump. The dive under braking is gone. The steering is much quicker and feels more connected to the road. I can lean the bike further and the wobbly feeling of the stock Max is missing. The bike is positively flickable in switchbacks. At 120 plus the bike is rock solid without a hint of wobble or headshake. And on hard launches the front end stays down where it belongs. All these things have worked together to dramatically change the handling capabilities of my Max. The bike rides better and is more comfortable and controlled in every situation. I can honestly say there have been no negative effects to any of this work.

I recently had the opportunity to ride a stock Max back to back with mine. The difference is nothing short of phenomenal. After a 2 mile ride on my bike the first words out of my buddy's mouth were "Whatever you did to this bike we are going to do to mine! It feels like a sportbike!"
Bring on those GSXR's as I can now scrape hard parts at will in a corner. Next I am going to brace the frame and the swingarm. I will let you know how it goes.
Race Tech emulators $125
Lowering kit $15 Fork Brace $100
Furbur Fix FREE
New Seals ancl Fluid $30
Total $270
Progressive Suspension adjustable rear shocks $350.

Roy & Leslie Richards
VBOOST Volume 1, Issue 3, 1997

Posted on: 2013/10/18 14:08
Be safe out there and enjoy the ride....

Mike Moore
VMOA Webmaster

Re: The Making of a GSMAX-R
Just popping in
2021/10/10 13:59
From Detroit Lakes
Registered Users - Ultimate
Posts: 9
Level : 1; EXP : 86
HP : 0 / 21
MP : 3 / 72
Nice write-up, thank you.

Posted on: 2021/10/10 18:33
1985 V-max bone stock 116 hp.

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