Budget Front Suspension Mod

[Nessism]

Didn't feel like springing $80 for Progressive springs on my 750ES, so took the cheaper route.

Used cut off wheel and hacked off 2" from the stock springs. Made PVC spacer to make up for lost stack height. Dressed down the end of the coil to flatten it down.

750ES is not overly soft with the stock springs, unlike the 850's, so going to try at 2" and cut more after playing with it some. I've done this mod on quite a few bikes over the years and it really works to stiffen up the front end. Saves a bunch of money on springs too.

[hampshirehog]

Any reason why you decided to cut the more tightly wound end rather than the other?

[Nessism]

The tightly spaced coils are the soft ones, they also face up inside the forks.

[Mark M]

Nessism,

Just make sure that you don't cut so much that the springs will coil bind at full bump. If they bind, you will have a super harsh bottoming and it will upset the bike quite a bit. Usually under hard braking or other situation where you need everything you have.

Also keep track of the spring free length because you can shorten the spring to the point where the stresses in the material are beyond the yield strength and the spring will begin to pack down and lose free length. At that point, the spring is toast and needs to be replaced.

Mark

[Agemax]

why cut off part of the springs? just add a spacer to compress the springs more to start with. i have katana forks with an adjuster on the top of the forks which is basically a spacer on top of the springs which you can adjust, just like adding different thickness spacers. then you can adjust it to suit your needs.
the katana forks are the same size as the gs forks so just buy the katana fork tops!
instant fork preload adjustment :-)

[Nessism]

Yea Mark,

Thanks for the warning. On bikes with super soft springs, like the 850, a lot of coils would have to be removed to get them firmed up to where no air was required. Not sure but coil bind could become an issue on a bike like that. On most normal bikes, l don't think there would be a real concern unless one were to cut out more than 5" of coils or so.

Regarding adding more preload, this increases ride height but does not increase spring rate. Adjust ride height to get the proper amount of sag. Stiffen the springs if you want a more firm suspension.

[Agemax]

Yea Mark,

Thanks for the warning. On bikes with super soft springs, like the 850, a lot of coils would have to be removed to get them firmed up to where no air was required. Not sure but coil bind could become an issue on a bike like that. On most normal bikes, l don't think there would be a real concern unless one were to cut out more than 5" of coils or so.

Regarding adding more preload, this increases ride height but does not increase spring rate. Adjust ride height to get the proper amount of sag. Stiffen the springs if you want a more firm suspension.

ok so it may increase the ride height slightly but it does put more pressure on the springs, hence why its called preload, cuz you are preloading the pressure on the springs. same as adding a spacer, so whack the preload on max and drop the forks in the trees by a couple of mm.

[Nessism]

Preload is so you get the SAG where it needs to be, not to stiffen up the ride.

[Agemax]

Preload is so you get the SAG where it needs to be, not to stiffen up the ride.

ok i see what your saying but why would they fit preload adjusters to brand new bikes then? and why do all modern bikes have preload adjustment on rear shocks,they cant have sag on new suspension!

[Nessism]

ok i see what your saying but why would they fit preload adjusters to brand new bikes then? and why do all modern bikes have preload adjustment on rear shocks,they cant have sag on new suspension!

All suspensions have sag, it's a tuning factor when setting up the suspension.

To do it properly you need to sit on the bike and measure how much the suspension is compressing while the bike is stationary. I'm not an expert but you want something like 25% of the suspension to be compressed in the static condition. This leaves 75% for road input related suspension action in compression and a small amount of extension available so the suspension doesn't top out when you unload the suspension such as when cresting a ridge at speed.

If you want more information on how to set sag I can search around and give you a link. Of course, you can do a search yourself - lots of information from members here - find Steve and send him a PM.

[Old Colt]

He is thinking of SAG as an age related lowering of the bike, not the designed amount it sets at ride height.

On most springs I cut I warm the cut coil so you can close it prior to grinding the face. Seems to let them sit flat like they did originally.

[Mark M]

ok i see what your saying but why would they fit preload adjusters to brand new bikes then? and why do all modern bikes have preload adjustment on rear shocks,they cant have sag on new suspension!

Preload adjusters are used to set ride height, as Nessism said.

Sag as we are calling it is the amount the bike settles on the springs due to it's own weight and the weight of the rider. Static sag is the sag due to bike weight alone and laden sag is the sag with the rider onboard. You typically want the laden sag to be around 25% of total suspension travel, as Nessism said. You measure sag by measuring the full suspension extension, then measuring how much travel is used up by the bike weight and then with the rider on board.

To get things really correct, you need the right spring rate for the combined bike and rider weight and the correct amount of preload to set the sag in the desired range. On our bikes, with their skinny forks, it is hard to get a stiff enough spring for the all up weight due to the dimensional limits on the size of the springs. Even the Progressives and Race Tech springs are on the soft side by current standards. This leads to using excessive amounts of preload, which makes the forks harsh over small bumps and easy to bottom over big bumps. We also have the handicap of a primitive damper rod damping system in the forks, which forces compromises between ride comfort and control.

Mark

[Agemax]

i get what you are saying now guys, sorry. just a mix up on intercontinental language interpretations. so you mean sag is how much the suspension drops when you jump on the bike, i thought you meant compensating for wear and tear and age by adding spacers etc. sorry,
i wish you westerners would speak proper english haha

[hampshirehog]

i wish you westerners would speak proper english haha

Yeah, I first thought when they started mentioning sag they were on about what happens to a lady at a certain age

At least they ain't Ozzies or Kiwis

[Old Colt]

i wish you westerners would speak proper english

When I was back there in school some 40 years ago the said they were techin me English. Seems to me it's not English, at least the French said so when I was over there. The boys down under say I'm speakin Murican.