Front end 'liveliness'

[Joe Garfield]

Yeah, I noticed with the new rear shocks, the back end sits up higher and the bike handles different. Hopefully I'll get used to that - it feels nice and has much more control on elevation changes, but I feel like I lost a little confidence in cornering (leaning). With the Sonic springs and stock shocks I was getting into a pretty good lean in corners (for me at least).

I'll play around with oil volume, then oil weight, and will probably resort to emulators once the number of 'pressing' projects settles down. If anything I'll at least get some first-hand experience with what changing each of these variables does. Or maybe I'll find something that feels 'good enough' - (which admittedly doesn't happen to me very often).

[mmattockx]

Increased preload shortens the rake and trail, making the bike tip in easier.

If we are still talking about forks you have that exactly backwards. Increased preload raises the front end, increasing rake and trail. While all set up on these old bikes is a compromise because of the lack of adjustments, you should be setting sag according to what I said and then altering ride height/chassis attitude by sliding the forks up (or down) in the triples if possible.


Mark

[RichDesmond]

If we are still talking about forks you have that exactly backwards. Increased preload raises the front end, increasing rake and trail. While all set up on these old bikes is a compromise because of the lack of adjustments, you should be setting sag according to what I said and then altering ride height/chassis attitude by sliding the forks up (or down) in the triples if possible.


Mark

Exactly. Using sag to adjust geometry isn't the way to do things, if it can possibly be avoided.

[Dogma]

If we are still talking about forks you have that exactly backwards. Increased preload raises the front end, increasing rake and trail. While all set up on these old bikes is a compromise because of the lack of adjustments, you should be setting sag according to what I said and then altering ride height/chassis attitude by sliding the forks up (or down) in the triples if possible.


Mark

Oops. Thanks for catching that.

Exactly. Using sag to adjust geometry isn't the way to do things, if it can possibly be avoided.

If possible. We can't normally slide them much farther out. I forgot to mention moving the forks in the triples when I tried to list all the variables available. Probably because I've never done that to make an adjustment. But it should be a moot point. With the recommended sag, handling on a big GS shafty will be very close to neutral already.

But I see your point about using sag to adjust geometry. It's best not to monkey with suspension travel to fix something else if you don't have to. I started that waaay back when I had the stock springs in my 850 and was trying to use air pressure to control preload, the way it was done back when these things were new. It was sluggish with no pressure, and fell into corners with too much. It could only hold air for a few days, so I learned to use the spacer to set preload and find neutral handling. I don't think I even knew why it worked back then, but I never shook the bad habit. So, thanks for the correction.

[Joe Garfield]

It's interesting how people say raising the back makes the bike turn faster. I just replaced the stock rear shocks with Hagons, so the rear sits up a bit higher due to the stiffer springs. It seems to me like it makes it harder to get into a lean, but hopefully it's just me getting used to the handling characteristics again.

I will check my preload/sag this weekend - I'm curious to see where it sits. Hopefully I'll get the 10wt oil in there as well and report on my findings.

It seems to me like a cartridge emulator is almost a no-brainer, but I'm curious to see how far I can go with the stock setup before making technology changes (I like to get a feel for how things are before making changes, to get a better sense of what the changes really do or how much improvement there really is).

[mmattockx]

It's interesting how people say raising the back makes the bike turn faster. I just replaced the stock rear shocks with Hagons, so the rear sits up a bit higher due to the stiffer springs. It seems to me like it makes it harder to get into a lean, but hopefully it's just me getting used to the handling characteristics again.

Raising the back makes the rake steeper and reduces trail, both of which should provide lighter, faster steering. How much is a 'bit' higher? If it is only 1/4" or something you won't notice it. I have longer than stock shocks on my 1100E, close to an inch longer. They very noticeably changed the steering as I described, making it both lighter and faster. What you are really doing when you jack the back up (or lower the front by sliding the forks up in the triple clamps) is reducing the stability. On these bikes that isn't much of an issue for the most part, because they have steering geometry more suited to a locomotive than a motorcycle. Stability is not normally lacking, so giving some away isn't a problem. Someday I am going to get bored and drop the front 1/4"-3/8" just to to see what that does for the handling when combined with the longer shocks.


Mark

[glib]

Raising the back makes the rake steeper and reduces trail, both of which should provide lighter, faster steering. How much is a 'bit' higher? If it is only 1/4" or something you won't notice it. I have longer than stock shocks on my 1100E, close to an inch longer. They very noticeably changed the steering as I described, making it both lighter and faster. What you are really doing when you jack the back up (or lower the front by sliding the forks up in the triple clamps) is reducing the stability. On these bikes that isn't much of an issue for the most part, because they have steering geometry more suited to a locomotive than a motorcycle. Stability is not normally lacking, so giving some away isn't a problem. Someday I am going to get bored and drop the front 1/4"-3/8" just to to see what that does for the handling when combined with the longer shocks.

Mark

PO on one of my bikes (83 1100E) dropped the front 1 1/2." I don't know if he cut the springs down or what. It was even lower via sliding the forks up as high as they could go but the V&H exhaust hit the ground leaning in right turns. This is a great thread. Learning a lot here.

[Joe Garfield]

... oops ...

[Grimly]

Someday I am going to get bored and drop the front 1/4"-3/8" just to to see what that does for the handling when combined with the longer shocks.


Mark

I've been running GS1000 forks on my 80 850 for the past seven months or so. They're ~19mm shorter than the OEMs. Sharpened up the front nicely, and compensates for the weight of the Vetter. Using a set of what appeared to be (anonymous) aftermarket springs that were in another set of GS1000 forks I bought for the sliders, it's all a bit of a mix'nmatch, but it works. Rear is a pair of ex-HD Showa air shocks, set at around 20psi. The whole plot hustles around the bends and bumpy backroad here quite well, but the GSs always did belie their weight once on the move.