Old GS handling limitations

[glib]

Agreed....front axle travel is linear to the shock...rear travel is not since the rear shock(s) are in a lever relationship and not linear....think fulcrum point(s).

So sag in front could be measured with vertical travel if the recommended range was vertical, but it's typically fork travel that is being measured whereas in the rear it's vertical. Feels a bit like useless regurgitation but that's how I absorb this stuff. I am constantly amazed at how much engineering goes into a motorcycle and it's fun to think how little I knew just four years ago before getting mentored on this forum.

Agreed....front axle travel is linear to the shock...rear travel is not since the rear shock(s) are in a lever relationship and not linear....think fulcrum point(s).

Ok...there would be the incidence angle of the front fork. While the axle does travel inline with the fork, it does not travel at the same angle as the up/down travel of the bike....ok, I guess I see why using suspension travel specs as opposed to actual shock travel...

Agreed....front axle travel is linear to the shock...rear travel is not since the rear shock(s) are in a lever relationship and not linear....think fulcrum point(s).

[glib]

I've gotta ask.....it was mentioned here that measuring suspension travel was the ticket to setting sag, front and rear. On the rear, where the swing arm can yield 5" of travel but the shocks are an actual 3" of travel, is the more accurate way of checking rear travel sag "on" the shocks, or by measuring suspension travel?
I was taught the old school way of a zip tie on the fork tube or the rear shock shaft....measure the free travel spec on the shock unweighted, note the amount of movement once a load is placed(rider...riders) and see the difference.

I had an exchange with Rich Desmond starting at post 35 in this thread that I believe relates to your question. I had assumed that the relationship between the movement of the shock was proportional to the axle travel--but it's not (talking about the rear here). Due to the forward angle of the shock, the axle moves MORE in relation to the shock as the two move up. Rich suggested my math was off and sent me back to my yellow pad. (It was my geometry that was off, by the way ). In the rear, measure the sag by axle travel--or at least vertical movement from a consistent point. But the shock shaft measurement would not give the same result. In the front, the zip tie on the fork tube should work because the front axle is moving at the same angle as the fork.

I've gotta ask.....it was mentioned here that measuring suspension travel was the ticket to setting sag, front and rear. On the rear, where the swing arm can yield 5" of travel but the shocks are an actual 3" of travel, is the more accurate way of checking rear travel sag "on" the shocks, or by measuring suspension travel?
I was taught the old school way of a zip tie on the fork tube or the rear shock shaft....measure the free travel spec on the shock unweighted, note the amount of movement once a load is placed(rider...riders) and see the difference.

[glib]

Back on post #33 in this thread, I mentioned that I had broken a spring retainer on one of my Ohlins shocks:

"I broke the spring retainer on one of my Ohlins. I ordered it from the only place I could find it which is in the UK so it'll be at least two weeks before I get them back on the bike."

Fortunately I had just rebuilt my Works Performance shocks so I installed them. However, I wanted to take the opportunity to compliment the supplier of the new spring retainer. Sadly, the first order was lost in the mail somewhere between the UK and my address. The seller, Ben, owner of Classic and Vintage Suspension, contacted me immediately upon getting my message requesting status. He offered to cancel the sale, (it was through Ebay), and ship another spring retainer if it didn't arrive in a time frame that satisfied me. Having already installed my Works shocks, I had the luxury of waiting and didn't want Ben to incur unnecessary costs so we waited to see if the package would arrive. Ben contacted me regularly--even from his vacation to this side of the pond--to make sure I was ok with waiting and continued to offer a refund. I could tell he is an honorable guy and we agreed to wait a bit longer. A week ago Ben messaged that he would refund my money and send me a replacement NO charge--and to just make a charitable contribution of my choosing for the value of the sale. I received the package yesterday and installed the spring retainer this morning (the clean one on the right in the picture).

So please consider Ben Penny at www.classicandvintagesuspension.co.uk to be a reliable and honorable resource.

Ohlins w new spring retainer by Gary L, on Flickr

[glib]

You also have to remember that, since time immemorial, Suzuki has generously provided employment as test riders for retired horse racing jockeys and anorexic ballerinas.

Thanks to the sensitive derrieres of these brave flyweights, some Suzuki motorcycles have arrived on these shores sagging through 2/3 of their suspension travel under the weight of the bike alone, with no rider, fuel, or luggage aboard, and to this very day, almost all arrive sadly undersprung.

Anyway, the tire pressure recommendations on vintage Suzukis were based on... well, no one knows exactly. But the pressures in the manuals and on the frame stickers are extremely low, especially with modern tires. Even back in the day, as mentioned earlier, corn-fed American (and wurst-fed European) journalists had to increase the tire pressures to get reasonable handling.

The "10% rise" test Steve mentioned is a great way to sort out the best pressures for your riding and your tires.


Tangential rant: Car manufacturers do the same thing too -- in order to make their cars feel cushy and smooth, the tire pressures on the door jamb stickers are often ridiculously low. It's less common nowadays since mileage is such an overriding concern. If you remember the Firestone tire/Ford Explorer debacle a while back, one root cause of the failure was that the factory tire pressure was something ridiculous like 28psi so the truck wouldn't ride like, y'know, a truck. After just a few months of the usual complete neglect, the tires would be down to 23-24psi or worse. Combine that with Firestone's nonexistent quality control at the time and you had a recipe for overheating, delamination, and blowouts.

Many times I’ve thought that Japanese engineers designed cars to be worked on by tiny-handed mechanics. Maybe the same bunch are your test riders.

When I moved up to 34 rear and 32 front on the GS the bike handled much better than it had before.

[bwringer]

You also have to remember that, since time immemorial, Suzuki has generously provided employment as test riders for retired horse racing jockeys and anorexic ballerinas.

Thanks to the sensitive derrieres of these brave flyweights, some Suzuki motorcycles have arrived on these shores sagging through 2/3 of their suspension travel under the weight of the bike alone, with no rider, fuel, or luggage aboard, and to this very day, almost all arrive sadly undersprung.

Anyway, the tire pressure recommendations on vintage Suzukis were based on... well, no one knows exactly. But the pressures in the manuals and on the frame stickers are extremely low, especially with modern tires. Even back in the day, as mentioned earlier, corn-fed American (and wurst-fed European) journalists had to increase the tire pressures to get reasonable handling.

The "10% rise" test Steve mentioned is a great way to sort out the best pressures for your riding and your tires.


Tangential rant: Car manufacturers do the same thing too -- in order to make their cars feel cushy and smooth, the tire pressures on the door jamb stickers are often ridiculously low. It's less common nowadays since mileage is such an overriding concern. If you remember the Firestone tire/Ford Explorer debacle a while back, one root cause of the failure was that the factory tire pressure was something ridiculous like 28psi so the truck wouldn't ride like, y'know, a truck. After just a few months of the usual complete neglect, the tires would be down to 23-24psi or worse. Combine that with Firestone's nonexistent quality control at the time and you had a recipe for overheating, delamination, and blowouts.

[glib]

Evidently you still have your setting on the forum defaults, which are VERY hard to read.

- Click on the "Forum" button in the upper left corner.
- Click on the "Forum Actions" tab, then the "General Settings" option.
- Scroll down a bit to the blue line that says "Thread Display Options"
- In the "Thread Display Mode:" option, select "Linear - Oldest First"
- In the "Number of Posts to Show per Page" option, select "Show 40 Posts per Page"
- Scroll down to the bottom, select "Save Changes"

You can now read threads as they happen, not jumping all over the place, and witn 40 posts showing on each page, there is a LOT less page-flipping when reading longer threads. This is only a drawback if you have a slower internet connection that might take a while to load longer threads, especially if they include a lot of pictures.

.

I see what you mean. I got used to the order but the 40 posts per page is especially helpful.

[Steve]

Steve went into some detail just down the page ...

Evidently you still have your setting on the forum defaults, which are VERY hard to read.

- Click on the "Forum" button in the upper left corner.
- Click on the "Forum Actions" tab, then the "General Settings" option.
- Scroll down a bit to the blue line that says "Thread Display Options"
- In the "Thread Display Mode:" option, select "Linear - Oldest First"
- In the "Number of Posts to Show per Page" option, select "Show 40 Posts per Page"
- Scroll down to the bottom, select "Save Changes"

You can now read threads as they happen, not jumping all over the place, and witn 40 posts showing on each page, there is a LOT less page-flipping when reading longer threads. This is only a drawback if you have a slower internet connection that might take a while to load longer threads, especially if they include a lot of pictures.

.

[glib]

One thing I haven't seen mentioned here is tire pressure. Back when these bikes were new, the magazine testers would complain of wiggling in the rear end that would clear up like magic when the tires were pumped up just 3 or 4 psi. Certainly worth thinking about.

Steve went into some detail just down the page but it is good to know that pressure was an issue even from the factory. I did think that the factory tire pressure recommendations seemed low.

[zuluwiz]

One thing I haven't seen mentioned here is tire pressure. Back when these bikes were new, the magazine testers would complain of wiggling in the rear end that would clear up like magic when the tires were pumped up just 3 or 4 psi. Certainly worth thinking about.

[glib]

Woo hoo! Nice ride yesterday. The setup adjustments, Works Shocks, and fork brace really impressed me. Sadly, there were wet spots and gravel on Hwy 26 that made for a tense ride in places and my new front tire has now arrived so that will be my last ride on this one. Fun season comin up!

[glib]

I dont want to minimize the importance of tire pressure but it did nothing for me trying to sort out a high speed weave. At 80 + mph it feels like the frame is hinged and moves back and forth. Very un-nerving. One of the many attempts to "fix" it was brand new tires. Nope. Same weave. and then multiple combinations of tire pressures, front and rear, cold and warm, from 28-48psi. Made no difference.

I did fix the weave though......set the tires at 35 cold (they go to 39 warm) and don't go over 80 !




I have that fork brace on mine. Didn't like the crossover piece cause even with the 4 bolts as tight as I dared get them it still seemed to flex. So I cut a new one at work. Yes, I stole the Yosh symbol.

Fast fwd to the 4:00 mark....

OMG I want to play with that cutter! I mean I want to safely use it for it's intended purpose.

Nice result! I had to file my crossover piece to get it tight.