Lowering GSX-S 750 - Suzuki GSXS1000 Forum
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post #1 of 10 Old 02-08-2019, 07:22 PM Thread Starter
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Lowering GSX-S 750

Has anyone here lowered a GSX-S 750. I've asked Lust about their lowering links. They have both 25mm and 40mm lowering links but suggest lowering the front only 12mm . I've always been under the impression that the front and back should be lowered equally so handling is not negatively effected.
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post #2 of 10 Old 02-08-2019, 09:57 PM
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Has anyone here lowered a GSX-S 750. I've asked Lust about their lowering links. They have both 25mm and 40mm lowering links but suggest lowering the front only 12mm . I've always been under the impression that the front and back should be lowered equally so handling is not negatively effected.
You can lower the front more or less than the rear but it will affect the handling dramatically

Lowering the front more than the rear - quicker turn in, sharper more twitchy steering , less stable

Lowering the rear more, slower turn in and steering, more stable (unless you go to far of course)

BUT You can't lower the front more than a few mm with the stock bars on the 750 as the forks hit the bars when you lower the top triple tree after a few (maybe 10) mm
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post #3 of 10 Old 02-08-2019, 10:12 PM Thread Starter
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Right. The fork shapes suggest I could move them up almost 25mm. But the distance between the top of the fork adjusters and the bars tell me something different.

Also, I am aware of lowering the front vs the back but I've never lowered the rear moreso than the front. I wouldn't want to compromise turn-in or loose front end feel.

That is why the response I got from Lust Racing, suggesting that installing lowering links to reduce height by 25mm was offset by raising the forks 12mm had no effect on handling, puzzled me.
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post #4 of 10 Old 02-08-2019, 11:04 PM
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Hi Greeg,
As I remember my 750 test ride experience, I found it very necessary to take the rear shock spring setting down a notch down from 3 to 2 position. This lowers the rear of the bike to make it more level as I found very quickly that standard is set too firm.
I was around a fat 90 KG then, so that may help you.. The bike rode a lot better, and I don't know why Suzi at least in Australian delivery chose that firm setting as it made the seat lean forward at an uncomfortable angle, and upset the rear turn in dramatically exaggerating the turn in on cornering, making the bike very poor to ride, the rear rock hard, and unsafe.

Rob.

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post #5 of 10 Old 02-09-2019, 12:07 AM
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Hi Greeg,
As I remember my 750 test ride experience, I found it very necessary to take the rear shock spring setting down a notch down from 3 to 2 position. This lowers the rear of the bike to make it more level as I found very quickly it from standard set to firm.
I was around a fat 90 KG then, so that may help. The bike rode a lot better, and I don't know why Suzi at least in Australian delivery chose that firm setting as it made the seat lean forward at an uncomfortable angle, and upset the rear turn in dramatically exaggerating the turn in on cornering, making the bike very poor to ride, the rear rock hard, and unsafe.

Rob.
I've set the sag or preload on a few 750s now with riders from 60 to 110KG and they all needed less preload at the rear
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post #6 of 10 Old 02-10-2019, 09:24 PM Thread Starter
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Rob: besides the reduced harshness, did you get a sense the bike was turning in more slowly after the preload was reduced?

Paul: Mine is very stiff in factory set rear preload. I'm like 65kg and I'll have to weigh-up with my gear before I go about sag set.

But what I'm really curious about is: Is the 750 geometry flawed from the factory, so much that they are delivering the bikes with rear preload jacked up to offset a low fork position and the resulting rake and trail?

Would that explain why a seller like Lust Racing is selling lowering links that reduce rear height 25mm or 40mm but tell me I only need to drop the front 12mm?
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post #7 of 10 Old 02-10-2019, 09:38 PM
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Rob: besides the reduced harshness, did you get a sense the bike was turning in more slowly after the preload was reduced?

Paul: Mine is very stiff in factory set rear preload. I'm like 65kg and I'll have to weigh-up with my gear before I go about sag set.

But what I'm really curious about is: Is the 750 geometry flawed from the factory, so much that they are delivering the bikes with rear preload jacked up to offset a low fork position and the resulting rake and trail?

Would that explain why a seller like Lust Racing is selling lowering links that reduce rear height 25mm or 40mm but tell me I only need to drop the front 12mm?
I don't think there is anything particularly wrong with the geometry, I think the 750 feel pretty good for what is pretty basic suspension - I have a feeling that most bikes come from the factory with too much preload as they feel firmer and sportier on a quick test drive than a bike with too little preload - I think the extra preload helps to mask the lack of damping as there is less movement of the suspension.

Of the 750's I have set up all have had to have less preload front and rear but we only lowered 1 of them at the front (as the rider was only 5'3" and couldn't touch the ground) and they all handle nicely now.

I think i have reduced preload on around 90% of bikes I have setup.
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post #8 of 10 Old 02-10-2019, 10:38 PM Thread Starter
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Excellent point about the use of excessive preload to mask limitations in compression and rebound capability.

Depending upon the sag adjustment, I may raise the forks as an offset prior to use of any lowering links. The three people that will be using this bike primarily are all 150lb/69kg or less.

Thanks
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post #9 of 10 Old 02-11-2019, 02:32 AM
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Rob: besides the reduced harshness, did you get a sense the bike was turning in more slowly after the preload was reduced? <snipped>
Hi Greeg,
The best answer is can give is that the front was after adjustment, now it's had accurate handling alignment with the rear. Sag was not measured for demo ride of course, but the seat of the pants meter said OK'. Meaning, through a curve it was neutral on acceleration or braking.
That's what is wanted by me, you don't want either end trying to pass the other in a curve, do you?

This 750 is the first Suzuki bike that I have ridden that needed less rear preload. Normally the front is quite stiff enough for me, and if I increase the rear preload up a notch, the ride handling over bumps and cornering feels great, gets too touchy.
In this, I mean I have to concentrate all the time, as it will steer very quickly - blink and your off the road quick.
A half a notch up on the rear is what was wanted most times and I would dismantle the rear shock and add shim's.

To increase stock fork preload to match the overfirm rear, may work for some, but not in your suggest weight range unless track days are your want.
An over adjusted front preload can be dangerous when braking hard downhill on a curve with soft OEM springs, the front tends to wash out unexpectedly like in MOTOGP. Good one minute, wrecked the next.

Just go down a notch on the rear and you will have a good bike.

People here around 65KG had said the 1000 has far too firm a front end and a softer rear, so Suzuki gave you the opposite; so you won't get the problem of the EFI 'snatchy throttle' experience over bumps. Swings and balances, heh?

Rob.
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post #10 of 10 Old 02-11-2019, 01:11 PM Thread Starter
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Thanks Rob. Excellent points. I have certainly experienced bikes with way too much front preload for my weight and I'd rather avoid that. Once it warms up - some simple, mindful setup and all should be well.

Swings and balances. For every action..........
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