what is ballpark cost to rework OEM suspension?

[SPP]

As shit happens I need a new bike.

This time I want to allow $ for suspension and sprockets upfront since these are the best bang for buck I reckon but easy put off.

What ball park cost should be left aside to rework stock front and rear (road & trackday) - Nothing flash just good re valve, re spring and solid setup on say a '08 GSXR 750 or '08 R6 or maybe even a 675 (not R)

• 1k
• 2K
• 3K
• more

I know of KSS and Dukic but anybody else worth seeing?

PM works too. Thanks.

[SuperSonic]

Hey

About 1 k for front, valve, springs(??) oil etc, rear is up to your wallet really, but I have been quoted 500 ish re work rear, and 1,5k for new shock all from KSS.

But before ya spring for all this and new bike check this out http://www.kiwibiker.co.nz/forums/sh...-to-get-a-spot think about coming along to this and learn some important info that might save ya some moneys and effort.

[SPP]

Yeah, I saw that thread. I’m surprised no Auckland shops are having him in.

If I had a bike I’d be in like a shot… Maybe I’ll try to get to the Bayride session anyway just to listen and learn, his OTT episode on tire wear was REALLY good!

[SuperSonic]

Hey

I tried a few, but did not get far, as they all say they have suspensions gurus all the time!!!!!!!!!!! Not surprised it is AKL/Jaffaland

OTT tyre vid is my most watched show, awesome as. Best part is you can email him pictures , send him some money via paypal and he will read ya tyres too! Next best part he will be here and can do in person. Saweet

Will post/PM dates of Bay motorcycles seminar once we have arranged a date.

[Robert Taylor]

As shit happens I need a new bike.

This time I want to allow $ for suspension and sprockets upfront since these are the best bang for buck I reckon but easy put off.

What ball park cost should be left aside to rework stock front and rear (road & trackday) - Nothing flash just good re valve, re spring and solid setup on say a '08 GSXR 750 or '08 R6 or maybe even a 675 (not R)

• 1k
• 2K
• 3K
• more

I know of KSS and Dukic but anybody else worth seeing?

PM works too. Thanks.

There are no fixed prices as such because there are so many variables with all of these models. If anyone is offering fixed prices then that is disingenuous. First and foremost we need to know your height and weight and what tyres you are using, that determines if you require alternative springs. If the spring rates are fundamentally wrong for you then no amount of messing with spring preload and valving will yield a decent result

I will run through the models;

GSXR600

SHOCK Will likely need respringing, the rebound needle needs careful reprofiling and the piston whilst not the best one on the block is decent enough for revalving. The top shock mount is able to be shimmed to raise the ride height, which the bike responds well to

FRONT FORKS Springing is ok for most average weight riders of everyday ability. The internal BPF pistons are a little restrictive in ultimate flow and will not absorb the abrupt bumps so well. No amount of revalving will fix that as the port sizes ultimately restrict flow. If anyone tells you different make sure they are not wearing sunglasses, hiding their eyes!! If harshness is an issue Race Tech make big port pistons for these forks.


CBR600

SHOCK This shock has the worst piston that is very restrictive of flow and very heavy. Ideally it should be changed, Also its not so easy to change the rear ride height in this bike, some will say make up different length pullrods. Sometimes this works but if not done properly you can create a ''dead zone'' of movement

FRONT FORKS Along with the R6 this bike has decent wall thickness in the fork tubes so they are more rigid under especially braking loads and will not distort out of shape and therefore bind as readily. Cartridges are 20mm, the rebound pistons can be successfully revalved but the restrictive base compression pistons must be replaced. Restrictive pistons cause crashes and we have evidenced this many times. The hydraulic bottoming cones need 80% or so of their function disarming and generally the springs need changing

ZX6R

FRONT FORKS Ditto as per BPF type GSXR600 forks

REAR SHOCK A decent piston inside this shock that can be easily revalved, often the spring needs changing. This shock also has an internal top out spring but its over firm and practically there for show

YZFR6

FRONT FORKS. Same agreeable rigidity as the Honda. In my opinion these are the best forks and have the most potential. We change the rebound /mid valve pistons to ''bending shim stack type'' that deliver much more instantaneous damping response. The base compression pistons we get waterjet cut to increase their port size and we then spend a lot of time setting up the base preload on the external high speed compression adjusters in these forks. If you learn to understand how this works its function and response range is wonderful

REAR SHOCK In my opinion the best 600 cc class shock. It has a great piston that responds well to revalving and the high speed compression adjuster has a great response range, just like the forks. Often requires respringing and you can easily shim up the ride height.

TRIUMPH 675

Dont rule out this bike as it has a great chassis, ergonomics and engine. There are some glaring faults with the suspension but these can be rectified

FRONT FORKS Very short on travel at around 113mm whereas all of the other 600 cc class bikes are in the 120-125mm zone. With an internal mod we can crib another 7-8mm of travel. It has the same old fashioned rebound pistons as the Yamaha and ideally also the base compression pistons should be changed to ones with better edge flow and flow capacity. The hydraulic bottom out engages too early

REAR SHOCK Just like the Ducati 1098 / 1198 and Yamaha R1 the Triumph is burdened by a link ratio curve that is riculously progressive and that problem is exacerbated further by a selected spring rate that is widly aggressive unless you are about 140kgs plus. The trick is to fit a much softer spring with a decent amount of preload. The preload holds the bike up in its stroke so it can do all of its best work in the first 1/3 and most supple part of stroke. But then if it does get deeper into the stroke the spring force curve is a lot shallower so there is a much better chance of nasty bumps being absorbed and keeping the tyre actually gripping the surface!! The internal shock piston is arguably the best of all the bikes but is totally bastardised by a rebound valving stack that is pretty much immovable. On our dyno the rebound damping force curve is over 100% stiffer in force than an Ohlins TTX36 specific to that bike. So using the dyno we revalve it to closely mimic the Ohlins force curve. Our suspension dyno is invaluable for such work as we are not ''flying blind'' and are the only people in the NZ motorcycle csuspension industry with such a heavy investment in such equipment.

STEERING DAMPER This just has to be mentioned. The damper itself is no worse or no better than those found on other 600s ( if fitted ) But the mounting is so close to the centre of the steering axis that the velocity imparted to it is very very slow. As damping is velocity dependent there is no useful damping produced and its next to useless. If you mount an Ohlins damper on the original mounts it too will be next to useless. The trick is to make a special bracket to move the working arc of the steering damper further away from the steering axis, to impart some decent velocity to it.

When you narrow down your choice a little further please send me another PM or ( preferably ) a regular e-mail , enclosing your personal stats etc. I will respond with a menu of options. We are not the cheapest at doing this work, we dont try to be as we refuse to cut corners. Its all about a great end result, helping you to understand response to adjustments and providing value for money.

[Marmoot]

TRIUMPH 675
....
REAR SHOCK Just like the Ducati 1098 / 1198 and Yamaha R1 the Triumph is burdened by a link ratio curve that is riculously progressive and that problem is exacerbated further by a selected spring rate that is widly aggressive unless you are about 140kgs plus. The trick is to fit a much softer spring with a decent amount of preload. The preload holds the bike up in its stroke so it can do all of its best work in the first 1/3 and most supple part of stroke. But then if it does get deeper into the stroke the spring force curve is a lot shallower so there is a much better chance of nasty bumps being absorbed and keeping the tyre actually gripping the surface!! The internal shock piston is arguably the best of all the bikes but is totally bastardised by a rebound valving stack that is pretty much immovable. On our dyno the rebound damping force curve is over 100% stiffer in force than an Ohlins TTX36 specific to that bike.

Seems like common European sportsbike problem?

[SPP]

Thanks for taking the time respond on here and via email Robert. When I'm closer to a specific bike to flip you an email.

To risk sounding like a kiss-arse, I like the fact that you have model specific knowledge and can show it on a chart.

It means I know exactly what I'd be getting.

Cheers