R6 Shock - RMT1983 - Positive Feedback

[EarlOfEasycore]

The time finally came after 55000 miles and 22 years, my venerable Fazer needed its shock replaced, so I managed to find RMT1983's listing for R6 shock and dogbones on ebay (I had a voucher code I was itching to use, so I'm so glad I did). The rebound damping was progressively worsening, but not to the point where the bike was unrideable; you just knew that it wasn't going to track predictably into and out of corners. Given where I live in the Forest of Dean, the state of Mark Harper's roads leaves something to be desired, so rather than tolerating mediocre, worsening handling, I thought I'd figure out what all the fuss was about. Order got despatched when it was supposed to and ended up on my door 24 hours later, so props to Richard for getting it sorted (he did advise he wasn't going to be around when I clicked through ebay, but I didn't mind the wait)




First thing's first - Time to hot glue gun the washers onto the upper shock mount bushing, just so I won't fill up my swear jar when fitting the R6 shock. 



After soaking the mounting hardware in penetrating fluid, noting that the nuts may not have been detorqued since the day it left Japan, and trying to find the easiest way to access the upper mounting bolt, the shock was eventually out. It's defintely seen better days. 



Took the opportunity to grease the roller bearings and attend to the pitting. I was expecting a lot worse than what came out, given that my 07 R1's linkage was graunchy AF when I replaced my rear for a Nitron R2. A little bit of pitting was tolerable and cleaned up nicely. 



Installation is the opposite of reverse, other than the fact that the 10kg weight plate I had used to jack up the wheel was a few mm too narrow to enable the final linkage bolt on the dog bone to slot in without much persuasion or the bearing inner ring from being axially displaced. But once fully installed and torqued up to 40Nm, it was all grand



I took it for a quick 10 mile test drive around my local bump B roads and twisties, trying my best to test the handling against the free roaming sheep and wild boar and noted the following. 

- I'd need to get some recommended settings for a 14 stone rider front and rear; twisty and hilly A/B roads. Obviously, I'd dial in the sag first, so if anybody has any reference values, it would be useful. 

- The bike felt more composed on corner entry and exit. Back end wouldn't squat as much under acceleration, allowing me to roll on the throttle earlier. It just tracks over the undulation a bit better. That's most definitely expected, now that the shock has a damping circuit that isn't comprised of expired 22 year old damping fluid. 

- There isn't that latent understeer on fast sweepers, meaning that I can trust the bike a bit more; useful coming into autumn and winter. I now have greater feedback on weight transfer and steering. 

- Despite pulling the forks up through the yokes by 5mm, I may have to increase the compression damping or preload, just so the front doesn't dive as much and make it feel balanced with the rear. I did get my bike mechanic to rebuild the forks 4000 miles ago when the stanchions and seals went. 

- Given that the Fazer was only meant to be a commuting hack, I've put 10 times as many miles on this thing in the last 3 years than my R1, even on weekend blasts. I just find it more comfortable and flexible. Weird to think I've had her for 7 years. Was thinking about replacing it for a Speed Triple (either 1200 or 1050) or Tuono 1000/1100, but this bike owes me nothing and is ergonomically tweaked to my preferences. I might be getting old, having had IL4 sportsbikes the past 19 years, but just a few light touches and refreshes here and there means that I've got a purposeful, usable bike I can daily drive without fear of anything malfunctioning. 

As for Richard, well, it's a 2 thumbs up from me    Thanks for your help 



-

[Trebus]

Nice write up.

Got an R6 shock myself and makes such a difference. Devilsyam legacy lives on.

[Gaz66]

Welcome to the R6 shock club, had one on mine for yrs.
Before going any further check shock has clearance to frame rail above alloy casting, this model shock usually needs a few mil filing off to clear the frame rail.

I was never happy with setting suspension until I read up on shock damping.
What I discovered & seems to be a little known fact is when you add rebound damping, you automatically add compression damping, it's all about fluid dynamics & how shock valving works.
This is why lots of bikers end up chasing their tale & can't get a good setup.

This R6 shock it's equipped with high & low comp damping, both upper adjusters need to be wound fully (out).
Remove all compression damping from lower adjuster, fully (out).
Get an assistant to hold bike upright.
1)Measure rear ride height (end of swing arm) to a fixed point on bike, bit of tape & a pen mark is sufficient (write it down).
2)Get an assistant to fully extend shock (lift rear end) measure again (write it down).
3)Bounce rear end a few times, measure again (write it down).
this is to see how much stiction there is in the shock.
Any difference between 2 & 3 you need to find the mid point, use this as your true ride height.
4) No rider, adjust spring pre-load until you can consistently see around 10mm sag after a bounce, then check with rider aboard in full riding gear, 30mm sag is desirable, if you max out the pre-load & still can't get around 30mm sag, shock needs a heavier spring... stock is 95N/mm.
Don't forget riding gear can be in excess of 1stone in weight, so it's crucial to add it's weight if you want decent results or you're just wasting your time.


Since you're now on shorter dog bones, this massively changes the leverage the swing arm has on the R6 stock spring, R6 spring now becomes usable up to rider weight of around 18st ish.
So take this into consideration if you plan to carry a pillion a lot, you'll defo need a stronger spring of at least 120 - 140N/mm from experience or you'll be riding arse end down even at max pre-load, ie, too much sag.

When adding rebound damping, keep bouncing rear end until shock won't go into its second stroke, ie shock compresses & comes back up & stops at the top of its 1st stroke without going over the top into a second bounce, this is an ideal starting point, you'll find you'll hardly need to add anymore rebound damping & may even need to remove a bit.

By adding rebound damping you're automatically add an amount of compression damping.
Go ride the bike around a chosen circuit that has some decent undulations, check shock isn't too bouncy, if it feels a bit of a pogo stick, add a tad more rebound damping until this stops.
Consider rebound as set for now, don't be tempted to mess with it (write down) where in the damping screws range you have it set at.
Leave high speed comp damping fully out for now.

Rear end bounce time again, keep adding low speed comp damping until you feel it starts to affect how you've set the rebound damping earlier, ie rear end will be slow to bounce back up, set comp damping till it just starts to slow shock from springing back up, then remove a tiny but of rebound damping to compensate, you'll find this will ride really well.
Leave high speed damping fully (out) ie no damping, ride the bike, put a good 100miles on it before adding high speed comp damping, this adjustment is only to reduce how much a bump bucks you out of the seat, if bike feels ok hitting bumps & doesn't buck you out the seat, there's no need for any high speed damping for you personally.
If you do get bucked out the seat from sharp bumps, gradually a few clicks at a time until you feels it improves (write it down) keep going until it get worse, you can always go back to where it felt good.
From experience you'll hardly need any high speed comp damping.

Same process to set the front.
Try forks flush with top yoke, the drop em thru 10mm, see which you prefer, 10mm works well, makes front end a bit more nervous at speed, but bike just drops into corners much easier.

Hope this info helps.
Enjoy?

[EarlOfEasycore]

Welcome to the R6 shock club, had one on mine for yrs.
Before going any further check shock has clearance to frame rail above alloy casting, this model shock usually needs a few mil filing off to clear the frame rail.

I was never happy with setting suspension until I read up on shock damping.
What I discovered & seems to be a little known fact is when you add rebound damping, you automatically add compression damping, it's all about fluid dynamics & how shock valving works.
This is why lots of bikers end up chasing their tale & can't get a good setup.


When adding rebound damping, keep bouncing rear end until shock won't go into its second stroke, ie shock compresses & comes back up & stops at the top of its 1st stroke without going over the top into a second bounce, this is an ideal starting point, you'll find you'll hardly need to add anymore rebound damping & may even need to remove a bit.

By adding rebound damping you're automatically add an amount of compression damping.
Go ride the bike around a chosen circuit that has some decent undulations, check shock isn't too bouncy, if it feels a bit of a pogo stick, add a tad more rebound damping until this stops.
Consider rebound as set for now, don't be tempted to mess with it (write down) where in the damping screws range you have it set at.
Leave high speed comp damping fully out for now.

Rear end bounce time again, keep adding low speed comp damping until you feel it starts to affect how you've set the rebound damping earlier, ie rear end will be slow to bounce back up, set comp damping till it just starts to slow shock from springing back up, then remove a tiny but of rebound damping to compensate, you'll find this will ride really well.
Leave high speed damping fully (out) ie no damping, ride the bike, put a good 100miles on it before adding high speed comp damping, this adjustment is only to reduce how much a bump bucks you out of the seat, if bike feels ok hitting bumps & doesn't buck you out the seat, there's no need for any high speed damping for you personally.
If you do get bucked out the seat from sharp bumps, gradually a few clicks at a time until you feels it improves (write it down) keep going until it get worse, you can always go back to where it felt good.

From experience you'll hardly need any high speed comp damping.

Same process to set the front.
Try forks flush with top yoke, the drop em thru 10mm, see which you prefer, 10mm works well, makes front end a bit more nervous at speed, but bike just drops into corners much easier.

Hope this info helps.
Enjoy?

This is definitely insightful and useful! I'll get my wife to help me out on that. We're quite used to setting the settings on our mountain bikes, so your bit about the damping circuits and adjustment makes perfect sense. In principle, once the static sag is set and your desired rebound is dialled in, it's a case of refining the damping as per your guidance, which is really helpful. 

I've got a bit of experience setting suspension, albeit on mountain bikes, so transposing with your guidance is helpful. I've got a very useful 5 mile loop from my hosue that's got everything from rough surfaces, fast sweepers, undulations and sharp bends, so I'll be using that to dial in the damping. Likewise with compression damping - There's not going to be much need to wind in high speed comp, given that big hits and high amplitude strokes aren't going to be much of an issue with the sort of riding I'm planning to do (It's not as if I'm going to hit a 6ft drop or a 20ft gap jump on the bike). 

Pulling the forks through the yokes by 5mm from flush feels really nice for me. The turn in is at a point where it's predictable and neutral. However, reading a 10 year old post on front fork setting when some Czech chap was trying to chase the tail with the damping, would it be worthwhile to just get some linear 10.0N springs? The relationship between compression and rebound was mentioned there too. What I took from that is that the standard dual rate fork springs is an absolute bugger to get a reasonable setting with, since most will add a bit too much compression to stop the diving, at the detriment to rebound. 

I've used a rudimentary calculator online that uses generic wet weight (I've assumed 250kg for a fully fuelled bike) and rider weight (95kg in kit) and style of bike, as well as riding style (normal road) to arrive at the spring rate. Again, not too fussed with going to linear springs - I remember when I took my 929 Blade to Perry Leask at HM Racing, it was generally considered to ditch the "progressive" springs and obtain a better set up with linear. 

But yeah, thanks for your useful pointers - I'll have a look at the clearance when I'm setting the sag with the wife and get the dremel ready.

[Gaz66]

Welcome to the R6 shock club, had one on mine for yrs.
Before going any further check shock has clearance to frame rail above alloy casting, this model shock usually needs a few mil filing off to clear the frame rail.

I was never happy with setting suspension until I read up on shock damping.
What I discovered & seems to be a little known fact is when you add rebound damping, you automatically add compression damping, it's all about fluid dynamics & how shock valving works.
This is why lots of bikers end up chasing their tale & can't get a good setup.


When adding rebound damping, keep bouncing rear end until shock won't go into its second stroke, ie shock compresses & comes back up & stops at the top of its 1st stroke without going over the top into a second bounce, this is an ideal starting point, you'll find you'll hardly need to add anymore rebound damping & may even need to remove a bit.

By adding rebound damping you're automatically add an amount of compression damping.
Go ride the bike around a chosen circuit that has some decent undulations, check shock isn't too bouncy, if it feels a bit of a pogo stick, add a tad more rebound damping until this stops.
Consider rebound as set for now, don't be tempted to mess with it (write down) where in the damping screws range you have it set at.
Leave high speed comp damping fully out for now.

Rear end bounce time again, keep adding low speed comp damping until you feel it starts to affect how you've set the rebound damping earlier, ie rear end will be slow to bounce back up, set comp damping till it just starts to slow shock from springing back up, then remove a tiny but of rebound damping to compensate, you'll find this will ride really well.
Leave high speed damping fully (out) ie no damping, ride the bike, put a good 100miles on it before adding high speed comp damping, this adjustment is only to reduce how much a bump bucks you out of the seat, if bike feels ok hitting bumps & doesn't buck you out the seat, there's no need for any high speed damping for you personally.
If you do get bucked out the seat from sharp bumps, gradually a few clicks at a time until you feels it improves (write it down) keep going until it get worse, you can always go back to where it felt good.

From experience you'll hardly need any high speed comp damping.

Same process to set the front.
Try forks flush with top yoke, the drop em thru 10mm, see which you prefer, 10mm works well, makes front end a bit more nervous at speed, but bike just drops into corners much easier.

Hope this info helps.
Enjoy?

This is definitely insightful and useful! I'll get my wife to help me out on that. We're quite used to setting the settings on our mountain bikes, so your bit about the damping circuits and adjustment makes perfect sense. In principle, once the static sag is set and your desired rebound is dialled in, it's a case of refining the damping as per your guidance, which is really helpful. 

I've got a bit of experience setting suspension, albeit on mountain bikes, so transposing with your guidance is helpful. I've got a very useful 5 mile loop from my hosue that's got everything from rough surfaces, fast sweepers, undulations and sharp bends, so I'll be using that to dial in the damping. Likewise with compression damping - There's not going to be much need to wind in high speed comp, given that big hits and high amplitude strokes aren't going to be much of an issue with the sort of riding I'm planning to do (It's not as if I'm going to hit a 6ft drop or a 20ft gap jump on the bike). 

Pulling the forks through the yokes by 5mm from flush feels really nice for me. The turn in is at a point where it's predictable and neutral. However, reading a 10 year old post on front fork setting when some Czech chap was trying to chase the tail with the damping, would it be worthwhile to just get some linear 10.0N springs? The relationship between compression and rebound was mentioned there too. What I took from that is that the standard dual rate fork springs is an absolute bugger to get a reasonable setting with, since most will add a bit too much compression to stop the diving, at the detriment to rebound. 

I've used a rudimentary calculator online that uses generic wet weight (I've assumed 250kg for a fully fuelled bike) and rider weight (95kg in kit) and style of bike, as well as riding style (normal road) to arrive at the spring rate. Again, not too fussed with going to linear springs - I remember when I took my 929 Blade to Perry Leask at HM Racing, it was generally considered to ditch the "progressive" springs and obtain a better set up with linear. 

But yeah, thanks for your useful pointers - I'll have a look at the clearance when I'm setting the sag with the wife and get the dremel ready.

Hi again.

Only just seen your 2nd post.

Yes defo go with linear springs if you've not done so already, dual rate/progressive springs are a compromise at best, you'll never find a good setup in a month of Sundays.
Linear 9.5nm (K-tech) springs in mine, I weigh 17.5st in full gear & they're more than enough for fast road work ... if you're not experienced in comp/rebound cartridge forks assembly, I advise follow a manual, it's all too easy to do damage if assembled wrongly.

K-tech stuff is a known trustworthy brand, most bike pro race teams use em for shocks & springs, they're not exactly cheap, but not that pricey either if you only need springs.
You can source cheaper springs if you go direct to other spring manufacturers like Faulkners, they'll do just about any weight, any size & from experience & will be quite a bit cheaper than K-tech, plus K-tech put a limit on the highest rate they supply, where as Falkners will do coils way heavier than K-tech if that's what you need, worth bearing in mind if you ever need to re-spring a rear shock, I've had some really heavy coils made for my old VFR800, no one else was that bothered in my business for one offs, but Faulkner supply the Motorsport industry, hence the heavy coil spring availability.
If you need any starting settings, gimme a PM, I'll pass on what works & what doesn't.