Has anyone successfully changed their progressive rear suspension rocker to the linear "corse" style rocker? I only ride my bike one-up and have been wondering about this for a while. There seem to only be 3 off the shelf options for rockers from what I can find. 749R, 999R, and 848/1098/1198. I have also found that previous gen super bikes (748/998/996) have used the same rocker as either the 749R or 999R. Does anybody have more clear information on this? Also, aside from a less plush rear suspension, what is the negative effect of swapping to this?
Thanks
Don't know if you consider this a negative, but spring and damping rates for SBK shocks are completely different. You would most likely need to change the shock also.
The bike already has a TTX on it so I could change the valving and spring to whatever was necessary.
For reference, I have a 10.0 Ohlins spring on my 96 Monster and my 996 has an 8.5. I weigh 185 with gear. Your S2R probably has a heavier spring depending on your weight due to the difference in the linkage rate.
I don't remember the exact details, but I'm pretty sure the "linear" shocks also have about 52 mm of travel, whereas the "non-linear" shock is somewhere around 70 (and the Monster about 66). Again, not beeing absolutely certain about this from memory, I think putting a linear rocker on a non-linear shock would turn the rear sub-frame into a bump stop for the rear suspension.
First off.... is this on a Monster?
I *think* the SBK rockers have different offset, the shock and pushrod are in a different position laterally on the rocker.
Not sure though.
This would be on an S2R.
Lots of "thinking" here ... "laterally", does that mean left-to-right? If so, I "think" the Monster and SBK rockers will fit both ways. Also not sure, though ....
I think I might have a linear rocker somewhere in my garage, intended for my St2-based track day bike project; if my memory is correct (on that issue, at least ....) I could check. Tomorrow :-)
I've got a rocker that's *purportedly* from an '06 749s.
It has a cast-in part# 37210031A, as do the rockers on a pair of 748's here.
My S4 has a part# 37210032A.
Neither of those are valid part numbers for a finished part that can be bought from a dealer.
Whether either of those part#'s mean much of anything, don't know.
And you can't buy just the rocker, it's an assembly with the bearings and seals.
S4 has 4 needle bearings, 748 and 749 have two.
And all three are different part numbers for the finished assembly.
I'll dig around in my garage and see what I might find. TBC ;)
You can compare the strokes of shocks fitted to various Ducs by consulting an Ohlins catalogue. The Wim Kroon imports website carries a link to the 2013 catalogue. Click here (http://www.ohlins.nl/wp-content/uploads/2013/12/ohlins-catalog-2013.pdf) to download (it's a 4MB .pdf).
As noted above, the S2R runs a 66mm stroke where the 749/999 run 71mm and the 848/1098 60mm. But that's not the whole story either, as the Monster also offers more axle travel (148mm nominally) than the Superbikes (around 120-135mm from memory), and that will also be affected by swingarm length.
For me the question is why would you bother. Get the damping set up right and the standard Monster linkage is really good, for road use. Go linear and you would feel the little bumps more, with the main advantage being that the spring firms up less as you approach maximum travel. Over the middle of the range, the linear linkage will perform much like the progressive one, all else equal.
For track use where you are changing the spring at each track so that it ... just ... handles the biggest hit at that circuit, I can see why you'd opt for the linear link. But for road use or occasional track days, I can't. Just my opinion - I may well have missed something. :)
For reference, the Monster / ST rocker gives a leverage ratio of about 2.5 at the start of travel, and about 1.73 at the end of the travel, so it's quite progressive.
Just swapping the rocker would not work for all the reasons discussed above, and a true linear linkage would not necessarily be any better for road riding. Quite probably a better rate of progressivity could be found for any specific rider with known weight and riding style, but that's a project. I agree with Moronic; for normal road riding the stock linkage is just fine.
Hijacking this thread slightly; Moronic, I read your old thread about the re-valve of the Öhlins and found that very interesting since I have the same situation with the Öhlins on my Monsters (one DU 5034, one DU 0462). The 5034 is considerably stiffer shimmed than the 0462; while overhauling the 0462 this winter I've softened that one up slightly as a first test of shock re-valving.
Are you still as happy with your re-valved Öhlins, or have you done somehing more to your rear suspension?
Quote from: MonsterHPD on May 01, 2014, 02:28:17 AM
Hijacking this thread slightly; Moronic, I read your old thread about the re-valve of the Öhlins and found that very interesting since I have the same situation with the Öhlins on my Monsters (one DU 5034, one DU 0462). The 5034 is considerably stiffer shimmed than the 0462; while overhauling the 0462 this winter I've softened that one up slightly as a first test of shock re-valving.
Are you still as happy with your re-valved Öhlins, or have you done somehing more to your rear suspension?
It is a bit of a hijack I suppose but the short answer is that I'm glad you asked. I have made no further changes at all to the valving Cogent Dynamics supplied, and the trend implied in the thread from my sig line has continued. As in, the more I ride on the shock, the better I think that valving is.
I probably should update that thread again.
I've had the shock serviced once since I got that revalve done, and I asked for no changes. I have gone down a spring size. Bear in mind that I do a lot of two-up work with this bike, and have had a custom dual seat built for it. I'd been running a 123N/mm spring on the rear - stock is 105N - and when the shock was serviced I went down to a 115N, which is the next size Ohlins currently offers over stock (they do not do a 110, as far as I can determine). It is just right for lightly loaded two-up work - 75/55kg riders, tank bag and tail bag. But not so stiff as to be painful solo. For all-solo work, the stock 105 spring is probably perfect.
So with all that as background, the two of us put 750 miles on the bike in a weekend a couple of months ago. And on the way home my passenger says: "You can never sell this bike. You might never find anybody who can give you suspension like this again."
Early in the life of the bike, we'd covered many of the same roads on the OEM 5034. In shorter stages. I can remember frequently stopping and adjusting to try and escape the pounding we were getting from roads that had seemed very rough. This time the same roads felt really smooth. But the rear end was completely under control. The damping ramps up so sweetly on big hits that you can feel the travel being used but there is no sense of the bike bottoming out or any harshness.
I mention the two-up trip because that was recent and it's fresh in my mind. But it's a great set-up solo as well. All the same stuff applies: roads that had rattled my teeth the bike now flows over in the most joyful way. And you can crunch the thing through big troughs in the middle of curves and she just soaks it all up. In fact I quite like that firm 115 spring for when I'm riding hard solo on challenging surfaces. It is only when I am taking it easy or just cruising gently down the highway that I sometimes wish for a bit more compliance.
Moronic,
thank you!
End of thread hi-jack ;)