Updated again: Cogent Dynamics Monster S4Rs Ohlins revalve

[koko64]

Great reports on the process and results.

[Moronic]

Thanks for the reply. It's deffinately something i need to get done.
I've had the bike 8 years and mostly ride 2 up. I get the jiggling on fast country side roads.
Your putting some serious miles on yours!

If you use the bike two-up then the simple fix is just to contact Rick at Cogent and ask him to put my valving in a DU 333 and send it to you. Rick is an Ohlins dealer, and if my experience is any guide he is very reasonably priced. The ability to wind up the preload for two from the hydraulic adjuster, and then back down again for one, is just about worth the price on its own. Doing that one eighth turn at a time with the twin lock-rings is a nightmare, as you probably know. And having the ride-height right with a passenger helps the steering a lot.

The shock will come with a spring, so consider what stiffness you want. I think the OEM 105 spring is nominally too long to accommodate the hydraulic adjuster, but you can get a 105 in the shorter length for the DU 333.  Unfortunately Ohlins does not do a 110 in the right length, so the next step is to the 115.

After fitting the 333, you could sell the OEM Ohlins shock to defray your costs. I have kept mine but should get rid of it - it is just rotting in a box. Had ideas about revalving the OEM and then refitting it before I sold the bike. But I doubt this bike will ever be sold.

Yes, just under 85,000km on my bike now - a bit past 50,000 miles. That is one problem with fixing the shock (and the seat): big trips start to look very exciting. 

[MonsterHPD]

As noted, old thread still attracting attention and replies ...

Any chance of getting the specific shim set-up you use on your shocks? It would be interesting to compare with what I use on my Öhlins shocks (also softened from the stiff Öhlins set-up).

//Torbjörn.

[Moronic]

Hi Torbjörn, no I can't help you with the shim spec Rick used. From our correspondence at the time I remember him saying he had used a small diameter shim quite low in the compression stack between bigger shims, to get that concavity in the profile. As I recall it, anyway - this was a long time ago and no longer very clear in my memory, so I may have that wrong. I never asked Rick to send me the spec.

You could always get in touch with Rick at Cogent, and ask him whether he would share the spec with you. Reference this thread and he will know what you want.

If I were ever to have another go at this, I would probably ask Rick to dyno my spec at about four clicks of compression from full soft, where I use it a fair bit of the time, and then see if he could soften the main valve a wee bit more so that it produced the same profile at 10 clicks or so. That would bring the adjuster back towards the middle of its range for most use.

Fair bit of fooling around for small gains. But I think the step from stage 1 to stage 2 compression damping remains a little bit sharper than optimal when I wind up the adjuster past 10 from full soft. The step to stage 3 seems perfect. (But then maybe what I am feeling is stage 3 cutting in early. I am an enthusiastic amateur here, not an expert.)

[MonsterHPD]

Hi Torbjörn, no I can't help you with the shim spec Rick used. From our correspondence at the time I remember him saying he had used a small diameter shim quite low in the compression stack between bigger shims, to get that concavity in the profile. As I recall it, anyway - this was a long time ago and no longer very clear in my memory, so I may have that wrong. I never asked Rick to send me the spec.

You could always get in touch with Rick at Cogent, and ask him whether he would share the spec with you. Reference this thread and he will know what you want.

If I were ever to have another go at this, I would probably ask Rick to dyno my spec at about four clicks of compression from full soft, where I use it a fair bit of the time, and then see if he could soften the main valve a wee bit more so that it produced the same profile at 10 clicks or so. That would bring the adjuster back towards the middle of its range for most use.

Fair bit of fooling around for small gains. But I think the step from stage 1 to stage 2 compression damping remains a little bit sharper than optimal when I wind up the adjuster past 10 from full soft. The step to stage 3 seems perfect. (But then maybe what I am feeling is stage 3 cutting in early. I am an enthusiastic amateur here, not an expert.)

Hi Moronic,
sorry for late answer, been down with a mancold.

I actually think I did mail Rick when you first published this thread, but I never got an answer. I did offer to pay, but I suppose he´d play it safe and not let that info out. After all, it´s his eperience, and most people will not open a shock to check so the secret is pretty safe there.
 
Good lead, though, with the small shim between the bigger shims, it does give a clue.

Early December I´ll go to a seminar at Reactive Suspension in York (England) where we´ll see how different shim set-ups affects the dyno curve, and (with Gareth´s experience) what that will do in real life. That will be really interesting.        

[Moronic]

Well it's a great thing about this form of communication that slow replies are okay.  

I'm just back from a trip away on the Monster, covering about 1350 miles in four days of riding - much of it high-country swervery. Plenty of ice-affected, and frequently patched, bitumen to give the shock a workout.

Once again, the rear suspension in use was even better than I remembered. It is so good to accept that nothing will unsettle the bike. You can attack every corner with confidence, rather than leaving a big margin for the possibility that you'll get thrown out of the seat on entry, or will have to control a weave mid-turn.

Obviously much safer too. You're more relaxed, and can spend your attention (and that margin) on other things.

I would be interested to hear about stuff you learn from the seminar. Either in a fresh thread or, if appropriate, here.

[Speeddog]

~~~SNIP~~~

Once again, the rear suspension in use was even better than I remembered. It is so good to accept that nothing will unsettle the bike. You can attack every corner with confidence, rather than leaving a big margin for the possibility that you'll get thrown out of the seat on entry, or will have to control a weave mid-turn.

Obviously much safer too. You're more relaxed, and can spend your attention (and that margin) on other things.

~~~SNIP~~~

That's why you don't need good suspension if you're not racing, all of that stuff is meaningless while street riding. 

[itsamonster]

Hi Monsterhpd, it would be interseting to hear how you get on. I'm just down the road from York, in Leeds.

[MonsterHPD]

Hi Monsterhpd, it would be interseting to hear how you get on. I'm just down the road from York, in Leeds.

I´ll be back with a report.

You could also attend the suspension seminars at Reactive Suspension:

http://www.reactivesuspension.com/courses.php

Gareth Evans is hugely experienced, knowledgeable and pragmatic down-to-earth in his attitude to solve your suspension issues, be they problems or questions. Attending his seminars will be a big aha-experience, give it a try!

   

[itsamonster]

My forks need a service. Just started to weep on one leg. 15,000 miles and never been done.
I didn't have the oil changed sooner on the advice years ago of a local independant ducati mechanic, as he reckoned that if not leaking, leave them as once disturbed , can be prone to problems?
Sounds like reactive suspension might be the place to go as so near to me. I'd want correct ohlins oil to be used.

[koko64]

Having suspension experts local to you is a beautiful thing. If a tyre change is coming up then put the bike on stands, get the tyre/s changed and whip off the forks for a service. Good solid stands give you peace of mind. Or you can grab the wheel while they are working on your suspension if the tyre joint can do it while you wait.

[Moronic]

My forks need a service. Just started to weep on one leg. 15,000 miles and never been done.
I didn't have the oil changed sooner on the advice years ago of a local independant ducati mechanic, as he reckoned that if not leaking, leave them as once disturbed , can be prone to problems?
Sounds like reactive suspension might be the place to go as so near to me. I'd want correct ohlins oil to be used.

istamonster, just a heads-up: consider asking the shop to replace the bushes/bearings on which the fork slides.

After my S4Rs Ohlins seals began weeping (can't remember what mileage, but not as late as one might hope), I had the seals done, after which I had serial problems with further leaks. Seals seemed to last about six months.

When one leg went yet again, I asked specifically that the bushes be replaced on that leg with the seals. No problem since, over about four years and more than 20,000 miles.

Coincidence? Maybe. No problem since with the other leg either. Not sure why. It is possible that the bushes had been done on that leg without my asking, during a previous seal replacement - the shop did say it customarily examined the bushes when replacing seals.

I had been alerted by a report online of a similar experience with an OEM Ohlins fork: serial leaks until bushes replaced.

That's why you don't need good suspension if you're not racing, all of that stuff is meaningless while street riding. 

Heh heh, bullseye. 

[itsamonster]

Cheers for the info/ suggestion moronic, I'll definitely clarify that when i have them serviced.
Koko64, I've got one of these to support the bike
( made in the city where i live, www.1jac.com )

[MonsterHPD]

Well,
the dyno seminar was very interesting and informative, and unavoidably causing as many questions as I got answers ..... as it should be.

I brought my Monster 800 and 749 / HYM1100 track bike Öhlins and ran them both quite a lot on the dyno (as noted in one of the other Öhlins shock threads on the forum). For comparison, here´s a graph with both shocks with comp 10 clicks out, rebound 12 clicks out, all in imperial units for comparison:

Skärmklipp 2018-02-04 16.01.36 by torbjörn bergström, on Flickr

On the track bike shock, I have since reduced clamp shim diameter 1 mm on both as an experiment, unfortunately I will not have the opportunity to runthis set-up on the dyno so it will be seat-of-the-pants when the track season starts again.

The M800 is pretty much OK as it is.  

BTW,
I think Gareth at Reactive Suspension will offer a dyno seminar sometime during spring. Keep an eye on his home page if you´re interested (and, presumably, not located too far away).       

[Moronic]

Hi MonsterHPD, thanks for the nice chart. Could you comment for us on what it demonstrates?