Evo 1100 rear shock - possible upgrade?

[bigredduke]

Originally Posted by Luddite

Aha! So what Öhlins shock have you gone for? The DU737? If so, then the preload rings will be at the bottom, as per here.



(The installation manual will tell you anyway).

And you're right about orientation, that PS version would work either way up, (assuming you could fit it 'upside-down').

Yup, looks as above so hopefully fitted correctly! The top mounting nut is awkward to undo & tighten though. Abba stand helped but I still needed to put a strap through the wheel and over the rear subframe (where the seat sits) to support the rear wheel when lining up the new shock. Hoping to try it out at some point over the next few days!

[bigredduke]

Another potentially stupid question:
The manual for the DU737 states standard settings as follows:
rebound adjuster = 16 clicks - is that clockwise from the top?
spring preload = 12.5mm - is that measured from the lowest thread at the bottom of the shock? Also, is that to the bottom of the lower adjuster ring or the top of the upper adjuster ring?

Thanks in anticipation!

[Luddite]

Two very sensible questions, Paul!

For rebound, wind the adjuster fully in then count 16 clicks out.

The amount of preload in millimetres is the difference between the spring's free length and its length when fitted to the shock and fully extended. Look on the spring and there will be a four digit number. I think for the DU737, it should be 1092. That means the spring is 170mm long when not on the shock. So 12.5mm of preload will mean that it would measure 157.5mm when on the shock with no load (i.e. fully extended).

Hope that helps.

[Luddite]

By the way, Paul, I've just remembered - when I fitted the DU737 with the factory settings, I found I had no static sag whatsoever and was getting pinged out of the saddle down bumpy roads. I wound off a couple of turns of preload and that improved matters considerably. So don't assume the shock will perform perfectly out of the box and check your static and dynamic sag before putting all your tools away!

[bigredduke]

Thank you very much Vince, you really are the eternal font of Evo information!

I haven't checked the static sag yet, I am going to get the bike set up properly by James Wood at JWR suspension but I might check the ss beforehand anyway.

Some reading required methinks!

[Luddite]

Originally Posted by bigredduke

I am going to get the bike set up properly by James Wood at JWR suspension...

Good idea. The 12.5mm figure is just a starting point and the final preload will be determined by the sag figures. Let us know how it feels once it's all set up.

[bigredduke]

I've read recommended static sag anywhere between 10 -30 mm. What should it be for the Evo do you reckon?

[Darkness]

Originally Posted by bigredduke

I've read recommended static sag anywhere between 10 -30 mm. What should it be for the Evo do you reckon?

10mm sounds very low, unless that’s just under the bike weight with you standing next to it!

[Luddite]

10mm would be fine, Paul, assuming that it also puts you in the ideal dynamic sag zone with you on the bike.

Here's the setup information I got with my shock (recommended figure 10-20mm).



For reference, my dynamic sag figure for the rear is 32mm.

[rollo22]

Paul,
Before you removed the old shock did you take a reference measurement eg a mark on sub frame to axel spindle.
Thats if the Ohlins is length adjustable as my Mupo shock is.
When swapped mine out the rear was to high only noticed after i had put it all back together and put tools and lifting rig away.

[Luddite]

Originally Posted by rollo22

Paul,
Before you removed the old shock did you take a reference measurement eg a mark on sub frame to axel spindle.
Thats if the Ohlins is length adjustable as my Mupo shock is.
When swapped mine out the rear was to high only noticed after i had put it all back together and put tools and lifting rig away.

No need, rollo, the DU737 is a fixed length - no adjustment available.

[rollo22]

Originally Posted by Luddite

No need, rollo, the DU737 is a fixed length - no adjustment available.

Thats one less thing to worry about..

[Darkness]

25-40mm rear and 35-50mm front seems a lot more like it than 10mm, otherwise you’d be topping out over some very minor ripples!

[Mr Gazza]

Darkness, The static sag is the smaller figure and that is just the sag from fully extended to having the weight of the bike only compressing it.

Dynamic sag is the larger figure and is from fully extended to the machine loaded with rider in full kit.

[Darkness]

Indeed, which is why I said 10mm sounded to be very small unless that’s the suspension sag whilst standing next to it. Ie. Self weight of bike only, a pretty irrelevant number as it is never riden in that state.

Much more important is what you are terming ‘Dynamic Sag’, the suspension movement under self weight of the bike, but with the rider in full riding kit seated normally on the bike. There’s nothing “Dynamic” about it though, as that’s also a static test.

Dynamic measurement of suspension would be better, but would require comprehensive instrumentation on the bike and a test track so that circuits are repeatable.

I don’t have those facilities, but make do with a cable tie around the damper rod to see how much suspension travel I’m using when stationary, and the maximum travel used whilst on a run.