Author Topic: Sachs Rear Shock Pre-load Adjustment - How To ???  (Read 767 times)

Roland Stone

  • Enertia Master
  • ***
  • Posts: 64
    • View Profile
Sachs Rear Shock Pre-load Adjustment - How To ???
« on: October 03, 2014, 01:25:31 PM »
Since an alternative to the Sachs rear shock is starting to sound like slim and none, or otherwise too expensive, as suggested, Iím going to make a pre-load adjustment on my Sachs spring for a little more sag to see if that softens things up a bit.  Problem is I canít figure how to get to the pre-load ring nuts using a shock spanner to loosen with the shock on the bike.  With that vertical frame tube in the way (another design oversight?) just canít get an angle on the ring nuts.  Wondering how others have managed the trick or do you have to completely remove the shock to make the adjustment?  Curious or pathetic, the Empulse Ownerís Manual/handbook tells you which way to turn the pre-load ring nuts and the factory setting, but not a word about how to do it, - on the bike/off the bike?  The Empulse Service Manual only tells you how to R & R the shock.  Why doesnít that surprise me?!  And since someoneís going to ask, - yes, I did my due diligence calling my dealer this morning for advice/instruction, but not having done a rear shock spring adjustment themselves as yet, they couldnít explain how to do it either.  Told Ďem Iíd let them know as soon as I found out.  Thanks again Brammo for assuming weíre all too stupid to accomplish something like a shock spring adjustment and hoping maybe the subject would never come up.   

Brammofan

  • Administrator
  • Brammovangelist
  • *****
  • Posts: 3020
  • Following the momentum of Enertia
    • View Profile
    • Brammofan Blog
    • Email
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #1 on: October 03, 2014, 01:48:41 PM »
Can you use a hammer and drift pin punch?
Follow me on Twitter at www.twitter.com/brammofan

Shinysideup

  • Brammovangelist
  • *****
  • Posts: 1289
    • View Profile
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #2 on: October 03, 2014, 02:11:58 PM »
I used a hammer and a brass punch, which still mangled the rings which are aluminum. I don't care too much about cosmetics, but I'm surely in the minority.

Since the suspension tuners were going to revalve the shock anyway, we took it off and it's VERY easy to adjust off the bike! That's the route I'd take, even though it's a bit of a hassle. We suspended the rear of the bike by the frame tubes and adjustable straps fastened to hooks in the ceiling.

barboo

  • Empulse Guru
  • ****
  • Posts: 128
    • View Profile
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #3 on: October 03, 2014, 03:51:55 PM »
I used a small chisel-ended screwdriver for mine. Wasn't banged up too bad but did add some indentations to the rings. Agreed with Shinysideup...the shock is the easiest I've ever removed from a bike. Literally takes 5 minutes now after some practice with swapping Ohlins/Sachs. Easier to adjust out of bike. In hindsight I would have done that instead.
1973 Honda CL350 (For Fun)
1999 BMW K1200RS (Daily ride)
2007 Aprilia Tuono R (Street)
2005 Suzuki GSXR 600 (Wife's Track)
2012 BMW S1000RR (Race / Track)
2013 Brammo Empulse R (Race / Track / Street)

Roland Stone

  • Enertia Master
  • ***
  • Posts: 64
    • View Profile
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #4 on: October 03, 2014, 09:57:21 PM »
I actually tried a hammer and brass drift just to see how much ring movement I could get and it wasnít enough to make me pound harder besides which we shouldnít have to resort to the hammer method on a brand new, beautiful, not to mention expensive bike.  So with nothing else to do this afternoon I pulled the shock off and using two shock spanners went ahead and made my first pre-load adjustment.  I did find that the two adjustment ring nuts were pretty tightly locked against each other which made me realize I would have to have been more aggressive with the hammer to loosen the rings one from the other.  Really glad I didnít go that way because those ring nuts are aluminum and it wouldnít take much to bung one up.  Although doing an R and R on the shock was a bit time consuming Iím actually glad I took that route because it gave me a chance to get acquainted with the procedure which was pretty straight forward.  A little tight getting fingers and wrench around the forward shock bolt nut but manageable.  Also learned where/how to jack the bike up for the procedure and didnít have to remove the fender or any underside fairings in the process.  Used my Pit-Bull swing arm jack to raise the rear wheel, then used a handy scissor type jack I have that has two sliding posts on top with a V-support bracket atop each post.  Positioned one each post bracket under the bottom rear-most extension of the aluminum center frame at left and right side, right next to where the swing arm connects to the frame.  Thereís about an 8mm empty screw hole at that location each side of the frame and just below that screw hole is where I positioned those scissor-jack V-brackets.  Not having done it before on this bike, I slowly, carefully cranked the jack up until all the swing arm weight was off the rear jack stand.  Really slick and again, didnít have to remove any plastic body components.  After making my pre-load adjustment, reversed the jack up procedure and took the bike out to see what if any difference in ride Iíd notice.  Wow! Ė definitely a smoother, less jarring type of feel, as smooth as my Bonneville with Hagon shocks front and back.  My sport bike is now a sport cruiser and Iím not embarrassed to say I like the transition.  The goal in the exercise was met and I must say that the Sachs shock turns out to be quite a bit more ride adjustable than I had imagined.  I weigh 150 lbs and was concerned that there wouldnít be much latitude adjusting for a softer ride and Iím pleased to report I was dead wrong and in fact it should be able accommodating a versitile range of rider weights.  Really glad I got off my rear end and effected a change which I should have done before considering another spring and possibly the expense of another shock.  If the Sachs can be adjusted to my hollow bone weight then it definitely has some range adjustment, and considering I cranked down the ring adjustment nut two turns from loose (factory setting is 4 turns), thereís still enough threads left to achieve even less of a preload than my 2-turn setting.  I am really impressed.  Unlike the more technical types, I donít have the patience doing all the suspension adjustment measurements to arrive at the ideal ride, rather once Iíve got my shock spring pre-load set to where it feels right, then I start making incremental changes in the compression and rebound settings until by some miracle the ride fits me like a pair of panty hose.  I do make somewhat of a measurement however and that is with the rubber bumper at the bottom of the shock rod.  After I get the pre-load to where I think it should be, and I got lucky first adjustment today, then I raise/push up the beige colored round rubber bumper until itís right up under the shock tube.  I go for a ride preferably on a rough, bumpy road surface and then park the bike to check where/how far down the bumper has been pushed by the shock body sliding down the rod.  The resulting gap between the bumper and the shock body tube gives you an eyeball idea of the encountered shock travel.  If the gap is slight, the indication is the pre-load on the spring is pretty stiff.  At the other extreme, if the bumper has been pushed all the way to the bottom end of the shock, then the shock is bottoming out indicating definitely more pre-load is required.  Itís not very scientific, but it is an easy way to gauge the set spring pre-load.  You can push the rubber bumper up to the bottom of the shock tube as often as you like to see how much your shock has travelled in its range of dampening the biggest bump encountered by the rear wheel on any particular ride.  Hope that makes some sense?!

All in all, Iím very pleased with the experience, - learning how to jack up my bike, doing a shock R&R, discovering how versatile the shock turns out to be, and happy as a clam that by some serendipity, I got the pre-load close to right first try.  An afternoon well spent.  Long winded, but if Brammo had some version of this in the Ownerís Manual we wouldnít have been left wondering how in the hell you get a spanner around that damned pre-load ring.  Even the hammer and drift method is better explanation than none.  Cheers!
   

JeffK

  • Empulse Guru
  • ****
  • Posts: 128
    • View Profile
    • Email
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #5 on: October 04, 2014, 06:55:27 AM »
You can push the rubber bumper up to the bottom of the shock tube as often as you like to see how much your shock has travelled in its range of dampening the biggest bump encountered by the rear wheel on any particular ride.
 

Thanks, I will try this too.

Quote
... wondering how in the hell you get a spanner around that damned pre-load ring....

There are some spanners around that come pretty close to being usable, so I modified one of those (was in the tool kit of one of my previous bikes)

Still a tight fit but it is quite easy to adjust the preload now, here are some pics:




Modifications so far:
Crash bungs
shortened chain tensioner bolts
GPS Satellite controlled chain lubrication system
Top Case

Roland Stone

  • Enertia Master
  • ***
  • Posts: 64
    • View Profile
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #6 on: October 04, 2014, 09:23:08 AM »
JEFFK, - neat looking gadget and great idea.  Wish I had some fabrication talent, but for those of us who don't, do your fellow Empulse owners a favor and sell the idea to Brammo so they could offer it in their "Gear and Accessory" page of their website.  Actually, in consideration they designed the present inaccessable shock mounting configuration they should be supplying the tool with every Empulse R!  As it is they don't even hint at how to do a pre-load adjustment, probably because they're embarassed admitting the shock has to come off the bike, - doable but tedious.  Then again, in consideration not much interest in the post, a lot of owners probably never attempt a pre-load adjustment.  Oh well, - thanks for yours.  RS

JeffK

  • Empulse Guru
  • ****
  • Posts: 128
    • View Profile
    • Email
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #7 on: October 04, 2014, 09:48:42 AM »
Yes, Brammo could have supplied a tool for the adjustment, but i'm pretty sure it is not a priority for them.

Brammo is a small company with limited staff, so I guess most hours are spent on developing the drivetrain.
The rest is pretty much "open source" as far as improvements go.

Don't get me wrong, it is the part of Brammo that I like too!
They are scouting the Internet (and of course this forum) to see what Improvements bubble up.
So we, as forum contributors, are part of the development crew...
We are building the future, right here, right now...

(stepping down the speakers crate, back to the lab.. garage  :) )
Modifications so far:
Crash bungs
shortened chain tensioner bolts
GPS Satellite controlled chain lubrication system
Top Case

nunux59

  • Enciter
  • **
  • Posts: 35
    • View Profile
    • Email
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #8 on: January 10, 2018, 04:07:45 PM »
I know this topic is old now but it is still relevant for those who want to adjust their rear shock, me included !

I found a tool that me be usable, I will probably buy one, you can find it by searching "Ratchet Spanner Wrench #T115W" on eBay or Google.

I will come and report my tests here.

EDIT : It would cost me $55 to import it from USA to France ... I will consider another alternative !
« Last Edit: January 10, 2018, 04:13:42 PM by nunux59 »

HadesOmega

  • Enertia Master
  • ***
  • Posts: 67
  • #139
    • View Profile
    • Email
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #9 on: January 14, 2018, 02:58:55 PM »
Yeah that adjustment ring is like in the dumbest place possible, you'd think maybe they should just flip it over or something.  I'm going to take mine to a motorcycle suspension specialist and have them adjust everything for me at some point.  The bike with the stock settings seems to handle fine to me but I suppose it could be better.
2016 Victory Empulse TT - #139

Shinysideup

  • Brammovangelist
  • *****
  • Posts: 1289
    • View Profile
Re: Sachs Rear Shock Pre-load Adjustment - How To ???
« Reply #10 on: January 15, 2018, 02:14:08 AM »
I found the suspension to0 harsh for my use on the potholed streets of San Francisco. I imagine it's perfect on a racetrack, once you have it set up for your weight and riding style.

I took it in to a suspension shop (Superplush in SF) and had them re-valve the rear shock. It's much more compliant now on sharp fast impacts. Still not a Goldwing! Very firm but no longer punishing.