Aprilia Tuono Rear Shock (Sachs)

[Xavez]

I just got around to finally installing my 2014 Tuono V4 Sachs shock. It does not have the length adjusters but I can confirm that it fits on a 2017 LED NC750X, although the reservoir does press on the plastics.



I went with the stock springs and max'd out preload settings but still couldn't get a proper sag setting. Bike was squatting a lot and slower to turn. However, together with the Showa Dual Bending Valves up front, the ride is now so much better than with the stock shocks! No more jarring shocks from rough roads. It also corners and holds a line like it's on rails and this is with the soft springs.

I set the compression and rebound according to recommendations from the forum below as a starting ball park, and it worked pretty well for my 80kg (175 lbs) weight.
Compression 1 ¾ turns from max out
Rebound 20 turns in from max out
Performance Bikes May 2005 issue - Tuono set up guide

I'd be ordering new springs based on the recommendations in the previous posts. Thanks for the info guys.

 

[SirBean]

Hello all.

For those contemplating I just wanted to pass on some information on my experience after I completed my install of a APRILIA RSV4 TUONO V4 OEM SACKS ADJUSTABLE REAR SHOCK. Again it was the adjustable version. I just used some long bolts between the top and bottom joints of both the OEM and Aprilla and eyeballed it as best I could. It seemed to work out well. Looking the the shock linkage, there is room and the height adjustability might be useful later on if I want to experiment.

I am about 200 lbs and researching the past threads I chose and was able to get a 1092-49 Ohlins spring from Cogent Dynamics for $90, along with my front fork emulators. They are a great crew there, and props to Todd for working so much with me.

Yes the shock was a tight fit with the reservoir but, as with the many before me, it fits.

My main point that I discovered and wanted to share is the top mount bolt design as seen in the attached pics.

Basically the head of the top mounting bolt goes THROUGH the mounting flange on the left side squeezes the shock tight against the only the right flange. The head of the bolt is obviously held secure by the collar for the vertical movements, but this essentially means that spacer width for the upper left side of the shock mount is not an issue. Its a small thing but may help those considering going to the details of very specific width spacers. I was able to find washes that were were .2 mm which for me was close enough.

And, with only 15 mile ride so far, with the Cogent dynamic emulators, fork springs, oil, the RSV4 V4 shock with the 1092-49 Ohlins spring, the bike is much better all around. The jolty road cracks are all but gone now. My wrists and back are much happier.

 

[Therapy]

The jolty road cracks are all but gone now

This is what made the cost of my RaceTech stuff worth it. Plus the all around better handling and feeling more secure and.......well lots I guess.
Ready for the next Dragon meet.

 

[ted007]

Tuono shock top eye

The new spring came in from KFG. I installed it Saturday and learned a few more things about the swap. I went with the 180mm X 120nm spring and my sag numbers are perfect. The spring leave plenty of adjustment so it should work for heavier riders.


First the springs. The 180 is to the left, 170 in the middle and the stock 160 Tuono spring is the right one.

This is the 170mm X 110nm spring installed and set to my sag (175lbs). You can see where the adjustment rings are set and I wasn't able to achieve proper free sag when the proper rider sag was set.

This is the 180mm X 120nm spring installed and notice now where the adjustment rings are set. This was close to where the rings are after sag was set.

I disassembled the NC's shock to see what I was working with and I was amazed how strong the spring was. I used a large spring compressor at work and it took some effort to compress it.

Comparison of the NC and Tuono.

I compared the two shocks and they are identical in both length and compression. The Tuono's shocks adjustment screw does both rebound and adjustment. Turn the adjustment screw out and compression is very easy and it rebounds almost instantly. Turn the screw all the way in and compression very difficult and rebound is very slow. Set the screw to a little over half way and it's similar to the NC. The screw has 42 positions and my final setting was 30 clicks in.

You can see how the stroke is the same and I did measure it and found them to be almost the same.

This is the Tuono shock installed on the bike with the 170 spring and for comparison the bottom picture is the 180 spring installed with the correct free sag and rider sag. Note the position of the adjustment rings. I set free sag to 5mm and rider sag was set to 38mm. My weight is 175lbs.

There is only one issue with using the shock that hasn't been discussed. The Tuono (Sachs) shock uses a rubber mounted bushing on the bottom and the NC uses a bushing with needle bearings on the bottom. How long will that rubber bushing last used in that position? The Sachs does have a needle bearing arrangement but in the top position when mounted to the NC.

The Touno shock top eye is a spherical bearing. What you see is the beige oil seal.
Pry out the 2 bushings , remove the seals & you'll see the brg.
Should last a long time.

 

[sdouble]

maybe the RSV4 shock upgrade deserves its own topic ?
Did someone who did this upgrade (RSV4 shock) with a 180 mm long, 12 k/mm stiffness could sumarize his setting including the preload adjustment ?

 

[Xavez]

A 2020 update: ran about 10 000km on the stock springs of the Tuono V4 shock with remote reservoir and finally decided to have it swapped. Here are the photos of the plastic shroud and shock reservoir:

No issues at all. Ignore the little scrape in the center; it came like that from the seller I got the shock from.

I put in a 6", 700lbs spring and... It's still short on the preload. Feels better than stock springs however. Will be trying a 7", 700lbs spring next. I weigh 176 lbs with luggage and gear.

 

[ted007]

I have a 6" 950 lb spring , never used 2-1/4 i.d., 3-3/8 o.d. for $50 + shipping, if you're interested. OR a 7" 950# slightly used for the same price.

 

[Dragonjoe]

A 2020 update: ran about 10 000km on the stock springs of the Tuono V4 shock with remote reservoir and finally decided to have it swapped. Here are the photos of the plastic shroud and shock reservoir: View attachment 41619View attachment 41620

No issues at all. Ignore the little scrape in the center; it came like that from the seller I got the shock from.

I put in a 6", 700lbs spring and... It's still short on the preload. Feels better than stock springs however. Will be trying a 7", 700lbs spring next. I weigh 176 lbs with luggage and gear.

I installed same shock with Ohlins 01095-44 spring.. 7 inch, 685 lbs/in. I weigh 170lbs plus gear. it will give you lots of preload threads. Lots of compression to install so not much adjustment Was needed. a few turns and sag was good. Set the dampers mid way and haven’t played around with them. Real good hiway and much improved on rutted dirt.

 

[nicecruise]

Just an update to anyone doing this:

I am 180lbs, maybe 185 depending how much beer I drink on a given weekend. I run a Top Box 24/7, though it's not heavily packed or anything.

The stock spring was no where near correct as far as setting sag. I ended up using 3 different springs (thankfully my race sponsor suspension shop was willing to repeatedly send me new springs until I found the correct one). Here's what I found:

Stock Sachs Spring Info
Length: 150mm
Diameter (interior): 57mm
Rate: .97kg

What ended up working for me
Ohlins
Length: 170mm this is important!
Diameter: 57mm
Rate: 115 (115 as its listed on the spring)

Here's why: The standard 150-160mm length spring from Ohlins is simply not long enough to work with our linkages. No matter how stiff you go (105 is stiffest a 160mm spring will go from Ohlins btw), it is simply too short and the travel of the linkage soaks up too much of the shock to begin with. What does that mean? That means you end up using a ton of preload before you even start working the spring. What you end up with is a bike that has too much sag, even though you have free sag (indicating the spring is not too stiff), but you have no more preload adjustment. You can solve this by doing two things: 1) Get a preload spacer or 2) a longer spring. I chose the latter.

So, for you 180lb riders, since I've done the leg work of running a .97kg Ohlins, a 100 a 105 and a 110 (all in 160mm), and finally a 115 in 170mm length -- I highly recommend you skip that process and call your local race shop, tell them you need a 170mm length Ohlins spring for your Tuono shock in a "115" rate. You won't be disappointed.

Hi there thanks for doing the hard yards on this? I am pondering why you chose to go new spring rather than a spacer? Did you investigate the spacer at all? Cheaper? Or would it have been less comfortable?
thanks

 

[BFair]

Hi all, I was inspired by this thread and sourced a 2018 RSV4, emulsion shock. I removed the spring using 2 racheting tie down straps. I am 209lbs so I figured sourcing a used spring would be an issue. I found a 1093-49-130 Ohlins spring used. The 1093 is 5.9" so compressing the spring wasn't an issue. Using Nicecruise's method of using Jack stands, installation on my 2014 NC700x was fairly easy. I adjusted the Sach shock to the same length as the stock shock although more height is available.

My sag numbers were perfect with preload on the spring maxed. Ride was amazing. The shock could easily handle anything the front forks threw at it. My back was sore at the time and I didn't have any issues. I hit every recessed manhole covers I could find. Riding faster smoothed the ride more. Can't wait to go off road. Shock setting is 2 of 3 turns on the top and 10 clicks of 30 in the bottom. I also installed Race Tech's cartridge emulator which really forced me to do something about the rear shock.

I don't haul a rider or much gear or a 140nm spring would be needed.

Thanks to all the pioneers who contributed to this thread, could not have tackled the project with out it. Made a great budget bike even better while staying in the budget.

 

[Deleted member 5383]

Those forks though. Did an extremely washboarded and potholed hardpack/rock road with some frost heaves yesterday, had to always keep it below 25, sometimes even 2/3 that. Same thing on my WR would have been comfortable at nearly double that. Good spring (and shock) in back, saves the back. But the forks, they eventually need to get attended to.

 

[BFair]

I was able to do some "spirited" riding with my son's friend on his Yamaha FJ09. I could keep up with him in the turns but obviously not on the straights. The rear shock performed perfectly, no wallowing, quick to dampen to set up for the next turn. I had backed the clickers off 3 clicks on compression and could feel the difference.

I was advised against this mod by a suspension specialist. He claimed I could easily overwhelm the damping ability of the shock. I did not find this to be the case. The gold valves were on the harsh side which may require a lighter valve spring or lighter oil.

We did some off gravel rides as well but not fast enough to challenge the suspension. So far very happy with the results. Budget money well spent.

As others have said, you must focus on the correct spring for your weight.

 

[jeremyr62]

Hello everyone. First time poster over here. I usually post into the UK NC forum but this thread helped me a lot (and the separate thread by NItecruise) so I thought I would post my initial results. I am an (academic) engineer by profession so forgive me if I use metric units all the time .
I have a new to me UK 2016 NC750S. I was underwhelmed by the handling when I got it, and when I had the rider sag set for me, I had no static sag. The preload was about 2/3 of maximum. Riding with no static and lots of preload is pretty unpleasant in my experience. I was going to get a new shock when I found this thread. I managed to get a low miles 2018 Tuono V4 Sachs shock (remote reservoir version). From this thread I learned the Sachs spring is about 95N/mm which is much less stiff than the OE spring which is about 140N/mm. So i knew i had to get a new spring for the Sachs. This is where I deviate from the general consensus. The recommended springs on here seem to be 170mm long springs with stiffness less than the OE spring. I suspect these work for people because they are not as heavy as me (~95kg) and are not chasing static sag. However the OE spring on the Sachs is 160mm long and the installed preload is about 4mm. If you use a 170mm spring you are already at 14mm of installed preload. I am not a fan of preload.
To cut a long story short, I have used a spring I happened to have. This is a 184N/mm (1050lb/inch) stiffness spring. It's a 5 inch spring too so I had to use spacers. I installed it with about 3mm of preload.

When I worked out my sag settings they were OK with 3mm of preload. Early days but bike feels very good. There is one disadvantage to using a very stiff spring on the Sachs, the damping has to be turned up close to the max. However there is still plenty of damping and if/when I get the Sachs serviced, I will get it adjusted then.

In conclusion if you are doing this I would urge you to get a 160mm spring to minimise the installed preload and get one with a stiffness at least the same as the OE spring (~140N/mm), unless you are a featherweight.

 

[PiperJohn]

Hello group,
I am getting ready to do this upgrade myself, and have spent hours to wrap my head around what spring to order, and to make sure I understand what needs to be done, etc. I started to compile data reported by members, and think that I am going to go with a Hyperco 187A0650 which is 178mm, 114N/mm for mine (155lbs, plus 35lbs full top box). I know this is a dusty old thread, and most contributors have not posted in several years, but I would be very glad to hear from anyone who has done this upgrade and has any new thoughts/data. I have gathered most of the data from the posts and put them in the chart below. I would like to add/update it to help others on this journey.

BTW: many Hyperco springs are available on Amazon (many sold by Amazon with great prices and free returns), but you need to look up the model number on the website (link). Then search Amazon for the spring model number that you selected.

Thank you very much to the innovators who made this affordable upgrade into something that a newb like myself can accomplish, thanks for thinking outside the box!

 

[PiperJohn]

I went with the 700lbs Hyperco Spring 187A0700 on a 2010 RSV4R shock, for a total of $139, and have taken a couple of rides now..

NIGHT AND DAY BETTER.

Thanks again to those who forged the path.

 

[milesprwr]

Hi @PiperJohn, I recently picked up a 2013 RSV4R Sachs Shock and was wondering how you decided on the 700lb spring? The shock I picked up looks adjustable so my plan was to adjust it to similar length as the OEM shock.

 

[PiperJohn]

Hi @PiperJohn, I recently picked up a 2013 RSV4R Sachs Shock and was wondering how you decided on the 700lb spring? The shock I picked up looks adjustable so my plan was to adjust it to similar length as the OEM shock.

View attachment 52788

Length is only one of the factors to consider, I did adjust the eye-to-eye length to be identical to the factory NC shock, but the spring MUST be changed out. The stock RSV4 spring has been tried, and if you read through this thread you will see that the results were not acceptable. I compiled a list of springs used by others, it will vary somewhat based on your weight, other people who have successfully completed this swap used springs between 650-800 lb/in and I believe the RSV4R shock comes with a 500 lb/in spring, so that is very much too weak. Also, to get the proper preload, a longer spring than the factory RSV4 should be used. This is a link to what I used: https://www.amazon.com/Hyperco-187A0700-Coil-Over-Spring/dp/B00TO62WU2 - the preload had plenty of room for adjustment with sag set properly. Bring it to a shop to swap the spring, I tried the compressor tool available on Amazon and would not recommend doing that, but the shock was an easy swap with a center stand.

 

[jeremyr62]

You guys must be very slim and lightweight. To get good sag in my Sachs I went to a 184N/mm (1050lb/inch) spring, as mentioned above (and ignored by the looks of it )

 

[milesprwr]

I'm about 175lbs (also have top case) and was considering a 170mm Ohlins Spring with a 115 N/mm spring rate. I figure the slightly longer spring would require higher preload, so a slightly lower spring rate seemed like a good idea.

This is my first rodeo so I'm all for feedback! I'm curious if 115 N/mm would be to light of a spring rate. I saw that people recommended 140 N/mm which matches the OEM spring rate.

 

[jeremyr62]

When I wrote my post in Jul 2020 I was a bit obsessed with preload. I would ignore my ramblings about it from then. The OE spring on the Sach is 160mm and I would strongly recommend you get that length as it will fit just fine. If you get a longer one it will much harder to fit for a start, and if you get a shorter one you will need to fabricate a spacer. You really need to measure your sag with the OE shock first. If you have too much rider sag then you need a stiffer spring. It's the sag measurement that tell you what spring stiffness you need. There are loads of guides on the interweb on how to this. I have a Motool Slacker Digital Suspension Tuner but if you have a friend to help it is very easy to do with a tape measure.

Don't confuse spring rate and preload. Completely different. As suggested on here, think of preload as ride height. As you wind up the preload you are just raising the rear of the bike. The spring stiffness is completely unaffected by this.