[YellowDuck]

Just ordered a set of the YSS piggy back reservoir shocks from Hitchcocks.  While waiting for them to arrive, I thought I'd look for an online review of them.

Of course what I found was Stu's two part series.  Folks, if you are new to suspension tuning, please be aware that almost every technical thing he says in those videos is incorrect.

His description of how the coil wind on the YSS springs differs from OEM springs, and how that might affect performance, is actually not terrible.

But then he goes on and about he fiddles with preload to adjust firmness.  This is nonsense.  That's not what preload does.

He refers to the compression damping adjustment screw as "rebound" and recommends not touching it.  He refers to the rebound damping adjustment dial as "damping", and doesn't understand that it primarily controls damping during shock extension.  This might be because all of his prior experience is with emulsion type shocks ( ?).  I don't know. 

But it is all bullshit.

Of course I didn't bother to post these comments under the video itself, because we all know how long those would last...

[whippers]

He left my reply up when I pointed out that his claim that most shocks only have preload and compression damping was incorrect.

[Hog Head]

Just ordered a set of the YSS piggy back reservoir shocks from Hitchcocks.  While waiting for them to arrive, I thought I'd look for an online review of them.

Of course what I found was Stu's two part series.  Folks, if you are new to suspension tuning, please be aware that almost every technical thing he says in those videos is incorrect.

His description of how the coil wind on the YSS springs differs from OEM springs, and how that might affect performance, is actually not terrible.

But then he goes on and about he fiddles with preload to adjust firmness.  This is nonsense.  That's not what preload does.

He refers to the compression damping adjustment screw as "rebound" and recommends not touching it.  He refers to the rebound damping adjustment dial as "damping", and doesn't understand that it primarily controls damping during shock extension.  This might be because all of his prior experience is with emulsion type shocks ( ?).  I don't know. 

But it is all bullshit.

Of course I didn't bother to post these comments under the video itself, because we all know how long those would last...

yes

[beagle]

Some tutorials should be labeled as "SUSPENSION FOR DUMMIES."  If only all OE shocks came out with rebound adjustment.....,

[CPJS]

Just ordered a set of the YSS piggy back reservoir shocks from Hitchcocks.  While waiting for them to arrive, I thought I'd look for an online review of them.

Of course what I found was Stu's two part series.  Folks, if you are new to suspension tuning, please be aware that almost every technical thing he says in those videos is incorrect.

His description of how the coil wind on the YSS springs differs from OEM springs, and how that might affect performance, is actually not terrible.

But then he goes on and about he fiddles with preload to adjust firmness.  This is nonsense.  That's not what preload does.

He refers to the compression damping adjustment screw as "rebound" and recommends not touching it.  He refers to the rebound damping adjustment dial as "damping", and doesn't understand that it primarily controls damping during shock extension.  This might be because all of his prior experience is with emulsion type shocks ( ?).  I don't know. 

But it is all bullshit.

Of course I didn't bother to post these comments under the video itself, because we all know how long those would last...

My YSS shocks felt like I had fitted steel rods, no movement at all. I backed off the comp damping to min.
Now they have a 1000mls on them I have added 1 click of comp. I weigh 155lbs.
I will put my preload and rebound settings on here when I get the opportunity, hopefully soon.

[YellowDuck]

My YSS shocks felt like I had fitted steel rods, no movement at all. I backed off the comp damping to min.
Now they have a 1000mls on them I have added 1 click of comp. I weigh 155lbs.
I will put my preload and rebound settings on here when I get the opportunity, hopefully soon.

Thanks for the info.  Mine will be here tomorrow so I will get to start playing with them.  What I am really trying to solve is the crazy slow rebound on the stock ones. 

Maybe in your case they are oversprung for your weight?  One option would be to try fitting the OEM springs to the YSS shocks. 

A good way to know if the spring rate is too high...if you set the rider sag to a typical 25-30 mm, then find you have over 10 mm of bike-only sag ("free sag"), the springs are too stiff for you.  You can definitely compensate for that by backing off compression damping, but only to an extent.  Getting the spring rate correct is one of the most fundamental things you can do in tuning suspension.

[YellowDuck]

For anyone else in Canada interested in total costs and delivery times for these...

I ordered from Hitchcocks late on Friday.  Monday morning I got an email saying they were on their way.  Tuesday (today) I got an email asking for payment for HST and handling charges owed to DHL.  Handling was only $19.20 which is nothing when you are used to UPS rates.  Delivery is scheduled for tomorrow.

The shocks were GBP 444.60, and shipping was GBP 48.77.  My VISA card gave me 1.75 exchange, so total was $CDN 863.40.  I think the HST (13%) was charged just on the 444.60 part with an exchange of 1.70, so that was 444.60 x 1.70 x 0.13 = $98.26.  So, total cost delivered on the third business day after ordering = 863.40 + 98.26 + 19.20 = $980.86.

I chose Hitchcocks because I have used them before for much smaller items, and delivery was ridiculously quick.  Better someone you have experience with for a fairly major purchase.

I'll report on fitting and setup when the arrive, but no ride report until next spring...bike is in the basement and snow is on the ground here.

 
 

[YellowDuck]

Arrived as scheduled.  Initial impression of quality?  They are not Ohlins.  Or even Penske.  But not clearly crap.  Installation and garage tuning this weekend.

[YellowDuck]

One nice thing about these is that the preload collar adjustment range is so big that if you wind it right out, the spring is completely loose with enough slack that you can dislodge the spring perch. It would be an easy one-person job to change the spring, except the rubber bump stop doesn't slide up the shaft so you still need to compress the spring a bit to get the perch off.  But still a million time easier than changing springs on the OEM units.

The rebound damping range is huge.  At full hard they are extremely slow on rebound; at full soft there is almost no resistance.  32 clicks range so that is looking good.

To be honest I can't feel much difference between full hard and full soft on the compression adjustment, but that could be because I can't generate enough velocity just compressing them by hand.  Compression damping tuning usually requires a road test.  But on the other hand, with past high quality shocks I've had on other bikes I could definitely feel the effect of the compression adjustment with a bounce test.  So, jury is still out on that.

[JLewis]

One nice thing about these is that the preload collar adjustment range is so big that if you wind it right out, the spring is completely loose with enough slack that you can dislodge the spring perch.

My Tec shocks are the same. It's actually pretty dangerous having shocks which are capable of bouncing the spring collars out.

[YellowDuck]

My Tec shocks are the same. It's actually pretty dangerous having shocks which are capable of bouncing the spring collars out.

That’s only happening if you are reducing the preload way past the point where there is no spring tension at all at full shock extension.  I am trying to imagine a scenario where someone would do that.   Maybe trying to lower the ride height a pile?

[whippers]

Arrived as scheduled.  Initial impression of quality?  They are not Ohlins.  Or even Penske.  But not clearly crap.  Installation and garage tuning this weekend.

Are they adjustable in length? Also are they set at the stock length as they come or something different?

[YellowDuck]

Are they adjustable in length? Also are they set at the stock length as they come or something different?

Yes there is a length adjustment at the lower mount.  I didn't actually measure yet, but holding them up to the stock units fully extended they appear to be the same length as delivered.  If you are interested in the range of length adjustment I am happy to measure that.  I'll weigh them and the stockers as well.

[lucky phil]

My Tec shocks are the same. It's actually pretty dangerous having shocks which are capable of bouncing the spring collars out.

Just eliminates the muppets from the planet. My DB1 Bimota was the same, you could back off the preload until the spring rattled around.

Ciao

[YellowDuck]

Okay, here are some measurements and such.

YSS shocks including springs weigh 1897 g each. OEM are 2439.

Length eye-to-eye of the YSS as delivered - 360 mm.  Stock are 355 mm.  If you wound the ride-height adjusters all the way in on the YSS you would be at about 355 - maybe a few mm less.

YSS springs are stamped 46-17-25-220.  220 is the length in mm.  46 is the ID in mm.  I suspect 17 and 25 are the initial rate and final rate of the progressive springs, in N / mm.  That works out to 95 and 140 lbs / inch, which seems about right.

With those springs and my 190 lbs aboard, I had to apply 22 mm total spring preload (spring length 198 mm with the shocks topped out) to get about 30 mm sag.  That left only a few mm bike-only sag which suggests that the springs are a bit light for me.  On the other hand, I like a compliant suspension for street riding, so we will see how it goes.

The springs are mounted right-side-up with the tight winds near the top, so it is easy to get a zip tie on the shaft to measure travel.

There are 33 total clicks rebound and 31 clicks compression.  The rebound gives a really good range of damping variation - for sure the correct setting is within that range.  So far as I can tell, the compression damping adjustment is purely decorative.  Seriously, not a hint of any difference between full in and full out in a really aggressive bounce test.

[whippers]

Great info thanks

[JessHerbst]

Okay, here are some measurements and such.

YSS shocks including springs weigh 1897 g each. OEM are 2439.

If my math hasn’t gone awry, thats 542 grams, a bad over 1lb per shock. So you lost 2lbs just swapping shocks.
 Losing 2lbs on a bicycle costs thousands$$$$ !

[YellowDuck]

If my math hasn’t gone awry, thats 542 grams, a bad over 1lb per shock. So you lost 2lbs just swapping shocks.
 Losing 2lbs on a bicycle costs thousands$$$$ !

Maybe if you think of it as a percentage of total weight you will feel better?

[JessHerbst]

Maybe if you think of it as a percentage of total weight you will feel better?

Should have rad ‘..a bit over 1 lb…’

[JLewis]

That’s only happening if you are reducing the preload way past the point where there is no spring tension at all at full shock extension.  I am trying to imagine a scenario where someone would do that.   Maybe trying to lower the ride height a pile?

Well quite, but I could imagine someone without much experience or a centre stand not realising their springs were loose at full extension.

[zimmemr]

Well quite, but I could imagine someone without much experience or a centre stand not realising their springs were loose at full extension.

I use to back the preload adjuster off to the point where the spring was loose on the shock when I set up my MX bike for ice racing. I also removed used cut down fork springs and slid the forks up in the clamps as far as they'd go. The object being to get the bike as low as possible. As a safety precaustion I'd use a cable between the frame and swing arm and the front axle and the lower clamp to keep the suspension from over extending. It was crude but it worked well enough for me to win a few races on the ice and on concrete indoor short tracks.