Advice with my rear spring rate on a new Wilber's shock

[AndyCBR]

Hello all,

I am planning on getting Wilbers rear shock and need some help with the rear rate. I selected the Wilbers as I have another on one of my other bikes that has served me well. The Penske group buy looked great but the HPA is a must have for me.

Anyway. I weigh about 260# in street clothes and 275# in full gear. I have Jesses that weigh 47# empty and they vary from empty to loaded out depending on the ride. Don't ride 2 up all that often and I don't treat the Tenere like my crf450x but I do ride the shit out of it. It handled the CDR during a 9,000 mile trip recently better than any bike I could imagine.

Sent my data to Wilbers and they came back with a 170 N/mm spring which is 970 #/in if my conversion is correct.

From the other threads most "big-boned" dudes around my weight are finding a 750 #/in spring the best solution. Maybe going to an 800 if they want to be on the stiff side and/or ride fully loaded/2 up more often.

Any reason why the Wilbers recommendation would be so high? Is there anything fundamentally different about that shock that would need such a high rate?

Thanks for any and all info. BTW I did read all of AVC and Firefights threads on their rates.

Best,
Andy

 

[Rasher]

For my mix of solo and two up (me at 80kg Mrs at 60kg) they recommended a 150nm spring (stock spring = 137nm)

A 170nm does sound very high, mine is definatley better than stock especially two-up, but still rides bumps better solo than the OE unit (probably down to much better damping)

I also get a perfect sag figure, about 33mm with no turns of pre-load that shifts to about 60mm with me on board, I normally put a couple of turns on the adjuster and lift it a couple of mm as I prefer the steering that way.

One thing I have learned over the years is spring rate is not everything, I put an Ohlins on a ZZR1400 and the spring rate was the same as the OE, but the way it felt was very different and where the OE unit just gave up when two-up a few clicks of compression damping had it spot-on.

 

[Firefight911]

At my 215 lbs, I run an 850 in/lb on my Ohlin's.

You need to define for yourself what you like and whet you are after.

The objective data is black and white and may call for what you are being told. There is not much dispute in hard numbers. The defining part comes in the range the spring they recommend has. Are you on the cusp of the range? If, for example, you like a "softer" rate and are on the low end of the range, you may want to go down a spring.

At the end of the day, I went with the 850 and love it.

Hope this helps. Ask away. Once I get back to a computer I can answer more and in better detail perhaps.

 

[3putt]

I ran an 800lb to Alaska and back, plus another trip with some 2up offroad, it was perfect for full load and camping gear. I have a 750lb now on my new Penske.

I am 195 with gear, 2up about 350lbs.

P.S. Your conversion is correct. Perfect sag would be around 57mm for the travel on this bike.

 

[AndyCBR]

I guess what I am learning is you could probably make many rates work well via preload adjustment and damping.

Obviously, you can get proper rider sag with any number of rates via preload adjustment. If you did that (set your rider sag properly) with a soft spring you would end up with less static sag, with a harder spring more...There seems to be many who preach 10-15% static sag and some who say much less (once you get the rider sag right). That's where the variance comes in. Once you throw damping into the mix you could probably make either rate work well.

On the stock suspension fully loaded out with Jesses and camping gear I could dial in as much preload as I wanted but then I got a very harsh ride since the stock, non-adjustable compression damping is very high. So, I found a sweet spot that rode well but then bottomed quite easily. The front end was very stiff due to me being past the "soft" rate on the dual rate springs so I ended up running compression damping all the way out to get an acceptable ride on gravel roads. By far the biggest and best change I made on gravel was to run the K60s at 30 psi (from 36), that really changed how the bike handled on gravel and I still got 9000 mile tire life from the tires.

The stock suspension is pretty good I think but it does get in a weird place when you put a heavy rider like me on it and load it up.

It's nice to hear what other peoples experiences are.

The Wilbers dealer said they would be happy to put whatever spring I want in but if I select the rate away from what the factory recommends any spring changes are at my expense. If the factory recommended rate does not give me 10-15% static sag at proper rider sag they swap me a spring at their expense.

I have a well set up suspension on other bikes and it does make a world of difference. I think if the stock setup had less rear compression damping and straight rate front springs I probably would leave it alone.

In my experience a little softer is better. If you're off road and riding hard if you don't bottom out sometimes you aren't using all of the stroke.

Thanks for the feedback.

Andy

 

[Rasher]

I guess what I am learning is you could probably make many rates work well via preload adjustment and damping

I have found this the case, the key being with good suspension, my ZZR1400 had a 95nm spring and the OE suspension was never that good two-up, an Ohlins with the same rate spring was a billion times better, just adding 2-3 clicks on compression kept it feeling really sweet two-up where regardless of what you did with OE adjustments it was always vague and wallowy forcing you to ride really steady and accelerate real slow out of bends.

Ob

viously, you can get proper rider sag with any number of rates via preload adjustment. If you did that (set your rider sag properly) with a soft spring you would end up with less static sag, with a harder spring more...There seems to be many who preach 10-15% static sag and some who say much less (once you get the rider sag right). That's where the variance comes in. Once you throw damping into the mix you could probably make either rate work well.

I think more is "known" about sportsbike suspension where it is pretty much universally agreed that 10mm static sag and 30-40mm rider sag is about right, I also think a sportsbike is more sensitive to having these figures right, with all the extra travel we have and the more varied uses these bikes tend to be put too I think it is less important to get the figures "perfect"

On the stock suspension fully loaded out with Jesses and camping gear I could dial in as much preload as I wanted but then I got a very harsh ride since the stock, non-adjustable compression damping is very high. So, I found a sweet spot that rode well but then bottomed quite easily. The front end was very stiff due to me being past the "soft" rate on the dual rate springs so I ended up running compression damping all the way out to get an acceptable ride on gravel roads.

I found the same but put up with harsher ride in exchange for more ground clearance and nicer steering and left the preload on max whenever two-up unless the roads were very bumpy. When MCT stripped my forks they reckoned I was probably often on the hard part of the spring - certainly my bike feel far better with it's 0.9s in place and some damping in the forks (oil weight up to 10)

The stock suspension is pretty good I think but it does get in a weird place when you put a heavy rider like me on it and load it up.

The rear is pretty decent for solo use, but hopelessly undersprung for two up, I also prefer to have both rebound and compression adjustment, an extra xxkg of passenger works well enough as additional rebound and on many bikes I find adding compression damping to control the bike on the downwards stroke when two-up works really well, I only add rebound if after getting a nice controlled feel without harshness the bike is still a bit wallowy. Even solo I try and run as little rebound as needed.

I have a well set up suspension on other bikes and it does make a world of difference. I think if the stock setup had less rear compression damping and straight rate front springs I probably would leave it alone.

In my experience a little softer is better. If you're off road and riding hard if you don't bottom out sometimes you aren't using all of the stroke.

I have always found I have got a lot of bang for the buck out of suspension work, I also prefer softer springing to harder springing, but as I do a lot of two-up it has to be a compromise and as I said earlier to balance the handling up with damping requires a good quality shock and ideally 2-way damping adjustment (my Wilburs has 3-way)

Not done enough testing of the Wilburs two-up as the Mrs selfishly broke here foot, but so far I am very happy on the 150 spring, I was also surprised to find the base settings for solo use work pretty well two-up, on my last two bikes I really needed to add a few clicks here and there, but on the Tenere it looks like it will just be a couple of clicks and a few turns on the pre-load adjuster - and for a little run up the road or potter around back lanes I could leave it on solo settings. I have backed off all the damping settings a click or two from the Wilburs setup and it still feels great, my theory is set it as soft as you can without it upsetting how the handling feels.

The forks feel great as MCT set them up, will probaby play with the adjusters at some point, although on the last forked bike they setup I ended up leaving them on the original settings for both solo and two-up use and think the same will be true here.

 

[Duconce]

I would agree with Rasher, it's better to setup on the soft side. If you order the shock see if they recommend a softer spring if you tell them half time is spent on dirt roads. I ordered a Wibers for a Multistrada and had it setup for rough roads, it was pretty close, but wouldn't have wanted it any stiffer. Very well made shock