How Coilovers Work 101

I was just playing. I Am Canadian and have Elka shocks on my Ski-doo

 

Thanks but I was referring to the coachbuilder shims on top of the shock not the bumpstop spacers.

 

Sorry, ya I have CB shims too, not sure, I wouldn't want to test it, depends how much travel before it hits I guess. I know David recommends the extensions if you install his shims, cheap insurance.

 

Yeah I'm getting the CB shims and CB bumpstop spacers as well. I feel like I've read a lot of feedback on this on this site and have never heard of anyone having any issues due to these shims offroad.

 

No expert here, I don't off-road, just paved dirt or gravel. I'm just going by the expertise of jberry813 and the physics makes sense, by using CB shims we are giving it more inertia force against the standard design. I agree with you that the increased amount of risk is difficult to measure and may possibly be small. The best thing to do is to make sure our bumpstops contact by extending them so it does its dampening job.

I think the lack of feedback may also be those who do dedicated off-roading use proper upgraded suspensions and less likely add CB shims, primarily a height adder, I may be wrong.

 

I guess i can be the guinea pig

 

But when should I change my oil? This thread sucks.

 

FYI. Per SuperBumps, these stops will compressed to stock height stops. You effectively have the same as stock, lol.

 

yeah those stops look a little too squishy in that video.

 

When you go HAM and hit whoops at 40mph. Broke the shock. Take me about 45 minutes to replace my shock.

 

Good to know. Ending up at the same compressed height but different dampening to reach it feels much nicer.

 

Here is something that I had never thought about, but is affecting me right now.

PRELOAD and TOPPING OUT

I have some ADS shocks w/ 700lb springs up front with enough preload to get me 3.5in of lift (and MCM UCA's). One thing I noticed the first time I went out was a horrendous banging sound when I was hitting whoops and large bumps. I thought it was the shocks bottoming out, but as I paid more attention to it, I determined it was on the up-stroke, not down-stroke.

Coming from a MTB background, I know a fair bit about preload and negative travel... Then it hit me!! If I have 1in of preload in the spring, at full extension there is still 700lbs of force pushing the two sides of the spring perches apart. If I have 2in, then it's 1400 lbs, and at 3 inches of preload, I'm looking at nearly 2100 lbs of force. Plus you have some kinetic energy from the speed at which the two sides are traveling (mitigated a bit by the rebound). In talking to Stewie, who has the same setup, he noticed a similar problem with his initial setup and said that lowering seemed to help.

So now that I know the culprit, I have a question for everyone...

WHAT IS THE IDEAL SAG % FOR OFFROADING?

Again, back to the MTB side of things, for downhill (long travel), you want to sit about 30% into your travel so that the wheels have enough room to stay in contact with the ground on little dips and stuff. On shorter travel bikes meant for more cross-country riding, you want 20%-25% sag (more preload) to stiffen things up a bit, plus you have less overall travel, so you don't want to blow through it too fast.

So what is ideal for us folks in the Mid-travel 1.5 setups? How much up-travel vs down-travel should we have?

 

sometimes has to do with springs # too. 600 lbs vs 700lba

 

OK - Stupid question time...

Why don't they make coil overs with longer springs and shocks to achieve the extra height instead relying on preload? I'm sure they can only go so much longer and still fit/work with the rest of the factory setup but I would have to think at least an extra 1" or so should be doable?

 

Now that shit’s funny!

 

I found this thread looking for a "Suspension 101." I learned a lot from reading it; especially that I should be looking for "Suspension 050" and a private tutor.

Seriously, great post. I'm a good year out from delving into suspension upgrades, and this gives me a lot to consider.