^^^^I agree with this. Most people would rather send there stuff out to get worked on then take the time to understand how things work and work on them in there garage. Threads like this one are the reason I like MTBR so much. Where I live, you just cant have a good tech conversation with anyone. If I start talking tech to any local riders(or even shops) they look at me like I am talking gibberish.
There is great info posted in this thread and for once, very little info that is unfounded or completely wrong. This thread should be stickied for the 4-5 times a year this topic comes up. Keep up the great posts
Beanbag, much of what you are asking is not difficult to obtain. A Racetech Shockclock is relatively inexpensive ($799 Retail) and can provide insight into not only peak values, but typical stroke and velocity values.
From there the most commonly utilized software for hometuners and even pros is Shimrestacker.
Shim ReStackor, Finally software to tune a shim stack
For rear suspension, Linkage can help show axle paths and leverage ratios. This is another suspension specific software.
Linkage Bike Simulation Software - News
This coupled with your homemade hand dyno or this inexpensive
shock dyno for less than $2,000
but capable dyno, the parameters can narrow quickly.
As I posted several times, the entire suspension thing is a huge compromise and all the theory and data acquisition are moot until it's ridden.
While the big players do have nice stuff, for short money someone in their garage with a good understanding of suspension and the ability to properly test and test ride could easily produce a much better setup than any of the big suspension shops.
Many times on local terrain, small smart tuners will achieve better setup results for off-road moto stuff than the big players and will accomplish it for less money...then again, some small shops promise the world and F stuff up big time or rob you blind.
Reps! We don't need no stickin' reps!
I am not really worried about the equipment at all.
The linear velocity sensors I got off of ebay a few years back for about $20. Or you can wind your own.
I can machine up some brackets.
For data acq, all you need is a cheap netbook and one of those USB data acq units for <$200. It will typically come with software.
For data analysis, I use matlab, or you could use any of the free variants like Octave or NumPy.
I am pretty happy about the advice I got earlier in this thread about tips to set up tuning, or how to "feel" that something is off, and what it means.
Manitou has done users a HUGE favor by releasing the ABS+ tuning guide, which has the dyno plots for all kinds of different shim stack. Now if they would also do that for the rebound... To be honest, I don't like putting the fork on the dyno. It is a lot of trouble.
What I don't appreciate is some people trying to throw up barriers to entry, like "it's too complicated" or "you need all this expensive stuff".
Going back on topic, today I put in that shim stack that I had shown earlier where there is less HSC. So far, I like it a lot better for single hits, but I did not get a chance yet to take it out on the trail for more testing. While rolling around in the parking lot, I realized two things. One is that at some point I need to start caring what the rebound curve looks like. I think that the compression is not supposed to be too much less than the rebound, otherwise you may start to get some packing-down problems. In the automotive world, I think they try to keep it within 1/3x.
The other thing is that if you look at the dyno plots, you realize that the adjustable orifice is still responsible for about half the flow even at 40ips. I still don't know what speeds impacts are (need to get the datalogger up and running), but this means that above 40 ips, all the colored lines are converging towards the black line, so it is sorta like spiking. I don't know whether it is useful for the knob to be adjusting damping at such speeds, but I figured that the knob would be more useful adjusting the low and maybe mid speed regions only. To achieve this, I think I would need an even weaker (or less pre-loaded) shim stack, while having the knob one more click closed.
Originally Posted by beanbag
That's just the thing I'm trying to convey, once the peak IPS are known for the type riding, and the feel the rider prefers, it becomes easier to establish a stack. You are getting there by a slightly different route. You will know what feels good, and then can see where it peaks or as you just mentioned, spikes.
BTW, try and run a needle style clicker about 1/3 open. A gate clicker, depending upon style may be different. If it is a style that blocks a round hole, find a setting that is mathematically 1/3 the holes area.
Not trying to spend your money, just letting you and others know that results / equipment with reasonably high IPS, plus lower IPS can be had for a reasonable dollar amount. You have the means and ability to buy the bits and build it. Others need it packaged.
Reps! We don't need no stickin' reps!
Interesting comment. You mean the ideal position is mostly closed, i.e. 1/3 of the way from the closed position? What's special about it?
Originally Posted by PMK