@WAKIdesigns, you mention leverage ratio and frame rate in your comment, can you distinguish between the two? As far as I am aware, a frame's leverage ratio imparts a force on the shock (spring) for a given rear axle movement. The shock (spring) will provide a resistance to the applied force. The combination of the frame leverage ratio and shock resistance characteristics give the wheel rate - which is essentially how the bike will 'feel' under compression through the stroke. Some bikes have a progressively stiffer resistance (bottomless travel), whilst others may be more compliant mid-stroke. Frame leverage ratios can be linear or non-linear, therefore applying a different force onto the shock through the stroke. Most bikes tend to have a linear progressive rate these days. A traditional coil spring has a linear resistance (Hookes Law), as RC explained in the video. Air shocks (springs) have traditionally had a non-linear, exponential resistance, i.e. the rate of resistance increases the more load that is applied. So, if you combine a coil shock (linear) with a linear leverage ratio frame you'll get a linear progressive wheel rate. If you combine a coil shock (linear) with a non-linear leverage ratio frame you'll get a non-linear wheel rate. Etc... That's my understanding - hope it makes sense!? ;+)

@Richard Cunningham: Loved the Tech Tuesday - absolutely brilliant. I do have a question which maybe you could answer? I understand the theory about the coil spring returning to a static position at the end of the rebound stroke, however what happens if you've applied pre-load to the coil? Surely then you have stored energy in the coil spring at the end of the stroke? Keep up the good work!!

I think it's worth remembering that the leverage ratio of a particular frame will also influence the sag/ mid-stroke/ progressive performance of a given shock.

Good on you Whatcom Trails Co-Op. Super video and great to see that you're taking positive action. Hope you get back what you put in.

Totally agree. Do they actually test their products before they release them on the market? Utter garbage (nice packing though).

@hampsteadbandit: your comments are really interesting to read. I think your point about forming a club is valid. In my (professional) opinion, when a club is formed they have a duty of care to ensure that the facilities they construct (trails and features) are safe. If little Timmy tries to land the 15m gap jump and comes up short resulting in a broken face the club responsible for the construction of the trail feature will be the first to be interogated by the health and safety autorities. Basically, forming a club to construct and maintain trails is a transfer of risk for the landowner. @James-Carey: I think your comments are interesting, however as a landowner why would you open yourself to unecessary risk, even if you are receiving some sweetners occasionally? Personally, I don't know where this will end. The utopia would be for someone to set up a fund structure in the UK to get mountain bikers to put into a pot to actually buy land and do what they want with it. The landowners would then be mountain bikers - problem solved ;+)

Amen to that.

rismtb: that is an excellent point IMO. Trails should be constructed from sustainably sourced materials. Not sure how you find nails and NS pre-cut planks in the forrest though? ;+)

Shoe2190: Bang on! I think it is very different in France were personal liability is king! If you are stupid enough to ride off a cliff then its your own fault! We are too reliant in the UK on safety signage to tell us what is dangerous as opposed to personal judgement. BenCtheMusicman: I think your point is valid, however how would you physically implement this?

Shoe2190: I've worked with the FC on trail building projects and they are relatively pragmatic when it comes to trail building. They accept trails and features get built on their land and they don't have a 'zero tolerance' policy on this - i.e. they don't demolish it without good reason. They do retain some trails because that means people are actually using the woodland, which is the remit of the FC. However, when trails or features are built in an obvious or dangerous location, or the feature itself is dangerous (e.g. a gap jump across a bridleway) then they will most likely tear it down. If the trail is out of the way they tend to turn a blind eye. This is not always the case, but I think the FC shouldn't be seen as a 'demolish all trails' organisation.