Draft dirt jump design/construction guidelines; feedback sought

[bikesarefun]

So.... a little side project on which I've been working....

This is a guideline document that explains some of the basic principles of dirt jump design. Having spoken with major insurers in NSW, a document like this (once suitably approved) will make it much easier to get approval for quality public facilities. It's still a fairly early draft, but I thought it worthwhile throwing it up here for feedback.

The post is looking a bit bare, so here's a few shots from places I was able to visit earlier in the month in BC and Washington.

 

[Ridenparadise]

Seeing as we had a massive dousing with rain overnight, now I have something to read instead of riding this afternoon. Looking forward to checking out the details.

 

[bikesarefun]

Thought I'd bump this up just to give Rotorburners one last chance to give feedback before moving this forward...

Come on guys - with the thousands of posts on here over the years whinging about certain jumps, surely there are some experts in how things should be built!

 

[crank1979]

I thought it covered the design ideas well. I was hoping for more information on the construction such as suitable materials, soil/clay ratios, appropriate timbers and projected longevity of materials, things like that.

Your Risk Management table is missing a few columns from what I'm used to dealing with and seems overly simplistic. However, I can understand why you wouldn't complete a proper generic RA and then have to be responsible if someone goes to court over an incident on a jump. You should include something about carrying out specific RA for jumps in your Important Caveats section.

"For example, other common feature types include “satellite dishes”, “whale tails”, “wallrides”, “elevated step-up platforms”, and quarterpipes."

It would be good if there were images of each as examples as well, for the reader who doesn't know what they are. A diagram of a line incorporating these features to show how they are used with jumps would also be beneficial.

It's a big effort. Well done.

 

[Kramer]

Epic. Lots of detailed analysis, including lots of aspects I had never consciously considered when working on trails and jumps.

A agree with crank that a template / formula for estimating the risk presented by a jump would be good. Something like approach velocity x lip height x release angle / margin for error. If you keep the current format you should breakdown the risks by likelihood of the risk eventuating and potential impact in the event of the risk being realised, then assign risk mitigation measures against reducing one or both of these.

Tips on how to build would be good (eg. how to get the lip radius dialled, determine distance of lander from take off).

I think another disadvantage of gaps (11.1) is that they are more easily damaged (eg. kids climbing on the jumps)

17. Ongoing maintenance should mention that there should be a regular inspection process to identify unauthorised modifications or degradation of the jumps. If timber or metal structures are used then this should be mandatory. Maintenance should cover correction of drainage issues and maintaining drainage clearance. Also, might be worth considering rubbish clean up and disposal (thanks groms).