Mountain Biking - Freeride story

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jdoglike
11-28-04, 04:04 PM
Ok so i built this thing to bike on. It was a very steep ramp going up to a 2 foot high 2 foot wide platform about maybe 2 - 2.5 bike lengths long. They were just 4 2 x 6 on top of two boxs. The second box right before you drop off calapsed. the boards fell and i rode down. i was fine but it was a little wierd. I plain to fix it and make it better and longer. any suggestions would be good.

MadMan2k
11-28-04, 05:45 PM
They weren't cardboard boxes, were they? :S

suggestion: be careful, lol. Use nails, and sturdy wood when you can, no point breaking a limb or a part on your bike.
Maelstrom
11-28-04, 05:47 PM
Support beams throughout. That my suggestion

.:MTB:.
11-28-04, 07:26 PM
www.bmxtrix.com has instructions for building all sorts of diff. ramps for bmx. I don't know if they'd also work for mtbing but maybe the instructions can still help you somehow.
wunder
11-28-04, 07:31 PM
They weren't cardboard boxes, were they? :S

suggestion: be careful, lol. Use nails, and sturdy wood when you can, no point breaking a limb or a part on your bike.
Wood screws are a better choice. :)
jdoglike
11-29-04, 12:57 PM
they were boxs made of wood and build with nails.
Maelstrom
11-29-04, 01:24 PM
Wood screws are a better choice. :)

With a proper build you can easily use nice big nails. Until this thread I had never heard of anyone using screws for stunts before.
Cornish_Rdr_UK
11-29-04, 01:28 PM
A few people in the UK use wood screws instead of nails, because, when the wind is going and bikes are riding across the wood it vibrates, even if only a little bit its enough to make the hole in the wood bigger, until it progresses to the nail coming right out.....

But generally, nails are used most..
a2psyklnut
11-29-04, 01:40 PM
Actually it's not the vibrations causing the nails to come out, it's thermal expansion. Since the nail expands at a different rate than the wood, they back themselves out. Also, since the wood is fibrous and has different moisture contents, as the wood dries out the hole gets bigger. As it gets wet, it expands.

Combine these two factors and you have nail backing themselves out of holes constantly. A screw will prevent this from happening. However, if your screws are not coated or galvanized, the force is so great that it can actually pop the heads off of the screws at the weak point.