What is the effect of rung width?

Anyone have any thoughts on the effect of the width of split cedar rungs? NOT the thickness. Looking at replacing the legacy dimensional lumber structure below with a similar (but slightly longer ramp) topped with split cedar.

Photos from 2007 shortly after original construction:

Photos from today:

Yes, it's an old janky structure, but it's one of 3 structures in this riding area and it's so beloved that people have removed large blockading piles of cedar from the entrance three times so they can ride it. (At least until someone went through a couple of the rungs towards the bottom)

The ramp is on an intermediate trail and drops about 6' over its 21' length. The dimensional lumber was slick as snot if the air is a little humid (never mind actual rain) so skidding down the ramp was a factor.

Less experienced riders would start down the ramp, grab a little brake to control speed (no effect), grab a little more brake to control speed (no effect), DYNAMITE THE BRAKES BECAUSE THAT BERM AT THE BOTTOM IS COMING AT ME WAY TOO FAST AND I'M TOO YOUNG TO DIE! (no effect) …then slide off the bottom of the ramp and skid through the dirt towards the berm. The masonry blocks below the ramp were an attempt to control skid erosion. The new ramp will be extended to cover that area.

I expect that split cedar will be much grippier and will allow a little speed control even when wet, but there will probably still be a some skidding. As a result, the rungs are going to be 3.5" thick to allow the possibility of one re-surfacing if a groove gets worn into them.

The current slabs available for rungs range from 8-16" wide (30x16x3.5", for example) You can just make out some of them piled on the take-off ramp in the recent picture. The question is: should they be split further?

Here's how I see things:

• More narrow rungs give more biting edges for braking, but they also give more opportunity for wear
• Wider rungs are stronger/more durable
• Wider rungs are more likely to have grain twist and not sit flat against the stringers leading to rung rocking and nail pull-out
• Narrower rungs require less total rungs to cover the area because you have more spaces
• More spaces give better cleaning/drainage, but that's more of a factor on the flat take-off ramp, not the downhill portion

Anything critical I've left out?

I think the way to go may be to keep the big slabs relatively large, but alternate, so there'll be a 10" rung, then a 6", 10"…

Whatever Turns Your Crank…

i'd say you can make rungs up to about 8-10" wide on two conditions:

1. the rungs are about 3-4" thick

2. the stringers that support your rungs have been milled or chopped flat - you want the rung to sit flat on the stringer so it doesn't rock at all.

narrow rungs don't necessarily mean inreased wear, but they do go further like you say because of the increased number of gaps. for what you're doing i'd suggest a 5-6" wide rung that's about 3" thick. the advantage of a wider rung is that it allows you to use two nails per side for far better holding power into the stringer.

if traction is a concern then what you could do is vary the thickness of the rungs by about 1/2" or so, so one rung at 2.5" thick and the next one at 3" thick. generally though, for higher speed downramps i think it's better to keep the rungs the same thickness and have a good run-out that's armoured - kinda like what you've already done with the bricks. if the run-out and sightlines are good people won't need to get on the brakes until after they are off the ramp. if people need to brake on the ramp then the next trail feature/section is too close to the ramp and the trail needs to be re-aligned.

[HTML_REMOVED]delete[HTML_REMOVED] - should have read Syncro's answer more carefully.

Cheers Ben

Syncro nailed it with his answer. Thats how i interpreted it.

i agree with what syncro has said.

however, if i was you i would not extend the ramp past where the blocks are. if anything i would shorten it up and add more blocks for the newbs to brake on. newbs will be too sketch to brake on any ramp most likely. i would try to make my life easier in terms of long term maintenance after the ramp …

http://nsmba.ca/documents/NSMBA%20Baden%20Powell%20Restoration%20Project%20Final%20Report.pdf

Check out the Stairs of Despair (disrepair) downramp that was rebuilt after only a couple of years. Same problem. Put a rocked in braking section in the middle of your down ramp.

Its not used too much on the shore, but you could use that half inch boxed fencing material on the down ramp. They got lots of options as far as grip tape material and the stuff does wonders

Thanks for all the input, guys!

One thing I forgot to mention is that the rungs are all coming from off-cuts of ~75yr old trees that were left behind in clear cuts and are typically from between 3' and 10' of height on the tree, so they've got some really gnarly grain. There is probably going to be a little more than normal variation in slat thickness as a result. I expect that the grainy cedar will have almost as much grip when wet as the dimensional lumber did when dry. Mind you, it will get polished smoother in time.

I only rode the old Stairs of Despair ramp a few times, but from memory and with the pictures in the report heckler attached, this ramp is much less steep. There were virtually signs of grooving on the old untreated 2x4 and 2x6 rungs (although that may have been because they were so slick tires couldn't get enough bite to groove them!) so I have high hopes that the extra rung thickness will provide enough insurance if the softer cedar proves to be a little groovier.

The stringers are going to cheat a little and be pressure-treated ground contact rated lumber (even though it will not be in contact with dirt) so flatness there will not be an issue.

Unfortunately, it's probably going to be a month or so before any progress is made on this, but I'll post pics of the final result. I think we'll probably split the wider slabs in half to wind up with mostly 7-8" wide rungs.

what purpose are those wood features serving?
why not replace them with some fun armored step-down or gap features with dirt and rock?

what purpose are those wood features serving?
why not replace them with some fun armored step-down or gap features with dirt and rock?

My good man, are you suggesting that we replace woodwork with flowy golden dirt and rock?

We shall defend our wooden gnar, whatever the cost may be. We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender!

Seriously though, I'm guessing the original thinking behind the ramp was (in order of importance):

1. We must have structure!
2. The grade is a little too steep to be sustainable with the soil present.

Ordinarily, I'm completely opposed to gratuitous trail carpentry. I'll even spend days to crib with rock instead of hours with wood, but in this particular case there is a historical reason for keeping the wood: This is one of only three structures in the riding area that were permitted to remain after the land owner banned man-made wooden structures. The intermediate and advanced free-ride trails are all more Cypressesque (although on a MUCH smaller scale) with zero structures, but steep rock faces, log rides, dirt jumps, step-downs, etc.

Somewhere, someone out there was fanatical enough about the old ramp that they took the time to move almost 500lbs of Cedar out of the way so they could ride down its snotty, rotten rungs one last time. Does that level of stupidity deserve to be rewarded? Maybe not, but they shall have their new ramp anyway.

what purpose are those wood features serving?
why not replace them with some fun armored step-down or gap features with dirt and rock?

that's what I was this thinking 8)

that's what I was this thinking 8)

me three

looked like the not so gnarly wood feature was hiding a potential gnarly section

Its not used too much on the shore, but you could use that half inch boxed fencing material on the down ramp. They got lots of options as far as grip tape material and the stuff does wonders

I picked up a couple pieces around 1' x 6' of what looks like what they call flat lath on this site: http://amico-lath.com/pdf/Metal%20Lath%20Catalog.pdf from a buddy that was doing some renos last summer. I haven't used it yet but I have a section in mind that I want to try it out. The previous builder used grip tape then chicken wire and both failed miserably. Not really sure how the fencing material would work. You will not want to fall on this stuff though. I'm guessing it will work like a big cheese grater.

I picked up a couple pieces around 1' x 6' of what looks like what they call flat lath on this site: http://amico-lath.com/pdf/Metal%20Lath%20Catalog.pdf from a buddy that was doing some renos last summer. I haven't used it yet but I have a section in mind that I want to try it out. The previous builder used grip tape then chicken wire and both failed miserably. Not really sure how the fencing material would work. You will not want to fall on this stuff though. I'm guessing it will work like a big cheese grater.

Quick derail here.. If your falling off the downramp and somehow managing to hit the center of it on your way down, seems unlikely. The stuff you have on that link there works reeal good, strictly from riding on it experience