# Ramps!



## pvd (Jan 4, 2006)

Hey Y'all.

I just posted about some ramp designs. I figure that folks here may have some more experience than me for the MTB ramp. It would be nice to get some input on improvements or refinements.









Jump Ramps and Kickers | Peter Verdone Designs






www.peterverdone.com


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## Darth Lefty (Sep 29, 2014)

I'm not a great jumper but building ramps with my kids and planning to make them higher all the time, so I'm paying attention.

Your skate kicker resembles the kit sold by OC Ramps, but yours is 60% bigger (2 ft vs 1 ft 3in) and has a flat section after the transition. I think theirs is designed to pack down in a 4x2ft box to ship. They have a spine that's very similar but just two kickers instead of the wall ride.

The joists of the bike ramp are really big pieces of wood which seems to flaunt the savings you are getting from the steel legs, and with that trumpet shape there's no solid right angle for a datum. You have 16.25 in on-center. The overhang of the slats seems like a lot. The overhang means that you can be riding with quite a bit of weight on the edge of one of these slats especially as you pop, and little deck screws are fairly likely to work their holes big and come apart. You could put the sides on the outside of the legs and still have the same stance, or looking at it another way, you there's a lot of stability you could have but don't. Is this about too big a span for the 1x slats? Perhaps three of steel instead of those two huge pieces of wood? Do you think you need that much steel threshold? It seems when I ride the current ramp that I've got, the approach angle of the tire just rolls over this bit, the most abuse it gets is from moving the ramp around. The thin section wood right there might be a bigger problem. It looks like you are welding the feet on, is there a hinged foot as a standard part or could you make one? Like the feet of an extension ladder.

The big ramp looks like it might just barely fit in a Tacoma crew cab.


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## .WestCoastHucker. (Jan 14, 2004)

never seen a kicker with a flat spot after the radius at the lip before. not saying they don't exist anywhere, but i would never build a dirt lip that way....


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## pvd (Jan 4, 2006)

.WestCoastHucker. said:


> i would never build a dirt lip that way....


What is the problem with it? Why wouldn't you ever do this?


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## pvd (Jan 4, 2006)

Darth Lefty said:


> You have 16.25 in on-center. The overhang of the slats seems like a lot.


That was a concern. I need to move the stringer out in 2" increments per the UniStrut registration on the front support. Would 18.25" be too far apart for the 1x4s? What is the most extension off the stringer that you think is safe? How wide should the whole ramp be?
The wood stringer transitions means that anyone can make this ramp. Going to a steel frame is something for a more established and professional program.


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## .WestCoastHucker. (Jan 14, 2004)

a flat spot at the end is like a rounded off lip. it will require more effort to pop off of instead of just popping you off it by itself. bmx tracks will have rounded off lips, but that designed so you can continuously pedal and never have your rear wheel leave the ground over them, kind of the opposite of what a kicker is intended for..


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## .WestCoastHucker. (Jan 14, 2004)

pvd said:


> The wood stringer transitions means that anyone can make this ramp. Going to a steel frame is something for a more established and professional program.


we've always just used a sheet of plywood and cut them with an 8' radius to the desired height. 2x's between the 2 sides as bracing and some thin plywood over the top and you can space out your transition cross members much more 
of course ours were probably much heavier than yours


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## pvd (Jan 4, 2006)

.WestCoastHucker. said:


> A flat spot at the end is like a rounded off lip. it will require more effort to pop off of instead of just popping you off it by itself.


That's what the lip angle is for. This ramp is drawn at 35 degrees for ease of use. If your goal is max loft and distance, you just change that to 45 degrees. While a full transition ramp will launch a marble at the terminal angle, that would only be true on a wheelbase vehicle if the rear wheel is ridden right to the very end, and that's still assuming a lot. That kind of timing and form isn't as critical with the straight section as it helps the rider stay true to the real angle. More clearly, the flat at the end helps with a stable takeoff. This is exactly why vert ramps have vert. That's how physics works. Your comment makes no sense.


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## .WestCoastHucker. (Jan 14, 2004)

i've built hundreds of dirt jumps and ramps, but you're obviously the jump guru, so i'm not sure why i bothered to give some thoughts. i'll just bow out and let you be, since outside influence isn't in your wheelhouse...


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## pvd (Jan 4, 2006)

.WestCoastHucker. said:


> i've built hundreds of dirt jumps and ramps...


I understand, but what you said doesn't jive with physics. There may be a better reason for extending transition to the end but that isn't it. Maybe if you take some time to write it out it will be clear.


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## pvd (Jan 4, 2006)

.WestCoastHucker. said:


> i've built hundreds of dirt jumps and ramps...


Can you share a print of one of your favorite designs that you've produced? That would help a lot.


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## cassieno (Apr 28, 2011)

lol. Print for a dirt jump. I like it.

I have an idea PVD. Why don't you explain what you are trying to achieve with this jump. Who is it for? What are they trying to get out of it? How does your design help them? Instead you leave it open ended and just attack people.

I know that's your preferred way of working, but, maybe try a different way once in awhile.


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## pvd (Jan 4, 2006)

cassieno said:


> Why don't you explain what you are trying to achieve with this jump. Who is it for? What are they trying to get out of it? How does your design help them? Instead you leave it open ended and just attack people.


I did mention the impetus for this post. I may need to elaborate on that if you missed it.

Who have I attacked?


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## Darth Lefty (Sep 29, 2014)

For decks there's a rule that the span of joists within the beam must be 4x the overhang. See pg 6 for example


https://www.sccoplanning.com/Portals/2/County/Planning/bldg/Deck%20Construction_IB900.pdf


The decking goes edge to edge on the frame and does not overhang.

Maybe not that comparable to a ramp! I started building ramps for my kids _after_ building a deck to code. The ramp designs just didn't make sense to me at first. On a deck everything is in compression and the fasteners just hold it in formation. Things that do go in shear or rely on bolts and screws get a lot of help. Joists get hangers, hand rail posts get big bolts and brackets. From that perspective, ramp construction seems very strange. It's half monocoque. The little screws in shear holding the stringers to the plywood sides seem especially like a problem. But it all works ok.

The slats are to let debris fall through and not rot the wood... also like a deck. Needful for a portable ramp?


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## pvd (Jan 4, 2006)

Darth Lefty said:


> For decks there's a rule that the span of joists within the beam must be 4x the overhang. See pg 6 for example
> 
> 
> https://www.sccoplanning.com/Portals/2/County/Planning/bldg/Deck%20Construction_IB900.pdf
> ...


Yeah. We always laughed and cried a little when a "carpenter" would build a ramp. The would always be terrible and fall into pieces quick. Ramps are a very strange thing. The service they see is unlike anything else, but they need to be built as cheap and as easy as possible by untrained 'labor'. Definitely worthy of an engineering study.


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## ssalmons (Apr 15, 2008)

I have never built a ramp or even jumped a ramp but I did stay at a holiday inn before covid. What is the purpose of the lower unistruts, at 30° up from horizontal? I don't think they would add any stability and looks like a waste of weight and money. What are you doing to increase shear strength? Sometimes referred to as racking in the building world. In your old BMX jumps you had closed the end of the ramp with plywood, that adds a huge amount of shear strength. I don't see anything here, but it could just be the drawing views. Also, one by lumber is not structural. The decking should at a minimum be 5/4 deck boards or two by fours. The unistrut you show has adjustment holes 1.875 on center. Thats probably OK for adjusting the take off angle but you don't have any mechanism to level the feet. I assume this is to be used in the dirt so you will probably want something to level and stabilize it. What is the frame or joists made of? They look like wood but too wide to be made of typical construction lumber, like a 2x12.

I also think there is some ambiguity in your target user. Is it supposed to be portable or stationary? For kids or adults? Cheap/homebuilt or professional results?


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## cassieno (Apr 28, 2011)

Buried in his post he says it's for his friends 5 year old. That's all I was able to find on the user.


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## marco529 (Jul 11, 2011)

Maybe take a look at what Hopper ramps are doing. I share the concern about trying to place the sides as far to the outside as possible for stability. Sam Pilgrim seems to make pretty good use of these.


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## pvd (Jan 4, 2006)

marco529 said:


> Hopper ramps


Obvious garbage.


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## Cord (Dec 10, 2006)

pvd said:


> Obvious garbage.


Based upon?


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## Shark (Feb 4, 2006)

marco529 said:


> Maybe take a look at what Hopper ramps are doing. I share the concern about trying to place the sides as far to the outside as possible for stability. Sam Pilgrim seems to make pretty good use of these.


Those are cool, but never thought people would spend so much on a ramp. Geez!

Sent from my SM-G960U using Tapatalk


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## marco529 (Jul 11, 2011)

pvd said:


> Obvious garbage.


Are you saying that the product is obvious and therefore garbage, or that the product is obviously garbage? I assume you mean the latter. I'm not a jump expert, so a few more words on this would be great because I'd love to know why, and it looks like Cord would too. I mean, by my cursory look, both your ramp and this one share a lot similarities.

Yeah, the Hopper ramps are really expensive (even taking into consideration the current ridiculous state of lumber prices here in North America) and I probably wouldn't buy one myself... But these are some of the design aspects of their ramps which I thought were clever compared to your design, and that I thought might spark something on your end.

Simple ball+socket arrangement for the feet to make set up on uneven ground easier.
Articulating toe kick/start section which makes it easy to adjust the height using only two adjustable legs at the kicker end (Your design with the four adjustable legs and non-articulating toe plate seems fussy and less flexible by comparison).
Feet placed as far apart as possible for greater stability.


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## Toivo (Mar 9, 2021)

Let me address the full transition vs end flat.
Experience: frequent at the jumps and skatepark between 2003-2014 on 26" and 20" wheels. Since have gone to almost only to riding trailbikes, which I also enjoy jumping.

I read the article on your website, and you got most of the bases covered.
You actually gave a really good explanation yourself on why to go round all the way:


> Where a full transition ramp really shines is where an expert rider can easily adjust their launch angle by how they absorb the end of the ramp.


At the transition you apply force to the ramp accelerating the velocity y component. "Experts" will pump, which is in essence a slow prolonged bunnyhop at the early stage of the transition to get free velocity in the vertical direction, so horizontal speed can be saved. With a flat part after the transition you are just "floating" on the ramp, with less force than F=m*g. This makes it very difficult to gauge the trajectory and speed at the end of the ramp surprising you in the air every time... most often in an unpleasant way. I think the amplitude and duration of g-forces are the primary thing you use to gauge a jump as you are sending it.

Ok. Maybe this ramp is aimed at beginners. The design is better justified. The same thing will happen if you are stiff, but not as stiff as a marble. The unweighting before the ramp end reduces control, when a beginner is starting to feel some.
This is somewhat amplified with full suspension bikes. The only benefit I could see is when you are coming very fast at a transition, with a small radius, and collapse at the transition(or your bike collapses into its suspension heavily) . Now you will still have good weight at the end of the ramp to create some control and the end of the transition will not buck your unprepared body over the bars. I guess a scared beginner might do something like this, but that technique should not be encouraged with a controlled successful jump.

So what makes a vert ramp with a yard of vertical flat different... (This is not from experience as that is a whole different technique that I will never master.) Ideally your takeoff angle is 90°. Independent of your speed you will always hit the landing, because there is no horizontal velocity component. For take off you have 2 goals. To maximize speed in the lower part of the ramp by pumping while maintaining a controlled body to the end of the transition and trying to not do anything in the final yard of the ramp to not land flat. Of coarse this is a simplification, because the you will use the vertical end to make minute adjustments to the errors you made in the transition.

If you still wan't to make the end flat for not bucking you OTB in any scenario- like a ramp for a car stunt - I suggest making it longer to really steady the body and/or chassis before liftoff.

Wow that was long winded.


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## pvd (Jan 4, 2006)

Cord said:


> Based upon?


It's designed for shipping cost and profitability. It's not a good ramps and will fall apart quickly. Ramps that fall apart are the problem, not the solution. Also, you could build 2-3 good ramps for the cost of this one, not a wise investment.


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## Cord (Dec 10, 2006)

pvd said:


> It's designed for shipping cost and profitability. It's not a good ramps and will fall apart quickly. Ramps that fall apart are the problem, not the solution. Also, you could build 2-3 good ramps for the cost of this one, not a wise investment.


i fully agree on cost, those things aren't cheap. However, they are (surprisingly) robust. A bloke I know uses them as a coaching tool, they get absolutely hammered, yet keep coming back for more. (And when I say hammered we've sessioned one with Trials motorbikes) When he first bought one I was incredibly sceptical, but they are actually quite well engineered when you really look into them, the triangulation and direction of forces all make sense. There are very few obvious weak points, and incredibly stable due to the wide footing. There's certainly LOTS of plus points to be taken from them, you'd be a fool to dismiss all that without investigating further.


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## Darth Lefty (Sep 29, 2014)

Relevant to DIY...

Was looking at the plans and thinking what could be done with a skil saw vs a table saw, what could be done with a jigsaw vs. a band saw, and it all seems ok for handyman handheld power tools. The shaping of the two stringers closest to the threshold on the skate ramp would be a lot easier with a table saw, and the decking with a table or miter saw, but not at all crucial. I think people are more likely to have wood tools than they are metal tools like a chop saw or angle grinder, but I also think a lot of people would like an excuse to buy an angle grinder...

I also see that the small sheets sold by Skatelite are 30x48, but the kicker is 36" wide and looks like 6 ft long deck. Aiming to use a single 4x8 sheet? That stuff is expensive to leave scraps, and the 4x8 sheets have catastrophic shipping cost, so maybe down to 30 or up to 48 wide? Size to max out two sheets for a smaller ramp or three for a larger one?

More about hauling the ramps, or sizing them for hauling. A current minivan is also >4 ft wide like a full size truck, and can carry 8 foot sheets with back row folded and middle row removed. You have to put some blocks underneath or you will scratch up the tupperware, it's radiused at the bottom of the door and the bottom of the wheel well covers. But that's only really good for raw materials. The 4 foot wide part of the gate opening is just about 15 inches high on the minivan in my garage, and I don't think you could stack anything that high without running into the seat backs. 3 ft high x 3 ft wide x 7 ft long is a reasonable guess for a finished ramp that would fit and you might need to play with the front seats.

On a D size wagon or a light pickup or SUV it's >3-1/2 feet between the wheel wells and on a C-size hatchback (for the WRX-snowboard crowd) it's >3. Any of them with a lift gate is going to be limited by the opening just like the minivan.


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## bme107 (Jul 23, 2008)

I design using Unistrut in a professional setting. An adult erector set, if you will. There are a few other competitors on the market some cheaper some more expensive. Obviously availability on a retail level is important and I’m not sure who or where does that. 

Reason I mention other brands is that some offer a different selection of connector pieces which may be of use to you. Most of the bits are interchangeable across brands. 

What is the purpose of the Unistrut that runs parallel to the deck? Is that just denoting a storage location for the propping legs?

Maybe consider turning the upper mounting points into a single bolt that can act as a pivot point and offering a series of holes at the bottom on a radius line to adjust the ramp angle while keeping the angle of the strut optimized for the forces as you telescope the height.


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## PHeller (Dec 28, 2012)

Toivo said:


> The only benefit I could see is when you are coming very fast at a transition, with a small radius, and collapse at the transition(or your bike collapses into its suspension heavily) . Now you will still have good weight at the end of the ramp to create some control and the end of the transition will not buck your unprepared body over the bars. I guess a scared beginner might do something like this, but that technique should not be encouraged with a controlled successful jump.
> 
> If you still wan't to make the end flat for not bucking you OTB in any scenario- like a ramp for a car stunt - I suggest making it longer to really steady the body and/or chassis before liftoff.


Interesting. I've always wondered about jump design relative to wheel size. BMX kickers are often really steep and feel terrible on an MTB or anything with bigger than 26" wheels. Then you go to a DH park and all the kickers are flat and long, more about speed and distance than overall height.

Here's a good video showing how even a good "jumper" will feel awkward on a DH bike on a course designed for BMX. 




Lately, I've been noticing that many local MTB skills parks are designed with BMX and smaller wheeled bikes in mind, and I've even asked local pros how it feels to ride their trail bike on such jumps and they always say "really awkward and not fun". I find this kinda silly because most people riding at least 26-29" wheels, and now most enthusiasts are riding slacked out, long bikes with lots of travel. Why then are we designing community bike parks for the infrequent BMX rider?

I think if I was designing a ramp for a kid, or even someone with your average 29er trail bike, it'd be more flat, or a bigger, continuous radius. In either case, it'd probably be longer.


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## Darth Lefty (Sep 29, 2014)

^^^ dirt jumping seems sometimes to have more in common with vert ramps than with MTB. The Elk Grove park looks like Monument Valley. They have a MTB line around the perimeter, it’s a lot flatter and the jumps are lower angle and wider gap


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## Darth Lefty (Sep 29, 2014)

@pvd did you build either of these, and how did they turn out?


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