Ramp Radius

  • Discuss Ramp Radius in the General BMX Forum forum in area BMX-Forum Community; I am considering another ramp to add to my ever growing collection in my driveway :) Only one neighbor complaint so far, and I have a big driveway :)... ...
  • Tags 180 vert
T

Trimix

Guest
Ramp Radius post #1
I am considering another ramp to add to my ever growing collection in my driveway :) Only one neighbor complaint so far, and I have a big driveway :)

I just can't decide the *EXACT* radius to use. My only comparison is of course what I know I have ridden. I am thinking 8' radius, but I want the last bit almost (but not quite) vertical at the very top (for airs) but not so much so that you can' easily manual right off the coping to the deck. Anyway, the thing is 12" wide (coping length) 5' tall, with a 3' deep deck with a subrail along the back, 3' high. It will transition down to the concrete. If no one complains, I will build the other half (facing this one) in about 3-6 months. 8)

Tips on the radius?
 
G

Guest

Guest
Ramp Radius post #2
hmm i think this is the forumula you should use bro

180(n-2)
---------- = i sub alpha
n


n = number of sides
i sub alpha = how much the interior angles add up to
 
S

sentaafEQpovar

Guest
Ramp Radius post #3
lol, only noobs use sub alpha, gotta use


12
Sigma 3r6^2 = 6(1/3)^t(pie)
n = -(2)^4t
 
T

Trimix

Guest
Ramp Radius post #4
How about the formula for determining how long it takes a one eyed jack ass to **** a bucket of water to the boiling point?

How about you just type:

7 or
7.75 or
8 or

Sheeeessh
 
I

infantry43RIDER

Guest
Ramp Radius post #5
wow pobey and sentaaf.
wanna fondle with my nuts for a bit?
 
V

Vic_Vega

New Member
Ramp Radius post #6
I'd say go with the 8 foot rad. Seven might be too small...then again you said you want it to go almost to vert so maybe 7.5? Ah f*ck I'm no help...
 
T

Trimix

Guest
Ramp Radius post #7
I am kinda waiting for evanc to give input, but I was thinking between 7.5 and 8. I also emailed the guy (Degroot) that owns Mission Skatepark, to see what he used on those ramps.
 
S

sentaafEQpovar

Guest
Ramp Radius post #8
ill fondle the, but not while pobie is around, cuase then he might think im ***
 
G

Guest

Guest
Ramp Radius post #9
wuwu i owned my math teacher today

he kept owning ppl that didnt know the forumula so i was like *****,

if you lookin fo n you gotta set it equal to 360 over i sub alpha n minues 180

wuwu
 
I

infantry43RIDER

Guest
Ramp Radius post #10
so uh yea ramp radius...
 
fenixbykeco

fenixbykeco

New Member
Ramp Radius post #11
Thats a kinda tight transition if you want almost vert for 5 foot but if you want it like that go for it.

My advice: Just take a piece of plywood and start sketching transitions. It takes a little bit to get the hang of making a nice smooth transition. You can always take a ramp apart if you dont like the transition. A ramp is a ramp. It doesnt need to be perfect. Start from the top and work your way down.
 
B

bruisedbob

New Member
Ramp Radius post #12
gotta agree^^ if the ramp is almost vert and 5', it is gonna be tight as prom night. i built a few half-pipes for skateboards and anything uinder 7' and near vert was cramped. those were 8'(i think) so i think 8.5' would work or a little higher. or sketch it out using your bike as a reference, laid down on the plywood and imagine. good luck on the neighbors.
 
T

Trimix

Guest
Ramp Radius post #13
I am hearing from other sources also that "stock" is 8', and 7.5' if you want steeper. The ramps I have been riding are 7.5' minis. 5' tall. So I am thinking 7.5 - 8 foot radius. Drawing a smooth, sweeping, transition is easy. I use a 2 x 4 and a pencil to scribe the tranny. Will let you know and get some pics up once I get it decided.
 
T

Trimix

Guest
Ramp Radius post #15
Thanks....I have perused that site several times, just wanted some OTHER input also.

Funny Chad Degroot with Mission Saktepark, emails me back and says. "You need to ride more at my park, and not worry about building ramps"......lol He is a pro, so I respect his advice.....but that doesn't mean I don't still want some ramp here :)
 
V

Vic_Vega

New Member
Ramp Radius post #16
Chad is awesome....I love his grips. Naked ladies...mmmm.....
 
T

Trimix

Guest
Ramp Radius post #17
Yea he is. Straight up guy. I currently use his grips. Soft....mmm Funny thing is, when choosing a new pair (to replace the cheesy grips that come on Haro's) they had some Primo options and I was like......naked laides, no naked ladies, naked ladies, no naked ladies....(weighing options).......H'ok.....Naked Ladies it is!!!
 
V

Vic_Vega

New Member
Ramp Radius post #18
I must say that having the naked ladies on my bike has added a whole new dimension to my riding. Thanks, Chad!!!
 
T

Trimix

Guest
Ramp Radius post #19
Ok decided, and have the quarter pipe half built. I will get some pics up when I get a chance. For the first quarter I went with a 7.5 tranny. The ramp is 12 feet wide, 5 feet high, and has a 4 foot deck and subrail on it. The entire ramp is 10 feet long. I have the sides, frame, middle struts and tranny ribs installed. Have to install coping and then the deck/surface. If I don't get any complaints in the next few months (after clanging my pegs on it all afternoon :) I will build the other (mirror image) quarter pipe to complete the half. My new Fit 2 would be nice to take on it's maiden voyage IF it had cranks on it. :(
 
E

evanc

Guest
Ramp Radius post #20
Trimix said:
I am kinda waiting for evanc to give input, but I was thinking between 7.5 and 8. I also emailed the guy (Degroot) that owns Mission Skatepark, to see what he used on those ramps.
7.75 would be a tad more mellow than 7.5. I used 7.75 on my 6' and it flows perfectly, but it's a tad steep. I'd say use 7.75 on your 5' and it'll be perfect.
 

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