How to Build a Mountain Bike Teeter, Part I
You know what I miss about Seattle? I miss riding with Bob. Trying — and often, succeeding — those constructed stunts on Tapeworm, Mr. DNA, and Cropcircles with Bob was good stuff.
The stunt I liked best of all was the Teeter. Back before I moved out to Utah, I said that I was going to build one. And I’ve kind of kept building one the back of my mind for months. The thing is, I haven’t been able to find any plans or diagrams that I really liked, because I have something really specific in mind for my Teeter:
- It’s got to be long: I’m thinking 12′.
- It’s got to be adjustable: I want it to be a simple matter for two guys to be able to move the pivot point up or down, so beginners won’t get too intimidated by the incline, and experts won’t be bored by it.
- It’s got to be portable: I’m hoping to find a place to donate this once I’m finished, so I want to be able to move it. Also, I like the idea of people being able to move stunts around, chaining them together in different ways.
- It’s got to be fun to build with my son: My 10-yr-old loves building stuff, and we have a great time working on projects like this together. I need this to be something he can be co-owner of.
So last night, frustrated with what’s evidently a total absence of well-conceived Teeter plans on the Web, I started looking for some free software I could use to plan my own (my pencil-and-paper drawings were totally useless).
I suppose I shouldn’t be surprised at this, but Google’s got a nice little 3D drawing program called "Sketchup." And like everything else Google does, it’s free. (Side Topic: I know that a lot of Google’s business model is based on advertising, but has anyone ever actually clicked on one of those ads or made a purchase decision based on one? I mean, I love my free stuff, but free CAD software? Sheesh.)
So I downloaded it and started to play.
Four Hours Later…
OK, I won’t say that this was the easiest thing to use. But hey, free’s hard to argue with. And once I start on something, I tend to get a little obsessive. So, around 2:00am this morning, I finished my Teeter design:
I admit, I am not a professional draftsman, and this was in fact the first thing I’ve ever made with a CAD program. But I’m pretty pleased. Here are the essentials:
- Length: 12′
- Plank Width: 15.5"
- Maximum pivot height: 40"
- Minimum pivot height: 36"
If you’ve downloaded and installed Sketchup, you can download and open the 3D model I created here.
I’m excited to start building this thing. So excited, in fact, I’ve got my shopping list all ready to go.
Fatty’s Teeter Shopping List
- 4 2" x 6" x 12′ boards (2 for plank rails, 1 for diagonal column supports, 1, for columns)
- 4 2" x 4" x 12′ boards (3 for riding planks, 1 for base and ad-hoc strengthening)
- 1 4" x 4" x 8′ board (for base)
- Coarse sandpaper
- Wood screws
- 16 sets 4" x 3/8" Bolts, nuts, and washers
- 8 sets 6" x 3/8" Bolts, nuts, and washers
- Loc-tite
- Wood glue
- 1 1" x 2′ pipe
- 2 elbow connectors for 1" pipe
- 2 short bars for 1" pipe
- 1 1" drill bit
- 1 3/8" drill bit
- 4 clamps
What’s Left?
My son and I are going to get started on this thing tonight. I’d like to finish it by next Monday. I admit, I’m nervous. I don’t even know how many times I’ve set out to build something and have it fail in a major way. And while I am not a anxious guy in most circumstances, when I’m woodworking, I can get pretty high-strung — mistakes are hard to reverse, you know?
There are a couple things I plan to do that don’t show up on my design here. I’m going to use my bandsaw to round out the corners at the ends of the totter, so it’s not a hard corner digging into the ground (which will be my lawn, at least initially). I also plan to put a couple of braces laterally, joining opposing diagonal braces. I don’t know if that’s necessary — probably overkill — but I expect it can’t hurt.
If you’re a woodworking kind of guy and see serious problems with what I’ve designed here, let me know. But be quick (and nice) about it, K? I want to get going on this.
Oh, and if you happen to know of some really great teeter plans that are on the net or in your top-left drawer at the bikeshop you work at, please keep that information to yourself. Too late now. Thanks!
Comment by BIg Mike In Oz | 10.3.2006 | 7:16 pm
I love projects with my kids. Sadly, and frequently, it ends with my fumbling incompetence creating something that looks a little like your CAD drawing. That’s OK except when you’re trying to build a fort.
Comment by STACEY | 10.3.2006 | 7:21 pm
Heya Elden,
Great plans! However, looking at your design, I think I see one potential problem. It looks like you may want to introduce some sort of cross bracing between the two towers (top of one to the bottom of the other and vice versa) to protect against a sideways collapse. Otherwise, it looks like a killer project. Make sure you publish its eventual location so I can go & bust my front teeth out on it.
SYJ
Comment by Unknown | 10.3.2006 | 7:58 pm
can i be there for the inaugural teeter try? i would so like to see it in action. hey, if it works out, maybe you have a future in north shore riding props.
or maybe its great entertainment watching guys fall off of the thing, as long as i am not one of those guys.
Rocky
Comment by BotchedExperiment | 10.3.2006 | 7:59 pm
If SYJ is saying to put a horizontal cross-bar on each side of the vertical support arms, then I agree.
I don’t think you need wood glue for anything. Just screw everything together with big a$$ screws.
Botched
P.S. Your geekiness nearly surpasses anything I’ve ever seen or heard of. Very nearly.
Comment by mark | 10.3.2006 | 8:46 pm
Two suggestions: first, your base looks a bit narrow. 24" will not provide enough lateral stability for a 42" high teeter; second (particularly critical if you ignore first suggestion), get a full-face helmet (one each for you and your son). $100 for a helmet is a pretty cheap insurance policy and will make you feel more confident, which will in turn make you ride better.
You should get another 12′ long 4×4, put it on a low platform with ramps on either side, and then you’d have a nice place to practice skinnies as well. You’re backyard could become a freeride playground.
-mark
Comment by birtscraps | 10.3.2006 | 8:57 pm
I would use 3/4 plywood or CDX for the top. The long sheet of plywood will add a lot of strength, be lighter, and be a lot easier to assemble. Also, I would cap the top and bottom, a rectangle like you have drawn will not be very strong, the ends will tend to bend. If you have wood on all four sides it will be much stronger.Trust me, I am an engineer…Scott
Comment by BotchedExperiment | 10.3.2006 | 9:10 pm
Scott, I like the added strength idea, but I think the 2×4’s give better traction when this thing is wet and muddy.
Botched
Comment by birtscraps | 10.3.2006 | 9:16 pm
You ride when things are wet and muddy, eww gross. Good point though.
Comment by Cinco | 10.3.2006 | 9:20 pm
On the 42 inch high fulcrum, if you lower the plank to one of the other two holes, the rider (a beginner?) also has to navigate an opening that is only 15.5 inches wide. That may be a little too intimidating for a beginner.
I have another option for an adjustable base. If you used a triangle with that was anchored at one base point and pivoted at the top, you could set other base varying diostances away from the first base and make it have several heights. Think of the old lawnchairs that had the bar you moved back and forth to make the chair upright or flat. I think this could work very well.
Let me know if you want me to email a sketch to you.
Comment by Unknown | 10.3.2006 | 9:46 pm
The old lawnchair concept is a good one. It eliminates the sketchy "teeth removers" when the teeter is on a lower setting. One little addition (that you would have eventually made through time) is some sort of additional bracing on the bottom of the 6"x12′ planks. They are well tied with the 2×4’s on top but the bottoms would eventually pull away from eachother. You won’t need much, just an occasional 2×4 every 3-4′ should do it.
Rob
Comment by Unknown | 10.3.2006 | 11:08 pm
Aaaand, you will want to bevel the ends of the 12′ plank…6" + 1.5" makes for a hefty lip coming on and off of the teeter. Probably taper it down to a 3" and bury it?
Rob
Comment by mark | 10.4.2006 | 2:02 am
The "lawnchair" height adjuster is a good idea in theory, but in practice building a teeter that way would be unnecessarily complicated. Instead, why not mount your pivot to the very bottom of the platform. The platform is going to be 8" tall, so given that it will only have 4" of adjustability, at the lowest setting the top would still barely come above the platform if at all and would be nowhere near as high as your bottom bracket.
As I suggested earlier, the base should be wider anyway, so you could also eliminate the 15.5" width issue by making a wider base and using some kind of spacer on the pipe to hold the platform in the center.
All of this ignores the probability that anyone who has issues with riding through a space 15.5" wide would probably never ride the teeter to begin with. :)
And as for using plywood versus 2×4’s, the 2×4’s will definitely provide better traction, but you can also nail or staple roofing shingles or chicken wire to the plywood and provide arguably better grip than the 2×4’s.
Check out http://www.thecollectivefilm.com for all kinds of amazing footage of people riding cool stuff like Fatty’s about to build.
-mark
Comment by Jsun | 10.4.2006 | 2:10 am
Your 2×4 uprights will split after about three teeter slams and even a 4×4 will not last more than a few days worth of riding. The hole, unfortunately, needs to be re-inforced with a steel plate because wood cannot stand the abuse. This advice is also free, at my (previous) expense. And the commentor’s other suggestions should be followed too, otherwise you will just be donating this to the garbage man.
Comment by Born4Lycra | 10.4.2006 | 3:43 am
I’m glad I read the comments first because any useful comments i could have made have already been said. However I too am concerned with sideways strength (bracing to restrict any sideways moment) and stability (width of base) and the need for reinforcing all of which seem to have been covered. As someone who has been paid to be a professional designer/draftsman for the last 30 years (and probably still is not one) I would like to congratulate you on your use of the CAD software and as someone who has chosen to be a parent for the last 15 years congratulate you on the formation of your project team. Sounds like Fatty & Son are going tp have some fun before during and after.
Comment by EricGu | 10.4.2006 | 4:28 am
A few thoughts from the guy who does remodeling in his spare time.
1) You definitely should build a plywood box. I would use 3/4" CDX and also put in some internal 2×6 cross braces. If you don’t put the braces in, the box will rack when you load it.
2) You need 4×4 as the verticals. 2x will be too tippy from side to side, and you need the strength in that direction. Alternatively, you could add braces that come out to the sides.
3) Use something other than wood as the weight-bearing. You will quickly tear wood up. One option would be to put some metal plates on the sides, or you could glue some pipe sections inside a larger hole (preferable in my book).
4) I don’t like how you do height adjustment – I think the uprights sticking up when on the lower adjustments are going to be magnets for pedals. My best idea is to build a vertical box open at the top that can hold different length 4×4 supports (email me if that doesn’t make sense).
5) You need lateral bracing. As you have it designed, it wouldn’t take much to tip it over on the side.
3)
Comment by Zed | 10.4.2006 | 4:40 am
I’m looking forward to your freeride video series, Fatty et al.
P.S. I may not be an engineer, but I do know that 2×4’s are actually 1.75×3.75 (give or take). I believe the same goes for 1.75×5.75’s (2×6’s). Since you’re using some of these on their sides, I figured you might want to factor that into your dimensions.
Comment by barry1021 | 10.4.2006 | 1:03 pm
I don’t get it. Where do you sit?? How do you hold on?? Am I missing something?
B21 (true roadie)
Comment by mark | 10.4.2006 | 1:34 pm
I don’t agree with all the calls for additional bracing and so forth on the platform. The base needs to be wider and could use some bracing, but the platform will be plenty stable as is. Check out http://www.spudhucksters.com/BogusProjectII.html to see some stuff that we’re working on here in Boise. All the engineers/draftsmen/carpenters are probably fainting at how rickety this looks, but it is plenty stable, even with big guys on big bikes hitting it with speed.
-mark
Comment by Unknown | 10.4.2006 | 11:21 pm
I am not an engineer. I was married to one, once. That was enough.
I do screw up a lot of home projects, though, and the Doberman always looks at me like she knew better, but she can’t talk, so she just watched and was entertained.
I like all the comments about bigger, cross-bracing, 4×4’s, beefier, beveling the entry and exit points…good stuff…
My only suggestion not already mentioned is to REALLY do a thorough job sanding and smoothing out the ends and edges of EVERYTHING, because riding home with a splinter or ten is one of most irritating things, ever. And seal it real good with some liquid stuff that the big Hardware stores sell in Gallon cans.
Comment by Unknown | 10.6.2006 | 9:07 pm
Thank you Fatty for introducing Sketchup to me. It is just the program i need. I have been thinking about things i could build on weekends and over summer when school gets out (im only 15). Love your sight, even though i dont ride as much as i use to, your sight keeps me connected to cycling.