Comments on: How to Build a Mountain Bike Teeter, Part I

By: Unknown

Unknown — Fri, 06 Oct 2006 21:07:33 +0000

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.

By: Unknown

Unknown — Wed, 04 Oct 2006 23:21:21 +0000

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.

By: mark

mark — Wed, 04 Oct 2006 13:34:58 +0000

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

By: barry1021

barry1021 — Wed, 04 Oct 2006 13:03:50 +0000

I don’t get it. Where do you sit?? How do you hold on?? Am I missing something?
B21 (true roadie)

By: Zed

Zed — Wed, 04 Oct 2006 04:40:19 +0000

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.

By: EricGu

EricGu — Wed, 04 Oct 2006 04:28:29 +0000

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)

By: Born4Lycra

Born4Lycra — Wed, 04 Oct 2006 03:43:55 +0000

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.

By: Jsun

Jsun — Wed, 04 Oct 2006 02:10:10 +0000

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.

By: mark

mark — Wed, 04 Oct 2006 02:02:17 +0000

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

By: Unknown

Unknown — Tue, 03 Oct 2006 23:08:59 +0000

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