Seat Tube length

[cgzdf]

I built a model of the rear frame on my trusty spreadsheet following the plans.

My reference point is the bottom rear corner of the Center Boom set at the correct height and angle. The angle between the Seat Tube and the Center Boom matches the notch cut in the top of the Seat Tube. This sets the Rear Fork parallel to the Center Boom. By the time I got to drawing the dropouts I noticed that the rear wheel axle is 11.5 inches off the ground. I expected more for a 26" wheel.

For Brad:

What is the rolling radius on the rear wheel of the prototype?

What is the length of the Seat Tube along the forward face?

May I post the spreadsheet?

Dave
(Draw, measure, cut then weld)

[trikeman]

I have a set of MTB 26" wheels with 26x1.25 tires that measure only 12" from ground to axle center. What they don't call them 24" wheels is beyond me.

[Radical Brad]

No problem, post away.

The radius of my rear wheel from axle to tire edge is 12.5 inches. I am using a pretty standard profile tire there.

The other side of the seat tube length I do not know since the seat angle is what counts there. I can try to measure it for you if you like.

Brad

[cgzdf]

I was unable to attach a spreadsheet but did manage the drawing.

I may be over thinking this as the trike has been built. Stretching tolerances on size and angle allow for a 12.5 inch radius rear wheel. I calculated 11 inches trying for "deadly accuracy" (assuming that I have found all of my errors).

For all of the time spent on this I would have been further along had I just started cutting. Sigh - where did I leave my grinder?

Dave

[trikeman]

I may be over thinking this as the trike has been built.

Dave

That's always a dead giveaway [g]. Reminds me of the old economist joke about and economist being someone who wonders if something that works in real life will work in theory.

One problem I see with your spreadsheet drawing is that the 11" inch measurement doesnt' go all the way to the ground, but I am not sure if you drew it by hand or used some complicated spreadsheet formula to do it. If the latter, might be interesting to see how you did it.

[trikeman]

By the way. I asked a question in the original Warrior thread (the one that gets erased when the plans come online). Since it was poorly worded it probably didn't deserve an answer, but this drawing reminds me of it

The old StreetFox required a rather complicated compound cut in the cross tube to achieve center point steering and caster. Two other trikes I have seen with square tubes (SJ's and 25Hzs) get around the complication. 25Hz eliminated it by welding the crosstube to a tube already tilted at 15% from the vertical. On the new Warrior design, the tube that the crossmember is welded to is also pointing towards the sky at an angle. I assume this means that a compound angle is not necessary when welding the head tubes to the cross member. That should make the Warrior easier to build than the StreetFox - an improvement if I am understanding it correctly.

[cgzdf]

That's always a dead giveaway [g]. Reminds me of the old economist joke about and economist being someone who wonders if something that works in real life will work in theory.

One problem I see with your spreadsheet drawing is that the 11" inch measurement doesnt' go all the way to the ground, but I am not sure if you drew it by hand or used some complicated spreadsheet formula to do it. If the latter, might be interesting to see how you did it.

Ground level is the 0.00 mark on the scale at the left. You were probably thinking that this trike will be fast enough to get airborne cresting a hill. Fly low :)

PM me your email and I will return the spreadsheet.

Dave

[trikeman]

Dave: Got your spreadsheet. Interesting and creative use of a spreadsheet as a simple CAD plotter program. I would have never thought of that. I may have to try that technique myself, since I find most CAD programs too complicated for this old dog to justify learning to use them.

[SirJoey]

...too complicated for this old dog to justify learning to use them.Who have I heard saying stuff like that before? Hmmm...

Oh yeah, ME! :laugh3:

For me, it's kinda like that with the metric system. Although not complicated, quite the opposite in fact,
I just don't wanna learn a "new" system, & I can't bring myself to think in those terms.

Anytime I see or hear something measured this way, I have to convert it to the old,
antiquated system I grew up on, to understand what's being described. :rolleyes:

Feet, inches, miles, pounds, quarts, gallons, farenheit, etc, FOREVER!
LONG LIVE THE NEANDERTHAL MEASURING SYSTEM, BABY!!! :punk:


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[Freth]

You are thinking this thing to death ...
buy tubing ... make cuts ... start welding!

I have enough tubing left over from my DeltaWolf projects to start making the frame ... rear forks and main tube coming up in the morning ... enough parts in donor scrap pile ... just got to purchase some hubs and string the front wheels together.

[John Lewis]

You are thinking this thing to death ...
buy tubing ... make cuts ... start welding!.

Yep that's just what I did and suddenly I had bikes popping up everywhere. If you spend time fearfully agonizing over the build and afraid to make mistakes you will never begin. Most mistakes can be fixed with an angle grinder and welder.

Another good tip is to do something on the project every day no matter how little. That tip came from a prolific homebuilt aircraft builder. It works because you keep doing a little until you finish. I find it hard to get back to a project if I have to leave it for a while. and the above strategy is a great help.

John Lewis