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 Trike time (see pg 5 for build 1)

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warren Posted - 11/03/2016 : 15:03:21
The gentle reader may ask, "Why don't you just pick a trike and ride it!". Oh, I have reasons gentle reader, reasons.

After riding and racing the Greenspeed Areo, I can say it handles corners well and is fast in a racing environment. I do not however fit in the seat as they are designed for "normal" height humans and major reconstructive surgery would need to be performed to make that happen.

After racing and riding the ICE Vortex (almost a VTX!) I can say that the seat fits me well and it is comfy, but due to a lack of triangulation it does not do well in a racing environment. The VTX is stiffer in the rear and has a seat which can be laid back more that the Vortex so it would be better, but is still has just a monotube and that will allow the rear wheel to deflect in the hard corners.

That leaves the Catrike 700 yet which I not raced or ridden in anger. It is however quite popular in the HPRA racing series. If I were to obtain one, it would need some modification including a hardshell seat to get me a bit lower, and probably a change to indirect steering. If my backside can fit between the seat rails they would make great side bolsters to prevent sliding off the seat in the hard corners.

The final option is of course, building one from scratch.

Here's my web page documenting my racing trike investigation and research.


So, What makes a recumbent trike fast? Build or buy?

25   L A T E S T    R E P L I E S    (Newest First)
warren Posted - 12/11/2017 : 15:19:02
No, I'm going to make it OSS.
carolina Posted - 12/11/2017 : 14:17:48
True tank steer like Ian simm’s trikes?

warren Posted - 12/11/2017 : 09:25:53

Yesterday I tack-brazed the kingpin head tubes and the cruciform in place. Yes, I had to do a bunch of measuring and re-measuring to make sure it was all straight, but I didn't build a special trike jig. I hope I don't regret that decision!

Today I added the wheels and eyeballed it and did some measurements to make sure all the angles are correct. It looks pretty good. The next step will be to build the Ackerman steering and brake brackets and then add them to the kingpins.
carolina Posted - 12/10/2017 : 13:43:04
Wow, looks great. Like perfomer trike crossmember.

warren Posted - 12/10/2017 : 09:21:56
As lamented above, I had cut the wrong sized hole in the boom tube for the cruciform, which basically ruined that tube. That's probably a good thing because it forced me to cut it off and make a new one that is actually at the right angle. This picture shows the boom stub tube tacked onto the main frame, with the correct size hole cut into for the cruciform tube.

Here's the cruciform tube inserted into the jigged up frame to eyeball it. Looks fine.

I made the fish mouth cuts into the cruciform tube, at the correct angle of 76 degrees to match my kingpins. To provide the correct caster (trail), the cruciform will be angled backward at 12 degrees. This should look fine as it will be about 90 degrees to the boom tube.

All the tubing holes and fishmouth cuts were done in my drill press.

Jerry Posted - 12/09/2017 : 07:01:51
I have had some luck with getting an aluminum tube out of fiberglass by spraying the tube with my wife's cooking spray and drilling a hole at about 45 degrees close to the end so I could stick a coat hanger or other stiff wire into the 45 degree hole. I would put a about a 3/4" bend on the end of coat hanger so it would look kind of like a "c". Stick the tube where it is very cold, and then give it a little tug. If the aluminum is just a little longer than the CF, you can put a twist on the wire. Good luck with it.
warren Posted - 12/08/2017 : 14:18:45
Failed miserably at cutting the hole in the frame by using the wrong hole-saw. It certainly looked like my 1.5" hole-saw! I think the problem is that stub of 2" tubing, it hates me. I cut it off and will add a new one, this time at the correct angle. Sigh.
warren Posted - 12/05/2017 : 10:54:42
Trimmed the ends off the tube. Next step is to cut a 1.5" hole in the frame tube for the cruciform and tack it in place.

Also I need to start thinking about the CF boom. My plan is to make a CF tube by wrapping the CF around a 2" aluminum tube, and then using a heat shrink sleeve to compress it. If the part is cured someplace warm, and is then put someplace cold, my hopes are that the aluminum will shrink enough to allow me to remove the aluminum tube. The CF boom will then be clamped to the 2" frame and BB assembly stubs.
warren Posted - 11/30/2017 : 15:51:46
The 1.5" x .035" tubing arrived, and I stuck it in the tubing bender. Here's my tube bending demo video:

After some work, the tube is bent to the correct diameter, yay!

warren Posted - 11/28/2017 : 09:53:25
I ordered a 1.5" x .035" tube for the cruciform arms. I should be able to bend it in the roller bender, hopefully to a small enough radius. I really do need to build the cruciform jig now, and I'm out of Acetylene...
purplepeopledesign Posted - 11/23/2017 : 11:48:16
Different distance to front wheel creates differing turn radius.


Those who claim to be making history are often the same ones repeating it.

Video of my trike
Photos of my trike
alevand Posted - 11/23/2017 : 07:43:35
Why did they scrub?

Tony Levand
Speedbiker Posted - 11/23/2017 : 01:35:03
Jensen, I built a mbb lowracer tilting trike that used the I-lean tilt system. It was just an experiment. Worked fine but the rear wheels scrubbed on hard turns.
warren Posted - 11/22/2017 : 08:57:58
I spent too much time changing the 2 inch dies to 1.5 inch dies in the tubing bender. The 2 inch die was stuck and I had to completely disassemble the tubing bender to get it out.

To make the bearing seats I used 1-1/4" x .058" tubing to fit over over the 1-1/8" steerer tube. Brazed in the bearing seats and the shims for the lower bearing race and then did a test assembly of the headset assembly. So far so good!

Made the 1X cruciform drawing. If I make the cruciform tubes straight my thighs may hit them, so I'm going to try to bend them.

Looks like I need to order some 1.5" thinwall tubing for the cruciforms. I thought I had some but it's heavy .058 wall.

purplepeopledesign Posted - 11/18/2017 : 16:23:00
You built a tilter?


Those who claim to be making history are often the same ones repeating it.

Video of my trike
Photos of my trike
Speedbiker Posted - 11/18/2017 : 06:26:38
Now I remember why I never built at trike( except a tilter nobody ever saw).
Jackrabbit Jimmy Posted - 11/18/2017 : 05:33:15
Warren, I see you use the same Newfie CAD system that I use.

Originally posted by warren

It took 5 hours to cut, mitre, jig, tweak and braze this joint. And it's off. How far off? Looks like the BB will be at 10.5" now. Hmm. 6" crank length plus 7.5" of shoe = 13.5" to the ground with foot hanging straight down at the bottom of the pedal stroke.

Apparently my plastic angle measuring tool is not good for low angles.

Fortunately your foot doesn't normally hang straight down at the bottom of your pedal stroke. I measured on my bike and it looks like I need about 10" of ground clearance while pedaling normally. Hmm. I'll try it and have to tweak it a bit if it's not enough clearance.

Jackrabbit Jimmy
warren Posted - 11/16/2017 : 10:29:06
More work on the kingpin assemblies - drilled out the axle hole to match the axle diameter, pressed the bearing races onto one of the head tubes, ordered 1-1/4x.058 tubing for use as bearing seats, found some sheet metal to use as shim between lower headset bearing race and the steerer tube. Now I have a complete assembly that I can use to make measurements to add the cruciform tubes!

Did the 1X cruciform drawing. Cruciform tubes will each be about 1ft long. These will be more tubing cuts that need to be right! The joint where the cruciform tube attaches to the head tube has to be angled in two dimensions, both kingpin inclination and caster. Fun (Not!) I think I'm going to cut the main tube at the point where the cruciform attaches to fix the boom angle. This will also allow me to attach the cruciform tubes together inside the main tube. Should be stronger and allow for some minor tweaking.
warren Posted - 11/13/2017 : 21:33:12
Brazed up the kingpins. I don't have a lathe so I had to fake it with concentric tubes. The holes in the sides of the tubes are to braze the axle tubes together. I was able to create the proper angle hole in the steerer tube with a 3/4" holesaw. Aaaand I'm out of acetylene.

Low tech construction pics:

The next trick is to make the seats for the headset bearings.

More here: http://www.recumbents.com/wisil/trike/default.htm

alevand Posted - 11/13/2017 : 10:32:50
Must be flexy if the trisled only weight 14 kG.
http://trisled.com.au/hpv/gizmo/" target="_blank"> br / http://trisled.com.au/hpv/gizmo/

Tony Levand
warren Posted - 11/13/2017 : 08:25:54
To save weight I'm going to make a CF tube for the boom that will bridge the gap between the cruciform area and the BB area. Otherwise I have to use the super heavy .049 wall 2" tubing. I can put a slight mitre in the CF tube. The CF tube will clamp over the 2" frame tubing so the boom will be removable. That way it will fit in my CRV.

A trike like this built from a bent tube would be very cool. I can bend the 1.5" OD tubing in the roller bender. How does Ben at Trisled get away with using 1.5" OD tubing to build his trikes? Are they flexy or does he just use thick heavy wall tubing?
alevand Posted - 11/13/2017 : 06:04:37
Are you using the boom off the donor bike? Its too short for the bender. I adjust frames by slicing the tube part way, near the joint, with a .030 cutting blade in the hand grinder, applying force to close it, cut again to get to close most of the way and weld it up. How hard it would be to redo the joint?

Tony Levand
Speedbiker Posted - 11/13/2017 : 00:07:42
Warren, run the boom through your tube roller!

Camber = slower.
warren Posted - 11/12/2017 : 14:57:24
The kingpin parts are cut and ready to braze. And I actually cut the angles right. Amazing.

No wheel camber, Tony.
Jerry Posted - 11/12/2017 : 10:25:13
Ha ha, I could lower the BB 3 more inches and still have heel clearance. I know the feeling Warren, been there, done that, way more than I want to admit! Looks like it will be a very fast trike though.

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