28"(or 700c) rear wheel in Warrior?

Joined
Apr 23, 2020
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Netherlands and France
A good evening to all of you!
May I ask a few questions? I am in the process of gathering the base material for the build of a Warrior trike. Since I have a roadbike spare (and ready to cut) as well as two wheel sets, all 28"or 700c, I was wondering, has anybody built a Warrior with a 28"rear wheel? If not, then why? And if you did, what has to change to the original Warrior plans to make things work? What dimensions need to be adapted to the other wheel size?
I still plan to get me an old BMX bike with 20" wheels and canibalize that for the front wheels. But if I can re-use the old 28"wheel it saves me from the purchase of an old mountainbike (26" wheels).
All the best, Kiezel
 
Joined
Oct 19, 2012
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Wakefield, UK
I'm currently building a 28" rear tadpole but not a Warrior. Other than making the rear wheel arms an inch or so longer I doubt it'd need any other changes. If following the plans fairly closely all other important dimensions and angles follow on from having made the rear end anyway so will naturally allow for that slightly bigger wheel as a consequence.
 
Joined
May 31, 2013
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South Benfleet, Essex, England, UK
Probably will make next to no difference, but some people have chosen to add strengthening gussets where the rear forks and backrest/spine intersect to add some triangulation and therefore strength in this area.
Maybe it is a good thing, maybe it just moves a potential for failure elsewhere on the frame. There have been suggestions that the frame might attempt to "fold-up" if a powerful mid-drive kit is added.
 
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Apr 23, 2020
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Netherlands and France
@Popshot, @DannyC, Thank you both for your replies, much appreciated.
The strengthening is something I already had planned to do, just to be sure. My main concern was that by changing the diameter of the rear wheel there also will be a change of the corners in the steering layout. But that can probably also be corrected when connecting the rear fork to the main boom.
Also, the transportation of forces induced by strengthening the connection of the rear fork could lead to more strengthening of the frame - by adding some bars to the front wheel booms and create small triangles there. We will see it when I get there. Building will start within a month or two - pictures are planned to be made.
 
Joined
Apr 16, 2017
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Winnipeg, Manitoba
When I built my Warrior it used the 700C rear wheel with a heavy hub motor. The first issue was the length of the rear wheel arms. I had followed the plans but the 700C was larger in diameter so a new set of longer arms was called for. No big deal just a bit more cutting, grinding and welding. The hub motor was a BionX unit 500 watts and fairly heavy and had quite a bit of torque. One day I stopped mid point going up a small hill and when I resumed the trike sagged in the middle. The weld at the junction of the rear chainstays was good but the metal near it had actually torn. My friend continued on and returned with my truck and the Warrior had the torn part of the frame straightened and then gusseted. At the same time some gussets were added where the front wheel arms attached to the frame. No more issues and the Warrior was ridden for a few thousand KM,s trouble free. As a side note I have now made a switch to the Delta style and have built 2. One loderunner variant and an Aurora delta. One change made to both plans was a switch to the heavier gauge of metal Brad recommends for heavier riders and gussets are still added to all frame intersections. Again, no issues with durability so far. All the Deltas use mid drive motors for assist. And Kiezel you are correct about the change of steering being corrected when connecting the rear chainstays to the main boom. One other piece of advice might be when you add the brackets for the axles to make the right side a bit larger ( ie lower) to provide a mounting location for you derailleur. That is what was needed on mine. Rear derailleurs come with some variation of mounting styles, its easier to trim then weld an extra piece on later.
 
Joined
Apr 23, 2020
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Netherlands and France
Thank you @Hugh for your reply. I plan to buy some 40mm square tube with 2mm walls (instead of 1/16") since we have no inch-based tubes easily available. That will be a bit heavier than what Brad prescribes. There will be also some additional lighter tubing (20mm square) on the underside of the rear fork, to close the triangles. Same goes for the back-rest tube, but there I plan to use some steel strip. On the steering booms I would like to use the lighter tubing, for the good looks of it. And maybe to mount a bottle-holder or something. Electro assist is currently not on my skedule, but I like to stay on the safe side (not always possible to reach out to someone to drag me home).

I expect to correct the steering angles of the frame when building the main boom. If this is according the original plan, then connecting the rear fork should have no impact and all steering angles will be as designed.

And thank you for the idea to keep the righthandside tab of the rear wheel a bit longer, this is something you will learn through experience - so thanks again (I will make my own mistakes, be sure of that).
 
Joined
Oct 19, 2012
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Wakefield, UK
40mm square would probably be fine at 1.5mm unless you're very heavy or intend to rag the trike over very potholed roads. A recumbent trike will be heavier than almost any bike to start with and adding more weight than you must is the easiest thing in the world to do.
 
Joined
Apr 23, 2020
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Location
Netherlands and France
Thanks, 40mm square at 2mm is a standard product for a reasonable price. I couldn't find the same (aproximately 40x40mm) at 1.5mm.
I plan to do a lot of the cycling here in France, not every road is padded with tarmac. Also, count in my (extra) weight due to the corona-staycation (and not a lot of exercise).
 
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