Jon's Warrior Build

Joined
Feb 5, 2008
Messages
563
Location
Fernley, NV
Website
miscdotgeek.com
I don't mean to be a nay sayer- it's a solid way to continue without solving the problem so that you can come back to it. But... I wouldn't. Steering isn't something you want to mess with. Do a Google Image Search for "Scary Steering" and you'll find they all feature one major thing: bent tie rods as part of the design.


Really- it's not worth skipping it. At the very least, split the rod in two and use an idler arm in the middle.
 
Joined
Feb 5, 2008
Messages
563
Location
Fernley, NV
Website
miscdotgeek.com
Yes, a pivot between them. Look up "steering idler arm" in a google image search to get an idea how they are used in the automotive world. For this application, I'd use an old American bottom bracket with one of the cranks cut down and used as the arm, and the BB used a the bearing. It's way overkill but perhaps you have parts on hand. Whatever you do, the geometry set by the steering arms themselves should be the pattern. The distance between the rotation axis and the tie rod mount should be the same as the kingpin to the tie rod on the steering arms and it should pivot in the same plane, ie have the same as the head tube angle.

In this picture, the red arms are all the same length and the blue angles are all the same:



But frankly, if it were me, I'd be fixing the underlying problem instead of adding complexity. Sorry :/
 
Last edited:
Joined
Jul 7, 2020
Messages
107
Location
Ontario, Canada
So I decided to fix the underlying problem.

I cut the bottom and side welds on the steering booms, and bent the booms slightly flatter, and then re-welded them (not finished, you can see on the right boom I haven't done the vertical welds yet).

The end result is a small amount of negative camber, and a straight tie rod.



I'm pretty happy with this - it remains to be seen how well it actually rides and corners. Next up I need to do the steering rod between the handlebars and one of the front wheels.
 
Joined
Feb 5, 2008
Messages
563
Location
Fernley, NV
Website
miscdotgeek.com
Hey that looks a lot better with a straight tie rod! Nice work :) It looks like you've got a lot of positive camber going on there. I don't know how that will affect handling. I wonder how hard it would be to reset the head tubes to compensate, and get back to the original angles? It's another one of those things that would be 1000x better to do now rather than later.
 
Joined
Jul 7, 2020
Messages
107
Location
Ontario, Canada
I don't think it will hurt to leave that for later - its not like that part of the trike gets any more complex. If it adversely affects the handling, I'll fix it then.
 
Joined
Oct 19, 2012
Messages
2,384
Location
Wakefield, UK
Straight tie rods are always better than bent ones. A good decision to fix the underlying issue rather than work around it.
 
Joined
Jul 7, 2020
Messages
107
Location
Ontario, Canada
I did a bit more work on things last night - started working on the second steering rod. This is the setup for getting ready to weld the steering arm to the handlebar tube.



I've got the other two pieces (for the part connected to the axle mount) cut, just need to grind rounds on the flat plate and do some more welding, and then put together a second tie rod.
 
Joined
Jul 7, 2020
Messages
107
Location
Ontario, Canada
So I finished up the steering tonight - I'm pretty happy with how it all came out.



Here's the trike on its wheels:



I have some handlebar halves that I will be welding to the ends of the mountain bike bar extensions, so the grips will be much higher in the end.
 
Joined
Apr 15, 2013
Messages
2,054
Location
Washington state
And if the pic is correct, where is the Ackerman steering angles?
 
Joined
Jul 7, 2020
Messages
107
Location
Ontario, Canada
The ackerman steering angles are built into the geometry of the system. Each of the front brake mounts has a tab that goes inward, where the tie rod is attached. The angle between the wheel pivot and the tie rod pivot is what gives the ackerman steering (see page 131 - 134 of the plan book).
 
Joined
Jul 7, 2020
Messages
107
Location
Ontario, Canada
Last night I welded the handlebar extensions, and I'm pretty happy with how they turned out.



Now I've started looking at how to attach the front calipers, and it turns out its going to be complicated. Older style disc brake calipers are screw-mounted from the side, perpendicular to the rotor, which makes it easy to just weld a shaped plate to the steering arms (like I did with the rear caliper). The ones I bought for the front are apparently the "modern" style, which screw from the top, parallel to the rotor, like this (just a random pic from google images):



This complicates the mounting somewhat.
 
Top