emiyata said:
AW I can only tell you how I made a standard trike at higher speeds more stable.
Well, the problem is really with tipping, but I suspect that preventing "wiggle" steering issues is gonna require a damper. I may experiment with other head angles or trail amounts, etc., but I'm pretty sure Chalo's right and having as little as possible is a good idea.
If you can find 3 bathroom scales and put one under each wheel you will know your weight distribution . It looks like the weight is in the back of the bike but pictures can be deceiving .
Most of the wieght is right where Im sitting, as this trike doesn't weigh all that much--even with the battery and motor I doubt it hits 80-90lbs, cuz I could almost dead-lift it (not that I'd want to, but I'm usually very strong ina dead lift straight up, with knees locked and just lifting something from belly height to mid-chest height, and if I can handle the pain I can do it with my knees from the ground, but that's only an emergency kind of thing these days), and I can't quite do that with either Hachi or Nana anymore, and they each weigh just over 100lbs last time I checked.
I only have two scales but I can probably setup a board across one scale and balance both rear wheels on that, and the other scale on the front. Then I could raise up the front by the height of the scales and then reweigh the rear one under each wheel, to get left/rgith distribution ratio to apply to the total rear weigth. But it's not in the "plan" for a while to do that (or much of anything else on the trike).
emiyata said:
AW go to this picture http://www.electric-bikes.com/trikes/trikes23.jpg I was thinking you should be heading more this direction.
Problem with that version is it has no cargo space, or at least, not nearly enough for what I have to be able to carry. I'd have to move the rear wheels back by at least 2 feet, and at that point I'd have a trike about as long as CrazyBike2 was with the trike kit (maybe even longer), with about the same COG characteristics, and I already know that would be worse tipping problems than what I've got here with Delta Tripper.
Best compromise is to do something like what "trike23" pic shows

but with cranks over front wheel to shorten the wheelbase a lot, yet seat down low like that. But that puts my seating postion very laid back, and I don't think I can see well enough to safely ride like that, as I doubt I can handle the head/neck position it would require.
Sancho's Horse said:
I just don't see a way out of the tipping issue, not without some seriously different geometry. The only two ways to effectively reduce tipping tendencies are by lowering the center of gravity or widening the track. Both look to be some serious mods with your rig.
Yes, and basically lead me to have to build a completely new trike instead. This trike is still useful, but only if I slow greatly for turns, and avoid all traffic situations that might require any kind of emergency steering maneuvers.
On mine I have a lot of very heavy things very low. The diferential is 12" off the ground (with heavy 1" axle +hydraulic brake accoutrements), the batteries will be only 8" off the ground, with a backup set at only 14", my trailer has the hitch up higher, but where the weight of that hitch is actually transmitted to the frame is only 8-1/2" off the ground, the motor axle is ~20" off the ground but I am hoping for a little gyroscopic effect to help, and this is on a rig with a track which is 44" wide inside of wheel to inside of wheel. This width brings my tipping point COG to 23-1/2". The COG must stay within a triangle 23-1/2" at the center of the trike down to the spot where the center of each back wheel makes contact with the road.
That's probably more like what I'd be after, but not possible with this trike.
Yours looks like a triangle with an apex at only 12-14". This is a very tall order, and the further you get the COG above this 12-14" mark the greater the likelihood of tipping, and the greater the amount of force being transmitted (due to length of lever arm) in the tip. And I still feel that tipping will not be a completely resolved issue.
On this trike, I don't think I can do much about it. Especially when it's loaded iwth cargo. If I were to spend the effort building the new square-tubing cargo frame and wheel supports I sketched in a previous post, it would likely help some, but not enough to make it worth the effort, when I could instead put that effort into a properly-designed tilting tadpole trike that would not really have these issues, and could be made to be however I want it to be.
Lengthening the rig can handle some stability at speeds, but as you noticed, it doesn't do much for tipping. It just opens up the space in which you can move the COG, but does not help tipping point COG. The front wheel geometry doesn't really help with tipping in a turn either (unless it is completely wrong in which case it can hurt). It is largely a matter of preference. I prefer the bigger offset. It allows the bike to continue forward without as much tendency for pull inducing occurances to create movement in the wheel/handlebars.
From what I could tell, it made tipping worse, because CB2 in the trike configuration was smaller 24" wheels, lower to the ground, my wieght much lower, battery weigth lower, etc., yet it was more prone to tipping than this one is, using the identical axle/kit.
If you are going with what you have trike kit setup wise (i.e. width, etc.), how about getting radical with it. See about some really, really small scooter hub wheels, think 12-14" which you can lace the motor into. Radical I know.
That's an interesting thought. I have some even more radically-small wheels, like 8" or something, 3" wide IIRC, from a little kids' scooter type thing, that could be fitted into the axle. I would have just about zero ground clearance for the axle, though, so I'd have to be careful about speed bumps in parking lots and such, ensuring I never cross one diagonally. :lol:
I have some 14" (I think) wheels from a powerchair, which I could even use the powerchair brushed motors that bolt directly to them, if I use a pedal chainline that goes to the front wheel instead (I dunno any good way to make a pedal drivetrain to these types of wheels taht would actually be useful and still simple/buildable with what I have--I thougth about this before). I could also use a wheelchair frame (which these are meant to bolt to) instead of this trike frame, which would be lighter (compensating a tad for the heavy motors and wheels). At this point, it's a completely different trike though, again. I even pondered doign basically this once before on my old electricle blog:
http://electricle.blogspot.com/2009/05/wheelchair-based-trike.html
http://electricle.blogspot.com/2009/05/wheelchair-trike-layout-ideas.html
But width-wise, I actually need to make it narrower by at least 3-4 inches, so I can take it inside my front door, and not ahve to leave it outside.
But if you don't mind pulling trailers, they could help with COG, hauling ability, seat placement possibilities, etc. But the one brake issue. Dude, sorry...I just don't know.
Brakes are easy. I just have to weld studs to the "stays" of the trike wheels, and isntall them, then find my dual-brake handle, meant for this purpose.
Trailers...I've dealt with my trailers ok on various bikes, but basically they are a PITA to laod and unload, espeicaly with big heavy cargo like I usually have (piles of bags of dogfood, or piles of usually-heavy scrap materials that I am saving from being trashed, are the two most common things). Loading the trailer so it will track right and not tip forward or backward too much and apply the wrong load to the tongue and hitch is difficult when I have to haul 200-300lbs or more of stuff like that. I don't have to do it every day, but at least every month or so, some opportunity comes up to need this option, but i have to do it right then--I can't go get the trailer and come back, hardly ever.
That means I have to haul the empty trailer around with me no matter what I'm doing, and it skitters around the road on turns, and bounces a lot on potholey roads, and in crosswinds threatens to flip. (none of which are an issue when it's loaded sufficiently and properly, but anythign I carry on it reduces what I could carry cargo-wise...and I don't feel like carrying a load of rocks or sandbags around with me all the time just so I have something I can dump in place of cargo).
it's also two more wheels to go flat.
So, I prefer to keep all the cargo capability actually part of the vehcile itself, and use the trailer only for things I can plan out ahead of time (which might be a few times a year, if that). Even though it complicates the actual vehicle in a number of ways. It's just far more convenient.
Maybe for now I'll just ride this one, found in the dumpster at work today (along with the big aluminum tube that used to be a "smoker's outpost" for dropping cigarettes into):
If I could weld aluminum (or bolt/clamp to it) maybe I could use this as a "downtube" on a bike or trike that could also hold a big battery:
Also gotten from work (the day before), something to make the dogs happy. Seems to be working:

(Fred and Loki each had their own smaller versions but didn't pose for pics).