The Trikes keep getting longer...

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Another thing to consider is what happens when you turn the front wheel on a typical bike, to make your turn. the front end of the bike actually drops slightly due the angle of the headset. If you have fixed rear axles that will cause the load to shift from the rear axle to the front axle of a tandem setup as you turn.

If you are set on having tandem rear axles...think of how to self steer one or install one axle with a caster like attachment for each wheel. Also consider some sort of suspension for at least one rear axle. Otherwise you might build a bike that only works for straight line or very slight turns on hard surfaces.

How many drive wheels will you use? Each wheel added to the rear setup means less of the load on a single driver, and less traction.

Not saying it can't or shoujldn't be done, but you will need to do some development of your ideas to get it to function well. Maybe we are being too technical and it will work just fine....you won't know until you build and pedal it.
 
This is cool. I love that trike in the first picture. And you know what? Just ignore all of the talk about wheel scrub and whatever, and do what you want. If it doesn't work, it doesn't work. When I was a teenager I built a sidecar for my BMX bike out of 2x4's and an old bike wheel -- it totally didn't work. Didn't matter, it was the engineering exercise that made it worth it.
 
I think this is a really cool idea. In my opinion, the center 2 wheels would be the drive wheels. Seems like the scrub issue would be lessened that way. And if you run more pressure in the back wheels, your contact patch will be smaller, and the force needed to drag the wheels will be a lot less.
 
Actually more pressure in the front might lift the rear axle away from the pavement and help out.. I am thinking if you mount the axles somehow that you can adjust height it will help you tune the suspension...
 
I do appreciate all the feed back. Gives me more ideas to consider as I go about this project. There is no way I could consider all possibilities before I start building. All of the trikes I have done so far have been trial and error. Its the best most expensive, time consuming, frustrating, and most rewarding way to build in my opinion. Nothing like doing something 5 times, lol. I seriously do appreciate all the input though. Gives me things to consider and possible solutions as I go. It will have only one drive wheel until I get the electric hub for the front. The trike units in the back are the ones from a Schwinn Meridian and only have one drive wheel on the right side. I could make one wheel on both trike units a drive but the amount of chain I am using is already starting to become an issue, keeping it tight and chain sag. I could even flip one of the trike axles and make a front left/rear right drive setup. For some reason I have a feeling that there will be a few versions of this before I get it perfected, lol. I enjoy the challenge though to be honest.
 
JGood said:
Hmm... How bad do you think it will be? So you are saying they will drag to the side that I am turning. I have seen this on trailers but figured the relatively low weight would help make it not so bad. It might be easier to make the front set of rear wheels take weight and the back be the ones that barely touch but then I imagine the drag would be worse because the front set would also be the drive set. Any other ideas as to how to make this work minus making them steer? Also I was planning on putting the electric hub in the front wheel so it pulled everything and I could assist by pedaling the rear when needed. Any input is GREATLY appreciated. Thanks everyone!
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It has nothing to do with weight persay. With dual axled vehicles, if you notice, they take wider turns than others without. the tighter the turn the more trouble turning they have, such as scrubbing and dragging. Think about how it turns now, ride it and watch the rear when it turns. You said it almost turns like a zero-turn lawn tracktor at a standstill, imagine another set of wheels in front of those in the same turn. At least two of the wheels won't be happy.

I'm not saying don't do it- it's not my place. i'm saying it'll need to turn as if it was a long bed pick up. Which it's about the size of already, lol. If a road coach cuts a tight turn, the dead axle wheels drag in to the turn. The situation with the dead axle in front, will be similar. If it where me, I'd just convert it to a dual rear wheel axle. I can picture the tandem setup killing tires. I actually had a similar idea accept my trike was going to be a halftrack. Again, it would've been a wide turner, if you do do it, it'll be your only saving grace. That's why trailers have that issue and the tandem axle trucks that pull them don't- their turning radius is wider than the trailers.

Then again, question; do dumptrucks and other multi axle vehicles have this issue, I've seen garbage trucks do really tight for them u-turns to get trash cans on the opposite side of the street with no problem, then again what axle and wheel on it powered varies. I've seen a stuck rig where it didn't know where to send the power, sending it to only the rear axle until one wheel slipped, then to the front where both spun and then the rear started spinning. I think the have torsen diffs and splitters.
 
I prefer "minor modification" no matter how large the modification is...

The more I hear and think about it the more I realize how important the front wheel drive electric will be to making it work. I am fine with wide turns. When I ride to the beach the only time I am on the sidewalk is going over the bridge so I have the whole road to turn. I like the dually style axle but with that I could not park it inside my shed (has to go through a door due to length) or ride the sidewalk over the bridge so that is a deal killer. So far I have made the longer extension arms and am getting the second set of wide rims laced, they will be back Friday. Saturday will be the build and test day. Wish me luck, hopefully I won't need it but can't hurt, lol.
 
I love the look with the single wheels on the back. I wouldn't change a thing. Why mess with perfection? Tweak it don't kill it.

Sent from my Nexus 7 using Tapatalk
 
either way, I want to see how it turns out. make it like a real semi and have like three hub mid drives and top tube mounted shifters. do you think a front drive ekit will be strong enough? This is me talking but I'd have a second kit running one of the rear nondrive wheels and a three position switch for front, rear, and both. I'll morally support whatever you do cause it's awesome now and cant go nowhere but up.
 
bidaci said:
I love the look with the single wheels on the back. I wouldn't change a thing. Why mess with perfection? Tweak it don't kill it.

Sent from my Nexus 7 using Tapatalk
Click to expand...

I can always use that back end on another bike. The nice part about the way I did it is I can switch it to just about any bike. Maybe I will flip from Dual to single every other weekend, lol.
 
Here is the latest version. It is the correct length, measuring in at 11-1/2 feet. I am getting tires for second trike axle today so I can see where to place them on the extension bars tonight. Also using this frame for now since I have an electric motor mounted on a 4" rim and this is the only frame that will fit that. Want to try the electric front drive first then will switch to the pedal version with the black frame and see how that works. That is the advantage of the way I did it is I can mount this on just about any bicycle frame. Hopefully will have pictures of the 5 wheel bike in the next day or two.

 
Ran into a slight snafu... The weight of the bike lifts the back wheels off the ground, the first set acts kind of like a fulcrum. So now I have to figure out how to mount them slightly lower in the back than in the front. Fun. I will figure this out though.
 

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