Science Project Goes Horribly Awry!

[SirJoey]

During the hiatus of waiting for paint for my Kroozer hubs, I've been working on THIS little "science project".

I already knew it would have too much trail, & a heavy front end, but SHEESH, I had no idea! Once you add the weight of your feet & legs to it, the front end becomes a lead sled, steering like a car that's just lost it's power steering belt! Trail is horrific, so in conjunction with the heavy front end, handling is difficult at best, particularly at low speed. Turning around in the width of the road is out of the question, without putting your feet down.

Haven't painted or quite finished it yet, but now that I've ridden it, I prolly won't even bother, LOL!

I was gonna call this one the "Alien", but now I'm thinking more along the lines of "Monstrosity", "Nightmare", "Disaster", or maybe "Waste of Time".

http://img363.imageshack.us/img363/8098/alien1dn1.jpg http://img363.imageshack.us/img363/5273/alien2ze9.jpg

http://img363.imageshack.us/img363/456/alien3zh0.jpg http://img363.imageshack.us/img363/3866/alien4ow7.jpg


It feels like a fairly fast little bike, but it's so squirrely, I don't have the cahonies to "open 'er up"! Oh well, at least it has nice lines & a low COG.
Maybe I'll just sell plans, with a "Fast, but Sucky Handling, Hard-To-Ride & Possibly Dangerous" disclaimer. :P

[trikeman]

A mistake isn't a waste of time - its a learning experience. Perhaps you can figure out where to cut and re-weld to fix it.

[TheKid]

It looks like you could relax the bend in the main to 120-130 degrees and raise the BB and crank to improve the handling. The seat bar would have to be extended as well, and maybe small to medium butterfly bars.
Or possibly modding the fork with enough rake to get the correct trail, and relocating the crank.
I like the design. Simple and elegant. Nice work.

[AtomicZombie]

I made one like that once when figuring out the SpinCycle. I added a steering damper from a motorcycle and it made the ride much better.

I think it has potential, and know there are MANY commercial bents out there that ride worse than you prototype! What about adding a second rear fork and trying a trike?

Brad

[trikeman]

You did a nice job bending that tubing too. Is is EMT?

[jimFPU]

OK, where can I get one of those seats cheaper than Actionbent? They want a ton for shipping!!!

[SirJoey]

It looks like you could relax the bend in the main to 120-130 degrees and raise the BB and crank to improve the handling. The seat bar would have to be extended as well, and maybe small to medium butterfly bars. Or possibly modding the fork with enough rake to get the correct trail, and relocating the crank. I like the design. Simple and elegant. Nice work.

Thanx, Kid. The whole bike is a copy of parts of 3 different things, with a little personal modding as well, so it's a mutt. Loosely based on another guy's similar ride, I used a 1-piece, curved boom, instead of 2 straight ones welded together, & a lot lower BB. Front end is, of course, based on Brad's SpinCycle front end, but with Dave Stout's suspension bike rear triangle mod.

If I relax that main boom bend, I won't be able to reach the pedals. I can barely reach 'em now. Same problem with a raked fork. You're right about BB height, though. Raising it would help, I'm sure, but it'd be so much work to try to make anything useable out of this thing, I'd basically be rebuilding the whole bike, so it'll prolly end up like Brad's ex-projects, hacked for parts. Oh well, it was worth a shot. Live & learn... :rolleyes:

Trikeman, thanx & yeah, the main boom & that curved front end brace are both 1" EMT. The little straight piece that the seat rests on is just a piece hacked from a donor frame.

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[SirJoey]

Looks like a keeper... just needs a little tweaking.
With that much 'trail' the steering will feel extremely heavy - as you found out. Don't mod the fork just yet - better to reposition the headtube angle first. To do this, just remove some of the bend in the main tube (where the seat tube is welded to the main tube - bend as low on the main tube as you can. This will help to retain the clearance between the wheel and the main tube - see modified image below) . Then remove your crank assy and reposition it back where it was originally. Piece'a cake.

Good one, Papa. If I had done it that way, it'd prolly be halfway decent. Ironically, I started out with my boom at almost exactly the angle you're showing there, but I was afraid I'd be too far away from the pedals, so I bent it further, trying to get closer, resulting in a head angle of about 45 bloomin' degrees!

Geez, I wish I could use this TruSpace program... PhotoShop is great, but it sux as a CAD program.

Jim, you're right, they want a fortune to ship those things, about as much as they want for the seat itself. Kinda ridiculous. Try prowling e-bay for awhile, you may get lucky that way. Otherwise, do like I did, & bite the bullet... :(

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[SirJoey]

A few other tricks to 'sweetin' the steering:
1. Install a narrow, high psi slick on the front. This reduces the rotational friction at the tire's contact patch.
2. Install your largest diameter tire on the rear - smallest on the front - this will remove a bit more 'trail'.
3. Rotate your stem 180 degrees to place the grips aft of the steering axis.

Some good tips there Papa, but for one thing.

On #2, I'd have to cut out the brake bridge I welded in, & re-weld it to a new location. No biggie there, & it's a big, 26" fork, but the problem is, my BB is already as low as it can go, which was intentional at the time. To raise it back up, I'd have to completely re-do the front end, not only the curved brace, but also where the front forks & triangle meet. That's getting into more than I care to put into it. :(

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[AtomicZombie]

You might also want to look into a twisting chain FWD. You will have zero pedal steer, and the project will only need slight mods. You will also need two 3 inch or better V-belt pulleys.

http://www.accrete.com/hpv/FWDcloseup.jpg

Brad

[SirJoey]

I get the feeling you are discourage by the way it handled, and are hesitant to make some changes - I certainly would be. Bare-in-mind, however, that the beauty of your creation, is hands-on lesson it taught you about 'trail' - an experience i'm sure,.. you won't soon forget.

Well Papa, you're right, the crash test WAS pretty discouraging, to think that I did all that work in this blazing heat for nothing, but I'm trying to just make light of it, & not let it bum me out.

Oh, and believe me, I already knew it was gonna have way too much trail & that the front end would be way heavy, too, but the combination of the two, just ended up being worse than I imagined. Still, as you & Trikeman both said, it IS a learning experience, if nothing else, so it's still not a TOTAL waste of time.

I will try at least 2, if not all 3 of your last suggestions, thanx. I've worked real hard on that stupid thing lately, so I'm pretty burnt out on it right now, but maybe when I eventually finish the Kroozer, I'll come back to it & get a fresh start & a new perspective. :)

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif