Dogman Dan's Trashrunner longtail

dogman dan

1 PW
Joined
May 17, 2008
Messages
36,392
Location
Las Cruces New Mexico USA
It's a trashrunner. I can't afford an edgerunner frame, so I'm building one from trash. The donor frame saved from the dumpster, then the other parts all from my backyard bike graveyard.


Step one is I finally went and bought one of those cheapo wire feed welders from Harbor Freight. I still can't weld for shit, but at least I don't burn through as much anymore.

Here it is naked, before adding a wood deck and bags. 99% complete.jpg
 
Here it is, more or less finished. All cables and wires long enough for any size handlebars I might add later. disc brake in the back working. Two saddle bags that can carry enough battery for really long rides.
 
If you plan to make major modifications to a bike frame, the next step after the welder, is to measure some things before you start.

If you do change the angle of the steering, you need to measure it first. If you have an angle finder, you can just measure the angle of the steer tube of the bike. Another way, is to measure your crank center height off the ground. If you don't change front wheel size or fork length, then making sure you don't change the crank height will insure that you don't change the steering angle enough to matter.Measure crank height..jpg

My plan this time, is to weld up a longtail extension to the frame, by using cut up parts from a cheap full suspension bike. Those have a steel rear swing arm, and I can reuse the dropouts. I cut the last 12" or so off, and welded a thick steel plate between the two stays. Then for test fitting, I bolted them together using an old rear axle. I set the distance from outside of the steel plate to outside of plate to 135 mm, and tightened up the bolts enough to hold it more or less in place.

Then grabbing an old 20" rim, I made adjustments until I had the crank again at the same height as it had been on the original frame. Here is the mock up. at the adjusting stage. The axle bolt holding the longtail extension is now in the dropouts of the front frame, and the nuts holding it tight.Test fitting extension piece.jpg

The donor bike, btw, is a girls huffy 21 speed mtb. Front forks are crap, and also crapped out. Cost was 0 dollars, a friend replaced her bike with a nice electra cruiser, and was dumptering this old huffy. Steel frame of course.

Here is a closer shot of the extension.Extension detail.jpg
 
Time to get the motor sorted out. Nothing fancy, a 28 mm 9x7 direct drive from E-bikekit, my employer. Swapped the motor into a 20" rim and rotor I had laying around. Pretty close to 9 continent, since the E-bikekit stator bolts right into the 9 continent rotor with no problems. Covers fit, bolt holes line up.Ready for first test run..jpg

At this point, the extension is still not welded to the frame. I have a temporary strut bolted on from the extension to the frame near the seat post of the donor bike. A bit shaky, but good enough to do some test rides. I spent a few days fussing about, trying to decide what I wanted to do. keep the steering angle the same, slacken it, or what.

I decided to slacken it some, welded the plates to the droputs of the donor bike and immediately regretted it. Steers more cruiser like, but I completely ruined the chain line, and have the chain rubbing lengthwise down the frame. GRRRR. But that's the thing about these projects, its cut and try, and often you have a do over to get things sorted. After much head scratching, I cut the extension pieces almost completely apart, relocated the connecting bolt location, and then relocated the plate of the extension from inside the dropouts of the frame to outside. This got me the room I needed for the chain. Then welded up the whole thing again. I removed the connection bolt completely, and replaced it with a welded brace on the very bottom of the extension.

More test riding, and this time I'm satisfied, the chain clears the frame in all 7 gears. Now I'm really happy with it.
 
Shoulda took more pictures at this point. But in the heat of creative bliss, I forgot to snap a few shots of the changes. The next step is the cargo deck. A simple frame built entirely from dumpster dive collected electrical conduit. Damn this thin stuff is hard to weld, not to mention the zink I'm huffing as I burn it. I try not to think about that, and do it outside.

Once more or less finished with the welding, this shot shows test fitting it to the frame. It will also somewhat help stiffen up the extension, bracing it from bending upwards. As stuff breaks, I'll know where to add in some diagonal braces. For now, I just want it to hold my batteries.

In this shot, you can also see how I repositioned the extensions to outside the donor frame dropouts.rough fitting the rear deck frame.jpg

A chunk of wood is then screwed to the top of the deck, allowing the saddle bags to attach to the cargo deck with more wood screws. For now, the controller is just strapped to the rear stay. This allows it to plug directly to the motor, without the extra long motor cable.Controller location.jpg

Repeating the first picture. Additional modifications include a cruiser spring seat, and Riser BMX handlebars. Rides real nice now, leans into turns beautifully, and like all longtails a much nicer ride for your ass. Your body weight should be centered on the bike between the wheels, not right over the rear wheel. The panniers can each hold 48v 15 ah, so very long rides are possible.

Much yet to do. I'm definitely thinking about repositioning the seatpost rearward, for a more pedal forward seat position. More importantly, I need to weld a chunk of steel to the left side dropout, so I can drill some holes and mount a rear disk brake. And then Lengthen the shifter cables. At present, the rear shifter is set to one gear.

And lastly, I need to grind on all the welds, inspect, and reweld all the defective spots. But all in all, I'm quite happy how this turned out. It's long, but still possible to fit on the bike rack of my Subaru, so I can take this bike with me on a road trip easy. The big frankenbike, that requires towing a trailer.

What I've learned here will be applied to another build later, one where I will try to make it somewhat pretty. Stretching a cheap beach cruiser. Not sure what size wheel I want for that one. I might revert to 26" for it, and only stretch it about 6 inches .

That would give me, an 18" stretch expedition longtail, a 12" stretch 20" wheel runabout, and a 6' stretch beach cruiser.
 
(apologies for poking holes in the build...I can't help seeing this stuff after having done so many reworks on CrazyBike2 / etc).

If you don't mind more cutting and rewelding, I've got some suggestions that will stiffen up the back end significantly, once it's loaded down (especially if you have the battery packs in the panniers or anything heavier on the rear rack).

On the pic below, the red line indicates the tube to cut and re-angle and add to, or simply remove entirely and replace with a longer single piece.

The green line nearly parallel to the red line is where I'd put that new one.

THe green line perpendicular to it is to stiffen the rack top tail end.

The rear green line almost parallel to the one above is to support the very back end of the rack and transfer sideloads downward for stiffening.


Then there's some other crossbracing to add that I cna't show clearly in that pic; I'd need a top-down pic to show. But I'd add an end piece directly across the rear rack tips, and then an X-brace from the tips of the top rear rack all the way up to the front end where it connects to the seatstays of the main frame.

Then at the bottom of the main frame, I'd add another X brace from just in front of the "crushed-in" areas for tire clearance behind it's BB, back to the plate behind it's dropouts, just above the rear new chainstays, so the X ends just to either side of the tire itself. Or to the dropouts themselves if the other isn't practical for tire clearance reasons.

None of these tubes has to be very thick or wide, except the ones on the rear tips to the dropouts, in case you ever have to put a heavy load on that end of the rack for whatever reason. Thinner than your pinky would be perfectly fine, I expect--it's all just there to connect the diagonally-opposing points and triangulate things, to make it stiffer in all directions.


If I was doing that setup myself, I'd probably just cut the main frame's seatstays just above the original droputs, bend them upward (pivot at seattube) and then overlap the tubing from the new rear frame section's seatstays onto the main frame's seatstays, so that it ends up essentially like the long green line in the pic, without all the other connection bits (or plates).

Then I'd bend the main frame's chainstays downward a little, and the rear frame's chainstays upward a little, and overlap those and weld together, adding a length of overlapping tubing if necessary.

Then I'd add the rack and other triangulating tubing and crossbraces where needed; this will net you a stronger frame that weighs a little less (two less long reinforcing tubes).


rough fitting the rear deck frame.jpg
 
Awesome. I abandoned doing same last year for having too many other things on, so for me I got a sense of achievement seeing someone else do it! Thankyou!
 
It definitely needs some kind of diagonal brace AW.

A lot is riding now on just those welds at the dropout. Especially the quality of my welds. Part of why I didn't do a complete cut off and rebuild is the quality of my welding, combined with a lack of decent material laying around to use to replace the original stays. Some kind of diagonal from the extension to the top of the seat tube makes sense for sure.

I mostly just couldn't wait to start riding it, as yesterday was quite warm. The rack is only about half done as it is now, and some of the welds on it need work with a grinder and re welding.

I also thought it might also be interesting to see if failures develop as it is now. I could definitely see the donor bikes dropouts start bending up over time.

I never mentioned how the motor was in 20" wheel. Very nice! John in CR has been right all along. I just needed to get welding to make a smaller rear wheel possible. I didn't want a bike that would need short cranks to keep them off the ground.

Eventually I want to put an old 5304 I have in a smaller moped or scooter rim. Then put it on a nicer bike. But like most projects, it could be a while before I get around to it. I like the large front wheel, if a pothole appears.
 
About the 120V welders, it's absolutely necessary to keep them plugged in as close as possible to the electricity source. An extension cord would need to be 10 gauge wire to supply the amount of electricity the welder needs to function correctly. Cutting off the plug and directly attaching to the #10 extension cord would be ideal.

Flux core doesn't weld nearly as nice as gas fluxing, BUT, I don't have access to the BEST flux core, as Aussie Jester says, works VERY well. His welds prove that. Just wiping off the wire as it goes into the feed tube, one would be surprised at how dirty the wire is. There are split round wipers that can be used for that purpose, IF you can find them. I use a piece of T shirt rag, wrapped around the wire before it goes into the feed mechanism.

No need for debate on what gauge wire will carry how many amps. I have had a 120V Miller Mig welder for over 25 years, and use it regular enough to know exactly what is necessary. I have a 10' run of 12/2 from a #2 Aluminum feed, and, IF I run a MUCH shorter 10Gauge piece from that #2 Aluminum feed, directly to the plug on the welder, I see a much better weld., ESPECIALLY on Conduit. Galv welding is never easy. Won't get into the sickness it causes.

Very nice compilation of scrap pieces and parts, Dogman.
 
Nice job Dogman!
 
dogman dan said:
Part of why I didn't do a complete cut off and rebuild is the quality of my welding, combined with a lack of decent material laying around to use to replace the original stays. Some kind of diagonal from the extension to the top of the seat tube makes sense for sure.

I've used practically everything to build stuff from, and not much of it has actually broken becuase of the materials, usually it was my design or workmanship. :/

Tonight in the alley next to the trashcan behind my house, I found a little tubular-steel thingy with a mirror that could be disassembled and provide tubing you could probably use on that bike. I betcha there's stuff like that in the local bulk trash pickups and whatnot, or yardsales, where you are. :) (if not, and if you still need the tubing for the bike by the time you come out here, and I still have the thing, you're welcome to whatever bits you need off of it).



I mostly just couldn't wait to start riding it, as yesterday was quite warm.
That is always what gets me on my projects--I get them almost finished enough to test out, so I hurry up and do stuff just enough to get it testable, and sometimes it works ok, and I leave it as-is (until it breaks later cuz I didn't finish it :oops:); and sometimes it breaks right then and I get to "finish it right". :lol:



I also thought it might also be interesting to see if failures develop as it is now. I could definitely see the donor bikes dropouts start bending up over time.
That's the biggest problem I expect to see, but the second is the twisting of teh tail end.


I never mentioned how the motor was in 20" wheel. Very nice! John in CR has been right all along. I just needed to get welding to make a smaller rear wheel possible. I didn't want a bike that would need short cranks to keep them off the ground.
The smaller the wheel, the better it seems to work for CB2--if I could put a tire on the spoke flanges it'd probably be even better for takeoff torque. ;)


However: beware that rim and spokes: the spokes in it are probably too thick for that rim, and even if you tension it up the rim will deform / crack and not hold the tension, and/or the spokes will start cracking at the elbows. That's what happened to the one you sent me that looks just like it.... If it had eyelets it might be a different story.




Harold in CR said:
I use a piece of T shirt rag, wrapped around the wire before it goes into the feed mechanism.

Ah, that's a good thought; I'll ahve to try that myself. :)
 
Good idea, run the wire through some sponge or rag on the way into the tube.

I run the welder from a nice stiff, short run to the breaker box 20 amps plug. Then a 25' 12g cord. A 10G cord a would be better I'm sure. No doubt there is some sag using a cord that thin. I hope the very short 12g run of wire in the garage wall makes up for it. It's about 2ft of romex to the mains.

My welds will always suck, because I see so poorly now. Next investment in tools will be an auto dark helmet.

I definitely don't expect this rim to last. Same as the one I sent you (AW) at one point. The real plan is eventually to lace a small moped rim on a 5304 I have laying around. Or, I might just say screw it, and build another with a huffy beach cruiser, and 26". That 5304 runs fine in a 26". This bike is more of a learn to use the welder project than anything else. Or maybe get hold of a dead electric scooter, and use that motor and wheel. Now that I have a better welder, anything is possible. My old welder was impossible, a 100 buck 110 stick welder. An experienced welder used it once, and was about to kick it across the yard in frustration.

No pics yet, but I'm working on welding on a rear disc brake mount at the moment. Once I get that done, I'll put some more conduit on that rack to create truss webbing. Surprisingly stiff right now though! Even before adding the rack it felt very solid. This one will never be asked to carry a huge cargo. Just want to carry 20-30 ah of battery and still handle great. It does. Hopefully that cheezy rim will hold up awhile with only 20 pounds of battery on board.
 
Dogman, I'm sure you know this, but, practice on a clean piece of metal. The 120V stick welder makes a kind of blowing sound. The Mig will do a sizzle, when it's working correctly. No Spit sputter blow out welds, etc. Try to get the heat at the lowest setting and you can bump up a little, if needed. Mine, has a 4 position switch for heat ranges. IF it only had a smooth rheostat adjustment, I could dial in a nice bead.

Another thing, try to keep the shield tube as close to the work as possible, to prevent air entering the weld area. Try to find that sizzle sound, and then, keep that wire moving in tiny circles. Mig is a much different technique, as far as I am concerned.

I got sick twice welding Galv, before I found out why. Use a fan to blow across the project, to move as much of that fumes away as possible. If you start getting ANY feeling of a head ache starting, shut down and go drink a glass of milk. That will help alleviate the poison from the fumes.
 
dogman dan said:
My welds will always suck, because I see so poorly now. Next investment in tools will be an auto dark helmet.
Get a better one than the HF version if you can: even on sale for $50 it's not that great, and it doesn't have as fast a reaction time as it probably needs, and probably isn't blocking all the stuff it should, regardless of darkness setting on there.

I end up with headaches / eye strain after lots of stop-start welding, that doesnt' have anything to do with the fumes. :/ (cuz I can weld long continuous welds that give the same total weld time and don't have the problem).


Also, it has annoying sensitivity issues where it will sometimes trigger just from a reflection off a tool or bike part as I move my head, cuz I have to do all my welding out in the direct sunlight to be able to see what I'm doing. (or sort-of, anyway).

The real plan is eventually to lace a small moped rim on a 5304 I have laying around.

YOu might see if Ypedal still has any of those ex-Zero rims. Mine's been beat up for months on the back of CB2 on that HSR3548, including quite a few serious pothole hits (some in puddles I couldn't see thru) and so far it just has one dent in it, and no sign of breakage. Works fine with the Hookworm or Ringworm from Maxxis, and should work with scooter/MC tires like the Pirelli ML75 (I think that's the one), though I haven't yet gotten any to try out on it.



Or, I might just say screw it, and build another with a huffy beach cruiser, and 26". That 5304 runs fine in a 26".
Run it in a 20" and it'll be better: higher torque, lower speed; you said you don't need the speed, right? Faster winding in smaller wheel does work. :) Remember I get 0-20MPH in 4-4.5 seconds with 320-350lbs gross weight, using the HSR3548 20" w/12FET 40A rear, and 9C2806 26" w/12FET 40A front.


Somewhat worse if I'm pulling the trailer full of dog, too. ;)
Hopefully that cheezy rim will hold up awhile with only 20 pounds of battery on board.
If you had suspension it'd do a lot better, but as long as you avoid the potholes and stuff, and ride on pavement it should be ok for longer, especially if you keep checking the tension on the spokes (cuz they work themselves loose since it doesn't seem to keep the tension correctly, or cuz it doesn't tighten up enough in the first place).
 
Harold in CR said:
Mine, has a 4 position switch for heat ranges. IF it only had a smooth rheostat adjustment, I could dial in a nice bead.
Iv'e considered using a brushed motor controller from a golf cart, like the Curtis, to see if it would let me weld using it's throttle for adjustment...but I suspect the RF from the welding arc woudl blow up the FETs. :(


I got sick twice welding Galv, before I found out why. Use a fan to blow across the project, to move as much of that fumes away as possible.
I usually just try to grind off all the coatings first (wearing a mask), so I don't have to deal with that. Or use non galv stuff, which is what I'd rather do. ;)


When I had to weld the fence up when I moved back in, I did it on a windy day and stayed upwind of it where I could.
 
Definitely understand about cooking that zink. Doing it outside, using the old hold your breath, work, then turn away to breathe trick. Same as when using spray paint on small jobs. Don't breathe that smoke!

Don't plan on doing much with conduit. I just had a little laying around. Got the disc mount built yesterday, and another brace on the rack. Little more welding to finish today, and I can start building towards a ride on the weekend. Weather should get better next week.

Like with your projects, funds dictates what rim size I end up using. Part of this experiment is to find out if longtail will help me ride without suspension. If I can't stand the road bumps with this bike, it's back to figuring out a lighter FS longtail. This bike may remain a runabout to go to the dollar store or flea market 2 miles away.

Rode one like that the other day ( lengthened DH bike), Mike from slowpoke cycles personal bike. A very nice FS bike, with about 6" lengthened by bolt on dropouts. Pricy! But rode so much better than the regular length one Matt rides.
 
Just about finished now. So more pics of the progress.

Here is how I cut the frame dropout, removing the rack mounts, making it flat to receive a disc brake mount.

Dropout cut to recieve the brake mount.jpg

Here is the finished mount, fitted to the brakes. This was a long cut and try process, starting with cardboard mock up, then moving to metal.

The key thing here, was positioning the brakes on the disc, on the bike, then sketching how much metal I'd need. Using some baling wire on the brakes allowed me to clamp the brakes to the disk in the position for use.Brake mount front.jpg

And the view from the other side.Brake mount rear.jpg

And now, by clamping the brakes to the disk, the piece is positioned at the correct spot and angle for welding.Ready to weld disc brake mount.jpg

Tacked in place, Now I removed the brakes from the mount to continue without cooking the brakes.Tacked in place, while clamped onto disc.jpg
 
And now in this pic, finished up. At various times during the process, I draped the motor and disc with a rag to keep the spatter off it. Then final welding was done after taking the motor off. But to get started, you need the motor and disk in place to get it lined up easy.Finished disc brakes.jpg

While the motor was off, I added another strut to support the rack. Not truly a diagonal truss, but so far it's not weak feeling when I ride. I really think I have it strong enough to carry 30 pounds or so of batteries. Plus my heavy ass. The weak link now I'm sure is the rim and spokes.

View attachment 1

And now just about complete, with the bags back in place.Both brakes, shifter, ready to ride..jpg
 
Finally got a chance to do a longer ride or two on the new bike. No real problems, The brake disk is pretty warped, and makes a scrape scrape noise, but the caliper alignment is good.

No issues with welds, to my amazement, nor any sign of spoke trouble. Part of the idea for this bike was to have it be lighter than the monster bike, hopefully making a radial spoke 20" rear wheel last longer.

Love the way it cruises, and feels in turns. With a small modification, it can carry on my swagman bike rack! I hadn't really planned that, but was pleased to see it could be done. Perfect now, for any road trips to nice places to ride.

Added a soft cooler, so now the trashrunner can carry a carton of eggs home, or loaf of bread, while the panniers are full of batteries. It destroys the cool look, but brings back the utility, as a grocery getter.

Trashrunner on the cars bike rack..jpg
 
This is like an "assault rifle" of commuters. Not really pretty by conventional standards, but....it just works in all the ways that a serious commuter should. After I disassembled my 26-inch longtail and moved, I have not re-assembled it (and realistically, I am not likely to, since I only have a one-car garage now). I believe I will build another full-suspension longtail someday, and since it will be for the street, I am certain I will use a 20-inch on the rear (or if a hardtail, it will have a Thudbuster/Suntour/etc seat-post). I hope to see more of these in 2015...
 
Always too many ideas, not enough time, money, energy, or garage space! 1200 foot house, and three garages adding up to 1200 feet. But it's not enough at all! I have to stop at about 6 ebikes.

I keep thinking something like this one, but using a 48v scooter rear wheel, and pit bike shocks would be a great utility scoot. Here, cops could give a damn about pedals. Start with a 99 buck huffy beach cruiser frame. Make it a recumbent seat like crazybike. This one rides nice if you sit on the cargo deck. But like crazybike, it would eat that wheel.

Though I do love the tiny wheel, I am still concerned about the weak radial lace. So I think my next one should be back to 26", just stretching a huffy 6" then running the fattest tires that won't rub the frame and adding disc brakes fore and aft. 18s lipo battery. I have this 5304 in the shed, begging to go fast.

Essentially, a boardtracker type build.
 
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