Longtail from junk build thread

emmetbrown

10 W
Joined
Oct 28, 2010
Messages
99
Location
Germany
So,
actual situation is as follows:
- my middrive-commuter is way to expensive to let it out the door for long, even locked up
- i need more place to haul things like grocerys to home
- i have a few LIion-packs and all sorts of motors lying around
- i have a fair amount of time left at the moment :D

My plan:
- finding junk-frames --> done
- building something really usefull and ugly out of them
- get a decent motor on, hills here are silly steep

Lets look at the frames:
DSCN1562.JPG


Lets try to combine them somehow:
DSCN1564.JPG





Perhaps you can see the mistake I made yesterday.
Right, for a nice chainstay-line I gave up a bit to much bottom-bracket height.
There was around 1" left under the pedals in down-position.




edit: attachments fixed, changed subject
 
To prevent as much wiggle of the rear end, I recommend adding tubing across the outside of the "middle dropouts" where the rear BB is welded, back to the rear chainstay where it meets the rear dropout.

If you extend them past the rear wheel, and make a "box" around the wheel, you can also use these as lower rails for cargo; or inner rails for something akin to the Xtracycle/Mundo/etc type frame, and it will be stiffer.


Without adding those types of rails on my CrazyBike2, it wiggled a lot at the rear wheel. After doing so it was a lot better, though still not really stiff with heavy loads, until late last year when I welded up a box/cross-frame for the whole rear cargo pod section, that goes around the back wheel.
 
Put a chain together from 2 old ones, changed frontwheel and did a testride two hours ago.
Chainline looks pretty good but chain jumps under heavy load (me :) ), perhaps I will need a tensioner.
Whole bike rides pretty well as is for the moment.
There is some welding still to be done, but first a little coffee-break...

@Amberwolf
Thanks for that AW but for the moment this frame is pretty tough, no wobbling or wiggling so far.
Box-type tubing has still to be done, so +1 on that.


christian
 
Hmm,
just beefed up the welding on the front BB to the chainstays.
After that drove again.
I noticed that I push the rearwheel on the chainside to the front if I pedal hard enough, thats why I get
a loose jumping chain.
At the moment this bike is singlespeed with a very high gear, so problem solved when mounting my IGH-wheel finally.
Bike rides very good, as said, but no freehand-riding possible 'cause the headtube-angle is to steep now
from that cutting and welding the seatstays for getting more ground-clearance.
No need to go freehand :) .

Here it is with attached chain:

View attachment 3

After that playing a bit with possibilities and another saddle:

DSCN1574.JPG

So for the moment all welding is done.
What needs to be done:
- make a cargo-"surfoard" from wood with mountings
- get better stuff on the bike like steering-bar, lights etc.
- decide which Motor to use

For the motor-decision i would appreciate your brainstorming, too.

What I have around is:
- already laced front-hubmotor, geared
- unlaced rear-hub motor, geared
- a somehow defective panasonic middrive i am sure i can fix
- a dd rear-hubmotor

Because of the steep hills here I won't use the dd, and the geared rear-hubmotor I don't like for not beeing able to use an IGH.
I think best would be to go first with the fronthub until I have repaired the middrive.

Some pics:

DSCN1576.JPG

DSCN1577.JPG

The middrive I've been told that the torque-sensor would be defective.
Even if I can change it I would not have the ready to go on display, because the one on the picture is for later models and has other connectors.
Haven't looked around if it would possibly fit when I use the right connectors or connect just the right cables up.
I have a spare Lyen MiniMonster liying around, so I would rather try to controll it with this.
Is this possible for the middrive has an brushless Inrunner?
Are the halls required for Inrunners to work or will it work without problems as it does on Outrunners?
I will see :D .

christian

Edit: Forgot, in this state the bike weighs in at 16,8 kg or around 37 lbs.
 
emmetbrown said:
I noticed that I push the rearwheel on the chainside to the front if I pedal hard enough, thats why I get a loose jumping chain.

You might need to make a retainer for the axle that is essentially a big fender washer, with the axle thru it's center hole, and drill another hole or pair of holes in the washer that line up with the accessory/rack mounting holes above the dropouts, and bolt it to those holes.

One of those on each side of the rear axle would keep the wheel from being pulled by the chain. This would be important if you use a middrive. :)



- make a cargo-"surfoard" from wood with mountings
Old skateboard decks work ok for that. ;)


Because of the steep hills here I won't use the dd, and the geared rear-hubmotor I don't like for not beeing able to use an IGH.

Well, if you didn't mind the more-complicated chainline you could stick the IGH in front of the rear wheel as a jackshaft, and still use the rear hubmotor with a singlespeed freewheel on it.

If I were building it, I'd probably go with the front hub and the middrive, both.

I have a spare Lyen MiniMonster liying around, so I would rather try to controll it with this.
Is this possible for the middrive has an brushless Inrunner?
Possible, should work either way. Inrunner simply means its got the magnets inside the stator instead of outside (outrunner).
 
Hi all.
No physical progress today, only progress in mind.
External controller on the middrive won't work 'cause I would need freewheeling cranks which are not necessary in
torqe-controlled mode.*
So I'll need to tear the pana-drive apart and change that pseudo torque-hall-something.
Hope to get the display wired up otherwise I have to watch out for the right sparepart.

@AW and all:
I knew that skateboard-hint already, just don't have an old one lying around (not even a new one).

-Your idea about the IGH somewhere in the middle as jackshaft is really excellent, never thought about it.
-I can't go with both motors here in germany, just one, only 250W, 25 kph max and only with PAS.
To be honest, that works ok for me, using it in this form in
my daily commuter/shopper etc. bike.
I'm not that hyperfit anymore after half a year foot-injury now, but I need the assist mainly
because of my both defective knees for not hurting them even more on these steep hills here.
And pedaling sure helps again against these extra pounds from the last two christmas festivities :oops: .

-I think I'm finally stuck with this fronthub, because everything is in fine working condition on another
bike, but that ones frame is just too bad flexing.

Nice evening to all,

christian


*Edit: I'm not 100% sure about that yet
 
Nice project. I admire your welding skills.
I like Amberwolf's idea about using a jackshaft for your freewheel system. I'm not 100% sold on Front Freewheeling Crank Arms. Did you ever notice the Giant Stiletto Chopper Bike's chaindrive? It looks sturdy. I would imagine the chain would stay tighter too. I also have seen Cyclone's Double Freewheel motor placed in between the cranks and the rear wheel used as the jackshaft. I've seen two motors added for power too i the mid set up. I will post my results of this set up soon. (I plan on keeping an extra motor on hand because they're affordable enough and I wouln't expect it to last forever)
 
You know I love it!!!

You mentioned something about you changed the head tube angle?

The way to keep it the same, is measure the height of the bottom bracket before you start. Then adjust the angle of the frame on the back, to restore that distance from the ground. Now the head tube angle is within a half a degree or so of original.

Also to nit pick, you could have done the square taper bottom bracket in the dropouts trick, rather than all that welding. What you did would work great though, if you were using a bike with one piece crank for the rear frame.

But all in all, great job. Steel donor bikes are either cheap or free. Much better to play with them, vs just scrapping em.

My next stupid idea I want to try. Mating a garden wagon with a bike, to make a non pedaling, delta trike. Front motor of course. No real need for it, just do it for giggles.
 
@DrChopper
Thank you, but my welding is a bit rusty at the moment,
if not for a junk-project it would look much nicer.

@Dogman
You're absolutely right about the height measurement of the BB, but when I noticed i had already welded :oops: .
Looking forward to see your wagonbike!

Today my try to a nice paintjob:
CIMG0492.JPG
Some clear coating after the blue:
CIMG0495.JPG

I'm sorry for the crappy picture quality the last days, the small cam I used is trash.
From the next posting on I'll use one of the good ones, again.
 
Did a bit more painting on the board, now it looks like a
painted board...

Began today to rip off everything I need from the el cheapo donor bike and,
if time will allow, will begin tomorrow with the "pre-build" of the longtail before painting
this whole piece with an ugly anti-theft color :mrgreen: .
Problem with the donor bike was extreme flexing, even with 15 kg less driver :oops: .

Have a nice rest-weekend!
 
emmetbrown said:
if time will allow, will begin tomorrow with the "pre-build" of the longtail before painting this whole piece with an ugly anti-theft color :mrgreen: .
Here's the perfect stuff for that:
http://www.workcycles.com/home-products/parts-accessories-books/high-tech-antitheft-bicycle-spray
:p
 
A bit progress and more pictures...

The rest of the donor-bike
DSCN1579.JPG

Almost nothing left
DSCN1582.JPG

I love my IGHs
View attachment 3

My actual commuter (for those who want to see)
DSCN1584.JPG

Looks like nothing but were a few hours work to get there
DSCN1585.JPG

The final painted board, I guess it will be the nicest part on the whole bike :)
DSCN1587.JPG

Hope you like the progress so far, I do :mrgreen: .
Can't wait to get it complete and painted...

Nice evening to all!
 
Sorry for not posting the last few days, but I'm still fighting the flu.
Before getting ill I managed to assemble the important things, mainly the drivetrain, and guess what, chain didn't clear the frame anymore :oops: .
So I put the frame on the anvil, a friend took the big hammer and now the chain has plenty mm's of clearance, like magic... :mrgreen:
Frame is painted and outside to dry now for almost a week, I hope to get back to it as soon as possible.
 
Went through that on my most recent longtail. I was amazed the chain cleared everything on the first try. Then deciding to slacken the head angle for a more cruiser like steering, I found that caused the chain to rub the stay on the bike.

Grr. I ended up cutting a bunch of welds, and doing a nearly complete start over. Part of the fun, this cut and try stuff though. 8)

In the end, I pried the donor frames back end way out, and welded the extension to the inside of the drops, rather than the outside. That put the original chainstays out of the chains way. My rub was right where the back axle had been, and the problem caused by the small wheel changing the angle of the chain run. In the end, I also put the head angle back where it was, simply because that way the kick stand was still the right length.

99% complete.jpg
 
Flu seems coming to its end, could make a little progress today.
Have to machine 2 torquearms, the old ones are very thin and won't fit right.
But first everything has to be at it's place and work.
Sorry for the pictures having a weird angle most time, but outside it's winter
and inside the shop there's not that much room :) .

DSCN1591.JPG

Cleaned up the bearings and added new grease.
View attachment 3
DSCN1596.JPG

Toruearms still to be machined.
DSCN1597.JPG

Begins to look like a bike again.
DSCN1599.JPG
 
Really looks good now!
 
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