Chopper / bobber morphs into a recumbent!

One of the things my original chopper design had that the latest design does not have is gussets. I really don't need them with these large diameter tubes.

OTOH, they do look cool.

Here's a company that makes them for cheap, but they are massively thick.
gussets_web_small.jpg

http://www.tmrcustoms.com/store/index.php?main_page=product_info&cPath=3_30&products_id=408

These are more expensive but not as massive:
SW-8.jpg

https://www.nolimitparts.com/prodinfo.asp?number=SW-6

-Warren.
 
If it can be done without adding too much work to an already challenging endeavor, I would go for the rear suspension. Since you can pedal, you can assist the motor, if needed. The main reason is comfort. You will ride it more, if it's comfy! Do you need to carry it down or up a flight of stairs? I do! The shock can help handling if set up right. Too much travel will mess up high speed cornering. With the length of the tubes you have, I hope you are considering gusseting the joints, and that the thickness is generous. It might flex it's way into a problem. My Spoiler flexes and that's with just me on it. I'm not entirely sure if it's all the frame, or the wheels, which I know are soft. Keep Rockin! Warren.
Brian L.
 
I received the head tube and bottom bracket and spent some time putting the main frame together. I started with attaching the head down tube to the head tube and worked from there.

Here's the tubing notcher I used to fish mouth the tubes.

Img_0462.jpg


I used my homemade frame jig to align each tube while I tack brazed it and it turned out pretty well. The fork is just hanging on the frame in this picture.

Img_0464.jpg


Wow, that one section of straight tube is really conspicuous. Don't worry, I will be attaching a seat and suspension spring and stuff to it so it will be somewhat disguised. Next step is to build the rear stays and the suspension pivot.

-Warren.
 
You ought to see our driveway. A standard OCC bike bottoms out the kickstand on the speed bumps, and the ramp is even worse. :shock: Lookin forward to some more build pics. Cheers.
Brian L.
 
Yeah hitting that pointy frame on a chunk of concrete would not be fun. The fork can be adjusted up & down a bit, I'll be sure to adjust it properly.

I haven't decided whether I should just use the relatively stealth BMC "600 watt" hub motor from my commuter MTB, or go completely crazy with a big new non-hub motor mounted in the frame. If I re-use the BMC motor I could just steal the wheels and components from that bike and make this build a lot cheaper. This bike will already scream "motorcycle" though, so maybe stealth is a good idea.

-Warren.
 
That Bmc is geared right? A Crystalite or 9C hub might be a better choice power wise. That BMC will be working hard to move that bike. At least you don't have the hills we have in Janesville. An external drive makes more noise, and increases maintenance time. I would hit up Methods, or one of the other guys selling new hubs and get a Xlite HS/HT and a Lyen controller, and throw 88v of Lipo at it. What's more important to you, take off power, or outright speed? As long as the pedals work, the bike is registered, and you're not making a menace of yourself, you should be ok. Chicago cops can be tough though, can't they. I understand the desire for stealth, in a big city, it's just not my style. I'm thinking a good set of front and rear lights and a conservative riding style, would go a long way toward reducing conflict with the Police. By all means try the BMC kit first, to shake down the bike and reduce initial startup cost, but eventually I would go for the Xlite setup, it's just too much fun to ignore. If I didn't have no less than 5 different 20% grades to contend with, there would already be a HS hub on order. But with 180mm dropouts, 20 inch wheel size, my weight, and the hills, I'm a tourqe fiend for now. :mrgreen:
Brian L.
 
The bike really won't be that heavy. Probably under 40 lbs without any e-bits, 70lbs total with the 10lb BMC motor and 20lb Ping battery. That's the advantage of working with thin wall chrome-moly tubing.

I mounted the front suspension fork last night. This is a nice fork that I picked up in a fleabay auction, but it was made before MTB disk brakes were standardized. It does have disk brake mounting tabs but I'll need to make an adapter to be able to mount a standard disk brake. In addition, the disk brake on my current disk brake front wheel barely clears the fork tube, and the brake rotor mounting bolts have hard interference. The only option I can think of it to machine several millimeters off of the disk rotor mount on the hub. Does anyone have any other ideas or know of a hub that would work better?

Thanks,

-Warren.
 
I read your thread back too front, and I don't see any data on the wheel in question. Other than the mention of another MTB with the EpartsUnless you can borrow the forks from the other bike too, I don't see any way arround some very hard work. At this point I would go shopping for a newer set of forks with the standardised disk brake mounts. Mabye after the holiday other users with more between their ears than turkey will reply with better advice. :D For now, Happy Thanksgiving!
Brian L.
 
You can buy adapters from ChoppersUS that allows disk brakes to be mounted on non disk brake
forks...

http://www.choppersus.com/store/product/307/Disc-Brake-Bracket-Billet/

Good ol ThudSTeR picked me up a bender from HF, he got it for 130 bucks all up thanks
to a 20% discount voucher...I'm heading out mid morning to the otherside of town
to pickup some chromo tubing from Go Gear Racing Services , not super cheap
but not to bad shouldn't cost more than 150 bucks for the tubing for 1 and half frames
leaves me some leway to f*ck a few bends up, which usually happens at least once per frame i have done

I noted you stated each bend took about 20 minutes? seems along time i thought the bender would be a little
faster, the old pipe bender i usd took about 10 minutes a bend, not an issue whatsoever i got all the time in the
world long as it comes out right, it just surprised me a little and was wondering if this
might be more of a "first time" user taking your time to get it right type
thing? It also surprised me the quality you got from this bender, if it is the first time
you have done such work its bloody good effort no, an exceptional effort as the bends
have come out exactly as you planned them :-| I'm guessing your not new to DiY
and a workshop/tools/machinery though, or you likely wouldnt have taken on building a custom frame?
You haZ skillz SiR ;)

Can't wait to start on my next frame using the new HF bender and some chromo...I will
be checking out the 1.5 x .035 no idea what that is in metric though hopefully
the mob at theing Go Gear Racing Services
will know... ;)

keep up the great work mate, shes coming along nicely, hope you sort the brake/fork issue out ..

KiM
 
Hi Kim,

Thanks, this is not my first build, but it was the first time I used a tubing roller. I'm happy that Thud got you a good deal. The roller bender is so cool (and takes longer) because you roll the tube back and forth in the bender, crank down the bolt a turn, roll the tube back and forth, crank down the bolt a turn... Well, you get the drift. The bend happens gradually. When it starts looking close, you take it out of the roller and see it it's right. If not, you take it back out and do some more rolling. Don't crank it down too much at once because that's going to kink the tube or cause the rollers to dig in. There's really no excuse for borking a tube if you take your time. I'll take a video when I bend the chain stays if you think it's worthwhile.

I got a good suggestion from lowracer builder Rick at the recumbents.com forum. He said to use a sturmey-archer XFD hub brake. A little research shows that this brake has about the same stopping power as a disk brake, so that works for me. Re-lacing the wheel with a new hub will be less work than getting the disk brake to work.


Here's the fork mounted in the frame.

Img_0465.jpg


The bars look cool but they would be tough to reach.

-Warren.
 
I love that massive top tube. :D And that triple tree with the rearward sweeping extensions is awesome! The brake hub idea is a stroke of inspiration, Lookin GOOD Warren, keep it up! 8)
Brian L.
 
www.recumbents.com said:
Img_0465.jpg
Click to expand...

That top tube is CHUNK-eeeee...LOVE it and thankyou for the pic! I was starting to think the 1.5in diameter was a lil much
as i just bought 4meters of it and been looking at it compared to the 32mm diameter on the current mild steel frame
..... for rear chain and seat stays went for 19mm diameter (sorry no idea in imperial) and thicker wall thickness to
cope with the flex the motor torque puts on the frame under hard acceleration...
I can't believe how much lighter the tubing is compared to mild steel :shock: having not
worked with chromo before and thus, i wasn't aware there was such a weight difference, ill knock KILOs
off the weight of the frame compared to the original mild steel job! also picked up some 4130 plate for gussets etc
so rigid .... love the stuff but is pricey... !

Can't wait to see this thing completed after that shot! its coming along very nicely Warren!!

KiM
 
All the tubes are the same diameter but that shot does make the top tube look HUGE.

Spent some time gathering the bits together for the rear suspension pivot and cut the hole in the frame for the pivot shell. I took pics but now it's time to go eat some turkey and socialize with relatives. :p

-Warren.
 
I love it already, a fat tube Chromo bobber FS cruiser. Four inch tires, and mile long forks would set it off for me. The turning circle would be nuts though. Cheers.
Brian l.
 
Brian: I would love to put a set of Surly Large Marge rims and Black Floyd 3.8" tires on it! Unfortunately, that's about $350 in parts right there. :evil: I was planning on just using the commuter MTB wheels with 1.5" wide rims and adding a set of Schwalbe Fat Frank tires, but now that I will be changing out the front hub for a drum brake, that plan goes out the window. I'll be ordering a set of 2" wide rims for the Fat Franks and will build them up. :)

This is also a good excuse to not use the hub motor. Probably I will end up with a recumpence RC drive system. I will need to plan for that when I build the rear suspension so it is mounted to the rear suspension arm, but on the inside of the frame. Should be interesting.

Hey KiM: When I was rolling the 1.5" chromo I found that the tightest diameter you can get without creating "artifacts" is about the diameter of a fat 26" MTB tire - just something for you to think about when you are laying out your new frame.

-Warren.
 
Here's the frame with the front fork mounted, sitting in the frame jig to ensure everthing is straight before I complete the brazing on the head tube and the joint that will be drilled out for the rear pivot.

Img_0467.jpg


Here's the rear suspension pivot shell, bearings, axle, and the clamp stock that will be used to fasten the axle to the rear stays. I was able to source all of the tubing from my box of tubing cutoffs, and the bearings were left over from an aborted project I was contemplating several years ago.
I have often joked that my hobby is making big pieces of metal into smaller ones, fortunately some of those smaller pieces do end up getting used.

Img_0469.jpg


I fully brazed the joint and then used a fairly standard bi-metal hole saw to cut a hole in the joint of the chrome moly tubing. It's important to take your time and use plenty of cutting oil to prevent dulling the hole saw teeth.
The frame was clamped in place on my drill press, and I used a level to ensure that the frame was perfectly perpendicular to the drill press.

Img_0470.jpg


After spending a lot of time attempting to make sure the pivot shell was straight using the frame jig, a small square, a micrometer, and my eyeball, I tack brazed the shell into the frame.
Probably not perfect but for using rudimentary tools in a cold garage it's fine.

Img_0490.jpg


Here's the bearing and axle in the frame.

Img_0491.jpg


Next it's time to bend the rear stays.

-Warren.
 
Hello Warren, I hope you had a great weekend. The last pic of the bearing in the frame worked, but the rest are fubar. Nice braze work, I think that's what I meant?
Brian L.
 
I couldn't before, but I can now. :roll: Not sure why that happened, but they work now, and that's all that matters right? I like thet jig ya got, I bet it makes the job easier huh. That bike is gonna be longer than my Spoiler!
Brian L.
 
Brilliant video Warren!! I can see by this it will take two passes
to do the top bend of my frame, 3-4 to do the rest of the bends
(my frame has alot less curves than yours) I anxiously await the bender ThudSTeR 8)
has sent for me, it is alot bigger than i initially imaged, funny that, read the
dimensions but it doesn't click to you actually see it. We decided to forgo the wheel
due to increased postage costs, so I made one up one on Saturday at makes work on the hydraulic bender, i iz
all ready now! ... 8 meters of chromo awaits! :D

Thankyou for taking the time and effort to shoot the video Warren
much appreciated. Certainly beats my old hydraulic pipe bender!

KiM
 
Hey KiM - It's also HEAVIER than it looks.

Brian - I had a friend whose house I would go to to build high speed recumbent bicycles. We called his basement the WISIL skunkworks. WISIL was the name of the Wisconsin-Illinois recumbent bike club. We did a lot of brazing, TIG welding and other fume causing stuff in his basement. He would prop a box fan up in the windows and open a door to get positive ventilation through the basement, even in the winter. It worked pretty well and we built stuff all year around. I learned a lot about building stuff from him. He died at age 50 with a heart blowout during a race. He knew he had diabetes, but did not know he had heart disease. Sorry, I am digressing.

-Warren.
 
You must log in or register to reply here.
Back
Top