Project Blue Bike (lowracer commuter bike)

[arcosine]

Just build it, the 1.25 inch tube is too small, use 2.0x.035 cr-mo tube

[Sven7]

1.25" is too small, even with all those gussets (I've been planning on this size since October)? I'd rather not redraw the entire blueprint; could I just use thicker tubing of the same diameter?

[California98Civic]

Subscribed.

[Sven7]

So much time has passed.

I apparently lost the pink bike's headset. I think it went out with the recycling at some point. Shooooot. So I sourced a Raleigh Grand Prix frame with bent seat stay for free from a friend. I chopped it apart and realized the top and down tubes are the same size I'd been planning on using, so I no longer have to buy tube stock.

With a new angle grinder in my hands, I cleaned the lugs off the Raleigh's head tube and with a hole saw got 90% done fishmouthing the new down tube. Next is to work on the down tube to "top" (bottom?) tube junction and to work the second (free spirit-sourced) head tube into that. And cut a couple gussets for my friend to weld in when he does the other stuff. At this point, the split-apart folding frame idea is off the table. It's too much complexity for little benefit.

My new push is to get this made into a frame (probably not even really painted) by a week and a half from now, if that is possible, so I can show it with my trailers and fatbike at the "Maker Fest" at work on the 28th IIRC. A long shot is to get it rideable and ride it to the MHPVA race at Waterford Hills in June. I don't know if I'll make that, but it's a good goal to am for.

Updated price/cost list:
Wheels
Front hub (Sturmey Archer XRD-8(W)) and 20T cog-....$166, Bikeparts.com
Rear hub (Shimano Deore disc front)-........................$21, Universal Cycles (UC)
Chrome 36h rims.............................................. .....$40, Calhoun Cycles
Spokes, store bought + nipples.................................$40, UC
Custom-cut front spokes.........................................$36 , Brooklyn Bike Doctor
Tires (Maxxis Hookworm)......................................... $40, UC
Rim strips and tubes............................................. ..$12, UC

Brakes
Rear caliper (Hayes MX5 cable disc from a friend's bike)..$30
Rear rotor (Tektro 160mm)........................................$20, UC
Levers............................................ .......................$free/parts bin
Front brake is a drum, included in hub price

Donor Bikes
Huffy [Granite?] (former winter commuter)....................$25/parts bin
-BB and frame segments
-Threaded steer tube

70's Schwinn Exerciser......................................... ....$10/parts bin
-65T chainring
-Minty Schwinn oval head badge
-Assorted tubing
-Minty BB bearings

80s Free Spirit Dynasty 10spd...................................free
-headset for under seat steering
-(the rest of the bike will be donated to the LBS)

Raleigh Grand Prix.............................................. ......free
-head tube
-frame tubing
-stem, maybe

Other
Crank, one piece (Schwinn Stingray or similar).............$5, East Side Bike Shop
Pedals (Shimano SPD).............................................$ free from a friend
Trek forks (2) to use for rear fork...............................$free from a friend

Welding
Front fork.............................................. ...............traded for snow tires

Frame welding jig
MDF 4x8............................................... .................$28, Menards
1/2 pint funnel x4 (to center headsets)......................$2


TOTAL
$477

22 April: Price list updated to reflect jig building costs.

[Sven7]

Wooooo! I got it welded! After working for 15+ hours this week I got a jig made of 3/4" MDF and leftover 2x4 scraps. I did my best with the tools I had; the miter saw was very useful! I then prepped the rest of the tubing, with a few different options for alternate welding strategies. I am not a welder, so I wasn't sure which would work best.

I took it over to a friend's house and he worked for three hours to get it put together while I made inconsequential design decisions. There were quite a few loose ends to tie up but it's together now. I'm gaining tons of experience that I'll be able to use on a hypothetical version 2.

When I got the bearing races pressed back in at the LBS I had them weigh the bare frame without fork. 3 lbs, 14 ounces. Not bad for a steel frame.

If this is all the further I get before the show at work, that's okay. I'm tired and broke, haha.





Next on the list:
-Get bearings and a stem that fit the rear steer tube; install.
-Center the crankset to get the chainline reasonable.
-Grind the front dropouts longer to have a little chain tensioning capability.
-Mock up rear brake mount.
-Start to build seat.
-Acquire heim joints, etc to hook up the remote steering.
-Add cable stops and other cable routing hardware
-Install shifter/brake levers/chain

At that point the bike should be rideable around the block.

Updated list. Welding cost more than I had hoped, but I could have planned the thing better so it took a lot of time. Live and learn.
------------------

Wheels
Front hub (Sturmey Archer XRD-8(W)) and 20T cog-....$166, Bikeparts.com
Rear hub (Shimano Deore disc front)-........................$21, Universal Cycles (UC)
Chrome 36h rims.............................................. .....$40, Calhoun Cycles
Spokes, store bought + nipples.................................$40, UC
Custom-cut front spokes.........................................$36 , Brooklyn Bike Doctor
Tires (Maxxis Hookworm)......................................... $40, UC
Rim strips and tubes............................................. ..$12, UC

Brakes
Rear caliper (Avid BB5 cable disc from my fatbike).....$free
Rear rotor (Tektro 160mm)........................................$20, UC
Levers, Avid.................................... .......................$free/parts bin
Front brake is a drum, included in hub price

Donor Bikes
Huffy [Granite?] (former winter commuter)....................$25/parts bin
-BB and frame segments
-Threaded steer tube

70's Schwinn Exerciser......................................... ....$10/parts bin
-65T chainring
-Minty Schwinn oval head badge
-Assorted tubing
-Minty BB bearings & cups

80s Free Spirit Dynasty 10spd...................................free
-headset for under seat steering
-(the rest of the bike will be donated to the LBS)

Raleigh Grand Prix.............................................. ......free
-head tube
-frame tubing
-stem, maybe

Steering
Rear headset cups, incl installation.............................traded for parts
SR aluminum stem.............................................. ......traded for parts
Bar ends (not sure if I'll use them)...............................$25

Other
Crank, one piece (Schwinn Stingray or similar).............$5, East Side Bike Shop
Pedals (Shimano SPD).............................................. $ free from a friend
Trek forks (2) to use for rear fork................................$free from a friend

Welding
Front fork.............................................. ...............traded for snow tires
Frame............................................. ......................$200

Frame welding jig
MDF 4x8............................................... .................$28, Menards
1/2 pint funnel x4 (to center headsets)......................$2


TOTAL
$672

[Sven7]

Quick update.

The 'bent drew quite a few interested visitors at the Maker Fest! It was a good time.

I wasn't planning on painting the fork for a while, but had the bottom bracket cups out so figured why not. It's a nice light blue now, but you'll see pictures eventually when something more interesting happens.

I threw in a spacer washer to move the crankset to the drive side just a few mils but that turned out to be both too little to straighten out the chain line and too much for the washer/nut stackup on the non drive side. So that idea's out the window.

What I'm figuring on doing to solve that is to mount the chainring normally without a spacer, then to create a two-piece chainring system. I'll cut the outside part off the chainring that's mounted to the crank, and that'll act as a carrier. Then I'll cut the inside out of another chainring and bolt that to the carrier via the 6 holes they all have. That should give me the opportunity to space it as little or as much as I need to straighten the chain line, but still have proper BB adjustment and crankarm clearance.

Lastly, I got new rear headset bearing cups at the LBS, so the rear steer tube is installed. Finding a good stem/handlebar combo to fit the 10-spd steer tube is the next challenge. I can file down the stem I have to fit the just-barely-larger-diameter handlebars, or find a stem that fits correctly. Money versus time. Stay tuned!

link for personal reference
http://www.niagaracycle.com/categori...FQ6maQod2KwGKg

[California98Civic]

Any update on this project?