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Pictures of my first brazed frame, a fat bike.

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  • Pictures of my first brazed frame, a fat bike.

    I thought that I had already posted pictures of this frame on the forum, but I couldn't find where I had done so. I think I was in a hurry to get the frame to the powder coater.

    This is a 4130 chromoly steel frame that can fit both Vee Snowshoe 2XL tires and a 70T chainring. It has a 190mm long, 48mm O.D. head tube, 100mm Standard English bottom bracket, 190mm vertical dropouts, and ISO mounts.

    The head tube angle is 72 degrees and the seat tube angle is 72.25 degrees. The bottom bracket drop is 95mm. The chainstay length is 520mm (the longest chainstay length allowable in a standard Anvil frame fixture). The fork offset (rake) is 43mm.

    I used the thickest tubes within reason. The down tube is 38mm, the top tube is 35mm, and the seat tube is 33.5mm for a 31.6mm seatpost. The down and top tube are .9/.6/.9mm double butted, and the seat tube is externally butted.

    I made the front triangle as large as possible because I will be using large Bluetooth speakers in the water bottle cages. As such, I can barely stand over the bike with my 32" inseam. A 32" inseam, by the way, translates to a 34.75" standover height. I buy 32" inseam pants, but the 34.75" standover height at the top tube has the top tube just starting to press into my crotch (while stopped at a stoplight, for example).

    The braze-ons include bosses for a cargo rack as well as braze-ons for two multiconductor cables along the bottom side of the top tube, rear hydraulic hose and rear derailleur.

    Click image for larger version

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ID:	69043
    Last edited by commuter ebikes; 07-10-2018, 07:29 PM.

  • treolan
    replied
    Really nice bike! Looking forward to seeing your custom works in the future.

    Leave a comment:


  • commuter ebikes
    replied
    Originally posted by paxtana View Post
    Are you taking orders for custom fabrication yet, shall I refer folks to you that want a custom frame?

    Got a guy that wants a stretch ebike like a long version of Luna banana that can seat three heavy guys. And I guess use some massive motor like monster cyclone to power it.
    The fixtures, milling machine and other equipment will actually take me 4-5 years to save up for! That is because I am going to welding school and then machining school which is pretty expensive. The schools always have a higher priority than the equipment.

    I will be around here moderating daily and posting when I get time. Once I get the equipment, I will definitely do custom stuff. Knowing me, I will post the play by play. I have 76 weekends alone at school with nothing to do. I'm sure I will rewrite my notes and post them up in this section along with pictures of the action if the schools allow photos.

    My paying job is 6 days/58-60 hours a week and my unpaid job is 8 hours on top of that, so I actually wouldn't have time to do very much until I retire. It's on then! I will be able to hit the ground running.

    I wrenched on this bike today. I shortened the hydraulic hoses (which was a hassle) and installed the water bottle cages. My wife was out here helping me with the brake bleed.
    Last edited by commuter ebikes; 09-21-2018, 10:37 PM.

    Leave a comment:


  • paxtana
    replied
    Are you taking orders for custom fabrication yet, shall I refer folks to you that want a custom frame?

    Got a guy that wants a stretch ebike like a long version of Luna banana that can seat three heavy guys. And I guess use some massive motor like monster cyclone to power it.

    Leave a comment:


  • commuter ebikes
    commented on 's reply
    I must like the ICT forks because they are 5 of my 6 bikes.

    Spacing between the axle & dropout can be challenging, but it can be a fun time.

  • MoneyPit
    commented on 's reply
    Perfect! Easy to get in different thicknesses from Amazon. I am going to test fit the wheels before I buy anything else. The dropouts on the ICT fork see nice and deep so I may be able to use a wider area washer than what I am used to. with the other no-name forks I have been using in the past.

  • commuter ebikes
    replied
    And the nondrive side:

    Click image for larger version

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Views:	1
Size:	2.22 MB
ID:	74378

    Leave a comment:


  • commuter ebikes
    replied
    Here is a picture of the drive side with a cleaner background:

    Click image for larger version

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Size:	2.22 MB
ID:	74376

    Leave a comment:


  • commuter ebikes
    replied
    Originally posted by MoneyPit View Post
    Love the chainring on that beast!

    Glad you made mention of the thrust washers. I wasn't aware of those. I need some for my own frame swap (which is progressing slowly as well) for fitment of the front motor (issues with the lawyer lips). For similar needs in the past I have relied on thin serrated washers but this might be a better option.
    The brass (copper?) thrust washers are awesome because they will conform to an irregular surface when you tighten the axle nuts.

    And check out those gunsmithing peel washers. I would not have been able to complete my builds without those shims. I also use them in my truing stand when I build a wheel with a hub motor.

    The .223 caliber and .308 caliber shims correspond nicely to ebike axle diameters.
    Last edited by commuter ebikes; 09-20-2018, 04:48 PM.

    Leave a comment:


  • MoneyPit
    replied
    Love the chainring on that beast!

    Glad you made mention of the thrust washers. I wasn't aware of those. I need some for my own frame swap (which is progressing slowly as well) for fitment of the front motor (issues with the lawyer lips). For similar needs in the past I have relied on thin serrated washers but this might be a better option.

    Leave a comment:


  • commuter ebikes
    replied
    It was really fun building the bike! The bike fits me perfectly. It looks like the seat is really low, but this is just a huge bike. I have a 32" inseam, and when I stand over the top tube, I make contact with it.

    Filing the dropouts for the oversize axle was aggravating. I was happy that the wheel went in straight after all of that filing, but I was using the torque plates from a "known good" bike as templates to show where to file.

    The wheels were already built and ready to go, but I had to add a 1mm brake rotor spacer in the rear (for a total of 16mm rotor spacing). I have never had to use any rotor spacers in the front of any of my 5 bikes.

    The headset was easy (no issues).

    I thought the BB was going to be easy, but I installed the spindle in the drive side crank arm without putting the keyed spline (one wide spline to index the non-drive side crank arm) where it should be. I had to use my hydraulic press to push the spindle out of the drive side crank arm.

    Fitting the 70T chain ring required a lot of BB spacers. I also needed some spacers on the non-drive side so that the crank arm would clear the chainstay. Using all of these spacers, I was left with no extra room on the spindle splines. It would be impossible to add a larger chain ring.

    The torque plates are a crazy tight fit. It is almost like a puzzle, and a challenging puzzle at that.

    Setting up the front brakes was easy, but the rear was a challenge. The front hydraulic hose is a little too short, and the rear hydraulic hose is way too long.

    Setting the chainline required adding a lot more freewheel spacers to push out the 5-speed freewheel. ith so many spacers, the freewheel extended beyond the axle so I used gunsmithing shims; the .308 caliber shims fit around the M16 (metric bolt size, not the rifle) axle, but the outer diameter of the gunsmithing peel washers remain inside the freewheel hub body. This effectively increases the axle length.

    I also put a brass thrust washer (plumbing part form the hardware store) on the outer edge of the freewheel side for the purpose of keeping my freewheel away from the frame. The brass thrust washers are like the gunsmithing shims--they aren't so wide like a fender washer or even a regular washer.

    Getting the chain length was straightforward; I needed two chains. Lovin' the SRAM PowerLinks.

    Tomorrow I will build a pedal bike that I will use to commute when it rains; I don't take my ebikes out in the rain. I find pedal bikes are so much less aggravating to build. Faster to build, but then they ride slow.
    Last edited by commuter ebikes; 09-20-2018, 03:07 AM.

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  • commuter ebikes
    replied
    And some pictures of the frame with only a bare axle and torque plates installed:

    Click image for larger version

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ID:	74122Click image for larger version

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Size:	3.05 MB
ID:	74123Click image for larger version

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Views:	1
Size:	3.22 MB
ID:	74124

    Leave a comment:


  • commuter ebikes
    replied
    Here is the other side of the bike:

    Click image for larger version

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Views:	1
Size:	2.65 MB
ID:	74120

    Leave a comment:


  • commuter ebikes
    replied
    I have the day off (I will miss three days because of a bicycle crash). After picking up the powder coated parts, I came home and got pretty far with the fat bike frame from this thread:

    Click image for larger versionName:	IMG_3581.JPGViews:	1Size:	2.72 MBID:	74117
    Last edited by commuter ebikes; 09-20-2018, 02:58 AM.

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  • commuter ebikes
    replied
    So the powder coater finally finished. This took 3 months and cost $700.

    Click image for larger version  Name:	IMG_3548.PNG Views:	1 Size:	3.08 MB ID:	74115
    Last edited by commuter ebikes; 09-20-2018, 02:57 AM.

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