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Pictures of my first brazed frame, a fat bike.

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    #16
    Thanks very much for the detailed response. Lots to digest and I learned some valuable info I'll need, I think. I am rebuilding a veteran bike - my main commuter - and trying to leave all the cheap Chinese parts behind. I am accumulating parts now with minimal fitment work, and waiting for the weather to cool. 107 Fahrenheit yesterday so not going into the garage for awhile. This is my Fall/Winter 2018 project.

    I did spot the pinching of the stays. My Motobecane Lurch frame (see separate build thread, updated yesterday) has them as well and they forgive a multitude of sins.

    Chainstay length on my new project frame is 435-455 depending on positioning of the Paragon sliding dropouts. Compare that to yours... I have another Chumba Ursa Major with the same stay length and it will fit 5" tires for sure, and probably the 2XL's if I tried, but I have standardized on 30 tpi Arisun Big Fattys (26x4.9... 4.35" casing width) across four working commuter/store/runabout fat bikes to simplify my parts inventory. Chief diff for this design is not tire width but chainring clearance, and handling. They turn on a dime which is good, but are a real handful when going over potholes, railroad tracks and similar. No free lunch in this world, although the sub-30" standover on an XL frame sure makes it close.

    I pretty much have to run 1x up front. I have no issues with front derailleurs per se but the complications they introduce when there are dual throttles/PAS panels are effectively fatal to ease of use. Its bad enough when you have a single shifter. I have gone thru literally every left and right half-grip throttle and thumb variant trying to find the best layout (I can split a single throttle to two controllers easily enough but prefer the finer control). I can only get something well-sorted with a rear shifter only.

    I had not caught onto the flippability of the Surly spider. I think the components I have will let me get past the short stays. If not I'll post up a separate brainstorming thread to keep yours on topic.

    Thanks for the help!

    Comment


      #17
      Originally posted by commuter ebikes View Post
      I found some higher res pictures on my computer. I replaced the original photos in this thread with the higher res photos and now I will add four more photos.

      The chainring is a 70T, and the tire is a Vee Snowshoe 2XL, 31.5" O.D. and 5.05" width. The motor is a Cromotor with 190mm dropouts with a 5-speed freewheel.

      Click image for larger version Name:	IMG_1709 (2).JPG Views:	1 Size:	1.44 MB ID:	69050Click image for larger version Name:	IMG_1678 (2).JPG Views:	1 Size:	648.5 KB ID:	69051Click image for larger version Name:	IMG_1747 (2).JPG Views:	1 Size:	881.9 KB ID:	69052Click image for larger version Name:	IMG_1755 (2).JPG Views:	1 Size:	1.03 MB ID:	69053
      Where did you get that chainring? Oops found it.
      Last edited by calfee20; 07-22-2018, 09:16 AM.

      Comment


      • commuter ebikes
        commuter ebikes commented
        Editing a comment
        Yes, TriSled in Melbourne, Australia. It was a wonderful consumer experience. I bought four of these 70T chain rings.

      #18
      Looks like the HT is too big for you and TT looks very short. Is this modeled after a bike you rode before? Was there a reason for the long HT?

      Comment


        #19
        Originally posted by geckocycles View Post
        Looks like the HT is too big for you and TT looks very short. Is this modeled after a bike you rode before? Was there a reason for the long HT?
        I have an issue where I refuse to cut my steerer tubes. Because of this, I have a whopping 65 mm of headset spacers my commuter ebike. The freakishly tall HT on this frame eliminates the need for headset spacers.

        The TT length is indeed copied from my favorite commuter ebike. I use a 60mm, 30 degree angle stem and 3/4" riser handlebars. This makes for a riding position which is a compromise between aero and comfort.

        The appearance of the frame looking small is actually an optical illusion from the huge tire and chainring. The bike in my avatar has the same huge tires and is actually a huge frame with a very long wheelbase. People who see the photo often ask why I have my seat so low, but the seat is not low.

        The front triangle on the frame in this thread is ridiculously large. That is my real estate for cargo.
        Last edited by commuter ebikes; 08-07-2018, 09:52 PM.

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          #20
          I have all of the parts that I need to build this bike (as well as one other bike), but the powder coater is taking forever (2 1/2 months and counting). I call it "powder coat jail".

          Here is the wheel set:

          Click image for larger version  Name:	IMG_3363.JPG Views:	1 Size:	1.08 MB ID:	71076
          Last edited by commuter ebikes; 08-07-2018, 10:05 PM.

          Comment


          • commuter ebikes
            commuter ebikes commented
            Editing a comment
            Looks like the rear tire is too bald for service. I guess I have one more part to buy.

          • MoneyPit
            MoneyPit commented
            Editing a comment
            I just dropped my new frame and fork off for powder coating. The owner - who builds bikes up himself and loves doing walk-in bikes - apologized for the delay as it may take up to 2 1/2 weeks to get done. Last job he did for me was beautiful and took a week. I am in central CA you could walk down to his shop and back and still save time.

          • commuter ebikes
            commuter ebikes commented
            Editing a comment
            To be honest, if the powder coater called me tomorrow I would NOT have the money to pay the bill.

            I have tons of projects that I am working on while I wait and save up for what will be about $575 for two frames, two forks, a rim and a large bag of other bike parts.

            When I DO pick up the parts, I will have two bikes and one wheel to build which will bring my current super fun welding practice project to a grinding halt.
            Last edited by commuter ebikes; 08-08-2018, 09:17 PM.

          #21
          Originally posted by commuter ebikes View Post

          I have an issue where I refuse to cut my steerer tubes. Because of this, I have a whopping 65 mm of headset spacers my commuter ebike. The freakishly tall HT on this frame eliminates the need for headset spacers.

          The TT length is indeed copied from my favorite commuter ebike. I use a 60mm, 30 degree angle stem and 3/4" riser handlebars. This makes for a riding position which is a compromise between aero and comfort.

          The appearance of the frame looking small is actually an optical illusion from the huge tire and chainring. The bike in my avatar has the same huge tires and is actually a huge frame with a very long wheelbase. People who see the photo often ask why I have my seat so low, but the seat is not low.

          The front triangle on the frame in this thread is ridiculously large. That is my real estate for cargo.
          Gotcha.
          I built bikes for Lennard Zinn for 8 years and he extended the HT above the TT several inches on some large frames to keep the triangle small and stiff for those very tall riders. I understand the need to put the battery inside the triangle at the expense of your manhood safety. LOL I am going through this on my wifes bike now. I'm looking into splitting up the pack and putting half under the DT and possibly even use 20 or 24" wheels. Smaller wheels have many pros, especially with gearing, battery management and stand over height. Then come the cons. Decisions decisions. I'm building mid drive Fat now so I have to make up my mind.

          Damn painter! I would send it someplace else, and one that specializes in bikes. Keep up the good work.

          I wish I had an Anvil Jig. Maybe someday, they are local.

          Comment


          • commuter ebikes
            commuter ebikes commented
            Editing a comment
            I hope you settle on large diameter tires because I regularly hit potholes that would swallow up a smaller diameter tire.

            It will take me years to save up for my Anvil fixture. BTW I put my batteries in aluminum boxes in my panniers. I use my triangle for a Bluetooth speaker and water bottle.
            Last edited by commuter ebikes; 08-08-2018, 09:19 PM.

          #22
          I love BIG tires. My issues with them is having to use aluminum chainrings or spend more than $200 for a Actiontec ring. The bike will be for my wife and see mostly bike path. THere is a fair amount of trail with sand wash to get to the bike path though and her easy motion just doesn't have the power or tire for it. She wants what I have but she is too small to have a sizable battery in a FS Zirkel. With out suspension she needs BIG tire I'm thinking. She isn't a very good cyclist anymore and needs all the help she can get. Boy she has her eye on the carbon FS Fat bike at Luna and it is in my cart now. $8300 but they are out of stock as of yesterday so back to plan A. 52v 24AH GA, BBSHD, Roloff and put it on my $220 17" Walmart Fat bike. I have several sets of different hyd disks and let her try that before I go building a frame for her. That carbon Luna is sweet but it may even be too big for her. I think we need to try it first before dropping that much on it.

          Interesting. I would definitely have lowered that TT then.

          My first ebike was a E-Boo that was given to me for a song because it had no battery. It is a freak of nature for sure. Carbon frame and fork with bamboo SS, TT and ST. I thought I would play with it and turn it into a shop bike for the guys. I used Headways and after deciding I didn't want the battery weight on a rack so high, I made aluminum panniers for them. The sides got welded panels with access doors in the rear and a removable top when it was all done.
          The ST and seat post is really weird and the bamboo started splitting so you could not put much weight on the seat. I am in the process of replacing the ST with a Ti one I have here. So it will be carbon, bamboo and Ti bike. LOL
          Last edited by geckocycles; 08-09-2018, 07:29 AM.

          Comment


            #23
            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.

            Comment


              #24
              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.

              Comment


                #25
                Here is the other side of the bike:

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                  #26
                  And some pictures of the frame with only a bare axle and torque plates installed:

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                    #27
                    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.

                    Comment


                      #28
                      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.

                      Comment


                        #29
                        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.

                        Comment


                        • MoneyPit
                          MoneyPit commented
                          Editing a comment
                          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
                          commuter ebikes commented
                          Editing a comment
                          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.

                        #30
                        Here is a picture of the drive side with a cleaner background:

                        Click image for larger version

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