Announcement

Collapse
No announcement yet.

New rear fat rear hub build went all wrong .... AOSOM gave me credit on the wrong HUB. Going to send new HUB.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    New rear fat rear hub build went all wrong .... AOSOM gave me credit on the wrong HUB. Going to send new HUB.

    I ordered all the parts and nothing fit. I ordered a Aosom 1000w fat rear hub which the axle measured 8" or 203mm. I ordered a Chinese fat bike steel frame which measured 9" or 228mm. So I started looking up the drop out for other brands. Minnesota and Nahbar said 170qr, Mongoose Dolnite 190mm drop out. The Mongoose malus 185mm drop out. So nothing is standard. What is the odd ball. What will my 8", 203mm 1000w rear hub fit. Suggestions


    AOSOM gave me credit on the wrong HUB. Going to send new HUB.
    Last edited by yonkk; 10-16-2017, 06:30 PM.

    #2
    You can use spacers and mount the 203mm hub on your 228mm frame, right?

    Comment


      #3
      The 1000w hub axle only touches the inside the bikes drop outs. It does not sit in the drop out like the original bike axle

      Comment


        #4
        Steel is squeezable. How many mm are we talking?

        Comment


          #5
          Originally posted by max_volt View Post
          Steel is squeezable. How many mm are we talking?
          Looks like about 40mm based on the pics. Unless you use a stack o' washers which is probably going to be a part of the solution here..

          Comment


            #6
            I couldn't make heads or tails out off the pics. Where are the gear cogs?

            Comment


              #7
              Looks like his pic is a composite of 2 pics stictched together with the tire in the middle so you can see both sides at once. The right side appears to have freewheel threads in the center that are out of focus. So he hasn't put a freewheel on yet. Probably a single-speed based on the length of the axle.

              Based on that, my WAG of 40mm was a bit high. Now that I have zoomed in, I can see he is going to lose some mm from the single speed freewheel he needs to fit. Thats the unthreaded part of the axle. Left side... stack some washers and squish it.

              yonkk , max_volt is right. To use this axle and this frame, You are going to have to compress the rear triangle some. Get yourself an allthread bar that is wider than the dropouts by an inch-plus on each side, some fender washers and some nuts. If you can also get yourself some rubber fender washers that will fit between the frame and the metal washer to protect the paint. You should be able to find all you need at the local big box hardware store assuming you are in the USA (thats where I got my parts).

              Place the allthread centered in the dropouts, the washers over the allthread and the nuts over the washers. Now tighten the nuts slowly and incrementally. Do this only so much as you must to give yourself full thread engagement for the axle nuts on your wheel. Needless to say you will want to remove the allthread tool and check with the wheel repeatedly as you progress.

              Needless to say, this is not the way you should be fitting bike parts but if this is what you got...

              Comment


                #8
                Here is a picture of the tool I am describing, installed on the bike. In this pic its set up to spread the stays. You want to compress them so move the nuts/washers to the outside. Also note the nut and eyebolt bit in the center: Thats something I added to be able to visually eyeball whether my stays are compressing evenly. I trighten each side evenly and the eyebolt is an indicator of whether each stay is coming in same as the other one. You could attach a string and hang a nut down the center of the rod, too.

                https://drive.google.com/file/d/1RLD...ew?usp=sharing
                Click image for larger version  Name:	20170307_204710.jpg Views:	1 Size:	513.0 KB ID:	47365

                Comment


                  #9
                  Well maybe all is not lost. The axle from the original bike was 9 inches and the axle from the hub motor is 8 inches. so it sat just inside the drop out. It was a 7 speed rear. Waiting on a FR1.3 to change it. I will try to squeeze it together. That could save me a lot of problems and money. I will give an update. Thanks guys. Greatly appreciated.

                  Comment


                    #10
                    I wouldn't squeeze a frame more than a few mm (e.g. 2-3mm maximum on each side) because the dropouts will no longer be parallel, although a brass thrust washer just inside the dropouts could help with this. Park Tool sells a tool to realign dropouts.

                    Also, if you squeeze the frame too much, it can cause stress on the welds on both the chainstays and seatstays (see blue circles in the diagram below). A bicycle frame was never engineered to manage this stress; the frames are designed to be used with a hub with dropouts more or less matching the dropouts in the frame.

                    It is a lot safer to use a frame with dropouts that match the motor dropouts. I would never feel safe riding a bike that has had the dropouts squeezed too much.

                    Click image for larger version

Name:	bicycle-frame-tube-names.jpg
Views:	668
Size:	54.5 KB
ID:	47584
                    Last edited by commuter ebikes; 10-07-2017, 06:02 PM.

                    Comment


                      #11
                      Here is a related thread: https://electricbike.com/forum/forum...rear-hub-build

                      I was not able to find out the measurement for the dropouts of your motor using Google. You can measure it, though, because you have the motor on hand.
                      Last edited by commuter ebikes; 10-06-2017, 09:58 PM.

                      Comment


                        #12
                        What is the total axle width and dropout of your motor axle (268 and 150mm respectively as in this drawing)?
                        Click image for larger version  Name:	axle.PNG Views:	1 Size:	78.3 KB ID:	47472
                        Last edited by commuter ebikes; 10-07-2017, 05:39 PM.

                        Comment


                          #13
                          Originally posted by yonkk View Post
                          I ordered all the parts and nothing fit. I ordered a Aosom 1000w fat rear hub which the axle measured 8" or 203mm. I ordered a Chinese fat bike steel frame which measured 9" or 228mm. So I started looking up the drop out for other brands. Minnesota and Nahbar said 170qr, Mongoose Dolnite 190mm drop out. The Mongoose malus 185mm drop out. So nothing is standard. What is the odd ball. What will my 8", 203mm 1000w rear hub fit. Suggestions.
                          An extensive Google search indicated that 170, 177, 190 and 197mm are the most common fat bike rear hub sizes.

                          This link http://fitwerx.com/thinking-about-a-fat-bike/ states:

                          "In order to use tires over 4″, your new Fat Bike should likely have 190-197mm spacing between the rear dropouts and 150mm between the front fork dropouts. This spacing is becoming pretty standard on current year Fat Bikes..."

                          Multiple other links stated that there is no standard.
                          Last edited by commuter ebikes; 10-06-2017, 10:38 PM.

                          Comment


                            #14
                            I squeezed it to 5 inches. Took lose this morning and sprung back to 7 inches. So from 9 inches to 7 inches. My axle is 8". Everything seen ok. I'm back on track. It worked. Thank you all for weighting in.

                            Comment


                            • commuter ebikes
                              commuter ebikes commented
                              Editing a comment
                              It looks like the squeezing operation deformed the chainstay tubes a bit which has probably degraded the structural integrity of the tubes.

                              It seems like there may be a safety issue here. I don't know how fast you plan on going on this bike, but you should weigh the cost of a new (straight) frame versus the cost of any accident resulting from this experimentation.

                              If you still are willing to put this frame into service, remember to align your dropouts so that your wheel bearings will wear evenly and you can properly adjust your derailleur.
                              Last edited by commuter ebikes; 10-07-2017, 06:11 PM.

                            #15
                            Wow thats a lot of squeezing.

                            As Commuter ebikes and I said... this is a far from ideal situation. I wouldn't have tried to get a permanent width reduction by going at it so hard. Just enough squish to get thread engagement on the axle and tighten the bolts just enough to get the job done. No more. I was thinking like 3-4 cm was needed, not 4 freaking inches.

                            I hope this bike isn't going to see anything remotely like a heavy duty cycle.

                            Comment

                            Working...
                            X