Announcement

Collapse
No announcement yet.

BBSHD Chainwheel offset

Collapse
This is a sticky topic.
X
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • BBSHD Chainwheel offset

    Because of the presence of the motor taking up space, the point where a chainring would mount onto the motor is pushed out to the right from where a chainring would normally be. Offset is defined as how much distance you are able to bring the sprocket closer towards the frame. This results in a better chainline, less likelihood of chain drop and less wear on the drivetrain.

    Here is how we measure the offset.

    The measurements are from the outside of the chain ring to the inside of the mounting point (inside face):

    First we measured the thickness of the mounting plate, I zeroed the caliper to subtract the thickness and measure total height:
    Click image for larger version  Name:	DSC00021.jpeg Views:	1 Size:	74.9 KB ID:	20360









    TOTAL HEIGHT with the mounting plate thickness subtracted
    Click image for larger version  Name:	DSC00023.jpeg Views:	1 Size:	69.8 KB ID:	20361








    RESULTS:
    The measurements are from the outside of the chain ring to the inside of the mounting point (inside face)
    ECLIPSE 42T MIGHTY 30T Bafang
    Alloy 42T
    LEKKIE 42T BAFANG 46T LUNA SPYDER
    24.8mm 8mm 9mm 20.4mm 19mm 7.5mm











    All the other chain wheels in the next pictures were measured the same way, screen caps are taken from the youtube video Luna made! Click to watch it (around 3:30m)

    Click image for larger version  Name:	image_4296.png Views:	1 Size:	2.73 MB ID:	20759

    Click image for larger version  Name:	Screen Shot 2016-10-12 at 10.18.01 AM.png Views:	1 Size:	2.20 MB ID:	20363




    Attached Files
    Last edited by paxtana; 2 weeks ago.

  • #2

    The new Luna BBSHD Spyder adaptor is 7.5mm in height but there is no chain ring mounted on it . Click here to get it
    Click image for larger version

Name:	Screen Shot 2016-10-12 at 10.42.53 AM.png
Views:	2
Size:	568.6 KB
ID:	20374


    The Luna Spyder is 7.5mm tall from the bottom to the inside face, but the chainring mounts in a recessed part of the adaptor, so depending on the thickness of the ring the offset will or will not change. See next picture :

    Click image for larger version

Name:	Screen Shot 2016-10-18 at 4.03.28 PM.png
Views:	1
Size:	324.9 KB
ID:	20805














    Here is a picture taken from our forum member Louis, The pictures are JUST to give you an idea.
    Click image for larger version

Name:	image_4308-2.jpg
Views:	1
Size:	776.1 KB
ID:	20760

    Click image for larger version

Name:	image_1846.jpg
Views:	1
Size:	1.52 MB
ID:	20376








    Hope that clears it up

    Thanks to Bicycle365 and Louis for their
    pictures and effort!
    Attached Files
    Last edited by Sebz; 10-18-2016, 12:08 PM.

    Comment


    • #3
      Mighty Mini 30T for BBSHD

      8mm from the outside of the chain ring to the inside of the mounting point (inside face)

      Click here to get it!

      Click image for larger version

Name:	Screen Shot 2016-10-18 at 4.09.45 PM.png
Views:	1
Size:	802.6 KB
ID:	20807

      Comment


      • #4
        What is the distance from the bottom bracket to the chain ring mounting spot on the BBSHD?

        Click image for larger version

Name:	IMG_0345.JPG
Views:	1
Size:	1.60 MB
ID:	22933

        Comment


        • #5
          These are the offset specs for the new Lekkie chainrings
          Click image for larger version

Name:	^6D262F8DE26EB4E06C328722B06BDE4AF61BB02856B737AE33^pimgpsh_fullsize_distr.png
Views:	1
Size:	547.3 KB
ID:	27015

          Comment


          • #6
            DIAMETERS for HD rings.

            Total
            diameter including teeth.
            • Eclipse 42T is 180mm
            • Eclipse 48T is 206mm
            • Mini 30t is 131mm
            • Lekkie 36T is 151mm
            • Lekkie 42T is 174mm
            • Lekkie 52T is 216mm
            • Stock HD metal ring is 190mm
            Last edited by Sebz; 08-04-2017, 10:38 AM.

            Comment


            • #7
              At this point you may be asking yourself how much offset you need for your application. Generally the more the better, however there are some situations where you can do without a lot of offset.

              One of the most common is using an IGH, since an IGH does not have an external cassette that physically moves the chainline, as long as it is in a good position it will always have that good position regardless of what gear you have it in.

              Another is to rework the rear sprocket, rearranging the sprockets in such a way that you still have the same amount of gear ratio but you aren't shifting through as many gears, meaning that when you do shift into the lowest gears it isn't pushing the chain so far towards the frame that it will create chainline problems.
              See this link for our documentation on reworking the rear cassette.

              Comment

              Working...
              X