Author Topic: Andra rim for Disc, OK for rim brakes?  (Read 198 times)

hendrich

  • Newbie
  • *
  • Posts: 19
Andra rim for Disc, OK for rim brakes?
« on: July 22, 2020, 07:00:36 PM »
I ordered Andra 35/559 rims for rim brakes. They (a dealer in US) sent the Disc version instead. From the Ryde site, the only difference is the width (28mm Disc vs 26.4mm rim). No paint/anodizing on sidewalls. Should these be acceptable for cantilever brakes?

Thank You, Mike

WorldTourer

  • Newbie
  • *
  • Posts: 5
Re: Andra rim for Disc, OK for rim brakes?
« Reply #1 on: July 23, 2020, 11:12:13 AM »
No, rims for disc brakes are not suitable for rim brakes. They do not have the right surface for rim braking, and they are not designed to withstand the abrasion that rim brakes inflict on rims.

niggle

  • Newbie
  • *
  • Posts: 5
Re: Andra rim for Disc, OK for rim brakes?
« Reply #2 on: July 24, 2020, 07:39:17 AM »
No, rims for disc brakes are not suitable for rim brakes. They do not have the right surface for rim braking, and they are not designed to withstand the abrasion that rim brakes inflict on rims.
I think it highly likely that the Andra 35 disc rim is the exact same rim as the rim brake version (the cross section looks identical), just without the final process of machining the brake surface. Once upon a time alloy rims did not have the braking surface machined, you just ran them in by braking on the anodised/painted surface until the the coating wore off, by which time the braking surfaces were just the same as a machined brake surface in use. How long that takes and what the braking will be like until it is achieved is another question (but a few minutes of hard braking on a wet and dirty off road ride should get the job done).

OTOH the rims may well last longer than machined ones, as the machining process removes some of the metal: the extra 0.8mm per side of the Andra disc version is a lot more than the thickness of any anodising/paint/powder coat is likely to be.

Obviously non of the above applies to disc specific designs that were never available as rim brake rims.
« Last Edit: July 24, 2020, 07:43:42 AM by niggle »

hendrich

  • Newbie
  • *
  • Posts: 19
Re: Andra rim for Disc, OK for rim brakes?
« Reply #3 on: July 24, 2020, 05:22:00 PM »
The rims have vinyl record-like grooves, so they must be MSW. However the width and weight match the website spec for DISC rims. Measurement with a caliber gives 28 mm which is of course the ridge to ridge distance of MSW. As you said, the machining may cut 0.8 mm into walls.  However the weight matches the Disc version (710g) and not the MSW version (660g). Perhaps, the Ryde website specs are out of date.

Thank you for the comments. Trying to best resolve before doing the work on building the wheels.

niggle

  • Newbie
  • *
  • Posts: 5
Re: Andra rim for Disc, OK for rim brakes?
« Reply #4 on: July 24, 2020, 07:11:32 PM »
If the sidewalls are machined they are definitely the rim brake version, Andra disc rims have the same finish on the sidewalls as the rest of the rim, no machining/milling.