Help needed for finding a replacement rim!

Discussion in 'Cycling Equipment' started by kovacsa, Jul 10, 2019.

  1. kovacsa

    kovacsa New Member

    Joined:
    Aug 14, 2016
    Messages:
    9
    Likes Received:
    0
    Hi All, These are my current rims: Wheeltech TD26 by Alex Rims (can't find much info about these online). I need to replace the rear wheel as it is cracked (cracks on the rims around a few spokes)
    It's a 700C disc brake rim with quick releases. What do I need to consider other than the size of the wheel when choosing a replacement? I'll likely migrate over the cassette and rotor (if need be). My knowledge of rims is limited so any help is appreciated!

    My bike is a hybrid, 2015 Rocky Mountain Whistler 70

    Thanks all!
     
    Tags:


  2. dabac

    dabac Well-Known Member

    Joined:
    Sep 16, 2003
    Messages:
    2,168
    Likes Received:
    111
    First of all, it helps if you're clear with the language.
    Rim is the (metal) hoop that the tire sits on.
    It's replaceable by itself.
    Sometimes you strike lucky and find either the same one, or one with the same ERD(effective rim diameter), basically where the spoke nipples rest. If you do, you can simply move the spokes over, get the wheel trued and tensioned and you're done.
    Sometimes you ALSO need to replace the spokes, at which point the economy of the repair usually goes out the window and a complete new wheel makes more sense. Particularly if you need to outsource the trueing and tensioning.
    TD-26 fits with the Alexrims naming tradition of rim profiles, but I'm not finding much either.
    If you want to go the rim replacement route, it seems like you'd have to measure the ERD of the rim yourself.

    The hub doesn't care what kind of rim its laced to. There's near enough zero drawback from using a rim brake rim with a disc brake hub.
    1) type of axle. You can switch between nutted and quick-release axles, but not between nutted/QR and thru-axles. Some thru-axle wheels can be fitted with adapters or end caps allowing traditional QR to be used.
    2) axle length/hub width. There are still some 130mm disc brake rears being sold, and clamping one into a 135 mm spaced frame isn't a great idea.
    3) is it a freewheel or cassette hub? If cassette, number of speeds? Sometimes you'll need a spacer or two to make the cassette fit properly depending on what the wheel was madde for and what cassette you want to run. Spline pattern? Shimano/SRAM dominates, but there are Campy splined wheels out there too.
    4) diameter, but you've got that. 700C = 622 mm Bead Seat Diameter, BSD. AKA 29", 29er. Sometimes also referred to as 28"
    5) rim width. A VERY tolerant measurement, but if you want to keep the tires, and keep the bike configured and handling as it was, try to get within +/- 2 mm of width.
    6) type of rotor mount, 6-bolt or splined. There are adapters that lets you mount a 6-bolt rotor to a splined hub, but not the other way around.
    7) spoke count/rim weight/ type of use. I don't know your weight, but if a 32H rim made sense, you probably don't want to go to a 24H, dedicated road rim/wheel.

    Unless the wheel got damaged in a crash or similar event, cracking around the spoke nipples is a fairly rare failure mode. Sometimes there's a bad batch of rims that have gotten brittle one way or another, but usually cracking means overstress, too high tension from build or trueing.
    If you buy a new wheel online, it might be worth it to have someone check and adjust spoke tension BEFORE you start using it.
    If you buy from, or order through a shop, they'll usually check and touch up if needed before handing the wheel over.
     
    kovacsa likes this.
  3. kovacsa

    kovacsa New Member

    Joined:
    Aug 14, 2016
    Messages:
    9
    Likes Received:
    0
    Hey, Thanks for the great and detailed info! I learned a lot. I can't find the ERD on my rim, would this be under the rim tape by chance? It seems as if I'll just be replacing the rim at this time as it maybe the cheapest and easiest option. I'm waiting for AlexRims to get to me as to what is a suitable replacement, but in the meantime, do you have any recommendations on performing yet economical rim brands? Thanks!
     
  4. dabac

    dabac Well-Known Member

    Joined:
    Sep 16, 2003
    Messages:
    2,168
    Likes Received:
    111
    That's quite common. It's of interest only to wheelbuilders and is usually found either in the spec for the rim, in the database for one of the spoke length calculators, or where someone have gone to the trouble of compiling a list of ERDs.

    Hugely unlikely.

    If you can do the job yourself, it may well be.

    No.
    Easiest is to buy another wheel. While wheelbuilding on the rim replacement level isn't that difficult, it is at least time-consuming. I can pretty much guarantee that you'd be back to riding sooner if you buy a replacement wheel.

    "Economical" is difficult, since that can differ a lot from person to person.

    IMO the biggest differences between otherwise comparable (hole count, intended use etc) rims are in price and weight. And those are the things that I mainly shop by.
    I'd be quite sceptical if someone said "I'm sure this wheel would have survived that impact if only I'd used a Mavic rim instead of an Xtreme rim."
    Mavic and DTSwiss make nice but often expensive rims. Notubes rims are nice too. The pair I built up using Xtreme rims came together nicely although a bit heavier than what I wanted and probably needed.
    If you want to reuse the spokes, tracking down a matching ERD will be your priority, and it's unlikely that the world will offer you a choice of manufacturers.
     
Loading...
Loading...