1

I have a Velocity Dyad (26” symmetrical) and a Shimano XT hub (T780) that I’m about to buy spokes for after using the Sapim spoke calculator. The frame is a 1995 Ritchey Comp. Leonard Zinn doesn’t specifically say not to use a symmetrical rim to build a rear wheel. I don’t ride trails anymore, just county roads with potholes and gravel. Will I be wishing for asymmetry on my back end soon?

  • 3
    Most rear wheels have symmetrical rims. It's simply the spokes that are asymmetrical -- one side longer than the other -- to compensate for the fact that the hub flanges are not symmetrical. – Daniel R Hicks Nov 5 at 17:50
  • 1
    Welcome to the site! To answer your question as it is formulated now, "will I be wishing for asymmetry on my back?", can only one person — yourself. It would help if you reformulate it to be answerable by others, e.g. by specifying what technical issues or potential problems bother you in your current choice: wheel strength, components availability, compatibility, other riding qualities etc. Maybe it is just me, but I did not understand your intention from your question. Thanks! – Grigory Rechistov Nov 5 at 21:05
  • I am assuming you've got rim brakes. From talking to wheel builders, an asymmetric rim helps balance the left-right spoke tension. The ones I have talked to did not feel an asymmetric rim was necessary for a good wheel. Also, some wheel builders I have talked to on forums feel that once the spokes are at a minimum tension, increasing the left side tension doesn't make a stiffer wheel, and it's more about the spokes' bracing angle. Either way, I suspect you're fine. I'm not inclined to make this an answer unless I can locate some objective sources backing this up. – Weiwen Ng Nov 5 at 21:12
  • In particular I am confused by this sentence with double negative (maybe because I am not a native speaker, but most likely because the sentence has what we programmers call "code smell"): "Leonard Zinn doesn’t specifically say not to use a symmetrical rim to build a rear wheel." Should it be interpreted as Zinn to endorse symmetrical rims at the back? or that he promotes asymmetrical designs? or that he is not specific at all on this issue? – Grigory Rechistov Nov 5 at 21:12
  • 1
    If you're hard on your wheels - you're heavy, really strong, ride rough, etc - an asymmetric rim can extend wheel life significantly if the alternative is a really-heavily dished rear wheel. An asymmetric rim can allow for non-drive-side spokes to have enough tension that they never go slack in situations where the low spoke tension of a wheel with a symmetric rim would cause the non-drive-side spokes to lose all tension. If you never load a real wheel in ways that cause the non-drive-side spokes to go slack, there isn't much difference between wheels with symmetric and asymmetric rims. – Andrew Henle Nov 5 at 23:27
2

I have built MTB rear wheels with both asymmetric and symmetric rims. As long as you do a reasonable job and pick the right components, both will stand up well over time. I am not sure of the axle dimensions of that era MTB, but generally MTB have a wider rear axle which reduces the dish and thus the need for an asymmetric rim.

Asymmetric rims are at best a marginal gain. However the heavier the load and the lighter and narrower you're building your rear wheel, the more that marginal gain helps extend the life of the wheel. Dyads are already pretty durable rims, with the appropriate spoke choice and count they should build up to very reliable wheels.

Unless you have a history of breaking spokes on non-drive side of the back wheel, I would not focus much on asymmetric rims for a general purpose rear wheel build. They do make getting the dish correct during the build easier, ( especially for narrower road wheels), but like a lot of bike things they only matter when you are pushing the edge of performance.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.