View Single Post
Old 05-19-20 | 12:14 AM
  #1059  
SethAZ's Avatar
SethAZ
Senior Member
Titanium Club Membership
10 Anniversary
 
Joined: Oct 2013
Posts: 1,394
Likes: 334

Bikes: 2018 Lynskey R260, 2005 Diamondback 29er, 2003 Trek 2300

Originally Posted by smashndash
I’m going to be honest, I don’t think my WR56 wheels are the stiffest in the world. Most people measure stiffness by looking at rim edge to rim edge, and of course, a super deep carbon rim is going to be way stiffer end to end than a shallow alloy rim. There’s more material across the same distance.

However, few people ever measures stiffness from the spoke hole to the tire bead. A 25mm deep rim is going to have to deal with less leverage than a 56mm deep rim. I think that is the “X factor” that separates amazing carbon wheels from meh ones. Corima, for example, has a torsion bar in all of their rims to reduce flex in that area.

I enjoy climbing way more on my cheapo alloy wheelset. My hypothesis is that it’s because there is less spoke hole to tire bead flex. I assume this is what you’re talking about, and not the amount of flex at the “brake track” which is almost purely dictated by spoke stiffness.

I highly recommend getting 28-32 Race or CX-Sprint spokes for track. I get a considerable amount of brake rub from my 24 CX-rays (on my WR56) and I weigh 140ish lbs.

I’m fairly uneducated about this topic and didn’t think rim stiffness mattered until I bought these wheels. So ofc I’m open to having my mind changed.
Have you ever read this article? Your brake rub is exactly what he's describing about halfway down. If this article is correct your problem isn't that your rim isn't stiff enough, it's that it's too stiff and your 24 CX-Rays can't keep the rim from tilting (not bending) in the curves. Maybe CX-Sprints would have just that little bit extra stretch resistance to keep the rim from rubbing the brakes, or maybe four more spokes would do it. I think that article was written specifically to contextualize wheel stiffness in situations exactly like yours.
SethAZ is offline  
Reply