Riv, brakes and super esoterica

[John Rinker]

Weird question, but I'm curious. 

The Tektro cable yoke has two grub screws to lock in the cable once it's positioned. Many cable hangers like Paul's moon units don't; presumably this allows the cable to self-center (or lose center?). Are the grub screws on the Tektro really necessary or even advantageous?

PS. Best brakes ad ever. In the early 2000s the Avid Arch Supremes ran an ad in bike magazines with the tagline: 'Good brakes help you stop. Great brakes help you fly.' 

[Bill Lindsay]

I remove the grub screws when using that hanger.  There have been bikes that had deliberately asymmetrical rear brakes (like 1990s Konas and Voodoos, some Ritcheys), where a lockable hanger like this would be helpful.  But with "normal" symmetric setups, they are not necessary.  Just one would be plenty even in an asymmetric setup.  Given most home mechanics' tendency to radically overtighten everything, I worry about people damaging their straddle cable by overtightening these unnecessary grub screws.

Bill Lindsay

El Cerrito, CA

[Tom Wyland]

I had this same question, so thank you!

[Ian Dickson]

The screws are not necessary. I just unscrew them and throw them away.

[John Rinker]

Thank you Bill. Makes sense, and makes me curious about asymmetrical rear brakes. Huh. Yet another topic to bring up whilst spilling a martini on a cocktail-party goer. 

Cheers. John

[Leif Eckstrom]

Bill, thanks for bringing up the tendency among home mechanics to over-tighten fittings on bikes. I suspect I fall into this group at times, and I’m wondering if you or other experienced mechanics might offer some other examples like this one of the grub screw that are frequently found to be too tight on bikes set up by the autodidact set.

I realize that hand feel, as well as material strength and design, are tough to describe textually or comprehensively, but if you have any other tips I’d appreciate it.

I appreciated learning, for instance, the trick of tightening quick release levers on wheels so that they make a slight indent on your palm when closing. One can also check that the quick release isn’t so tight that it stops the hub from oscillating back and forth after spinning away it’s momentum in the stand.

What about quill stem bolts? I’ve read it’s preferable that brake levers are not so tight that they can’t rotate and break if the bike crashes or falls over. Is the same true with stem bolts? Not so tight that the wedge damages the steerer tube, but just tight enough that handlebar doesn’t rotate in clamp or stem within steerer tube? Certain vintage seat post bolts can break if over tightened. That’s an object lesson you hope you only have to learn once.

Any other examples that spring to mind?

Thanks,
Leif in Chicago

P.S. In a previous thread about a Tektro straddle cable that features two grub screws, Bill Lindsay wrote: “Given most home mechanics' tendency to radically overtighten everything, I worry about people damaging their straddle cable by overtightening these unnecessary grub screws.”