Technical Update – Two favorite products

Two of Lennard's favorite new products.

By Lennard Zinn

Prestine PT-1756A

Prestine PT-1756A


Prestine PT-1756A Double Sealed Replaceable-Bearing Threadless Headset
THE SCOOP: You can unscrew the cups and replace the angular-contact bearings
PRO: Well-made and completely serviceable
CON: None

I have used the Prestine headset for almost a year, and it has held up so well that there is no need to service the bearings. But, let’s say over the course of the next year I do abuse it until it stops turning freely. It’s quite easy to replace the angular-contact cartridge bearings themselves, rather than replacing the entire headset.

That’s a big plus, since, the cartridge bearings are pressed in and not removable in other headsets.

Describing this unique serviceability in print in the magazine seems but a pale version of what Web video offers, so for this column, here are a thousand words in the form of the picture, and the equivalent of yet more words in the moving picture.

CNC-machined from 6061-T6 aluminum alloy, the headset weighs 98 grams without the bolt, top cap and star nut, or 125 grams with those items. That’s a perfectly acceptable weight; it’s as if you get the bearing-replacement functionality for free. And at $94, the price is nice, too, especially since you can replace the bearings rather than the whole thing when it wears out.

The threads are the same in the removable bearing covers in both the upper and lower cup. The smooth, stainless steel cartridge bearings are double sealed to minimize moisture permeation and reduce the frequency of replacing them.

The headset stack height is: 15.5mm top + 13.2mm lower cup = 28.7mm total. It comes in silver or black.

Deda Zero100 Servizio Corse road stem
The Scoop:
Lightweight 3D forged oversized road stem with detailed shaping and an optional titanium-polish finish
PRO: Elegant styling, light, stiff
CON: None


Deda's Zero 100

Deda’s Zero 100


This 3D forged aluminum road stem has stress directional grain orientation dictated by the forging process. It comes standard with titanium 6/4 bolts and weighs under a gram per millimeter. I have two, one black in 130mm weighing 126 grams, and one 120mm in titanium finish weighing 148 grams, but this was an early one I have used for two seasons; Deda says a 120mm now weighs 107 grams.

I find the styling particularly appealing, which is why I am writing about it to bring in the New Year. All extraneous material has been omitted, yet it retains very nice shaping of what remains. And that Dolce & Gabbana-type polished titanium-like finish called “Dark Metal Polish” is particularly nice. The flat black finish is not bad but less unique and eye-catching.

It is a minus 8-degree, a.k.a. 82-degree down-angle stem that comes in lengths of 80-90-100-110-120-130-140mm. It accepts a 31.7mm oversized handlebar and is not flippable, unless you don’t mind upside down logos.
Deda Zero100 Servizio Corse road stem

VeloNews technical writer Lennard Zinn is a frame builder (,
a former U.S. national team rider and author of numerous books on bikes
and bike maintenance including the pair of successful maintenance guides
and the Art of Mountain Bike Maintenance
” and “Zinn
and the Art of Road Bike Maintenance
” as well as “Zinn’s
Cycling Primer: Maintenance Tips and Skill Building for Cyclists

Zinn’s column is devoted to addressing readers’ technical
questions about bikes, their care and feeding and how we as riders can
use them as comfortably and efficiently as possible. Readers can send brief
technical questions directly to Zinn (
Zinn’s column appears each Tuesday here on

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