Author Archives: Justin Fox

Running out of ways to shave grams off my SL8, big time! These carbon shifter clamps are designed and made by Aandrea Campenni Design in Italy. They came in at 13g for the pair (SRAM ones were 32g, so that’s a 19g savings!).

Visit: @andrea_campenni_design

I spent some time hunting down some lighter wheels to replace the heavy AF (1571g) Roval C38’s on Gina’s SL8 and found a guy on the Weight Weenies forums (username: Sander7721) who’s obsessed with buying and testing the best value for money wheelsets out there.

Sander7721’s theory is that it’s just not worth spending huge dollars on Western wheel brands that have jurassic specs, and whilst the big brand Chinese wheel companies offer much better value for modern specs (wider internal width, wider external width and lighter weight), he’s found a few OEM manufacturers who have been willing to work closely with him to develop and offer modern wheelsets at even better pricing.

One company (which I obviously had an instant vested interest in!) was Zen Carbon Bike who are based in Xiamen, China. The story goes; Sander7721 dealt with Zara at Winspace a few years ago. Her dad’s a carbon fibre engineer who started Zen as an OEM factory. Zara left Winspace and joined him there, and they’ve been growing steadily since.

Using specs which Sander7721 suggested and taking Gina’s weight into consideration too (she’s light which affords us an even lighter wheelset) we opted for a 40/45 wheelset with 24mm internal width and 31 external width. 3.1mm carbon spokes and ZEN SL hubs which came in at an amazing $809 USD shipped.

Whilst Zara’s communication was often instant, she never gave me updates on the wheels without me prompting her first, nor tracking information (only when I asked did I get the tracking information).

The wheels took a month to get here, they were boxed well (came with spare spokes, rim tape and tubeless valves) and they look amazing. The included rim tape was trash so I used Schwalbe tubeless tape instead (much more elastic and easier to apply). At 1058g a set they’re 513g lighter than the Roval C38’s (which are also a shallower at 38mm front and back). I fitted a Conti 29C Aero 111 to the front, 30C GP5000 ST R to the rear with RideNow 19g TPU tubes and Gina’s bike now comes in at 6.3kg’s.

Visit: @zencarbonbike

Gina’s SL8

2025 Tarmac SL8 Expert
Satin Champagne / Black Pearl
Size 44

Brake Calipers: Shimano Ultegra Di2 R8170 (327g)
Brake Rotors: Galfer E1 160mm/140mm (97g/79g)
Shift Levers: Shimano Ultegra R8170 (403g)
Battery: Shimano Di2 (52g)
Derailleurs: Shimano Ultegra Di2 R8150 (FD 111g, RD 260g)
Direct Mount Derailleur Hanger: Framesandgear Oil Slick (14g)
Cassette: ZTTO SLR Gen3 12 Speed ​​11-30 Oil Slick (132g)
Cassette Lockring: ZTTO (6g)
Chain: ZTTO z12 12-speed Oil Slick (223g)
Crankset: Shimano Ultegra R8100 165mm 52/36T (720g)
Pedals: Xpedo Thrust SL Titanium (165g)
Bottom Bracket: Shimano Threaded BSA BB (77g)
Wheelset: Zen Carbon Wheels 40/45 (1058g)
Rim Tape: Schwalbe tubeless rim tape (13g)
Front Tyre: Continental Aero 111 29C (272g)
Rear Tyre: Continental GP 5000 S TR 30C (312g)
Inner Tubes: RideNow 45mm valve (19g/19g)
Stem: Tarmac integrated 70mm 6-degree + Ti bolts (130g)
Handlebar: EXS R175 360mm (175g)
Bar Tape: EXS Airtape (29g)
Bar Ends: Extralite (1g)
Saddle: Specialized S-Works Power with Mirror (203g)
Seatpost: S-Works Tarmac SL8 Carbon 15mm offset (141g)
Bottle Cage: Celoco + Ti bolts (9g)

WEIGHT: 6.36kg

Couldn’t help myself!

Chaser 160mm rotor (lighter than Galfers!).

Chaser 140mm rotor.

Direct mount chainring bolts (save 4g over original bolts).

Crank cover bolt.

Chaser rotor lockring as the CRW’s force me to use this style to clear the preload adjuster on the rear wheel.

Forever chasing grams.

5.53kg’s now with the Gelu saddle (41g), but I’ve gone back to using my S-Works Romin EVO with Mirror 143mm (189g) as it’s just so damn comfortable. Absolutely hate the extra weight of it, but it’s just too damn good. So with the Romin the final weight (without crankarm cover bolts as I have no tool for it) is now 5.68kg’s.