Cockpit
I chose Dura Ace levers for two reasons: weight and hood shape.
While it’s hard to beat Sram Red rim brake grouppo for lightness, it's a different story for disc groupsets. For some of you, this is old news but I recently discovered that DuraAce R9170 is significantly lighter than Sram AXS and it’s mostly in the levers. ST-R9170 are over 100g lighter than Red AXS levers. And they managed to make it fit in the same volume as their rim brake levers. Impressive! Can't wait to see DA 2021.
With the modded battery pack and the RS910 junction stuffed inside the XXX integrated handlebar, I was able to connect everything without additional junctions and still have one port open for the rear derailleur. I spliced a pair of thin wires to a shortened Di2 connector to plug into the open port on the right lever and shrink wrapped the wires with the brake hose from the handlebar to the frame port so everything is tidy and well protected. The thin wires make for a thinner overall shrinkwrap as well as saving weight. Wire longevity is unknown, however. With gen 1 XXX integrated bars, I had to drill cable holes in the front part of the drops. Gen 2 are pre-drilled. Use a dremel instead of a drill so you don’t fray the unidirectional carbon fiber. With the battery pack in the left grip and charge port on the right, both grips feel identical with wires running down the front of the bars from the levers to the battery/junction.
I was hoping to further lighten the DA levers with Schmolke carbon lever clamps but unfortunately, they don’t fit. The hydro system takes up the space needed for the threaded part of the clamps.
The only other improvement I wanted to make on the cockpit was the stem clamp to head tube area. While the integrated bar/stem combo is cleaner at the front, the stem clamp bulge leaves a lot to be desired. Newer aftermarket combos like the Alanera, Metron ACR and F1 offer some improvements with spacer/headset cover options but they are not light. It’s time to spiff up the XXX integrated bar.
On my previous build, I designed and 3D printed a spacer/headset cover to fit the Metron ACR handlebar to the 3T Strada. This worked out pretty well so I did the same here. It was a bit more work matching the shape of the XXX clamp because of the irregular shape. I had to print and tweak several versions before everything matched up but I think the final version came out pretty good.
- Each prototype fitted and adjusted, 4th one was high resolution Nylon 12 SLS print (bottom right)
- before - spindly neck
- after - integrated look
- Stock carbon headset cap and 5mm spacer
- 3D print and 10mm inner carbon spacer for structure - same weight as stock
Small item but another weight saving potential is the expander. Specialized bung for Aethos has been lightened but still not that light. There are lighter weight options like the ultrastar but I’ve been experimenting with gluing in a carbon sleeve to anchor a nut inside the steerer. This creates no expansion and therefore no stress to the steerer but effectively holds preload, up to 8 Nm of torque with an M6 bolt which is more than enough for the headset.
- stock Aethos expander
- glue-in custom bung
For bar tape, I ended up using Lizardskin DSP 2.5mm for balance of comfort and lightness. I realize there are lighter weight solutions but the purpose of this bike, one of which is long ride comfort, drove the decision. With finishing tape and end cap, bar tape came in around 50g which is pretty good for a relatively cushy grippy setup. Not 100% with the color choice but I wanted something other than black. I might make some vinyl decals that match the color to add some coordination on the otherwise stealth frame.
More to come.
