The Analyzer Presents: Top Fuel Diet Series – Axles

Going through the bike looking for weight to shave, you start to look at the little things.  When I pulled the wheels off to install the Ashima rotors, I noticed the stock QR Thru axles weren’t the lightest things in the world.  Some people (myself included) are willing to give up some convenience of a Quick Release style axle for a true bolt through axle.  These axles require a tool to remove the tire, but do save some significant weight in many circumstances.  Back in the day of standard QR skewers it was easy to find a set of Titanium skewers and drop some weight quickly, however today with the advent of thru axles it’s a little more tricky.  

Each brand of fork has a different size and shape of the axles, and then within each brand you need to determine which hub spacing you need.  Frame manufacturers seem to follow a similar path, with different diameters and thread pitches for each model.  After doing a little digging online I found a few options and settled on getting a pair of HardLite Ultralite bolt through for the Front and Rear of my Trek Top Fuel from eBay.  While you can get them in all kinds of fun anodized colors, I went with boring black.

Coming from Eastern Europe, they took a few weeks to come in so I didn’t get them before ORAMM, but they were waiting for me when I came back.  Install was pretty quick and one thing I noticed was that it looked so much cleaner with the bolt through axles instead of having a big lever hanging off the back.

Putting them on the scale told the tale.  The rear axle was 41g, which was 26g lighter than the stock Trek/DT Swiss built unit.  But the biggest savings was actually the front axle, coming in at 34g which saved 33g over the stock Fox QR thru axle.  That works out to right around $1/ gram, so not too bad at all.  While it’ll take a bit more time to remove the wheel in case of a flat, I’m actually moving to a heavier more flat resistant tire so hopefully that minimizes that downfall entirely.  Yeah, I went heavier with tires, I know…more on that soon!

Part Weight Difference Price $/gram
Hylix 31.8×400 Carbon Seatpost (eBay) 182g 89g $54 $0.61 / g
Carbon 34.9mm Clamp (eBay) 12g 17g $20 $1.18 / g
2x Ashima Ai2 Rotors 139g 84g $40 $0.48 / g
Delete Remote Lockout 0g 118g $0 N/A
Mt Zoom 720mm Flat Bars 138g 41g $90 $2.20 / g
Trim Steerer 0g 15g $0 N/A
Mt Zoom Top Cap 5g 10g $10 $2 / g
Race Face Next SL G4 – 34t & crank boots 451g 202g $0 N/A
Race Face PF92 Bottom Bracket 71g 12g $51
Specialized Renegade 2Bliss Ready Gription 29×2.1 613g 44g $55 $1.25 / g
Hardlite Ultralite Fox Boost Axle (eBay) 34g 33g $29 $0.87  g
Hardlite Ultralite Trek ABP Boost Axle (eBay) 41g 26g $29 $1.12 / g
Total 602g $324 $0.54 / g


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