Crumpton BMX, Worlds Lightest PROXL.
I imagine that quite a few people reading this have already seen this project we did for Interbike, but we figured this was a good time to complete the details on it. Complete finished weight of the bike was just under 5.4kg, (11.89 pounds). The frame is a custom handbuilt by Nick Crumpton of Crumpton Cycles. The frame came in at 957.2 grams. Being almost the same weight as a superlight 29er frame which is twice the size, this one could certainly have been lighter, however the goal was not to have just the lightest but something that could truly be race worthy. The bar/stem combo is a Bombshell handlebar and Enve stem with bonding by Calfee. Hubs are custom made by Tune. The rear started as a Mag150 and had a new axle and end caps machined as well as the alloy freehub body replaced with a titanium single speed version. Rims were custom from Velocity based on the tried and true A23 extrusion. Spokes were custom Pillar Titanium. Bladed profile with beefed up 13g ends matched to custom 13g alloy nipples.
Complete Build List 5.4kg (11.89 pounds)
- Frame: Crumpton Custom, (957.2g)
- Fork: Sinz Carbon (175 lbs weight limit.) (462.2g)
- Wheels (407.9g / 438.5g):
- Rims: Velocity Custom A23 rim
- Hubs: Tune Mig45 Custom / Tune Mag150 Custom
- Spoke: Pillar Custom Titanium spokes
- Rim Tape: Rox Superdute (8.1g)
- Tyres: Tioga Powerband Kevlar 1.85. (267.6g) / Tioga Powerblock Kevlar 1.75. (301.7g)
- Tubes: Eclipse, front (40.7g), rear 41.1r
- Crankset: Tune Smartfoot (508.2g)
- Bottom Bracket: Extralite PF30, HSC Full Ceramic Upgrade (55.7g)
- Chainring: Absolute Black, 36t, (51.4g)
- Chainring Bolts: Kcnc SL (4.6g)
- HandleBar/Stem: Bombshell Carbon bar / Enve Carbon stem,
- Gips: Kcnc w/plugs, (19.6g)
- Headset Spacers: Parts of Passion (2.8g)
- Top Cap / Bolt: Fair Wheel (5.9g)
- Fork Expander: Tune GumGum (8.7g)
- Cog: Recon Titanium 13t, (21.1g) (includes all spacers)
- Lockring: Far and Near, (5.1g)
- Headset: Kcnc Radiant R1, (46.7g)
- Chain: KMC X9SL (194.8g)
- Pedals: Bebop Titanium, (146.9g)
- Brake Caliper: Kcnc V-brake, (84.9g)
- Brake Lever: Kcnc Brake Lever, (23.4g)
- Saddle: Tune KomVor, (92.1g)
- Seatpost: Tune Carbon, (101.1g)
- Brake Cable: Kcnc Titanium, (7.3g)
- Brake Housing: Aican Bungarus, 12.1 g
- Chain Tensioner: Custom, (14.6g)