Description The Sturmey Archer Front Drum Brake Dynohub X-FDD is a 6V, 3W dynamo hub. This front hub suits a 70mm drum brake, with 100mm OLD. And it’s compatible with just about any Dynamo lighting system available, including Busch Muller. Sturmey Archer Front Drum Brake Dynohub X-FDD Specs Front Hub Model number HDS73T 6 Volt, 3.0 Watt A356 Aluminium hub shell Sealed cartridge bearing 36H 100mm OLD Nutted Axle Natural alloy finish (silver) Weight – 1220g Check out the complete spec list from Sturmey here. And for instruction manuals if you’re building your wheel at home are here. WHEEL BUILDING USING DYNAMO HUBS Considering a dynamo conversion? We can help! Abbotsford Cycles has been hand building wheels for 25 years & we are passionate about the process. Give us a call, email or text… or just drop by our RICHMOND BIKE SHOP and we can talk wheels.