With disc brakes making inroads into road and cross bikes, tandems with disc brakes and larger than 130 mm hub spacing are getting more company. Chainline and hub spacing are discussed in considerable technical detail here at Bike Rumor.
TECH BREAKDOWN: HOW 135MM REAR HUB SPACING AFFECTS ROAD BIKE CHAINLINE & SHIFTING
Thereís no doubt disc brakes are well on their way to the road bike market. A few major brands like Colnago and Specialized recently introduced production models, Volagi built their brand with them from the outset, and disc brake cyclocross bikes are pouring in.
But what does all this mean for the other side of the wheel? Weíve covered (here and here) some of the technical challenges and concerns of using disc brakes on road bikes and the changes required for wheels. But the conversationís been missing one critical element of the shift. Virtually everyone thatís making or planning a disc brake road or cyclocross bike has 135mm rear hub spacing on the drawing board.
Thatís 5mm wider than what road bike frames have been designed for. 5mm wider than what decades of drivetrains have been designed around. Sure, thatís only 2.5mm per side, which doesnít sound like much. Until you consider that Shimano only needed 1.8mm to add an 11th cog.
We spoke with the engineers and product managers at FSA, SRAM, Shimano, Specialized, Parlee and Volagi to see how this will affect chain line, shifting performance and heel clearance on what could very well be your next road bikeÖ
More at link, includes complicated tables: