Hi Tim!
Hope you don't mind me jumping into the weeds here :)
re: 157: our decision to move in this direction is that we did NOT want to just jump on the bandwagon for 148 when it was released. My position has always been that 148 was a "half step" technology wise, based around existing 2x10 drivetrains at the time, pushed by one very large brand that was having issues with low cost 29" wheels. 142 and 157 existed at the time and both were well supported throughout the industry. Fast forward a decade and while 148 is for sure the dominate standard, 157 continues to generate increasing interest. Crank offerings from all major crank vendors exist now (SRAM, Raceface and Shimano) across their entire mid and high end product ranges which means there is enough demand industry wide for them to support this product spec. I suspect we'll see it continue to increase and possibly be driven by e-bikes as they are starting to have their own complete range of products designed to deal with the higher loads and weights that e-bikes generate.
Where the real benefits of 157 show are in 29" bikes: they are simply less precise (more flexy) by nature given the increased spoke lengths of 29" wheels. The rear wheel carries the large majority of aggressive cornering forces given that the crankset is closer to the rear wheel than the front wheel (also the fork will "twist up" a bit, reducing load on the front wheel): certainly more than a frame should. We feel that 157 offers a performance advantage in this situation. Having it throughout our product line ensures consistency with drivetrains and our supply chain.
Additionally, our heal clearance is excellent and better than the majority of 148 bikes on the market currently due to our dropout and pivot designs.
Cheers!
Nov. 13, 2020, 11:44 a.m. - knollybikes.com
Hi Tim! Hope you don't mind me jumping into the weeds here :) re: 157: our decision to move in this direction is that we did NOT want to just jump on the bandwagon for 148 when it was released. My position has always been that 148 was a "half step" technology wise, based around existing 2x10 drivetrains at the time, pushed by one very large brand that was having issues with low cost 29" wheels. 142 and 157 existed at the time and both were well supported throughout the industry. Fast forward a decade and while 148 is for sure the dominate standard, 157 continues to generate increasing interest. Crank offerings from all major crank vendors exist now (SRAM, Raceface and Shimano) across their entire mid and high end product ranges which means there is enough demand industry wide for them to support this product spec. I suspect we'll see it continue to increase and possibly be driven by e-bikes as they are starting to have their own complete range of products designed to deal with the higher loads and weights that e-bikes generate. Where the real benefits of 157 show are in 29" bikes: they are simply less precise (more flexy) by nature given the increased spoke lengths of 29" wheels. The rear wheel carries the large majority of aggressive cornering forces given that the crankset is closer to the rear wheel than the front wheel (also the fork will "twist up" a bit, reducing load on the front wheel): certainly more than a frame should. We feel that 157 offers a performance advantage in this situation. Having it throughout our product line ensures consistency with drivetrains and our supply chain. Additionally, our heal clearance is excellent and better than the majority of 148 bikes on the market currently due to our dropout and pivot designs. Cheers!