If you’re on the fence over the 1x road argument like we’ve seen on 3T’s own aero Strada road bike, most likely gearing & gear spacing has been one of your sticking points. 3T has known that getting proper road gearing was key to having a good single chainring road experience so they’ve been developing their own unique cassette. Now ready for the big reveal, the Strada Bailout & Overdrive cassettes deliver the same wide range we’ve seen take hold off-road with a middle cog set that keeps the close gear ratio steps to maintain optimal pedalling cadence.
The key to the two cassettes is that they offer the same gearing range from a tiny 9 tooth cog up to a 32 tooth that pretty much any modern mid cage road derailleur can handle, with two different approaches at either end.
Both cassettes get gear spacing for roughly 10% steps through out all but two shifts. The Bailout cassette keeps the gears close from 9 up to 22 and then makes two big 20% jumps to 26 & 32. Ride fast & smooth through the bulk of your shifts then the last two shifts will save you as you struggle to get over a big climb. (9-10-11-12-13-15-17-19-22-26-32)
The Overdrive on the other hand keeps the smooth 10% transitions through the middle, but with a big 20% step on either end. Pick this cassette if you want to climb a little more smoothly and when you still need that fast gear & bigger step to catch up with your riding buddies on the downhills. (9-11-12-13-15-17-19-22-25-28-32)
Each cassette offers the same 356% range. It’s not quite the same as you’d find on SRAM off-road offerings, but essentially matches a compact road double without the need for a front derailleur.
3T says paired with a 36T ring it matches the gearing of a gravel friendly 48/34 by 12-30, with a 40T the gearing of a compact 50/34 by 11-27 or with a 44T a flat road standard 54/39 by 11-28. It does all that while keeping cadence friendly steps for 9 out of 11 of the shifts.
3T developed the 9-32 Bailout & Overdrive cassettes to make their 1x aero bike feasible, but they are also selling it on its own for $290. The steel cassettes are machined from a single piece, and then they get an alloy back plate. This Bailout will come in a long wearing hard black anodized coating, while the Overdrive will be a gray/silver hard ano to make them easier to differentiate.
Both versions work on a standard SRAM XDR driver, so can be fit to a huge range off wheels bringing wide range gearing possibilities and tight spacing to a ton of cross & gravel bikes floating out in the market, using what looks like it is the future-proof standard for however many extra cogs get added on in the near future. Availability will be first on 3T’s own Strada which look like they are heading out the door at the start of September 2017 (as in next week.) 3T says they don’t have plans to set themselves up as a cassette company, but they will make the Bailout & Overdrive available separately. There was even talk that another gearing option with the same range and a 10T smallest cog could also be in the works.