If you didn’t already hear about it on CNN or the BBC, we recently we switched the Surly OD outer chainrings from Aluminum to Stainless Steel. This was done, well, because steel chainrings rock. That, and we wanted to make some updates to the chainring shifting details (ramps, pins, gates, teeth, etc.) and improve the durability. The new chainring not only shifts better from the machining updates, the material is harder which makes the chain slide on the surface much easier and keeps your shifts butter smooth. The new steel outer chainrings are available in the same sizes as the previous aluminum versions, 33t, 36t, and 39t.
While we are talking about the OD crankset, I would like to reiterate the CL that this crankset gives you. The chainring positions are basically in the same location as the middle and outside chainrings on that old triple that might be collecting dust in your garage. The result is a CL of 55mm. That’s 6mm wider than the 49mm CL of your traditional bike and 3mm wider than the new fandangled Boost 52mm CL. It’s like Boost+….wait a second.
Anyway, if anyone out there is struggling to get chainrings to fit in their Boost, plus, or fat bike frame, the OD crank and its wider CL could be the answer to all your problems.
For reference, you can get exact OD and Mr. Whirly dimensions in the Information Hole (Tech Docs) on our website.
Happy riding folks.