Twenty Nine Inches has been fortunate to have J&B Importers “Origin 8” brand let us try some of their new 2X9 mountain cranks recently. You can read a first post on the cranks here. This is my report after several rides on the cranks.
The Origin 8 2X9 cranks are mounted to my Dos Niner, as shown and are mated with a 12-34 SRAM cassette. The bike was ridden on a combination of fast cross country type trail, single track, gravel/broken rock strewn climbs, and fire road climbs.
Shifting performance was excellent after my slightly worn chain got happy with the new teeth on the chain wheels. As long as your front derailluer is adjusted properly, I can not see any reason why your shifting wouldn’t be at least as good with these cranks. If you were to use a brand new cassette and chain, it should be trouble free from the get go. By the way, I adjusted out the low gear setting on my X-9 trigger shifter and I had excellent results with this.
On rolling single track, I found that the 44T ring was the way to go. I could use the entire cassette out back, and shifting performance was normal. The interesting thing I happened to find was that I could attack the hill in the big ring, then shift down to the 29 tooth ring and find myself either in, or a click or two at most from the perfect gear to finish off the climb with. Get over the top, shift once with the left thumb, and I was in a hammering gear for the down hill. It is easy to see why a racer might like the 2 X 9, or new 2 X 10 drive train option.
The 29 tooth chainwheel was sufficiently low enough to mimic granny ring climbs for short steeps, and medium length fire roads were done quite nicely here too. However; if your climbs start out steep, and last for anything longer than a football field, you may be wishing for some lower gears. (Unless you are in really great shape!)
As this crank set is sold, it may not work quite as nicely as it did for myself. The gearing is specific to a more rolling, shorter climb sort of terrain, to my mind. If Origin 8 would offer options, or aftermarket rings that matched the look of the originals, one could tailor the gearing to their locality. For instance, it might make more sense for a Rocky Mountain rider to go with a 37 X 22, as an example. Or perhaps a 34T X 22T set up.
The cranks do work well as they are, and shifting has been normal. I will continue to flog these and report back later with how they do in the long run.
GT-Great report as always?
You said that when you were in the big front ring that you could use the entire rear.
Was the same true when you were in the small front ring? Thanks again.
Willie: Yes, but with the caveat that in the highest two gears of the cassette, (smallest two cogs), the chain rubbed on the inside of the big chain ring.
40-27!!!! That is the ratio. And yes you will experience some ugly chainrub when in the small ring and the smallest cog for sure, in some cases the second smallest as well. However those gear ratios are easily mimicked by others when in the big ring. The chainline does permit the use of the entire cassette when in the big ring when doing a 2×9 that is why racers dig it, less shifting.