Thursday, March 15, 2012

Gear Heads

2X, 29"er gearing
Gearing: Ask a single speeder what gearing is best, and it might spark some mild debate, but ask a 29"er freak about gearing and you may be in for a long rant on the disparity between gearing for 26"ers and 29"ers. I found out about that from a recent post we put up on Twenty Nine Inches recently, (seen here).

The thing is, what is 29"er gearing? I don't have any clue, since the comments I read are all over the place as to what folks think that is. Some want super low gearing. Some want triple crank sets for the widest range of gearing, and still others are saying a 1X set up is all they will ever need.

What about me? Well, I never have liked the front dérailleur. I will say that Shimano's and SRAM's latest have gone a long way in impressing me though. I also will say that a lot of what I ride can be done on a 2X set up hear on my local trails. That doesn't mean I think it is perfect at all.

Probably the coolest set up I have ridden is the new DynaSys 10 speed. The thing that makes it work is not what you would expect at all though. Shimano actually identified something I wish was focused on more than it is, or seems to be.

Road riders have identified an advantage in close ratio cassettes, and actually, that's been the case for that discipline for a long time now. However; in the case of mountain bikes, it wasn't possible to have a close ratio and a wide range of gearing with only 15 speeds, so jumps between gearing were big. This persisted throughout the modern mountain bike's development up until recently.

Shimano realized that tightening up the jumps between cogs meant less loss of momentum and less rider fatigue due to a lower cadence when shifting to higher gears and a cadence that was too fast when switching to lower gears. They fine tuned DynaSys to help eliminate this, and to my mind that was the major selling point to me for the new 10 speed group.

I found there was less shifting between cogs up front, and when you did, you only had to readjust one, maybe two clicks in the rear to accommodate your cadence. I found the tighter ratios in the middle of the rear cassette to be gold for me on longer, grinding climbs when you could find a gear that was "just right".

Is DynaSys my perfect set up then? No, it is not, but to my mind the way Shimano is thinking about mountain bike gearing is making sense to me more and more. I just wish that Shimano would give the riders that low, low gear some are wanting, but Shimano has never really been about low, low gears either. I don't expect to see a change there.

Maybe an "ala carte" system similar to Surly's "Mr. Whirly" cranks, but without the weirdness that crank set has would be the ticket. Then make a cassette with user customizable ratios and we'd have everyone covered. But whatever the "perfect 29"er gearing" is, I'm sure it won't be available anytime soon. That is something you can take to the bank!


rideonpurpose said...

I'm going to try running 1x and swapping between 34t and 38t chainrings based on course. I don't like how all of the doubles require more front shifts than a triple... last couple years just ran the traditional 24/32/44. Spent the majority of my time in 32 obviously. How many more shifts would I have made to stay in the same gear range with a 27-39 or 28-42 gap?

Exhausted_Auk said...

To echo @rideonpurpose: It strikes me that a 2X10 setup must have the same issue that a compact double for the road suffers. The gears you want to be in most of the time are either at the top end of the cassette in the small ring, or the bottom end in the big ring, forcing frequent front shifts. I am not a mountain biker, but for endurance riding on the road I have long favored a close range triple, enabling me to stay on the middle ring most of the time.

I am not sure that Shimano has a very good handle on the issue of big jumps where you don't want them. Witness the fact that Shimano's 10-speed 12-28 cassette lacks a 16T cog, where SRAM's cassette has one.

Matt said...

One thing that fascinates me is how an industry as large and the cycling industry can't offer more choice. In the grand scheme of things, bike parts are relatively simple, and there are truck loads of bikes out there, but we still can't get much variety in certain areas.

Barturtle said...

I'm sure the "customizable ratios" would be awesome, but then you're requiring people to think, or even do math. Of course, those who already do both those things are pretty used to buying bikes and ditching the stock gears to replace the rings and cassette, even cracking open the cassette to build one with the ratios they want.