michaelm101

I can no longer ride my 2x roadies due to a neck injury. So, awhile back I began I primarily riding my "adventure" bike (D-back Haanjo EXP Carbon) that I just love due to its comfortable geometry. It has 48 36 26 up front. It came with set of 650b rims - 2.1mm knobbies with 11-34 for off road endeavors. I have another set of wheels with 25c tires that also have 11-34 and I'm on the middle ring 98% of the time when riding on the tarmac around here. Is there a cassette configuration for this application that is more suited or is 11-34 ideal? I ask because I also have a 1x9 Haanjo super commuter with single 36 and 11-34. It works well for the application, but sometimes, I would like a bit less of a cadence disparity between gears. I'm not the same rider I was after a high speed car crash. Currently pedaling with lateral meniscus tear and chondromalacia. Thanks in advance!

abshipp 

I would think that your bog-standard 12-28 or 12-24 cassette would work fine for your road riding. With the 26t small ring you would be close to 1:1 as a bailout gear, which seems for me to be adequate for most terrain, but then again I don't live in the mountains. It would definitely help keep your cadence more consistent.

I ride my Velo Orange with a 48 40 30 triple and 12-28 cassette, and like you I spend 95%+ in the middle ring. 650B x 38 tires, and loaded weight of 32lbs. Never ran out of gears even if it gets a little hilly.

michaelm101

Thanks! I want to be able to swap quickly--Would i have to shorten the chain to run the 12 x 26?

atwl77

As your current configuration is 11-34, you do not have to make any changes to your chain or drivetrain if you're swapping with another cassette that falls within/inside the 11-34 range. Stated differently, you only need to make adjustments if you switched to a cassette with greater than 34 teeth, or less than 11 teeth.

kingston 

I have a 46-34-24 triple on my Rivendell that I run with a 12-23 HG50 for brevets or mixed terrain, and I like that gearing a lot, but I have a strong preference for close ratios and don't need super-low gears in the Midwest. It's easy enough to get another chain so you have one for each wheelset. A KMC X9 is under fifteen bucks, and with practice you can swap a chain in less time that it takes to swap a set of wheels.

bwilli88 

Look into half step gearing and a 12-36 cassette.
Half step gearing has 2 front chainrings that are very close in tooth count and that is used to get the middle gears. By middle gears I mean that if you are riding on the big ring 48t up front and a 17 in the back and it seems a bit hard, changing to the 19 in the rear makes it to easy, a half step middle chainring of 45t would put you right in the middle of the 2 rear cogs. This means alot more shifting of the front chainrings but it gives less to no overlap
Here is a gear calculator that shows what I am talking about
https://www.gear-calculator.com/?GR=DERS&KB=26,36,48&RZ=11,13,15,17,20,23,26,30,34&UF=2240&TF=90&SL=2.6&UN=KMH&DV=gearInches&GR2=DER S&KB2=26,45,48&RZ2=11,13,15,17,20,23,26,30,34&UF2=2240



Here is a image capture of the above site and shows the overlap your current setup has where a half step would put the ratios evenly spaced giving you 18 distinct gear ratios in the back



I like the ratios provided by a 12-36 even better with 45x42 gearing up front

This is actually a 2x10 with a 11-36 with 45-42 chainrings.

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IMG_20180514_165851694 by Bwilli88, on Flickr

bwilli88 

Here is a 2x8 with 42-39 chainrings

IMG_20150912_165035843 by Bwilli88, on Flickr

The drive

IMG_20150912_165043754 by Bwilli88, on Flickr

bwilli88 

If your are riding that 36 middle ring a lot change to a 39 big ring and use that half step setup, works.

79pmooney

I love 53-42-28 (50-38-24) and the like with tight cassettes (and FWs). I went Campy on my 9-speed bike and love the gear options. Over the years I've collected several cassettes and outside cogs (have 12, 13, and 14 outside cogs and everything down to 28 except the 20, 22, 24, 26 and 27 - not Campy options to the best of my knowledge). Favorite: 12,14-19,21,23 Close second: 12, 14-17, 19, 21, 23, 25. I spend most of my time on the 42 and use all of that cassette. Soon I will have to start using smaller chainrings (I'm 65) but I will stay with the system and rear cogs.

Oh, chrondomalacia the past 40 years.

Ben

michaelm101

Ok, thanks all! Great answers. I'm assuming by using the 12-25 cassette wheels, I'll have to index every time I swap wheels? If that's the case, I'll just stick to the 11-34...

79pmooney

I haven't run indexed systems (still old-school friction DT) but if the hubs and cassettes are all to the same standard except cog size, the locations should be the same and likewise the shifitng. I'd try it before I gave up. I don't mess with my limit stops at all between three different wheels, nor when I re-cog a wheel. (By standard I mean Campy 9-speed or Shimano 9-speed. Other makes to those standards should also work with no issues, but no promises.)

Ben

CliffordK

If you are swapping back and forth, then keep your chain the size you have. If this is a permanent change, you might take out a couple of links to find a more neutral position for the rear derailleur.

Always check the wear of your chain before putting on a new cassette. No sense in damaging your new cassette with a stretched chain. When in doubt, replace.

rhm

I know this isn't the answer to the question asked, but nonetheless: I'd suggest you just find tires that work on both tarmac and gravel. Fat and smooth. If you can fit 650b tires 2" wide, why not try Compass Switchback Hill tires? (https://www.compasscycle.com/shop/co...itchback-hill/). I've been riding their Rat Trap Pass tires, which are similar (but 26", rather than 650b) a lot (two fleches, a whole SR series, a 1200, and a lot of commuting) this year, and I don't think they slow me down at all.

I admit that 25 mm tires feel a lot faster. But it's an impression that isn't borne out by the evidence.

unterhausen

swapping cassettes isn't really all that successful unless you do it regularly and wear the cassettes in with the chain. I don't think that's really that easy. I have some scars on the back of my head due to doing that back when I raced. I went over the bars twice, one time ended up staying in the hospital overnight. Wouldn't be so bad, but they woke me up every two hours to see if I was dead.

But if you're working through an injury, I would keep the low gears anyway. No reason to stress an injury. I'm pretty happy with my 28 front, 32 rear on my gravel bike. I have 34 front, 36 rear on my road bike. With 10 speed, I don't really feel that the gaps are that bad.

Tourist in MSN

If later you decide to try half step, I am running a half step plus granny system on two of my touring bikes. I am using a 46/42/24 chainring set and in the rear a standard Sram eight speed 11/32 cassette (11/12/14/16/18/21/26/32).

You end up shifting the front much more often with a half step setup, so if that is something you want to avoid, then it might not work that well for you. One of my bikes has a brifter for the rear, but friction downtube shifter for the front. I use the downtube shifter rarely, so it is a good thing I do not have that bike setup with half step gearing.

I try to avoid the two most cross chained gears for each chainring, which means when I am on the middle ring I do not use teh 11 and 32. Thus, I only use six gears per chainring for a total of 18 gears.

The upshift from the 24 to 42 is not very smooth in front, a friction shifter is necessary for that shift. But otherwise everything works great. I use bar end shifters on my derailleur touring bikes. The photo below is my 700c touring bike with this system. A chain catcher is also used, although I do not really know if it is needed or not. I put it on when I built up the bike.



And the chart below shows my gearing assuming the wheel circumference with a 37mm wide 700c tire. The chainrings are color coded on the chart. As noted above, only 18 gears shown because the two most cross chained gears for each chainring not shown. The big advantage with half step is that I have a lot of gears in the 55 to 95 gear inch range, that is the range of gears that I use most often. A couple really high gears for long shallow downhills, and a small number of lower gears for the serious hill climbing. But since this is a touring bike, I probably have a lower lowest gear than you might need for rando riding.