Gear ratio selection
 

I have a 2017 Kona Sutra touring bike. It has a 11-34 9 speed in the rear and 26/36/48 front chain ring. I live in BC Canada and plan on doing most of my riding here. A rider that tours a lot suggested I need lower gearing but didn't make any suggestions. So does anyone here have any ideas what might work for me. I want to do the Duffy lake road(89 km) as part of my first tour and it has some steep sections 13% very hot area of BC and I am 68 but in pretty good physical condition. Any help appreciated. Cheers Roscoe

We run a 24-35 on our tandem and successfully climb hills that steep, we are a 1338 yo team. I think you should try it before you spend $.

I'm fairly certain that the crank with the 26 granny gear can be changed to a 22, I would highly recommend doing this. You will very much appreciate having the lower gearing.
My lowest bike gearing is a 22 front, 34 rear, and with 26 inch wheels it gives me a very nice low gear that I have used a lot and I am about 15 years younger than you.

The way to know is to get the BCD of your crankset, this will tell you the smallest chainring you can put on.

The only downside to going from the 26 to a 22 is that when you change from the 36 to the 22, you will have to study up a gear or two at back, but balanced against the lower getting, worth a click of two on your bar end shifters.

On a different bike than yours, but with same gearing (Cannondale T2000), I did this change to a 22T from a 26T. I was not happy with it due to difficulty shifting, poor gear selection, and occasionally dropping the chain off the ring (chain suck).

For best shifting and overall good gearing I would recommend a 24T first, then ride it a while. if still not low enough, change cassette to a 36T. Cassettes are fairly inexpensive, and in my mind this combo would just work better.

If you do decide to go for a 22T or even 24T, consider getting a chain keeper so you don't shift the chain past the ring. It's cheap insurance.

Tim, on two occasions on two different bikes from different eras I have changed grannies down 4 teeth with no issues.
First was from 28 to 24, DT shifters, friction front. No issues, no adjustments required. 1991

2013 or 14, Around three four years ago, on a sti brifter bike, 30 granny to 26t, no issues, no fd adjustment, great tiagra sti shifting as always.

Yes on chain catcher, although the sutra may have one.
Dropping the chain generally is a fd limit screw issue, but certainly can happen with a bigger tooth difference. Catchers are about 10 bucks, totally worth getting. Chain suck is not about dropping chain, it's when you back pedal and the chain sticks to the chain Ring a bit.

i would recommend changing all three rings.
common ring sizes for touring would be 22/32/44.
lower the fd, shorten the chain.

your knees will thank you.

? 22/36 jump on the front may not work with your fd ?

Roscoe, use a gear calculator to see how many gear inches your present low is.
I looked and with 35mm tires, 26/34 it's nearly 21 gear inches. Good but not great, depending on how much weight you'll be carrying.
My lowest geared bike has 16.7 g.i

Bicycle Gear Calculator

Change "teeth" to gear inches and put in rest of info.

It's very often cheaper to just buy a new crankset, chainrings can be expensive. Deore MTN cranks are about 100 bucks Canadian online.

Re the fd I strongly suspect it will be ok, given my experiences, although it really well depend on the fd, probably a sora Rd, probably a clone of my tiagra 9 speed triple stuff.

The one thing is that 22t granny can be found at a reasonable price, but a MTB crank triple is great to tour on....

All you have to do is whack a 24T chainring on the crankset, and with that combination you should be right. If you already ride most of your miles/km in the middle chainring and are comfortable with it, then the small chainring is all you have to worry about. By the way, you don't say how much load you are carrying, which also might influence your decision.

I used to run 22-32-44 up front, and 32-11 on the rear of my old Fuji Touring bike. It got me just about everywhere on tours and randonnees, and commuting. When I built up my Thorn touring, I went with a 26-36-48 crankset, but remained with the 32-11. It has been fine, although at times I have thought the 22 granny might be a better bet. Or a 34 big cog on the rear.

Chainrings really are pretty cheap if you order from one of the UK suppliers. I think the smaller ones are under $20. However, and here is the big warning: Make sure the ring(s) you buy are compatible with your crankset. 9sp or 10sp or 11sp? Double or triple... or single? 104mm BCD, or 104BCD but with the bolt holes not equidistance apart? Thick/thin or plain? Steel or aluminium? XT, Deore, XTR, SLX or...?

I've just been through the process of ordering replacement parts for our randonnee bikes, and Machka's Marinoni. Trust me (a) you have to double check everything to ensure that you getting what you need if you have older Shimano parts and (b) 9sp is starting to become more difficult to source if you want original Shimano parts (even new 9sp, triple Ultegra shifters have become like hen's teeth). Not sure about SRAM.

As Rowan and other have detailed, it can be a bit of a minefield for the uninitiated.

I would, as a first step, work out what your BCD is to determine potential front chain-ring compatibility.

Some cranks and some rings have this stamped on them but certainly not all so you might have to break out the ruler.

Certainly for touring lower gear inches are enjoyed generally more than high ones.

Some arent so fussed but having bad knees from past grinding in too low a cadence amongst a litany of other things I'd say its definitely worth a squiz at what can be gained from dropping a few teeth at the front.

More detailed help might be available should you let it be known what model group-set your currently running and what year.

Hi Roscoe, I answered you in the other thread but will explain here.

I have an older mtb that had 13-30 7 speed rear and 24 34 44 front gearing. Ok most of the time but when loaded for touring I could feel myself cranking up steep hills. In BC we have not only steep hills but sustained steep hills so for me it got a bit much on my knees. Plus I like to ride gravel logging roads that have steep grades. BTW, Ithink the Duffy Lake road is one of the steepest sustained grades in N.A. and would hate to ride up it - down is another story!

I could have tried to swap out the rear cassette for something like a Shimano mega range which I have done in the past, but then you get a big gear jump. Instead I found a SRAM 22 32 42 crank that lets me keep my evenly spaced rear intact. I had to swap bottom brackets for a narrower axle but it works with my current derailer fine.

With a 7 speed you don't have a lot of options in the rear because of the large gear jumps that result from trying to create too wide a range from high to low. With a 9 or 10 speed cassette you can probably create a smoother transition from high to low there.

This weekend I took my loaded bike up and over the Malahat and could really tell the difference with the 22 granny. I'm happy but you need to take your time and think about what will be involved with either a front or rear gear swap. You could need a new front derailer, BB or axle, shorten or lengthen chain and rarely a new rear derailer. Mostly, if you can just swap out the 26 for a 22 granny it's a pretty easy swap that gives you that edge without affecting your higher gear range but you have to see how much the then reduced chain length effects the rear derailer.

The other comments about compatibility are correct. I had a 22 chain ring but it would not mate to my original crank. I bought my new triple crank for $66 and BB for $25 so less than $100. But that is old 7 speed technology that is cheaper than modern stuff.

Before taking on the Duffy Lake Road head out to Hope and try either the Coquihalla Summit or Fraser Canyon to Hells Gate routes. Two day trips that let you get a taste for hill climbing. I park at the Hope Visitors Info Center and go from there.

22-32-42.

As low as you can go without going custom.

On my cargo bike, even unloaded at 24kg, my most comfortable cruising gear on flat is 42/18, on long smooth roads it could be 42/16. Never felt the need for bigger chainring.

Thanks for all the great info. Just to answer a couple of questions, I weigh 195 and plan on being self contained for a few days but eating mostly in restaurants. Someone or two mentioned BCD? not sure what that means.
Happyfeet thanks for your answer on the other thread and thanks for the suggestion on the Coq. and Fraser canyon, I actually had been thinking of those routes. I live on the Island but have a friend who goes to archery shoots on the mainland and may be able to hook a ride to Hope with him. Maybe even do a two or three day ride and get a pickup from him on his way home. I will do more research into the gears, thanks everyone. Cheers Roscoe

BCD is the term for the bolt pattern on your crankset; the little bolts that hold the chain rings on. Like rims on different makes of cars they have to line up. Some are 4 bolt, some 5, some narrow, wide etc..

BCD = bolt circle diameter. What that means is it's the diameter of the circle of bolts on the chainring. For your crank, the outer ring has a BCD of 104 as your crank is likely a "trekking" crank based on mountain bikes. The inner ring has a 64mm BCD. The BCD limits how small you can go on the chainring. For a 64mm BCD, you can use a 22 tooth inner ring. Just to be sure, measure between adjacent bolt holes. If the measurement is 45.3mm, it's has a 64mm BCD

One of the features of the gear calculator that djb linked to is that you can compare different gear combinations. The graphical way that the calculator is set up allows you quickly see how the gears change and interplay. For example, here's what changing your inner ring to a 22 from the 26 tooth would do to your gearing. Play around with different gear combinations. You can drag the chainwheel or cassette gears any place you want so you can see what effect changing the combinations has on the gears.

Just a note on how the calculator works. For miles per hour, the calculator gives you the result in "gear inches" which is a throwback to the old days of ordinary or "big wheel" bikes. A "gear inch" is the wheel diameter of those kinds of bikes. For kilometers per hour, the calculator uses "meters development" which is how far the bike travels per revolution of the crank. Both methods are useful and which you use usually depends on what you learn first. Personally, I can't make much sense out of meters development without thinking about it. Gear inches are easier for me to visualize. Your mileage may vary.

Roscoe, these are very good points.
Here is my take on overall riding (mostly unloaded, some loaded--but as mentioned, how much weight you expect to carry is a factor)

---a 36 mid ring is a good compromise size that will be used most of the time anyway, unloaded or with any sort of panniers. When I ride my two bikes with 32t mid rings unloaded, it is a bit low at times so get up to the 44t ring past a certain speed, high 20s kph lets say. That said, at those speeds we are at for the vast majority of the time, 15-25kph, its fine, but as Rowan suggested, if you find the 36t to be fine for lots of your riding, even with panniers on, then you will want to keep it.

re finding inexpensive smaller granny gears, I have found over the years of finding them in Montreal bike shops for my bikes or friends bikes, that a good bike store will generally have a cardboard box of small rings, but one 22/24t ring will cost 50 bucks, and another will cost 20. I've always gone for the cheaper ones and they have lasted fine (often the really expensive ones are top racing ones, so lighter, no point in my opinion, and a "heavier" steel one will last longer anyway, and who cares really about 30g or whatever)

Your stock setup has 21.8 gear inches with 35mm tires
with a 24/34 it will be 19.2, and will feel like one gear shift lower essentially
with a 22/34 it will be 17.6, and will feel like two gear shifts lower.

as others have said, for you to really know, put stuff on your bike like you expect to have, and go out with your bike as is and find some hills and see how it is.

Everyone has an opinion on gearing, and unfortunately a lot of boasting, or "poo-pooing" of lower gears will get said, but as someone 15 years younger than you, I am very happy with about a 17 g.i low on one of my bikes, and so are my knees.
So what if I dont use it that often, who cares. My knees do care when I can use it.

I've toured in mountains with 21 g.i and it was ok
I've toured in mountains with 19 and it was ok, a bit easier

but then recently with more weight on a bike (50lbs) and in mountains, the 17 g.i was great, and the 44/32/22 combo works wonderfully loaded, where I was nearly all the time in the mid 32 on the flats, and 22 for climbs, and only in the 44 for downhills or tailwinds.
No matter what folks say, when touring, it is pretty rare to be able to go along at more than 25kph for any period of time.

and on that cool chart, change "teeth" to "gear inches", and the gear inch for each gear will appear above each cog.

the reason some of us go on about all this gearing stuff is because with these gearing chart calculators, they give you a black and white number for what your low gears are, a real number, not a bike store employee saying "oh, the gearing on this bike is fine for touring, see its got a 36t rear cassette (but maybe only a 34t small ring up front).

of course, if you dont have a reference of what gear inch is like to you, then getting the number for your bikes low gear and putting panniers on your bike with weight in them and finding some hills near where you live is the best way to know that "25" or "22" gear inches is almost doable going up X hill, but I do have to work damn hard....sort of thing.

and don't forget, there will be days or times of the day when you are touring when you aren't feeling 100%, tired, hungry, you have a cold....whatever, and having an easier gear to shift into that you dont often use is a godsend.

I realize that some of us come across like a bunch of evangelicals trying to sell our point of view, but you know, we just want folks to have a more enjoyable time touring, and not straining ones knees is frankly more enjoyable, especially for someone who is not 25 and doesnt think at all about it being harder or the consequences.

I have a similar Deore 26/36/48 crank and it cost $16 and 1/2 hour to swap the 26t chainring for a 22t. There's just not much of a downside to having this increased range.

You want the lower gear-set 44-32-22 for mountains. Swapping out the entire chain-set is what I'd do. I'm a fit-64-yo and that's what I'm using currently for loaded-mountain-touring. The high-end of 48 is never missed but the low-end 22 can be very welcomed at times.

I got in a lot of touring miles over the years , on my 700c wheel bike.

13~34t freewheel (Phil hub), 24,40,50 triple, 74-110 crank.

Ice Sheet Glaciers flattened most of eastern Canada , only the rockies on the western end of Alberta will you find younger mountains.

Banff is worth the trip.

Newer bikes; Rohloff .. 16:38x26; 16:53x20"





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Agree with the others that a 44/32/22 makes more sense for touring particularly given the terrain.

Roscoe, The amount of your load will make the biggest contribution for how you want/need to gear the drivetrain. While it was suggested to you that you should have lower gearing, what has been your experience thus far? How much weight?

I am a huge fan of the 22-32-44 crank set, but there is no need to purchase one if you only need a little help at the bottom. A 24T inner chain ring maybe all that's necessary, and inexpensive to test. I would recommend a chain drop device if you use an inner chain ring less than 24, which might be nice to have anyway.

Brad

+1

I can often buy the entire crankset cheaper than I can get 3 individual chainrings. I have 2 sets of brand new crank arms minus their chain rings in my parts bin.

FWIW I haven't have any issues switching from a 26 to a 22 chainring. No dropped chains, no FD or chain length adjustments.