Touring Gear Ratios for Wimps!

[rmurphy195]

My disc-braked Condor Heritage has 8-speed claris brifters, an 11-32 rear sprocket and a Spa XD-2 touring triple with 26/36/46 rings giving me 22" - 112" and it all works perfectly.

I don't think I would use smaller chainrings (I originally had a Tourney 22/32/42 on the front and it didn't change very well, and the tail of the front cage was almost touching the chainstay).

I am thinking of replacing the rear with a 12 - 32 unit, if I can find a silver one instead of black, there's a bigger jump between the 2nd and 3rd sprocket on the 11-32 that I'm finding annoying - apart from that I'm very pleased with the setup. And it looks smart!

[fausto99]

To echo Brucey's point No.1, an MTB crankset will space your pedals as much as 2cm wider than a road crankset. Yikes!

...and there was me thinking of changing my FC5703 (105) triple chainset to a FC-M590 (Deore) to get round the 110mm bcd which prevents me getting a middle chainring with less than 39teeth. How much wider will my feet be if I do this?

[pwa]

To echo Brucey's point No.1, an MTB crankset will space your pedals as much as 2cm wider than a road crankset. Yikes!

...and there was me thinking of changing my FC5703 (105) triple chainset to a FC-M590 (Deore) to get round the 110mm bcd which prevents me getting a middle chainring with less than 39teeth. How much wider will my feet be if I do this?

Having your feet a bit further apart may only matter if you have short legs. People with long legs naturally tend to stand with their feet further apart than those with short legs. I have longish legs and find "road" chainsets put my feet just a little too close together, and MTB chainsets get it about right.

[iandriver]

I just bolted a 26t inner onto a bog standard Sora 9s triple groupset and it was kind of job done as long as I avoid small to small (which I have never tried to do). Does it need to be that complicated?

[hondated]

If you try to get a road triple mech to shift via a triple STI on an MTB chainset it is a route that is fraught with difficulties, and (IMHO) is best avoided.

cheers

Interesting comment Brucey given that Roberts built my bike with a 44t Shimano Deore XT triple chain set, a Campag front mech and Campag Veloce levers so they couldn't have struggled too much could they !

In which case you have ergos not STIs. Not the same thing at all; an easy job with most ergos.

Anyway it isn't impossible even with STIs; it is just that there are very many ways it can go wrong, and there are easier ways of solving the fundamental problem.

cheers

Thanks Brucey spot on as usual.

[meic]

I just bolted a 26t inner onto a bog standard Sora 9s triple groupset and it was kind of job done as long as I avoid small to small (which I have never tried to do). Does it need to be that complicated?

Depends on whether you need lower gearing than that. 24 teeth is the limit by that method and the OP wanted 22.

[iandriver]

I just bolted a 26t inner onto a bog standard Sora 9s triple groupset and it was kind of job done as long as I avoid small to small (which I have never tried to do). Does it need to be that complicated?

Depends on whether you need lower gearing than that. 24 teeth is the limit by that method and the OP wanted 22.

The GS cage should take an 11-34, which I think takes the OP within a couple of gear inches of what he is looking for with a 26T up front. If that's a deal breaker, I think I'd be looking to go the whole hog with a 36 rear and a 22 up front.

[meic]

11-34s in 8 speed are awful things going from 26 to 34 teeth in one step at the bottom.
I even decided to abandon my 11-32 for 11-30 to avoid a smaller version of a large jump either side of second gear.

[CJ]

I just bolted a 26t inner onto a bog standard Sora 9s triple groupset and it was kind of job done as long as I avoid small to small (which I have never tried to do). Does it need to be that complicated?

It IS that simple if you have a few year's old chainset. In fact you could just as easily (and I always did) fit a 24T inner on the 74mm BCD that USED TO BE ubiquitous. But the OP is buying a new bike, so he'll be getting a current model of triple chainset, and the big brands don't make 'em like that anymore. Road triples are on the way out. Now we have ten or even eleven in back, we don't really need three in front! So to save having to forge a different shape of crank, current road triples are double cranks set a few mm further to the right and equipped with a 'triple converter' style of middle ring, that has an inner hanging off it via some non-standard BCD that won't allow anything smaller than 30T. So you can't ring the changes.

But actually you can, but you have to buy a new middle ring too: specifically one of those actual TA or Stronglight triple converter rings, that hang the inner off the middle on the standard 74mm BCD, so smaller rings down to 24T CAN be fitted.

To stop you doing that however, Shimano are now mucking about with the number and spacing of the bolts. At present it's only the top end groupsets, designed and priced to separate fools from their money. But it'll surely trickle down to the good and (previously) useful stuff.

I meant what I said about not needing three in front now we have at least nine in back. Although I've run triples most of my life since the 70s (when we had only five or six in back and really needed three rings) and always made them work very well: I have to admit that doubles do shift better. And most of my bikes now have them - but not like any doubles you can easily buy anywhere. Up-to-date touring calls for a MTB 10-speed cassette (11 to at least 34) on an MTB hub, to be driven by a chainset with the same chainline as a road-double but far fewer teeth. I'd say that 46,30 is the most that anyone needs (given a nominally 27in wheel that's a 113in top already!), that 42,26 or 40,24 is about right for most people and that something as small as 36,20 may well be wanted by campers and those with shorter legs and cranks. That's what touring/trekking bikes ought to be sold with, but since touring isn't receiving any attention from the big component makers these days, such chainsets are hard to get and very expensive. There are plenty of MTB doubles of course, but the chainlines and pedal track are wider than you need or want on any touring or hybrid/trekking bike. The hybrid bike market is woefully undiscerning, so MTB chainsets with stupidly bigger rings is what they get!

[CJ]

11-34s in 8 speed are awful things going from 26 to 34 teeth in one step at the bottom.

But they don't have to be. I buy the good old 13-34 7-speed 'K' cassette from Rosebikes in Germany, where it is still readily available as a spare, although not sold in Little Blighty these last 20 years. It has a beautifully even progression of 11,13,15,18,21,25,29,34. I unscrew or grind the heads off the pins that hold it all together and take it apart, discarding all the spacers and the top sprocket. I also buy, or salvage out of an old 11-up 8-speed cassette, a set of 8-speed spacers and top two sprockets (11,13) plus lockring. Add these to what's left of the 7-speed 'K' cassette and Voila!, a nice even 8-speed 11-34.

I have three bikes thus kitted out at the moment, one of which my daughter is currently using to tour Patagonia (with her friend Jess). It's an old MTB with a 44,32,22 chainset. With the tyres she has fitted that'll be a sixteen and a half inch bottom gear! Wimps? They're camping, in the Andes, on gravel roads, and apparently averaging over 100km per day.

[Valbrona]

Stay away from the TA 110 BCD tripleizer middle chainrings - they don't work.

Interlock Racing Design do 110 BCD tripleizer middle rings in 34 or 36t.

A suitable triple crankset is the Miche 110/74 BCD triple, which comes with integrated axle for threaded BB shells. I used to run one of these with 26/36/46.

[iandriver]

I just bolted a 26t inner onto a bog standard Sora 9s triple groupset and it was kind of job done as long as I avoid small to small (which I have never tried to do). Does it need to be that complicated?

It IS that simple if you have a few year's old chainset. In fact you could just as easily (and I always did) fit a 24T inner on the 74mm BCD that USED TO BE ubiquitous. But the OP is buying a new bike, so he'll be getting a current model of triple chainset, and the big brands don't make 'em like that anymore. Road triples are on the way out. Now we have ten or even eleven in back, we don't really need three in front! So to save having to forge a different shape of crank, current road triples are double cranks set a few mm further to the right and equipped with a 'triple converter' style of middle ring, that has an inner hanging off it via some non-standard BCD that won't allow anything smaller than 30T. So you can't ring the changes.

But actually you can, but you have to buy a new middle ring too: specifically one of those actual TA or Stronglight triple converter rings, that hang the inner off the middle on the standard 74mm BCD, so smaller rings down to 24T CAN be fitted.

To stop you doing that however, Shimano are now mucking about with the number and spacing of the bolts. At present it's only the top end groupsets, designed and priced to separate fools from their money. But it'll surely trickle down to the good and (previously) useful stuff.

I meant what I said about not needing three in front now we have at least nine in back. Although I've run triples most of my life since the 70s (when we had only five or six in back and really needed three rings) and always made them work very well: I have to admit that doubles do shift better. And most of my bikes now have them - but not like any doubles you can easily buy anywhere. Up-to-date touring calls for a MTB 10-speed cassette (11 to at least 34) on an MTB hub, to be driven by a chainset with the same chainline as a road-double but far fewer teeth. I'd say that 46,30 is the most that anyone needs (given a nominally 27in wheel that's a 113in top already!), that 42,26 or 40,24 is about right for most people and that something as small as 36,20 may well be wanted by campers and those with shorter legs and cranks. That's what touring/trekking bikes ought to be sold with, but since touring isn't receiving any attention from the big component makers these days, such chainsets are hard to get and very expensive. There are plenty of MTB doubles of course, but the chainlines and pedal track are wider than you need or want on any touring or hybrid/trekking bike. The hybrid bike market is woefully undiscerning, so MTB chainsets with stupidly bigger rings is what they get!

I take all that on board and don't doubt your opinions. The bit I don't get is the past tense regarding the triples. The Shimano site today shows the Soa triple as being 74mm BCD. https://cycle.shimano-eu.com/content/se ... -3503.html Granted this isn't a deluge of choice, but this thread makes it sound like it's already a thing of the past.

[Trebor]

CJ/Brucey - a question from a novice, after playing around with the Gear Calculator:

For a nominal 27in wheel, why not have a triple with closely spaced outer and middle rings - say 48T and 44T and and a 30T or 28T inner, coupled with a 9 speed 12-36 cassette (or customised using the top 2 sprockets from either a 14-25 or a 13-25, if the smallest sprocket is felt to be somewhat redundant) ?

http://www.gear-calculator.com/?GR=DERS ... 6&UF2=2185

If you find the 18T-21T or 24T-28T 16.67% steps, on the middle ring, a jump too far, then half-step them. Otherwise, it makes for a very easy single shift sequence, with only a 9.1% step (8.7% for the 50T,46T combination) between the outer rings.

This assumes that an ultra-low bottom gear is not required, but there are a number of posts stating that some are (currently) happy with a bottom gear of approximately 22 inches. I assume that a double front-derailleur such as a Shimano CX70 (top-pull) would have no problem, if prepared to forgo the indexing, with this type of configuration?

For a 26 inch wheel a 50T, 40T, 30T triple with the same cassette (but customised in the example shown by swapping the top 2 sprockets for those from a 14-25 cassette ) seems to work, perhaps even better?

Shimano might be unhappy that cassettes might then last considerably longer than they desire but are there any other problems anticipated with such a retro configuration? Peter White states that 46T middle chainrings are available in 110 BCD (for the 26 inch wheel setup) but they don't appear to be commonly stocked.

[Brucey]

the great thing about triples is that you can create almost any range of gears you like; there are almost infinite possibilities. And, if you are touring, even 'imperfect' sets of gear ratios usually work well enough.

True half-step systems used to be very popular; they use a constant percentage ratio between adjacent sprockets in the cassette. This approach can work reasonably well with a small number of sprockets with a large interval (say +25%) but because the sprockets are usually smallish and don't all divide very well the approach doesn't give such uniformly spaced gear ratios if you try for a smaller percentage ratio and more sprockets.

However there are various issues with half-step systems

a) there are a lot of front shifts if you want to get the benefit from all those ratios

b) similarly there are a lot of double shifts

c) currently there are not front derailleurs made which are intended to be used with a small middle to big interval; most of those you might want to use have a deep inner plate and won't work on a half-step chainset unless the FD is set too high, which in turn risks that the chain regularly overshifts off the big ring.

BITD half-step systems were used for racing too, and indeed such setups were so common that most FDs didn't have a deep inner cage plate, so that they could be used in such an arrangement. The half-step plus inner arrangement shifts pretty well, with a decent FD, but (as with an Alpine double) the shift from inner to middle ring is a real whopper.

If you use a one and half step arrangement there are even more double shifts (every shift is a double shift if you go through the gears in sequence) but there is a smaller jump from inner to middle, and block shifts are readily available.

It is said that there is more than one way to skin a cat, and that is so true of triple gear setups that in fact there is a near-infinite variety of different ways to do the deed.

BTW this 3x8 system

http://www.gear-calculator.com/?GR=DERS&KB=24,43,48&RZ=11,13,16,20,25,30,36,43&UF=2185&TF=90&SL=2.6&UN=KMH

is a bit more like a classic half-step. It works almost as well as a 3x6 too, i.e. without the smallest and largest sprockets.

cheers

[pwa]

For me, the small "granny" ring is for "real hills", not just short rises, so in flat or gently undulating terrain it gets no use. Which means that the size of the jump from middle to inner is unimportant. I don't do it a lot during a ride, and when I do I am settling in for several minutes of twiddling the pedals. Back on the flat I am using the other two rings almost as a double. I suppose that means the small ring can be as small as I can get away with given that my mech has to work with that and the other two rings. It is some vintage of Tiagra on the tourer.