Home
Smaller chainrings mean lower gears — is this the way to go for riders who don't race?

With this version of its Alba chainset, Praxis Works is in the vanguard of a new trend in gearing, the sub-compact chainset. What’s the idea, and is it the way to go for you?

The chainrings are the feature that separates this version of Praxis’ Alba chainset from similar-looking five arm chainsets. They’re a 48-tooth outer and 32-tooth inner for a slight drop in gearing over more common set-ups.

The bike industry is variously calling this ‘sub-compact’ or ‘adventure’ gearing because it takes the existing idea of the compact chainset a step further, yielding gearing that’s ideal for bikes used across a range of surfaces and terrains. (Praxis calls it ‘Micro-Compact’ which I think is over-egging things a shade.)

Praxis Works Alba M30 - reverse side.jpg

Praxis Works Alba M30 - reverse side.jpg

For over a decade the compact chainset has been the most common gearing set-up for road bikes that aren’t specifically intended for racing. The concept shot to fame in 2003 when Tyler Hamilton used a bike with 50/34 chainrings in the Tour de France.

Hamilton had broken his collar bone and couldn’t pull on the bars to push a high gear. Sponsor FSA supplied him with a chainset that gave him lower gears so he could spin up the hills. He went on to win a stage and finish in fourth place overall.

The dark side of what should be one of cycle sport’s greatest stories of heroism and willpower triumphing over pain is that Hamilton’s career ended in ignominy after a string of positive doping tests. In the 2012 book he wrote with Daniel Coyle, Hamilton admitted to having received a blood transfusion the night before his stage victory. (That book, The Secret Race, is a truly hair-raising tale of the ambition-fuelled doping insanity of pro racing, and deserves a place on your bookshelf.)

Hamilton’s sins aside, his use of a compact chainset legitimised the idea in the eyes of enthusiast riders who didn’t have the power to easily climb hills in the standard racing combination of 53/39 chainrings.

Since then, your options in gearing have widened even further. The advent of 10- and then 11-sprocket cassettes means you can get close ratios and a wide gear range without going to a chainring as small as 34, and that’s led to the compromise between race gearing and compact, the ‘semi-compact’ 52/36.

And now there’s yet another option: sub-compact, with chainrings that are two or four teeth smaller than a compact.

Why? Well, for starters, gravel/adventure bikes. Dirt roads can be long and steep, so it’s a good idea to have lower gears than are possible with a compact. For its Sequoia adventure bikes, Specialized is using FSA chainsets with the same 48/32 combination as this Praxis set, and we think we’ll see more of this in future.

There’s another thing, though. For general road riding, the gears afforded by these chainsets make a lot of sense. There’s been a trend in the last couple of decades to higher and higher top gears on road bikes. A pro-level road race bike that would once have had a 52x13 top gear now has 53x11, a whopping 20 percent higher.

Mark Cavendish might have use for a gear that high when he’s diving for the line on the Champs Elysees, but you and me? Probably not. Even when you’re descending, the extra speed you can add by pedalling a big gear is very small; you’re better off concentrating on getting into as deep a tuck as possible.

Sub-compact options

Sub-compacts come with either 48/32 chainrings or 46/30. A 46x11 top gear is still higher than that old-school 52x13. What would you rather have, a top gear that you can only really use once in a blue moon, or some lower gears to get you comfortably up an unexpected 20% grade?

If the latter, there are three obvious ways a chainset maker can accommodate you. The old-school answer is a triple chainset, but they’re hopelessly unhip and few shifting systems now work with them; you can’t get a triple-capable left hand shifter above Tiagra in Shimano’s range, for example.

An alternative is to go to a smaller bolt circle. Most Shimano road bike cranks use a four-bolt, 110mm bolt circle, as did five-bolt compacts. Four-bolt mountain bike cranks, on the other hand, have a 104mm bolt circle, allowing rings as small as 32 teeth; five-bolt mountain bike cranks are 94mm, so you could go down to 30 teeth.

Or you could have two bolt circles, as Sugino has done for a while with its OX cranks. These have a 110mm outer chainring bolt circle and a 74mm inner for a huge range of possible combinations down to 40/24. FSA has taken a related approach with its various Adventure cranks. The Tempo has a 110/80 five-arm spider; the SL-K Modular crank has an outer ring that mounts on the crank and an inner with an asymmetrical 90mm four-bolt circle; and the Omega Adventure has 120mm and 90mm four-bolt circles.

Fans of the quaint, old-fashioned notion of standards will be grinding their teeth at the introduction of yet more chainring attachment patterns to the already excessive number that bike shops have to try and handle.

For this five-bolt crank and its 110mm spider Praxis has come up with a clever fourth way: dispense with the chainring nut and screw the bolt straight into the inner ring. That provides the necessary couple of millimetres of extra space needed for a 32-tooth ring.

Praxis Works Alba M30 - chainring bolt detail.JPG

Praxis Works Alba M30 - chainring bolt detail.JPG

The chainring bolts screw directly into the inner ring. A conventional chainring nut in this location would overlap the teeth. 

The hole in the inner ring is very close to the bottom of a trough between teeth, though, so you can’t go smaller with this trick. And you probably can’t just put the Praxis rings on a 110mm five-arm chainset that you happen to have spare. To make room for the chain on the 32-tooth ring, Praxis has machined a shoulder into the arm of the crank; without it, the chain will almost certainly hit the spider arm and skip.

The lighter, hollow-forged Praxis Zayante chainset also has the cutaway crank spider ends, so you can use the 48/32 rings with those cranks too.

You also get Praxis’ intricately-shaped outer chainring. Praxis claims to be the only manufacturer beside Shimano to cold-forge its outer rings. The advantage of that, according to Rory Hitchens of Praxis importer Upgrade bikes is that “shift accuracy can be detailed into every ring combination for better than great shifting.”

Praxis Works Alba M30 - shoulder in spider arm.JPG

Praxis Works Alba M30 - shoulder in spider arm.JPG

The end of the crank spider is stepped to make room for the chain to sit on the inner ring.

Is it all worth it or would Praxis be better off going for a whole new chainring bolt pattern? For a chainset maker, the big advantage of this approach is they’ve not had to create loads of new tooling. If the idea doesn’t take off, well, the Alba crank will work just fine as a regular compact.

Compatibility is important too. Rory told us: “I would say it’s for better industry compatibility at this time. 110 ring sets are more available in the Praxis range right now.

“If you look at the other 2-D forged crank from Praxis, the Cadet MTB crank, you will see that is SRAM style direct mount for the rings. I would not be surprised if Praxis looked at this system going forward for Alba as you would then have a choice of a single direct ring — very clean — or a direct mounted spider for a 2x set up with the choice to make different BCD options at lower cost.” There’s that cost consideration we mentioned.

The Alba costs £150 for the cranks and chainrings, which includes the beefy-looking 30mm hollow aluminium axle built into the right hand crank. You’ll also need a pair of Praxis M30 bottom bracket cups, which are £34.99 for threaded units or £64.99 for BB30 press-fit.

It’s going on my gravel bike shortly, and I’ll report back in a few weeks on how it all works

Our official grumpy Northerner, John has been riding bikes for over 30 years since discovering as an uncoordinated teen that a sport could be fun if it didn't require you to catch a ball or get in the way of a hulking prop forward.

Road touring was followed by mountain biking and a career racing in the mud that was as brief as it was unsuccessful.

Somewhere along the line came the discovery that he could string a few words together, followed by the even more remarkable discovery that people were mug enough to pay for this rather than expecting him to do an honest day's work. He's pretty certain he's worked for even more bike publications than Mat Brett.

The inevitable 30-something MAMIL transition saw him shift to skinny tyres and these days he lives in Cambridge where the lack of hills is more than made up for by the headwinds.

36 comments

Avatar
keirik [152 posts] 1 year ago
23 likes

I'm sure the superheroes will be out in force to run this idea down, but as a 55 year old living in North Wales I think it's a bloody great idea!

Avatar
King_Louis [28 posts] 1 year ago
5 likes

If this helps more people get on bikes then I'm all for it. The more bikes the better!

Avatar
psling [275 posts] 1 year ago
3 likes
keirik wrote:

I'm sure the superheroes will be out in force to run this idea down, but as a 55 year old living in North Wales I think it's a bloody great idea!

As someone in their 60th year I've been thinking of fitting a compact for the same reason and now this comes along!  I'd rather see smaller chainrings at the front than bigger and bigger cogs on the back. Could never understand this fashion for putting saucers on the back along with associated vulnerable dangly bits to make the hills easier (especially on mountain bikes, seems daft).

Avatar
Carton [395 posts] 1 year ago
2 likes

About - time. Standards will take a while to sort themselves out (I hadn't realized how problematic things curently were in that regard), but it's great to see more of these sub-compact options coming out to market.

P.S. Even if you're Nairo Quintana, I would still venture that the only way to get "comfortably up" a 20% grade would involve a cable car cheeky

Avatar
1961BikiE [405 posts] 1 year ago
0 likes

It's ideally what I would like on my Bokeh when I buy it. Would love a Shimano 4 bolt crank (maybe just at 105 level or none series) that would take 48/32. I just think they are the best looking crank at the moment, IMHO.

Avatar
Simon E [3206 posts] 1 year ago
8 likes

46/30 would be even better IMHO.

As for keirik's "superheroes", they are fools and should be ignored.

Avatar
Lungsofa74yearold [293 posts] 1 year ago
2 likes

Really nice thoughtful piece - more please.

I think it's great idea. About to run 46-34 on build I'm doing - would love a 32 inner ring but won't fit...

Avatar
Valbrona [321 posts] 1 year ago
5 likes

Have these people never ridden up a 25% hill or a mountain like the Mortirolo?

And is it only me that needs a 26 chainring and 30 rear sprocket?

Avatar
Yorkshire wallet [1696 posts] 1 year ago
5 likes
Valbrona wrote:

Have these people never ridden up a 25% hill or a mountain like the Mortirolo?

And is it only me that needs a 26 chainring and 30 rear sprocket?

No, it's not just you. I'd happily run 46/30 with a 32 at the back and my average speed wouldn't suffer.

Avatar
cyclisto [360 posts] 1 year ago
4 likes

Well maybe the 2x doesn't make that much sense. For me it is 3x or ditching the front derailleur and live a simpler life if crosschaining doesn't get too bad. It is a pity that 3x setups are so rare. With my 26/36/48 setup I will use all 3 rings during my daily commute and they are crucial for my loaded tours!

Avatar
kil0ran [701 posts] 1 year ago
0 likes
Yorkshire wallet wrote:
Valbrona wrote:

Have these people never ridden up a 25% hill or a mountain like the Mortirolo?

Me too. As would weight weenies - smaller chainsets are lighter chainsets  1

And is it only me that needs a 26 chainring and 30 rear sprocket?

No, it's not just you. I'd happily run 46/30 with a 32 at the back and my average speed wouldn't suffer.

Avatar
MamilMan [60 posts] 1 year ago
2 likes

I say fit whatever rings you like. It's why I ride a very unfathomable 50/39.

It does however annoy me that Shimano now make their rings 'matched' as pairs whose shifting performance is reduced if you abandon their oriental wisdom.

48/32 sounds like a perfect set up for somwhere with lots of hills.

Avatar
Topcat [39 posts] 1 year ago
1 like

My touring bike has a 46x11 top gear and even on a very steep downhill you're never spinning out, if anything you're probably at a better cadence to go even faster. I took it up and then down Ventoux from Malaucene and I had no problem overtaking campervans and lots of cyclists on the way back down.

 

A smaller top ring also makes sense as far as not having a huge jump to a sensible small ring for loaded or off road riding. 

Avatar
Nick T [1112 posts] 1 year ago
0 likes

I don't get it, if you're a leisure cyclist get a triple chainset. They never stopped working, and you've got plenty of low gears along with some high ones if you need them. These look like they're just aimed at folks who want to look like they're "serious cyclists" without having to do any hard work with it

Avatar
DaveE128 [981 posts] 1 year ago
4 likes

Finally, manufacturers are making gearing for people who aren't pro-level fit, like to ride up hills, and don't like to destroy their knees!

About time too!

And I won't be buying one just so that I can run a clsoe range cassette! I'll probably still run 30t or more on the cassette!

Avatar
CXR94Di2 [1959 posts] 1 year ago
2 likes

40/28 mated to a 11-40 Cass will give 95" at the top and 18" at the bottom or 25mph @90rpm cadence down to less than 5mph at the same cadence.

How many riders will be moving at 25mph on the flat outside a racing situation and who are older and need low gearing for mountains, very few?

I have ridden with 53/39 cranks and 50/34, both have their uses but I always find I can't use the whole range of gears and stay in my cadence comfort range(90-100) With 40/28 I will use all the gears. This is my setup on my new sportive/ tourer build.

Avatar
Cugel [19 posts] 1 year ago
2 likes

Personally I have lotsa low gear configurations atwirl below the knees. Two bikes have triple chainsets, all have dinner-plate sprockets and the MTB has a 27/42 chainset with a 36 tooth sprocket at he back.

I have no bike with a gear larger than around 100" (in old money). As the article mentions, I spent years road racing and TTing with a highest gear of 52/13 - used only in sprints and on those wind-ahind days. Wot are these 11 tooth things for? (Posing).

But there is a problem with many modern frames in fitting a chainset with a big ring that isn't (that big, I mean). Those road frames with a braze-on fitting for the front mech are often configured so that the smallest possible big (outer) ring is 50 teef. The front mech will not slide lower - although you can slide it higher for your 55 toofer (wanted only by Cav).

This is a nuisance when you desire a 44-30 on there.

Cugel

Avatar
Pauldmorgan [234 posts] 1 year ago
3 likes
Nick T wrote:

I don't get it, if you're a leisure cyclist get a triple chainset. They never stopped working, and you've got plenty of low gears along with some high ones if you need them. These look like they're just aimed at folks who want to look like they're "serious cyclists" without having to do any hard work with it

 

Not a huge amount of choice for triple systems though and this approach means you only have to change your cranks - not your shifters and mech as well. Each to their own.

I'm hoping Cannondale make a 48/32 spiderring so I can just swap that bit out.

Avatar
Shades [349 posts] 1 year ago
6 likes

Good idea; if you were spending a week in the Alps grinding up HC climbs, then this would be ideal.  Was staying in a place near Alp d'Huez a couple of years ago and someone in another group had a super-light custom carbon bike with disc brakes and sub-compact gearing.  Could have climbed all day on it.  Went into a small bike shop in the Vosges and every bike was a triple.  These people live near proper hills and seem to have a different attitude to gearing.  I think we should all be getting bikes that suit our riding style, fitness, age, aspirations etc rather than trying to look like a pro.

Avatar
Batchy [392 posts] 1 year ago
4 likes

Well . Before long someone somewhere is going to invent a 26/36/46 mountain bike triple . De je vu then !

Avatar
gmrza [35 posts] 1 year ago
0 likes

For road, I am now generally happy with 50/34 - that gives me a very wide range of gears, and I don't lose out on much at the top end.  (In my 20s I used to be able to descend at nearly 80km/h on a MTB with a 46/36/26 chainset.)

What I would really love for commuting is a 50/39 chainset.  48/39 would probably be even better.  I tend to be at the range of speeds that is at the top end of what you can do with a 34 (or just above that) or the low end of what you can do with a 50.

Avatar
Alb [158 posts] 1 year ago
1 like

Yay - FSA 48/32T & 46/30T at various scaled price points

Nay - Proprietary BCD combos tying you into their chainrings 

Direct mount chainrings/spiders borrowed from the mtb world is the way forward. 1x, 2x, standard/disc chainline, etc. John - might be nice to give a nod to Middleburn(BETD) in this article seeing as they've been doing just that for quite a while now? 

Avatar
BertYardbrush [60 posts] 1 year ago
0 likes

48/32 and 46/30 have been around quite a while.

I think Middleburn did one but it was quite pricey, then Sugino brought out the 601 series.

I got a Sugino at enormouse expense from the USA as no one in UK stocked them. Got lamped for a load of customs duty, (we're going to have to get used to that.)  It worked well with a Shimano CX70 front derailleur and 10sp cassette. It's a hollowtech bottom bracket so you can use Shimano or Hope or similar bearings. They did a product recall on the original, which has now been modified. I think it is now available in the UK.

I've gone back to 105 Triple but the double 46/30 was really more elegant.

 

 

 

Avatar
therevokid [1017 posts] 1 year ago
2 likes

run a 50/36 - only because the 34 wore out and i couldn't find one !

now love the combination, especailly with a 28 rear  1 but this .... hhmmmmm - where's

me wallet gone ...  1

Avatar
HowardR [142 posts] 1 year ago
2 likes

It's a shame that, now the manufacturers have decided what's best for us, it's no longer (easily) possible to put together a half step & granny gear combination. I found that for touring a 2 tooth step at the front made for a very useful overdrive/underdrive type of gearing and ,even ye olde front mechs, behaved flawlessly with such a small gap.

When I last used it I had bar-end shifters which worked well, modern 'brifters' would be all the better. The combined front/rear shift can happily be accommodated in one action

Front: 44, 42 & a 28 (or 26)

Rear: 12,13,15,17,19,21,23,25,27,30

gives:

           12       13       15       17      19      21      23     25        27     30
28  || 63.0 | 58.2 | 50.4 | 44.5 |  39.8 | 36.0 | 32.9 | 30.2 | 28.0 | 25.2
42  ||94.5  |87.2  |75.6  |66.7  | 59.7  | 54.0 |49.3  |45.4  |42.0  | 37.8
44  ||99.0 | 91.4  | 79.2 | 69.9 | 62.5 | 56.6  | 51.7 | 47.5 | 44.0 | 39.6

 

Avatar
Schweiz [35 posts] 1 year ago
0 likes

Where will this STOP?!  Gears getting easier and easier until all challenge is gone out of bicycle riding. We know real reason manus are pushing this is because they need to make less teeth and use less metal but price will be same. Riders will LOOSE

 

Avatar
alexb [163 posts] 1 year ago
0 likes
HowardR wrote:

It's a shame that, now the manufacturers have decided what's best for us, it's no longer (easily) possible to put together a half step & granny gear combination. I found that for touring a 2 tooth step at the front made for a very useful overdrive/underdrive type of gearing and ,even ye olde front mechs, behaved flawlessly with such a small gap.

When I last used it I had bar-end shifters which worked well, modern 'brifters' would be all the better. The combined front/rear shift can happily be accommodated in one action

Front: 44, 42 & a 28 (or 26)

Rear: 12,13,15,17,19,21,23,25,27,30

gives:

           12       13       15       17      19      21      23     25        27     30
28  || 63.0 | 58.2 | 50.4 | 44.5 |  39.8 | 36.0 | 32.9 | 30.2 | 28.0 | 25.2
42  ||94.5  |87.2  |75.6  |66.7  | 59.7  | 54.0 |49.3  |45.4  |42.0  | 37.8
44  ||99.0 | 91.4  | 79.2 | 69.9 | 62.5 | 56.6  | 51.7 | 47.5 | 44.0 | 39.6

 

Half-step plus granny makes a lot of sense if you have big steps between gears, less so if the ratios at the rear are a little closer - in that case you'd be better off with a triple.

My Campag triple (50,40,30) matched to an 11-26 cassette gets a lot of use right across the range at both ends. I spend a lot of time cruising along on the 50t with the chain somewhere in the middle of the cassette (changing up or down as required to maintain cadence), that seems to be a good combination for flat, fast roads, so the 50t isn't only of use for sprinters.

 

 

Avatar
TypeVertigo [421 posts] 1 year ago
0 likes

This reminds me of the 46/36T cyclocross crankset my bike came with stock. For a lot of urban riding, a 46T big ring is very usable, and the tight 10T gap to the 36T small ring meant minimal shock to my knees when shifting at the front. I had mine paired with a 12-30T cassette.

That said, I later switched to a 50/34T crank because I wanted both a higher peak speed and an easier ring to climb with. I sure do miss using all combinations of my gears though.

My only beef with Praxis' cranks is the 30 mm spindle. Why they can't make the 48/32T crank concept work with 24 mm spindles, I don't understand. For bikes that use BB86 bottom brackets, smooshing a 30 mm spindle doesn't leave enough room for good bearings to spin.

Avatar
HowardR [142 posts] 1 year ago
0 likes

Re: 30/40/50 & a 11-26

Hi AlexB,

I can appreciate your use of the smaller cassette with a wider triple but I find that the 10 tooth front gap ends up with a lot of duplication - as shown below.

            11        12         13     14        15      17      19      21       23    26
30 || 73.6   | 67.5   | 57.9 | 50.6  | 45.0 | 40.5 | 36.8 | 32.4 | 28.9  |25.3
40 || 98.2   | 90.0   | 77.1 | 67.5  | 60.0 | 54.0 | 49.1 | 43.2 | 38.6  |33.8
50 ||122.7 | 112.5 | 96.4 | 84.4  | 75.0 | 67.5 | 61.4 | 54.0 | 48.2  |42.2

30 X 11 = 40 X 14 = 50 X 17  e.t.c

I couldn't find a campag 10 speed so I used SRAMs PG1070 as a guide

Avatar
joules1975 [497 posts] 1 year ago
3 likes
Schweiz wrote:

Where will this STOP?!  Gears getting easier and easier until all challenge is gone out of bicycle riding. We know real reason manus are pushing this is because they need to make less teeth and use less metal but price will be same. Riders will LOOSE

 

Is this a sarchastic comment, or a stupid one?

We don't all have legs of steel or want to ride at high speeds. I rather like the idea of lower gears, particularly on my cross/gravel/allroad bike, and espcially when it's loaded up. For this reason I blew quite a lot on a middleburn 46-30t crankset.

Just need Shimano to bring out a similar crankset as then they'll also introduce a front mech that actually works properly with the smaller rings (before anyone says anything, the shimano 11sp mechs work, but not perfectly, as they are not designed for rings smaller than 34t).

Pages