21 August, 2015

Building a Bike From the Frame Up - Drivetrain History and Gearing

by Igor

We are spoiled today with the abundance of cassette and crankset options available. 10-40+ tooth cassettes, wide range triples, mid-range double gearing, 1x chainrings, and time trial gearing. You can mix and match to get the perfect gearing for your next adventure or just to get up and down that darned hill on your commute without walking. Alas, it wasn't always like this. Back in the days of guns mounted to bikes, moustaches that hipsters can only dream about, and fantastic riding wardrobe, your options for gearing were basically non-existent. Bicycles have come a very long way from simple beginnings, so let's explore gearing options ranging from fixed/single speed, internal, external, and nuances.

Safety Bicycles were the successors to Penny-Farthings/Ordinary/High-Wheelers. They were called "Safety" because if you hit a curb or bad cobble, you wouldn't have to worry about taking a header and ruining your day. Early safety bikes were fixed gear that often did not have brakes, or, if you were a serious rider, leather-padded rod-style brakes that were speed modulators at best. Riding a fixed gear drivetrain means you have one gear and the cranks will continuously turn as they are directly connected to the rear wheel via chain.
Fun fact: If you look closely at photos of wheelmen from this era, you'll notice many bikes had foot rests on the fork blades so that the rider could remove his feet from the pedals as he traveled downhill. Isn't fixed gear grand?
This style of gearing has become a staple for simplicity and a "connected" feeling to your bike. Today, flip/flop style rear hubs are popular because you can get two gears with just a flip of the wheel. 
Going into the 1920's, internal hubs were basically standard on most English-made bikes. These 3-speed hubs are hearty and rarely fail, even with little to no maintenance. Think about it, you get an uphill, flat, and downhill gear. What more do you need? Today, you have your choice of internal gearing ranging from the modest 3 speed to the complex Rolhoff 14 speed. 
If you're looking at doing a fixed, single speed, or internal you need to be aware of a few things. Ideally, your frame has horizontal dropouts like the Polyvalent or Camargue to keep chain tension. A frame that has track dropouts is great as well, but mounting fenders can be more difficult. If you have vertical dropouts, you'll need a chain tensioner. Fine for freewheel gearing, but tensioners are not a good idea for fixed gear.

Pros to fixed/single speed: Simple, reliable. Cons: Severely limited gear range on the fly. Have to carry a 15mm wrench to remove wheel.

Pros to internal: Simple and reliable, perfect for city bikes. Cons: Limited gear range, low and mid-range models are not suitable for touring as the gearing typically cannot be made low enough for extended use. Rolhoff drivetrains are very reliable and surprisingly light, but are a significant monetary investment. Have to carry a 15mm wrench. Changing flats is a pain, even more so with modern systems with "quick release" cables.
The invention of derailleur style gearing is commonly, mistakenly attributed to Tullio Campagnolo, but in fact it was a French cyclist, Paul de Vivie (who wrote under the name Velocio) who first conceived the derailleur. The story goes that he was passed during a race by another cyclist smoking a pipe and thought that if he increased his gearing he would gain speed on the flats, but struggle uphill. Decreasing his gearing meant that he would gain time uphill but lose it all on the flats. What is a man to do?

By first installing 2 chainwheels and moving the chain by hand, and later modifying his hub, he was able to gain 4 gears by pedaling backwards and adjusting the gearing of the proteon hub. A revolution!
Campagnolo Cambio Corsa is perhaps the very first "1 By" drivetrain system. A single ring crankset paired with 4 cogs on the rear wheel provided the rider a whole 4 gears. Moving the gears involves releasing tension from the hub to the dropouts using the upper lever, pedaling backwards and moving the lower level to achieve the correct ratio for the hill. Then, the wheel moves forwards and backwards in the dropouts depending on chain wrap. Lastly, closing the upper lever. Check out this video to see how it works in practice: https://www.youtube.com/watch?v=AIZhSNdO_Zo

Granted it's a weird mismatch by today's standards, but it works well for rooty East Coast mountain biking.
The modern 1x systems are characterized by a single crankset, multiple cogs on a cassette, and a rear derailleur. This drivetrain style is gaining popularity with mountain, cyclocross, city, and more recently road cyclists. The allure is simplicity and lighter weight by ditching a front derailleur, shifter, cable, and housing. Wide range cassettes (11-40T+) give riders a low range that used to only be achieved by the use of multiple chainrings. In addition, a 1x drivetrain allows the use of wider tires for off-road bikes without the worry of chainrub. I'm even using a 1x system on my Piolet.

For city bikes, simplicity is king and a 1x system with a medium range 11-32T cassette just makes sense. Novice riders would also benefit from this system. Click one way, gets easier, click the other way, gets harder. No need to explain cross chaining and duplicate gears between chainrings. Just hop on and go.

There are some downsides to consider with a 1x system. Low gearing for MTB is nice with a small front ring (less than 34T), but this leads to gearing that many riders feel is too low for flat and downhill terrain. Unless you're using a narrow-wide tooth profile of chainring, you'll need a chain keeper, like above, to prevent dropped chains off the chainring. In addition, most tourists I've spoken to say that they need at least two chainrings to get a proper gear ratio to get up the hill and not spin out on flat land.

Pros for "1by": Simple, lightweight, great gearing options, perfect for novice riders. Cons: The use of narrow-wide chainring is suggested for off-road, gearing might not be suitable for tourists, use of super wide range cassette (40T+) requires special adjustments and/or derailleur.
Enter the double drivetrain, my favorite by far: 2 chainrings, 2 derailleurs, 2 shifters, multiple cogs. Lucien Charles Hippolyte Juy, who started Simplex, is credited with inventing the first cable actuated rear derailleur. Chain tension was kept by a single jockey wheel and a piston moved in and out to select different gears. Simplex was wildly successful with more than 200 race wins in 1932 alone.
In 1949, Tullio Campagnolo perfected the rear derailleur and released the first parallelogram version dubbed Gran Sport. Though they were not as accurate as Simplex, they were more durable and could be used with more gears. The Simplex system needed different cage/plunger styles to accommodate greater number of gears, which was difficult for shops to stock.
In early 1960s, Suntour perfected the slant parallelogram design rear derailleur with the introduction of the Suntour Skitter. This redesign allows the jockey wheel to stay a constant distance away from the variable sizes of the cogs, allowing for easier shifting. With obvious influences from Huret, this layout had improved adjustment screw locations and pivots. This design is what most manufacturers use today.
In the 1940's Simplex introduced a front derailleur which was a simple lever and cage. It worked well to move the chain form one ring to the other. Simple and beautiful. Campagnolo perfected the front derailleur parallelogram design which was paired to a shifter on the downtube. "All Campy".
Doubles are easy to maintain and can have a wide range suitable to touring, commuting, and racing. A wide range cassette (11-32T) paired with a wide range crankset (30-46 or 34-48) such as the 50.4 or Fluted Double gives you plenty of gearing on the low end and flats, without having to really worry about spinning out on the downhill. Seriously, if you're spinning out in 48-11, you will benefit a lot more by tucking and saving energy than from furiously spinning.
As far as compatibility, pretty much all friction shifting in the Campagnolo, Shimano, Simplex, Suntour world is compatible. Derailleurs move around by tension in the cable, which is what the shifter is creating. I love friction shifting.

Indexing is where things get weird. Shimano, Campagnolo, and SRAM all use different pull ratios. Shimano's compatibility is easier than the rest, which is why it is the standard for quality touring rigs. Many of my bikes use Shimano components for indexed system because it is so damn simple, reliable, and affordable. Otherwise, Campagnolo for friction.

If it is 8 speed or higher and does not say "DYNASYS", you can mix and match pretty much everything. That's how I'm using a 10 speed shifter Ultegra 6600 shifter with an old XT derailleur on my Piolet.

If it says Dynasys, you are limited to only mountain pull shifters and derailleurs. This is the more common question we get. Dynasys only works with Dynasys.
Doubles are very popular for off road touring and mountain bikes, too. Paired with a wide range cassette, Shimano's Deore 38/24 crankset is fantastic for an all-rounder such as the Camargue. This crankset is also compatible with 73mm bottom bracket shells for those using 2.4" tires on the Piolet.

Pros to doubles: Huge variety of options for gearing and drivetrains from "corn cob" to "climb a tree", make it as simple or complex as you'd like, many classic crankset options. Cons: Indexing compatibility can be variable, might not be enough low gear for some riders, heavier than 1x system.
Triples are still popular for the hardcore tourist but have fallen out of use with many cyclists in favor of a wide range double with wide range cassette. This falling out is probably due to over complication compared to doubles and the number of duplicated gears. Scott clings to his triple for his touring Piolet.

Compatibility is slightly hairier than doubles because of the additional little ring. Indexed shifting requires a triple compatible shifter for that extra click. Front derailleur typically need to be longer to grab the chain off the tiny ring.

Pros to triple: Super wide range of gearing options, never have to worry about not being able to get up the hill, fine tuning the gear you're in. Cons: More complicated and heavier than double, indexed front requires triple compatible shifters, duplicated gearing.

To sum up, gearing is a vital part of your bike build. Gearing that is too high can lead to aching knees and walking hills. Gearing that is too low can lead to inefficiency on downhill/flat portions. Think about what type of riding you plan on doing, what terrain you plan to conquer, and if you're anticipating carrying a load.

What's your ideal gearing? What's the wackiest combinations you've seen out and about? Quadruples? Internal + cassette + Schlumpf? Let us know in the comments!


Anonymous said...

Brilliant post. Despite the modern luxury of being able to have dozens of gears, my favorite drivetrain so far has been a simple internal 3-speed.

adabeie said...

I'm looking at modding a fixed gear to an internal SA 3-speed for a touring rig.. I'm happy to walk, I just want the simplicity and reliability. (And maybe the guilty pleasure of coasting downhill.)

David Spiva said...

That orange bike with the dura-ace drive train looks interesting...

bradslade@byu.edu said...

On my daily commute I use a 24x 34 going up and a 46x11 going down. Everyone talks like triples are a thing of yesterday, but unless you live in a flatfish place I don't see doing with less than three chainrings. Two of my kids have doubles and grumble as they stand and grit their way up while I comfortably spin. The triples don't seem more difficult to use, maintain or live with. I've never understood complaints about how sloppy they are.

Mark Stosberg said...

My ideal would a wide/low double chainring up front with an an outer chain guard ring. My 1984 Panasonic tourist has that setup, but it's hard to find modern parts for, and using a triple chain ring is reportedly less optimal.

Zed F. said...

I agree with Brad about triples. But I have to ask, what would happen if I paired a Patterson crank with a Rohloff hub?

Kendra said...

One of the things I love about a triple is that I can essentially treat it like a 1x by leaving it pretty much permanently in the middle chain ring. No worries about cross chaining. But I still have access to the little ring for particularly big hills and the big one if I want to push myself down a hill.

Tony Hunt said...

I've got an old Trek converted to fixed gear, an old Schwinn to single speed for city life (basket on front), and a 2x rando with your BCD crank and a 11-34 9 spd cassette, friction shifters. Couldn't live without that BCD ratio. I'll probably never go 3x so long as I can kick it down to 30 or less on a double.

Anonymous said...

A well written post although you did not cover much on 'chainline'. In fact, that in my opinion is the biggest pro of triples and even doubles. Using your available gears with a relatively straight chainline increases the useful life of all the drivetrain components and it is smooth and quiet pedaling.

I believe it would be useful for many if VO again offered internal geared wheels built on VO Rims.

Ever onward,
Bruce in MT

Anonymous said...

Thanks for the great post. My problem with triples is that they make for more and fussier shifting. It's fine with a fresh indexed front, but that crispness doesn't last unless you don't mind getting a new shifter every couple of years, and even then, you still end up shifting more. I love my 1X8 and 2X9, both with 11-32 cassettes, used for different levels of responsiveness. The key is insisting on human-sized chain rings that meet your needs, which can be challenging to find. I have a 38 on my 1X and a 44/30 on my 2X. Very few unused gears on the 2X, and that mainly due to chain line. I'm old and heavy. Maxed out on a descent with the 2X, trying to get up the next rise, I stand up and I'm squarely in good-enough territory.

Brooks said...

I enjoyed the article - derailleur history is serious interest of mine. I need to point out, however, an error regarding the SunTour Skitter. The Skitter was SunTour's first parallelogram derailleur, and probably a copy of a Huret model called the Svelto. But it was not a "slant-parallelogram." The first slant-parallelogram was SunTour's Grand Prix, which came out in 1964. Within a couple of years, most of the SunTour derailleur line was reconfigured with the slant-parallelogram design -- and that did include an updated version of the Skitter which incorporated the slant-parallelogram, but kept the Skitter's stamped steel construction. There is an article on The Retrogrouch Blog about SunTour derailleurs that has some history that might be useful. Here's a link: http://bikeretrogrouch.blogspot.com/2014/06/suntour-derailleurs.html

Mark Holm said...

I am 100% happy with 48, 36, 24 in front and 9 speed 11 - 34 in back. I have a ratio for every need. The system is no more troublesome than a double crank. A plain Jane long cage Deore in back and an IRD Alpina-d in front. Shift with friction. Oh yes, the Deore is the old 9-speed variety with a nominal capacity of 45. I actually have a capacity of 47 with my setup, but it still works fine. I can even cross chain it to both extremes and it still runs smoothly. Why should I want anything less? Today I was struggling up gravely hills in bottom gear. A few days ago, whizzing down smooth slopes in top.

Thinking too much about gearing just leads to confusion. A wide range setup like I describe is far and away best for a general purpose bike. If you want a pure mountain bike, or a town bike for a flat, midwestern town, or some other special purpose, sure, give it special purpose gearing, but it will be a limited bike, a special purpose bike.

MT cyclist said...

Thanks for this informative post.
I have several bikes set up with triples, and I find them quite reliable. Nevertheless, I'm looking forward to trying out a compact double setup on a future build.

RoadieRyan said...

Started out with triple indexed shifting and found it to fussy, liked the compact double while I had it but finally setting on a nice 1x9 setup with an 11x36t cassette and a 36t chain ring which even for hilly Seattle gets me around and since I am long past worrying about top end speed the 1x9 works great. I do have a old school Motobecane that I am going to run one of your lovely 46x30t cranksets on for longer rides.


Zed F. said...

I'm currently using a 3x9 setup, and the only problem is the 50 ring is bigger than I can use most of the time. It's a Shimano 105 drive train from 1999 that still works well.

I'm wondering about replacing it with a cyclocross 46/36 crank, or maybe your 48/34. I've done the math and 36/31 or a 34/30 ratio will match my current low gear, but I'll be giving up the closer spacing of my 11-26 cassette.

So, I'm curious whether anyone else has made a similar move, and what they thought about the results.

Anonymous said...

I run a 1x9 ergo shifter on my Pass Hunter, which I ride daily, and I couldn't be happier (okay, maybe an internal hub would be even less maintenance). On my cross bike, I have a double. I recently did a moderately loaded week-long tour with about 3000ft/day in Spain and the triple on my bike didn't seem worth the hassle - maybe if I had been fully loaded.

The teasing of the orange Orange is driving me nuts. What's the story around the apparently shortened chainstay? Vertical dropout (I like this!)? Replaceable derailleur hanger? Double rear braze-ons are a treat. When can I time my anticipation for?

Anonymous said...

@Jim Mearkle, I have replaced the outer ring with a bash guard and adjusted the limiter screw on the front derailleur, for one possibility before splurging on a nice shiny VO crankset, as a way to test out whether you can be satisfied with a double. It may be cheaper to simply get other rings for the ratios you want than to swap out the whole crankset, especially if you like the crankset. I have used Sheldon Brown's gear calculator and trial-and-error. Inevitably, getting a full range onto two chainrings will require a more spread-out cassette. I guess you have to decide how important it is that you hit a precise cadence at a particular ratio. I leave such precision to the professionals. Finally, the effect of a fully loaded bike is definitely something to factor in. If my 44-30 doesn't cut it with a load, I would be inclined to reduce the load. I set my sister up with a 40-24 and an outer bash guard, and that sucker can swallow up a serious load, more than any sane person could want to haul. This is all assuming pavement. If you do a little off-road touring, your numbers could be spot-on, or you might try a 36-28, again assuming a pretty light load. Once you know what you want, you can splurge on the big shiny guilt-free and confident.

Anonymous said...

Fun Article.

A valuable reference is "The Dancing Chain", by Berto.

I think the first reliable, widely used deraileur is the Cyclo Standard.

See: http://www.disraeligears.co.uk/Site/Cyclo_Standard_derailleur.html

People only know about/used the original Campy quick-release based shifter, well, because it was a Campy, and Campy is still big in the bike business, building much better components. Since Campangolo started out by inventing the quick release, it's less surprising that their shifter used a quick release. What a hack! I'm glad to have started riding after Suntour, but I had a lot of bikes with Shimano Eagle gear in my youth.

Unknown said...

Well written article.

josh said...

I have a triple on a beater commuter Trek rigid MTB and I use all three rings more for distributing wear than because I need the extreme ranges. I have literally been in one situation where I used the 44-14 high gear at the brink of spinning out, but I was probably going more than almost 30mph on a flat to catch a train and if I am going downhill, I'll just coast.

On my main bike, I have a 48-34 double and 11-34t cassette and I think it is as wide as I need for most riding, though I would probably go lower for more off road or loaded touring, but I personally wouldn't need it to be any wider. I don't really imagine spinning out at 30+mph and I absolutely prefer a double to a triple, even if just to reduce redundancy but I think the shifting is much better, too.

I also have an Xtracycle with a 34 or 36 single ring and a 11-34 cassette and I haven't walked it yet, even quite loaded, though I would prefer a little wider range.

The moral of the story for me is that a triple gives me high gears that I don't need if I actually use all of the cassette and am pedaling a decent cadence.

Anonymous said...

As someone who rides at high cadence (105) I have your Grand Cru 50.4 crank and have put even smaller Specialties TA 44/28 rings on it to work with my 11x32 cassette on 650B wheels. At 56 I'm not out to impress anyone, just manage my pace. I am very happy with this combination.

Zed F. said...

Josh, what brand is your crank set? I've been thinking of a 34/48 or a 28/38/48 to replace my road triple. I hardly use the 50 ring since I can't keep up a decent cadence on the flats w/o being cries chained, and I think a 48 would be more useful to me.