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.

http://www.sterba-bike.cz/produkt/clement-et-cie-safety-bicycle-1889?lang=EN

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?
http://www.louisvillebicycleclub.org/page-917031

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. 

http://www.all-about-hubs.com/start.php?action=naben_galerie1_en

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.

http://www.cyclingburylancs.com/velocio.htm

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!

http://www.classicrendezvous.com/Events/Cirque/Cirque_05/photos/cirque_2005_lawn_party_pics2.htm

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.

http://cycling-passion.com/2013/06/22/top-10-cycling-innovations/simplex-champion-rear-derailleur-1934/

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.

http://velobase.com/ViewComponent.aspx?ID=C9705308-3BC1-4BCD-AEDF-8F22D18BF3EC&Enum=108

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.

http://www.disraeligears.co.uk/Site/SunTour_Skitter_derailleur_%281st_style%29.html

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.

http://www.bikeraceinfo.com/photo-galleries/derailleurs-50s.html

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!