The Driveline

In picking a driveline for my bike, I had four classes of drivelines to choose from.  Singlespeed, derailleur, Internal Gear Hub (IGH), and frame based gearboxes.

Wheel and Drive System

Surly 1×1 (Photo credit: mikeywally)

Singlespeeds

Singlespeeds are the simplest drivetrain out there, like my BMX bike as a kid.  But with only one gear, I had to choose one ratio to work everywhere.  Luckily where I am living now is fairly flat, but I don’t think it fit my wishes for a go anywhere bike — especially loaded.  I know Kent Peterson rode the Tour Divide on a Singlespeed — but I am a wuss.  I used to have a blast on my fixed gear road bike in hilly Seattle (and became a better cyclist), so I decided that I don’t really need just one bike and picked up a used Surly 1×1.  This will be so I have something to ride in the meantime and stop trashing my vintage Bianchi road bike :).  It is a pleasure to pedal around on, but I do want to be able to go up and down steep hills without trashing my (out of shape) knees.

Derailleurs

Derailleurs are without a doubt the most popular drivetrain for road and mountain bikes.  I have one on my Bianchi.  I’ve had them on many bikes.  They work well, they are efficient, they are light.  There is only one problem: I really don’t like them.  They can be noisy, fiddly, finicky, have things dangling precariously low to the ground, and are just annoying.  When they get dirty, things really start going south.  My biggest problem with the derailleurs is that in order to get appreciable gear range, the front needs multiple speeds with a derailleur to push the chain back and forth.  When cross chaining (big cog and big chainring) this means trimming out the derailleur so you don’t have to listen to the chain rubbing.  It’s not hard, it’s not difficult, but it’s annoying.  If I went with a single chainring in the front and 10 cogs in the back — I would have less gear range but it would be better than a singlespeed.

Internal Gear Hubs

Internal Gear Hubs are a way of trying to get the range of the derailleur with the simplicity of the chainline of the singlespeed.  The three types commonly outfitted on mountain and road bikes are the Rohloff Speedhub, Shimano Alfine, and Nuvinci.  The downside is that you can’t shift while mashing the gears, while the upside is that you can shift at a standstill or while coasting down a hill while keeping the cranks parallel (think turns and obstacles).

If you ask anyone which is the best, they will no doubt say it’s the Rohloff — German engineered and built with the largest gear range (526%) and a long history of reliable performance.   The only thing they haven’t done is make any changes — because it works and they keep selling them — for $1400 street price.  If I were to build a bike with just one wheelset it would make sense.  However, if I wanted to swap a bike between Surly’s fatbike wheels like the rolling darryl, the semi fat wheels of the rabbit hole, and some “normal” MTB wheels like Stan’s flows — I would need to either relace my wheel or buy three rohloffs.  That gets pretty expensive!

English: Shimano Alfine S-GS700 11 speed epicy...

Shimano 11  (Photo credit: Wikipedia)

Shimano has recently started making and pushing their Nexus and more rugged Alfine line of hubs.  Though they are not marketed at the MTB market, they are used fairly frequently.  Undertstanding why is pretty simple — I can buy an 8 Speed Alfine (306% gear range) on Amazon for $200 and have it here tomorrow or an 11 Speed Alfine (409% gear range) for $425.  So I can buy three Alfine11s and still have money for a spare 8 speed if I need it for the price of a Rohloff.  Reliability for the Alfines has been mixed, some have said the 11s are more problem prone than the 8s.  But here is where the Alfine sticks out ahead of the Rohloff — Shimano is willing to make changes — they want that money that Rohloff has been getting.   They’ve already released the 11 speed, and now the Di2 electronic shifting versions of the hubs.  In the future they may rival and even exceed the Rohloff hubs.

Newcomer Nuvinci uses planetary gears to make a continuously variable transmission.  The N360 offers a 360% gear range with infinitely variable ratios — so there are no set gears here.  Dial in exactly what you you want within the 360% range and you’ve got it.  The downside is the spongy feel and lack of efficiency reported by users in the lower gears.   It does have the plus of having a good 49mm chainline vs the 41.8mm (stock) chainline on the Alfine.  They run about $350 — or just between the Nexus 8 and 11 — which is also what its gear ratio is.

Frame Gearboxes

There has been the Schlumpf, the Gboxx, the Hammerschmidt, etc…  They all fell short of expectations for me.  What is looking very promising however, is the Pinion P1.18.  18 gears, equally spaced, to deliver 636% gear range.  Rated service life is over 60,000 km or 37,000 miles.  While it is not available by itself, it runs an $1800 premium on the german frame makers that have it.  The advantage is that every wheelset is essentially a singlespeed wheelset.  Efficiency is supposed to be between an IGH and derailleur.  The disadvantage is the lengthy engagement and the chainline is fixed (albeit at a nice 54mm) so even with dished wheels like the Pugsley or Moonlander, you won’t be gaining appreciable chainline clearance.  What needs to happen is new cranks need to be made with a spaced chainring so fat tires will fit fine.  This would allow someone the ability to have all the benefits of an internal gear hub, with a 170mm frame, running whatever combination of wheels from 100m clownshoes to skinny road tires.  Fat bike one day, tri bike the next?

My Choice

If I were making this choice many years ago, I would have gone with a Rohloff.  But now, I don’t see the value there.  An Alfine 8 offers nearly all the benefits for much less, making it affordable for multiple bikes.  The future is in something like the pinion — but I am waiting for that to mature a bit more (fat bike friendly please).  I went with Shimano because they are moving the fastest and it is also the most compact.  The Silent Clutch should also be nice as I am not a fan on the “angry bee” ratcheting hubs.   I am going to try the Alfine 11 for now to try out the range, if it gives me trouble I will switch to something else.  If I decide in the future that I don’t need 4 inches of fat, then I might look into one of the pinion frames.  Also the Alfine will let me monkey with gates’ centertrack offerings fairly easily to see if going chainless is worth it.

One thought on “The Driveline

  1. Pingback: Stick a Fork in It | Mister McFeely's Outdoor Adventures

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