Single speed drivetrains have significant appeal. They’re simple, lightweight, and tough. They boil the riding experience down to its most basic form, eliminating the distractions associated with more complex drivetrains while putting the rider more closely in touch with the terrain. The trade off for this simplicity is the inability to change gear ratios (of course) which makes riding in varied terrain more challenging, particularly if any kind of loads are involved. Plus, riding a high gear at low cadence can put considerable strain on joints and connective tissue which can lead to injury over the long term.
At the other extreme are 3×9 27-speed drivetrains designed for mountain biking or loaded touring. These drivetrains are well-suited for riding in rugged, off-road conditions or carrying heavy loads long distances over mountain passes and across deserts. In other words, they provide a wide range of gears to suit those who ride in a wide variety of conditions. They’re so effective that they’ve become standard issue on many bikes, even bikes that may never see a single track or a mountain summit. The downside to these versatile drivetrains is the added complexity and cost, as well as the higher maintenance required to keep them running efficiently.
After riding a number of 8-speed and 9-speed IGH-equipped bikes for the past two years, I’ve found they cover my needs for city riding quite well as long as the overall range is sufficiently low. And on my bikes with double and triple cranks, I’ve found I spend nearly 100% of the time on a chainring in the 40-42 tooth range. This has me thinking that a 1×9 drivetrain with a single 42 tooth ring up front and a 11-34 cassette in the rear may be a perfect set-up for the type of utility riding that I do on a daily basis.
Consider the following:
- The gear combos I use 99% of the time on my derailleur bike: 42 x 11/34 (700c)
- The gear inches for that range: 33.4″ – 103.1″
- The gear/cadence/speed relationship in the highest gear: 42×11 @ 80 rpm = 24.5 mph
- The gear/cadence/speed relationship in the lowest gear: 42×34 @ 60 rpm = 6 mph
On a city bike to be used for commuting or running errands, I rarely top 20 mph, and I certainly have no need to spin out past 80 rpm at 25 mph, even on a downhill; beyond that I just coast.
On the low end, I find 33” (6 mph at 60 rpm) plenty low for loads up to 60-70 lbs on moderate hills, the typical max I experience. Of course, on a cargo bike in mountainous terrain, where the loads are greater and the hills are longer and steeper, lower gears are a must.
I’d say that I’m going to give a 1×9 drivetrain a try, but the fact is, I’ve effectively been using a 1×9 drivetrain for a number of years. You only have to look at my crank to see what I mean; the outer ring was replaced with a chainguard long ago, and the inner ring has zero wear on it. I do plan on replacing the triple with a single crank, if for no other reason than to make it official.
All calculations were made using the late Sheldon Brown’s excellent Gear Calculator.
Mayor Antonio Villaraigosa says “thank you” to those who reached out after his accident last week, while promising a bicycle summit in Los Angeles.
A few random thoughts triggered by this morning’s commute photo:
- Bike commuting beats the heck out of sitting on the freeway in bumper-to-bumper traffic.
- The new bars and saddle really changed the character of this bike. I didn’t think the below-the-saddle bar height was going to work for me at all, but it’s nice having my weight distributed a little more evenly between the bars and saddle.
- Speaking of saddles, the Selle An-Atomica beats the heck out of the Brooks it replaced for sheer comfort. BTW – does anyone know the status of S-A with Tom Milton’s passing?
- The Pass & Stow porteur rack with matching Freight Baggage Rack Bag make a super front catch-all carrier.
- I realized the other day that I’ve probably shifted to the granny ring on this bike all of 3 times over the past two years, and then only to test a shifter. With that in mind, I have in the works to turn this into a 1×9 drivetrain. More on this later.
- At the right of the photo is an intersection where one of our bike trails meets one of our bike lanes. Notice the stop sign and the generous width of the the bike lanes going in either direction perpendicular to the path. The same type of on-street lanes connect with the off-street path on the other end as well. It’s not a bad system.
- That Arkel Bug is a tough bag. It’s seen a ton of abuse and it looks like new.
- Surly needs to put kickstand plates on their LHTs.
- The Canon G10 is a sweet little on-bike camera.
- The best thing in this photo is the little highlight on the top tube.
Have a super day and a safe commute!
You’re looking at the first foreign object to penetrate my Marathon Supremes’ impenetrable Vectran layers in nearly two years of riding. I pull these out of Supremes all the time with no ill effects, but this bad boy made it all the way through to the core. It’s such a grand specimen I may have to give it a coat of shellac and mount it in a shadow box.
The wimpy racing tires on our little fixie were attacked by a handful of these same (but smaller) thorns and every single one penetrated the tubes. It goes without saying that the tubes were toast. It’s official: I hate wimpy racing tires (you would too if you were the designated flat fixer in a family of five).
Burton Avery, the industrial designer at Civia, posted the first in a series of articles about the design process behind their belt drive Bryant. From the blog post:
I’m the industrial designer here at Civia. I collaborate with a team of people, such as engineers and a brand manager, on Civia’s products. I am responsible for what industrial designers call form, or the way our products look in terms of shape.
In the next few blog posts I’ll be delving in to the design process for the Civia Bryant. By explaining design features in detail, hopefully you’ll get the idea that the Civia Bryant is more than just the sum of it’s parts. The Bryant’s modular dropout allows for a range of different drivetrain solutions.