The Economics of Bike Commuting

So recently, I started bike commuting again. It’s a long haul from home to work, and I stopped driving over a month ago and have switched to primarily the bus, with the bike subsituting once or twice a week.

Immediate Costs

Assuming $3.59/gallon of gas, and $6.25 for a day of parking, taking the car would cost $13.43 per day, or $67.15 per week.

The bus is $3 each way, for $6 per day, or $30 per week.

The bike costs $0.00 each way, making it effectively cost-free.

Given the costs, driving to work is just fucking stupid. With the weather, I’m operating under the assumption that riding year-round is, at best, foolhardy, and suicidal at worst. Hence, I’ll do savings analysis for a 4-week (mythical month), 26-week (the realistic block of time in which I can commute in a given year), and a 52-week (yeah, right).

Savings

# of Bike Days Weekly Bus Cost Weekly Savings 4-Week Savings 26-Week Savings 52-Week Savings Annual Cost
0 $30.00 $0.00 $0.00 $0.00 $0.00 $1560.00
1 $24.00 $6.00 $24.00 $156.00 $312.00 $1248.00
2 $18.00 $12.00 $48.00 $156.00 $312.00 $936.00
3 $12.00 $18.00 $72.00 $468.00 $936.00 $624.00
4 $6.00 $24.00 $96.00 $624.00 $1248.00 $312.00
5 $0.00 $30.00 $120.00 $780.00 $1560.00 $0.00

Based on this table, if I’m not riding my bike, we’re spending $1560 per year just on getting back and forth to work. That’s a lot of money. Of course, what it doesn’t take into account is maintenance costs. So let’s look at that a bit, shall we? (Again, I’m leaving the car off the list as even considering spending that kind of money on a commute amounts to epic dumbassery).

Routine Maintenance

For the purposes of making things simple, let’s assume I need a new chain and cassette every 3000 miles — this can vary with power output and maintenance/riding conditions, but I have most of my own tools and am pretty fastidious about keeping my drivetrain clean, which helps lengthen the service life.

Right now, my only road bike is my Salsa Campeon, which isn’t the best commuter rig in the world (it’s for road racing, primarily), but it’s what I’ve got. The parts group is expensive — 10-speed Dura-Ace all around, etc. Parts are expensive to replace as they wear out — a chain will run around $65, and a cassette around $180. Tires usually last about 3000 miles as well, so figure a pair of decent Conti Gatorskins or Bontrager HardCases will run in the ballpark of $80 to $100.

So, how often will I need to do this?

My commute route has been varying a bit — it’s different outbound vs. inbound, but to keep the math simple, let’s assume I’m riding about 48 miles per day.

# Bike Days Weekly Miles 4 Weeks 8 Weeks 26 Weeks 52 Weeks Weeks to Service*
1 48 192 384 1248 2496 62
2 96 384 768 2496 4992 31
3 144 576 1152 3744 7488 21
4 192 768 1536 4992 9984 16
5 240 960 1920 6240 12480 13

* Weeks have been rounded to nearest whole number.

So, if a service on my road bike costs $325 (new chain, cassette, and tires), versus $170 for the more pedestrian stuff I used on my commuter bike, it obviously makes more sense to use the commuter. Math would indicate, based on the length of my ride that I can commute to work 62 times before hitting the service threshold. On the road bike, that leads to a cost per day of roughly $5.24, which is not much of a savings over the cost of the bus, but with the commuter and it’s more pedestrian (pun intended) parts, that cost works out to about $2.74 per day, which is a significant savings.

Ideal Situation

So…how to best do this? Riding twice a week seems to offer the best balance of cost savings, when compared against the maintenance costs…of a commuter.

So, ideally, I’d be riding a commuter-only bike and not my road machine. The downside there is that, while I have most of the parts, I still need a few…including a frame. What would it take to get the commuter bike running again?

Item Cost
Frame Tubing & Dropouts $200
Powdercoat & Decals $100
Crank, Pedals, and BB $225
TOTAL $525

Which all wipes out a pretty big chunk of the money saved by riding.

What to Do?

Right now, I’m going to keep riding what I’ve got — the Salsa. Probably once or twice a week. Until I figure out a better solution. Still cheaper than taking the bus, and WAY cheaper than driving to work.