Economies of bike commuting

Since gas appears “stuck” near $3.00/gallon, the psychological price that encourages me to bike commute when the weather is cruddy, I was kind of curious how much, if anything, I was saving.

Barring calamity, I should hit 3,000 miles (and 150,000′ ascent) before my trip to Minneapolis later this month. Less than half of that has been from events. (RAW: 431, Lilac Surprise: 93,
Flying Wheels: 94, Chelan, etc). That leaves about 1,700 miles spread among 80 commuting days since I started the last week of April.

The IRS reimbursement limit for automobile mileage is $0.405, or $745.20.. I’ll compare that to my accumulated actual expenses:

  • Chain ($25) — I replaced my chain at about 1,800 miles with one of the SRAM chains with the fancy whoozit that lets you remove and reinstall it without knowing the secret Shimano handshake. With the weather on the downslide, I’m experimenting with cleaning it by soaking it in kerosene.
  • Tires — ($25 x 5). Three tires had worn out from use. The Schwalbe Marathon was worthless, flatting four times — on the front! — during RAW. As soon as I got back, I tossed it. The Continental Top Touring model, while durable, has very poor traction in wet weather. Before I kill myself going around a corner too hard, I’m replacing it with a Comet Primo Kevlar.
  • Tubes — ($5 x 3) When I get a flat, I swap out the tube and patch the flatted one, thereby giving the patch time to adhere. After five patches, I’ll toss the tube.
  • Patch kit ($5) — I’ve had a lot of flats this year…
  • Freewheel ($30) These wear out after a while.
  • Handlebar tape ($10 x 2) – I did a double-padding job
  • Seat bag ($8) The velcro strap thingie wore off.
  • Cycle computer — The transmitter of my cycle computer broke on the first day of RAW. I haven’t replaced it yet. ($20)
  • Brake pads($10 x 6) I have gone through too many of these, four pair on the back, two on the front.
  • Wheels ($300) Ouch The steep, curvy descent on the way to work is generating lots of heat as I brake. I think this caused my rims to develop excessive wear. I replaced the wheels just before RAW. I could have saved $90 reusing my existing hubs but (a) I couldn’t find anyone who’d work with the proprietary hub on short notice and (b) I hope to eventually upgrade to disc brakes, preventing this from occurring in the future.
  • Miscellaneous ($10) — zip ties, black electrical tape, bungee cords, bolts, and a large rubber band so my fender doesn’t flutter. I’m starting to channel Kent Peterson.
  • Labor ($190) I had a bike tune-up done in January, but have since taken a “derailleur/brake maintenance” class so I can deal with the chronic issues on my bike myself. The guy who built the wheels for me charged $120 for the work, but was four days late. That, and the sheer hassle factor of small-wheeled bikes, and especially proprietary Shimano components is such that I’ll take the next wheelbuilding class at Wright Brothers’ bicycle in Fremont so I can do it myself. Next time.)

So, that all adds up $808. However, a large chunk of my mileage was for events. Applying the weighting, my commuting expenses account for:

1700 / 3000 * $808 = $452.48

I’ve purposely omitted any expenses for clothing (I mostly wear old biking T-shirts), lights, special tools to do my own maintenance, and the bike itself. These are “capital expenses.” (Like this) I also omitted cleaning supplies and the opportunity cost of my time doing my own maintenance since I often do it while watching The Daily Show.

Now, to calculate the offset of savings by this particular mode of transportation. My driving commute clocks in at 23 miles, which coincidentally is the estimated fuel economy of my Subaru Impreza in city driving conditions, and with my lead foot. Fuel not bought:

80 days * (23 miles/day / 23 miles/gallon) * $2.799/gallon = $223.92 gas savings

I dunno, I thought this was going to be a lot higher.
According to Edmunds, the theoretical depreciation on my car is $.0425 per mile. By reducing its use, I save:

23 miles/day * 80 days bike commuting = 1,840 miles bike commuting
1,840 miles * $0.0425 / mile = $78.20

My auto insurance is paid regardless of my commuting choice, therefore I can’t “save” any money there.

Finally, there’s maintenance. If I assume an oil change costs $36 and is done each 5,000 miles, I’d save $13.25, which I already blew to see Serenity.

Directly calculable savings: $315.37

At this point, I’m at a net loss of $137.11, mostly in the wheels. If they last through next year, it’ll look much more favorable. (SIgh.) Okay, the economic argument isn’t working.

I will ponder this some more on the way into work tomorrow…

13 thoughts on “Economies of bike commuting”

  1. Hmmm…Makes me wonder how much I’ve spent on everything this year. I rarely put gas in my car since I have only used it a handful of times to drive to Microsoft and the rest of the time driving back and forth to Marymoor Velodrome for the track season. The good days with warm weather I’ve commuted on one of my bikes but the rest of the year I take a Metro bus. While the car is still getting insured month to month, not putting gas in on a regular basis saves a good bit to pay for the $54/month $1.50 bus pass. I’ve bought several tubes – knowing I’ll use them sooner or later, but I’ve only gotten one flat this year – during STP over the 2200 miles I’ve ridden so far.

  2. No chart? No graph? I feel cheated and used.

    I did something not at all similar for my own scenario comparing the price of gas to the price of a bus pass. Driving my car is still cheaper. But the roads are so much safer without me behind the wheel.

  3. (Susan: I’ll add a chart next installment. Just For You. 🙂

    As far as the clothes, I wear a t-shirt and gym on my commute, unless it’s cold, where I’ll go with tights and a jacket. I only use my jerseys and padded shorts on stuff over 20 miles.

  4. Director Mitch

    I dunno about not including the clothes. You don’t need special clothes for driving, but you need at least a decent pair of bike shorts. And to keep up with the other bikers, it seems that a jersey is almost required, although I am staying with t-shirts for now.

  5. You know, if you calculated in a gym membership fee to keep you fit enough to be able to bike to work each day i think you might find that you are actually doing quite well economically. Just a thought!

  6. If you don’t use them already, I highly recommend liners for your commuting wheels. Liners are a strips of plastic that you place between your tube and tire. They add an extra barrier without adding much weight. It does add to rotating mass but I’m not sprinting that much with my commute bike/wheels.

    As for the economics of cycling, toss the health benefit variable into the equation. Hmm, and what about food? Jeesh, there are so many variables.

    Wheel building… you must buy the wheel building bible “The Bicycle Wheel” by Jobst Brandt:

    With that book I have built at least 12 wheels.

  7. Jim, you missed the single most expensive thing – fuel! I did a cost analysis for the extra calories I burn to get to work by bike (24 miles at 800 calories) and found that gas at $3/gal is cheaper than food to fuel my body. Even if I could eat nothing but powerbars, and bought them at bulk prices, that would still be about $4 just to get to work. My Honda gets almost 30mpg if I baby it, so I’m not saving money on fuel. With the maintenance costs added in, it’s definitely cheaper to drive in the short term, but no where near as much fun!

  8. I agree with Sarah on the gym membership thing. It’s more than that, though. If I were to belong to the Y, there’s not only the cost of membership, there’s the time and expense of driving to there. The hour spent at the Y more or less equals the extra time it takes for me to bike vs. drive to work.

    As for car insurance, you sure you can’t get a reduction in your insurance if you’re a bike commuter?

    If you were going to participate in these events, anyway, I think some of your cycling costs are going to be incurred whether or not you’re commuting. If you’re going to riding in centuries and tours, you need to get in a certain number of miles a week. So, you’d just be riding before/after work, and still wearing out various bike parts, AND you’d have to pay for all that gas and so on.

    The real question is: does someone save who is not a recreational cyclist? Let’s take my next door neighbor, who, to my shock, has taken up a multi-modal commute this fall. She rides a mile to the bus stop, uses her company-sponsored bus pass to get a ride to Montlake and puts the bike on board, and then rides a couple of miles to her workplace. She’s riding a 20 year old mountain bike that was a garage ornament before. Total investment to date: $35 on a new bike helmet.

  9. Investigating the insurance reduction is a definite benefit though you may find your insurance company, like mine, doesn’t grasp the concept that you don’t drive a zillion miles a day. (Literal conversation between me and insurance company rep: Rep: “We can only reduce your mileage coverage to 5 miles per day but that will get you a substantial savings.”
    Me: “Well, I don’t drive even that much but something’s better than nothing in cost, right.”
    Rep: “Just out of curiosity, how do you get to work?”
    Me: “We have a very good subway system here.”
    Rep: “Oh, well, we’re in San Antonio.”)

    Think of all you’re saving in medical bills because you’re fit. Plus, mental health is worth more than it’s possible to determine in dollar value. Just imagine how much higher your blood pressure would be if you drove every day. [g]

  10. Interesting…

    AFAIK, the IRS rate is now $0.48/mile.

    I also did some calculations on the cost of bicycling — I don’t commute by bike (I walk), so it’s all recreational riding. As of this moment my cost is about $0.49 per accumulated mile; you’re running $0.26, but I did include “capital” costs.

    See if you’re interested — click on “Cost per Mile”.


  11. That’s a boatload of money on major repairs and tuneups! Having to replace your wheels with less than 3K miles really sucks. I think it’s more typical to get at least 10K. I’d be religious about keeping my brake pads clean if I were you.

    Also, don’t be so sure that your insurance costs are fixed. It’s not a huge difference, but annual estimated mileage is often included in calculating premiums. See if you can get a new rate quote based on reduced commuting mileage.

  12. Interest payments on the car are a big factor and then there’s the kicker: Parking! Maintaining a car is an expensive exercise that loads up over time as well; the ratio of consumable auto expenses to part replacement expenses has to tilt at a fairly early point in a cars life. When that happens, you can buy yourself the entire bike (and sometimes more) guaranteed yearly.

    I bring that up as a NYC’er whom has thought about the comparison of costs -bike/car. If I were to buy an affordable car, the cost of all the above yearly would probably exceed what I’ve spent on my Dahon Jetstream XP (an expensive folder) 5 times over.. and that’s per year.

    Riding my bike isn’t cheap (and is not fun for much of the winter), but compared to the cost of a car, I’d do better riding the bike when it’s nice and _renting_ a car on the terrible days.

  13. I really like what you’ve done here. I especially like the fact that these are real numbers. By “real” I mean that it appears you have tried to compare just the cost of commuting by bike versus the cost of commuting by car.

    I particularly like the fact that you calculated the amount of maintenance costs attributed to actually commuting. A lot of people skip that.

    I would like to comment on a few things.

    * Food
    You are calculating the amount of gas you save by not driving, therefore you should probably calculate the amount of extra food you have to consume to bike. For me, this wouldn’t be much as I haven’t changed my diet by bike commuting. I just eat a little more oatmeal in the morning before I take off. If you are scarfing down $4 power bars as suggested by another respondent, than you should definitely include this cost in your calculation.

    * Car maintenance savings
    I feel like you are really low here. If I read your calculations correctly you have only figured in gas saved, car-depreciation avoided, and oil changes. However, the true cost of driving a car per mile is much higher because you are wearing out tires, drive trains, windshield wipers, etc.

    Here are some links:

    Basically, you should be able to google around and find a more accurate number for this. I believe that it will be quite a bit higher, perhaps even $0.30 per mile.

    * Car insurance
    Can you drop coverage? For instance, can you go from full coverage to just liability? This may or may not work for you, depending on how much other driving you do, but if you can, it could be a huge savings.

    * Health benefits
    I would continue to leave these out. You’ve done a nice job of trying to compare only items that can be quantified between the two modes of commuting transportation. These numbers are very strong and easily make a defendable point.

    If you add in health benefits, in my opinion, you will have to start getting pretty deeply into the realm of probability. My wife is a public health nurse and we talk about this a lot. Nobody has a real good grip on the protective health benefits of weight loss, gain, blood pressure, etc. Studies argue about whether it is good to be a bit under weight, or maybe five pounds over weight.

    Unless you have a specific health problem (obesity, etc.) that you are addressing via the bike, I would stay away from this argument.

    Just my $0.02, nice study, thanks for sharing.


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