BIKEPGH MESSAGE BOARD ARCHIVE

Some initial questions: don't heavier bikes go slower uphill and faster downhill? I dont have time to read the whole study; can someone say whether or not there were hills? Interesting nonetheless.

The premise of the article is good, it's not about the cost of the bike. What I take from this is that this guy gets to commute 27 miles each way every day through some of the most beautiful landscape on the planet, Yorkshire, the stuff of paintings. So I hate him.

Anyway, based on the photo, the "old heavy bike" isn't exactly a beach cruiser, it's just a used road bike, so he's really just analyzing diminishing returns.

27 mile (43.5 km) round trip...

The journey, predominantly on urban A roads, included 0.62 miles (1 km) of dual carriageway, 1.86 miles (3 km) of country lanes, and 328 feet (100 metres) of farm track. The total ascent for the round trip was 2766 feet (843 metres; fig 2?).

138 ft/mile on average. Not the dirty dozen, but some hills.

The study notes that reducing the weight of the bicycle only reduced the weight of the rider+bicycle by 4%.

It also does note the effect of wind resistance.

All in all, about what I'd expect, except for being published in BMJ.

His "heavy, old" bike looks pretty nice. I think I'd prefer that over the carbon fiber one for commuting too. His materials and methods do not list the make and model, but he does note that they have different tires. I can't believe that got past peer review!

In any case, the highlight of the article for me was this bit: 'I looked into the UK government’s Cycle to Work scheme. This scheme allows an employee to purchase a bicycle (up to a cost of £1000 (€1180;$1560)) at a significant discount by using tax incentives, provided the bicycle is used for commuting to and from work. The initiative aims to “promote healthier journeys to work and reduce environmental pollution.”'[1]

[1] Department for Transport. Cycle to work scheme—implementation guidance. 28 October 2009. http://www.dft.gov.uk/pgr/ (really http://www.dft.gov.uk/pgr/sustainable/cycling/cycletoworkguidance/ )

After reading that, it doesn't seem like you get to buy a new bike and get all sorts of tax breaks. It is some goofy program where your employer has to purchase the bikes and gear, and they loan them to you for the term of the program. It seems kind of odd, and would only work if your company is on board with it. Sad.

One thing I did find amusing, is that if you aren't getting a loaner, and own your own bike:

"Employers can pay up to 20 pence per mile tax free to employees who use their own cycles for business travel. Journeys between home and work are not business travel for this purpose."

Awesome.

This makes me feel better about my main wheels, which consist exclusively of old steel-frame road bikes.

If I ever do buy a new/better bike, with the equivalent of £1000 to spend, I'll go for low-end decent ($500ish) and fit it out with higher-end accessories like a hub generator, lighting, disk brakes, and clothing upgrades, etc.

The main lesson learned here for me is, if I really want to lug around 10 pounds less, to have 10 pounds less of me, not the bike.

@Stu: I believe the correct phrase is "tarting up the lights."

I don't know... I have a 10 mile one way commute and there's a difference in speed when I go without any luggage and when I go with my clothes and laptop and lunch and breakfast (extra ~10#) to the tune of about 10 minutes (on a ~1 hour journey).

I can't seem to swing more than about 11 mph average for any journey more than about 7 miles (centered on my house), regardless of bicycle used. When I was on Becky the Crate Bike, may she recycle in peace, I was averaging less than 10mph and more exhausted.

I'm betting the shape you're in plays a not so insignificant role, independent of the weight of your body. Like someone who can average 15mph would see less of a difference than someone averaging 10mph, if they weighed the same?

And none of this speaks to how he felt at the end of the journey. Switching to the new bike from the old, I felt like I could actually make it back that same day via bike, whereas on the heavier bike I couldn't walk the next day when I tried it. Granted I did get in better shape, but not overnight like that.

I dunno, there's a lot more variables that I dont' see accounted for. I'd like to see more data, more study done. I'll volunteer for it, if someone will carry my bags to work half the time for me

Ejwme. A better bicycle fit will make you feel like superwoman too, and I bet the new bike has better tires. Also, carrying bags and milk-crates creates a lot of wind resistance which is sometimes worse than carrying weight.

Marko you're totally right - the new bike, before I got used to it, made me feel like a centaur on a unicycle. Ridiculously powerful, and totally unbalanced. Now I just feel human and capable, and wonder how I managed before.

I guess a better study of weight would be empty saddle bags compared to saddlebags filled with sandbags. Same bike, same fit, same rider, same journey, just different weights. But that's not as much fun

The most significant factor in my commute is traffic. The more traffic there is around me the faster I go. Unless the traffic is congested of course. My bikes range in weight from 18 to 35 pounds and I don't think any are "slower" than the others. Gears and environment control.

He could have done an almost-blind study. He just needed to put panniers on his steel steed, and get a friend to randomly add or remove weight from them, with several different variations. At the end of his study period, he could perform a regression analysis to determine the precise effect of weight, holding everything else constant.

I definitely notice the effect of schlepping a heavy laptop or not. It forces me down a few gears on the uphills, which clearly means I'm slower. But I'm pretty sure that once you take traffic signals into account, it's lost in the noise.

My commuting bike weighs about 30lbs with lights and rack and fenders.. When I rode my lighter bike (about 20lbs) it felt faster, but I also rode it differently. the speed could also be a function of tires and wind resistance.. Road bike has 25mm, commuting bike, which is an aluminum cross which cromo fork, has 38mm tires on it now. Also once you add racks and panniers, wind resistance goes up considerably.

I know I go slower on my heavier bike, but thats because I ride slower on it. it is for a different purpose. I also wonder how much of the similarities or differences in the experiment were psychological, even at an unconscious level. Did he ride the heavier bike harder just to try to keep up with the carbon bike or vice versa.

My heavier bike rides more smoothly and over long winter commutes is less tiring as long as I dont try to burn down the trails at >20mph. if I stick to 14-17mph, its easy as pie.

Unless he rode with a power meter to account for bias, I don't think he can make any real claims about one bike being faster than the other. But the results are really not surprising. Position on the bike -- both in terms of aerodynamics and ability to produce power -- makes far more difference than a few pounds.

I have no data, but... I often wonder about ultra light bikes, aerodynamic helmets, gear choices that weigh a grams less here or a gram less there, shaving your legs... all that kind of thing... I guess if you're a 135 lb. rider in the right posture, etc., all that might add up to an incremental difference compared to the riders you are competing against of tenths of seconds, which is the difference between winning and losing.

But in practical terms, these fine distinctions can't really make much difference. Of course having a laptop, some books, a change of clothes and shoes in bulky panniers - you're going to feel that. But then factoring in for traffic, etc. You're not likely to realize any greater efficiency, are you?

Maybe it's me. I prefer a degree of ignorance about such things. Once I start thinking too much about that type of thing, it sucks some of the fun out of it, because inevitably I'll do something "inefficiently," and it would ruin my ride.

But that's me.

@ALMKLM all that might add up to an incremental difference compared to the riders you are competing against of tenths of seconds, which is the difference between winning and losing.

Tenth of a second here. Tenth of second there. Over a few months, you save an extra minute.

@ALMKLM: I thought cyclists shaved to make cleaning up road rash less horrible. Along with some less intense reasons, but that it doesn't help with speed. (Different story for swimmers though.)

I thought they shaved so the hair wouldn't get caught in the spandex. OT-sorry.

Pros shave because they get massages after hard days. Amateurs shave because the pros do. It's easier to put on sunscreen (not pro), or embrocation (pro). Road rash. Show off well-defined leg muscles and tan. Whatever.

Really, it's a culture/tradition thing. Most roadies shave because all the other roadies do.

I think it's funny that our culture has embraced chest and back depilation for men (well, at least partly embraced it) but still treats leg-shaving by roadies as somehow suspect.

Human obsession with hair (they want less where there is lots, and lots where there is less, sometimes) is one of those things that has always confused me. Why people can't groom and let groom is totally beyond me. We're such a nebby species.

That being said, I've still always envied Pacific Islanders, south east Asian, and many Africans their often genetic lack of leg hair. Their ancestors also got the tastiest foods, and mangos native to their climates. All my ancestors got was first to the industrial revolution, a tendency towards lactose intolerance, and plaid. All now of questionable long term benefit, except maybe plaid.

I was talking about this with Bob from Iron City and we concluded that rather than spend another $1,000 to save two pounds, we could easily drop a few pounds ourselves for way cheaper.

Pay attention to the total miles and the pounds will take care of themselves.