Doctor claims carbon offers no benefit over steel

Well, I ride a Cannondale CAAD2 alloy racer (old but nice) and a Claud Butler steel tourer (even older and retro-nice). The Cannondale is a little under 30% lighter, and I do the same training runs on both (depending on weather and mood). I do go faster on the Cannondale, but this is due I think mostly to psychological reasons: it "feels" faster (geometry, handling, etc.), I'm more likely to chase down blokes on mountain bikes, and also the gearing is higher. But the only time I really notice the weight difference is when I have to lift the bikes back into the shed!

I wish I never weighed my colnago. Now I might have reduced the weight a little but my wallet is a lot lighter!

Dr. Duh - you don't need an expensive bike to ride 15 mph

Any bloke gullible enough to think there's a possibility a different bike will knock 10% off his commuting time – a proportion of which he's stationary at traffic lights – deserves to be a grand down.

Just nipping round to sell him a few tins of tartan paint.

Yes clearly a commute is going to be determined by factors such as traffic and lights.

However I can offer proof that carbon is faster than steel.

Pretty much all my riding is training, and I use the same route three or four times a week. It has virtually no interruptions or variables, and I set my computer to pause below 20km/h anyway for the few times I do slow down.
Once a week I ride with a group so there is less control but generally we also ride the same route and pace each week.

Until July I was riding a steel Colnago Master with 10sp Chorus and Racing 5 wheels,and my average speed was 34.57 km/h .

From August I have been riding a carbon Ridley Noah with 11sp SR and Eurus or Racing 3 wheels and my average is 35.66.

So the extra speed costs about £600 per .1 km/h.

Whether that helps in the n+1 debate is another thing.

There's no easy win, is there? My 'top end bike' (a very average Trek 1400) is without doubt quicker and leaves me less tired. It's easier up hill but slower down). On the contrary my aggregate of of bits and pieces clumped on to a 25 year old road frame is heavier (especially up hill), but it does cruise nicely over Oxfordshire's battered and neglected roads and cycle paths and means I don't have double vision for 80% of the commute.

To wit: leave the mince pies alone this Christmas

@fish_n_chips The BMJ is a bit of a headline grabbing rag, and like the Lancet is the equivalent of a red top (at best). Not well respected in the scale of medical journals. The Christmas edition usually has a number of tongue in cheek pseudo scientific studies, all harmless, but often of better quaity than the more regular articles!

It's an interesting article, but he *does* make the point that this is a commmute. I find my commute takes the same time whether on my steel tourer complete with panniers or my light alu racer with just a bottle of water. But I wouldn't do a triathlon on my tourer (not least because I'd probably be laughed out of transition!!!) So the rider's weight is going to be critical. Lance Armstrong in his autobiography said that he was advised to lose weight when he started doing the Tour and I belive there's a forumula for the ideal power to weight ratio. Happily the best way to lose weight (I find) is to go cycling...

I'm stunned the BMJ would even print such trollup!

Scientific? I'd be thrown of my A'levels/undergraduate degree with methodology of research lol

Well I dont think this research applys to the population that I am interested in, currently I have a £1k bike made of aluminium but I want to buy a £3.5k carbon bike therefore the quality will be 3.5x better than the bike involved in this sample and therefore the results do not apply.

Serioulsy though, 1k for a carbon bike, everything is surly going to be a bit ropey and the frame wont be that good either, a much better choice would have been a really good alu bike and probably faster.

My journey, irrespective of bicycle manufacturing material is always faster when the end result is cake and coffee!

I remember chasing other riders on my commute across London. i was on my heavy steel mountain bike and they were on lightweight racers and a lot of the time I'd still get past. I was younger then.

Alternative Heading;
"Doctor speaks out his arse!"

Body weight and fitness are the two prime factors in increasing speed. So long as the bike is comfortable and efficient to ride, times will come down.

The next issue having achieved a good weight and level of fitness is achieving average speeds above 20, 25 and then the magic 30mph. At these levels of speed fitness and body weight tail off as wind resistance takes over as one will be thwarted by an invisible barrier whether the bike is made from carbon or lead. The material the bike is made from is irrelevant.

I agree with the Doctor but I also agree with the above comment - there's just no room in this research for new toys.

sad but true;
Wife bought me new CAAD9 because I was cycling so much, but the old Giant ALU hardtail (40 bob from a recycling scheme) still gets far more regular use; school run, shopping,library.
The CAAD flies, urging me on, but I'm so nervous of it getting damaged or pinched! I'm totally relaxed on the hardtail, throw it around, jump over gutters, lock it up, do my thing.

This research is fundamentally flawed. It takes absolutely no account of my need for new toys...

I lose the most time when riding or training at traffic lights, so this really isn't a very scientific study. 44 minutes for 13 miles between Sheffield and Chesterfield isn't to be sniffed as it's hilly round there (unlike where I live). So for someone who rides fast already (compared to most of the population) he isn't going to see much improvement with a carbon bike.

"Such a minor difference, he says, had little effect on some of the forces acting against the cyclist, such as rolling resistance and acceleration, and none at all on others, such as drag and traffic.

So what does it all mean? Mr Graves concludes, “A new lightweight bicycle may have many attractions, but if the bicycle is used to commute, a reduction in the weight of the cyclist rather than that of the bicycle may deliver greater benefit and at a reduced cost.”

that's one of the most sensible reports i've read in a while! and cervelo have done a lot of work to prove that reducing drag has a greater effect on our speed than reducing weight. i get asked about bike weights all the time, but never aerodynamics, thankfully!

Looking back at some figures from 2009, I'd say my SCR 2 road bike averaged just over 31mins for the commute home while the 12 year old Kona MTB (rigid w/slicks) averaged high 33s. There was a difference of 2 minutes on the morning commute over the same route (10 lumpy miles along Shropshire B-roads and lanes). Weather was usually better and warmer when on the SCR than on the 'hack' bike.

No need for tears Miggers step-hent has just played the get out of jail card. I was thinking exactly the same thing about my commute, the time varies a bit as I get fitter on sections of it like hills, but overall traffic lights, traffic all conspire to slow you back down again.

This article has not helped my n+1 (where 1 is carbon or titanium) cause with my wife… Damn you BMJ

himself - the carbon bike was 30% lighter than the steel, but as his weight remained the same (and made up the majority of the total weight) the total weight was only 4% difference.

i find it doesn't matter which of my bikes I ride on the commute, it usually takes around the same time. But that's because the major factor affecting my times is traffic, and traffic lights. Whereas on a ride around the park, or out in to the countryside, the difference is noticeable in times over the same route.

Hang on...

"although the carbon-framed bike was 30% lighter than the steel one, the reduction in total weight (including the rider) was just 4%"

Even though he was choosing his bike randomly between days? What extra ballast was he carrying to make up the 22%?