Why train on a lightweight roady?

[VamP]

Surely buying a expensive lightweight bike to loose weight is like going to the gym for a bit of
weight training and only lifting the bar?

What if you'd have bought a cheap fully kitted mountain bike at 16.5kg ... but then did the same
distance as you would have done on a 8.5kg road bike during every outing?
You'll probably ride at the same "perceived effort" but with the extra aero drag and hill climbing weight
the average speed will be less.

My garmin edge 800 has been set up with the weights of my three bikes.

If i ride a 30 miler at 70% of max heart rate, my 8.5kg road bike burns 900 calories (average 17mph).
If i ride the same 30 miler at 70% of max heart rate, my 13.5kg road bike burns 1300 calories (average 15.5mph)
Again, if i ride that same 30 miler at 70% of max heart rate, my 16.5kg mountain bike burns 1700 calories (average 13.5mph)

Basically by choosing bike 3 over bike 1, i'm taking 15% longer on a ride, but burning almost
double the calories.

As a side note, my garmin 310 watch gps seems to over estimate calories burnt ... i understand
it doesn't take into account heart rate whilst calculating calories burnt, whereas the edge 800 does?

You shouldn't think about distances ridden, you should think about time spent riding. Then your training 'advantage' disappears in a puff of logic.

 

[Sittingduck]

I agree with Vamp. Forget about distance and concentrate on spending the available time you have, riding... however far you happen to go.

 

[Arsen Gere]

Here is a discussion on the different methods used. http://www.dcrainmaker.com/2010/11/how-calorie-measurement-works-on-garmin.html to calculate calories.

 

[Dan B]

Training is all about specificity - the closer your training is to the race (or other performance) you are training for, the more useful it will be.

 

[Arsen Gere]

You could also plug your numbers in here and see if you get different results for power http://www.analyticcycling.com/ForcesPower_Page.html and work that in to a calorie calculation to compare against your devices.

 

[Boris Bajic]

This is an odd thread. I'm not sure what the real point of the OP is. What is important to one person may be utterly trivial to another.

Does anyone (apart from pro-racers or serious club riders) really just go out on the roads and grind away to improve their performance? Is there not a degree of pleasure and escape involved too?

I do train on a bicycle and have done for decades, but there is more to it for me than just crunching wattage and calorie numbers.

The bikes I train on vary, but I prefer the steel fixed-gear or the 'lightweight' geared road bike. They are nice to ride. It is a pleasure to ride both. I ride as hard as I want to ride.

I am amused by the recent fascination (and it is recent) with all the data-guffology that people quote from their Garmin doo-dahs. It has spawned a sub-set of Prince-Geek Geekologists, although I am sure that the OP is not one such.

It reminds me (apologies for any offence) of the "Let's Off-Road!" sketches on The Fast Show. It all seems a little showy and pointless.

I have a friend with whom I ride from time to time (nice chap). But... he is endlessly telling me how many metres we've climbed, how many calories burned, how many sweat droplets we've sweated and what their diameter was. It all seems a little joyless and geeky to me.

I imagine I'm both very wrong on this and in a minority of one, but I'm all for people training as they want to on whichever bike takes their fancy.

 

[ohnovino]

... data-guffology ... Garmin doo-dahs ...

 

[airbrake]

Performance can 'stagnate' if we use our muscles in the same way - such as on the same bike on a particular loop. It's known that off-road riding on heavier bikes with increased drag improves performance on the road. I've forgotten most of the science behind it, but the benefits are there.

You could argue that using a heavier road bike would give your muscles similar challenges - and there's no reason why heavier bikes can't be fun to ride either - provided they are set up well.

In principal, change is good - and as we all know 'change is as good as a rest'

 

[GrasB]

Performance can 'stagnate' if we use our muscles in the same way - such as on the same bike on a particular loop. It's known that off-road riding on heavier bikes with increased drag improves performance on the road. I've forgotten most of the science behind it, but the benefits are there.

You could argue that using a heavier road bike would give your muscles similar challenges - and there's no reason why heavier bikes can't be fun to ride either - provided they are set up well.

In principal, change is good - and as we all know 'change is as good as a rest'

Problem is you're talking about massive weight differences, in terms of bike weight, to make significant changes to the leg load in terms of flat to rolling terrain (as is found around the parts the OP is riding on). Almost doubling the weight of a road bike makes a <1% difference in leg load on a rolling terrain ride overall....

 

[MattHB]

The wattage required to maintain speed/accelerate and/or climb is significantly higher with increased weight. So yes, it would be better to train on something heavier, but its more fun to fly along on something nimble.

The other huge factor will be body position on the different bikes. An upright position on an MTB will produce HUGE drag compared to a low slung roadie.

 

[BikeLiker]

As speed increases so does air resistance which is directly proportional to velocity. I

Exponentially proportional, actually. Double the apparent wind velocity and you quadruple the wind shear (air resistance). This is because shear is a function of surface area which is measured in square meters .

 

[GrasB]

The wattage required to maintain speed/accelerate and/or climb is significantly higher with increased weight.

When accelerating people will tend to push out the same power for the same duration, they just don't reach the same speed. Eventually when riders read the power/speed equilibrium the heaver bike rewards the rider with less noticeable changes to leg load in undulating terrain. When climbing to see significant differences in climbing speeds actually needs surprisingly high weight differences.

 

[boydj]

The OP's argument is a spurious one. If you're not enjoying your cycling, you'll not keep it up.

If you are cycling to lose weight and generally keep fit, then simply spending time on the bike in an enjoyable way - is the way to do it. If you are into training more seriously the right equipment is important. If you really want to make it hurt, find some decent hills and do hill reps.

 

[Mr Haematocrit]

Exponentially proportional, actually. Double the apparent wind velocity and you quadruple the wind shear (air resistance). This is because shear is a function of surface area which is measured in square meters .

I was making the assumption that the wind velocity was a constant and that the only velocity changing was that of the mass of the bike.

I believe that if you hit a 30 MPH head wind with one bike, and then hit a 30 MPH head wind on the same bike but at a higher velocity the increase in wind resistance is proportional to the velocity as stated in newtons second law, I believe this law is valid as the mass is not changing.

Net force on object = mass on object x acceleration

What is your reasoning, behind your perspective, just curious.

 

[screenman]

Seems like a ton of feathers question to me.

As for the reply about riding off road making you quicker, I would like the specifics behind that as I ride both on and off, and have found the opposite. I also do not know of any fast road riders that use off road to improve speed on the road.