On 4/02/2011 9:56 PM, Dave Hughes wrote:

Dunno. Maybe you are right in that I was working a bit harder without
realising it. The brain is a weird thing - or maybe it's just me that's
weird and not me brain

I found today's ride a touch easier than the rest of the week's because
the breeze cooled thigns down a touch. That'll help you ride home. Other
than that, momentum on the flat is increased due to increased mass, but
once you're up to speed it'll be the same effort to stay there. The extra
mass will help a bit over lumps and bumps, but uphills will hurt more.

True, true - the lumps and bumps did seem a bit easier. The bike did
kinda feel a bit more wobbly which I put to the extra weight changing my
centre of gravity.

The extra incentive to push (out of the saddle) will drop the time a
touch, so it's not that surprising.

I did feel a bit more effort but not that much more. I put that towards
the technique I was using - ie driving down using my hips whilst
directing the weight of my backpack down thru my hips.

The other way of looking at it: 12kg is going to be roughly 10% of your
total bike and body weight (assuming you're not either annoyingly light or
disturbingly heavy, and giving a reasonably leeway in "roughly). On the
flat it'll make virtually no difference, uphill it'll add 10% to your
time, downhill it'll drop about 8% from your time. The overall effect is
bugger all, but you'll certainly notice it being heavier.

I think I have been barking up the wrong tree here when I saw it as a
matter of physics. It seems that becos the majority of my ride is
relatively flat, the additional weight counts for very little - as I
kinda suspected but could not figure out with seeking more advice on
physics.

The uphill section towards the end of my ride, although a bit more
difficult due to the additional 8kg weight, is most probably offset by
me working harder on the pedals (with some contribution from load
balancing) and I didn't notice it becos there was not really that much
additional weight anyway.

Things would most probably be very very different if I was loaded up
with an 80kg load which I have no intention of doing anytime soon

Oh, and Moike - you should do OK at Physics, mail me if you ever need a
hand!

Yeah, Moike did alright in straightening me out. He also gave me the
clue that physiology, rather than just physics alone, may be involved as
well. Bloody obvious, really - I knew it all the time - as soon as
someone points it out of cos