The Weight Weenie Episode

Great podcast, but, … you did not address the added flexing of components like wheels, frames as they get lighter. Don’t you have generally more loss of power in additional flexing of a component? This theoretically would be magnified the heavier you are…

This is quite late – but I’d be very curious to see how weight matters in two contexts – Bikepacking endurance and different weight of riders. Surely a system weight of 20kg matters more for a 55kg rider than an 80kg rider? Watts/kg to overcome this but in particular calories/day

I also have a very similar question to JG before me.
At 93kg its easier for me to ride in a 3-6 man breakaway at 45+kmh than it is to do so in a bigger group because the speed tends to change a lot more in a bigger group, like harder accelerations out of corners. The question is how much easier would it get when I lost lets say 2kg or 5kg. How much less watts are needed to accelerate from 35kmh to 50kmh in 4seconds for example?

Thanks!
MM

Great episode guys.

I grew up with the saying “An ounce in the wheels is worth a pound in the frame”. The one time I tried a tubular wheelset in the 90s it certainly felt like it was true; except when I was stopped by the side of the road with no second spare tubular to fit. A super light but stationary bike isn’t very fast.

When I worked to move down from 92kgs to 71kgs around a decade ago and moved from a 12kg 853 Norco mtb to a 7.5kg Cervelo RS road bike I know which kilos made the most difference to my system performance. When I fitted Reynolds 1330gm 32MVC wheels and GP3000/latex tubes to the Cervelo I know that it was more than just a placebo effect on my performance.

If Fattie told his neighbor that his new bike weighed 2 lbs more than his last new bike but that he had saved 5 lbs from his gut and now was riding up AND down hills faster and on the flats too, if his neighbor wasn’t equally impressed perhaps he needs to stop caring about his neighbor’s thinking?

I spend too much money on my bikes and too much time thinking about the parts and the weight but cycling is a passion even when I’m not riding. If I spent more time working out to save weight and gain strength I could work less hours as I’d need to earn less money and I could still ride faster. Riding to work has been a great way to invest time being active and gain some extra time each day. Sitting in a car doesn’t burn many calories but does spend more money than riding. Spending on an extra bike for commuting can save time (by exercising while journeying to work) and weight from total system weight (by losing weight) can cost less than trying to save such equivalent weight from a racing bike with diminishing returns.

At 71kgs on my Cervelo nobody was lifting my bike to be impressed. Me riding up the hill ahead of them was the impressing I learned to care about much more. Waiting at the top of the climb and being recovered to blast down the other side faster than my buddies when they finally arrived was what impressed them. Still, my next project is an all aero Cervelo RCA frame build (second-hand thanks to covid; I didn’t pay $10,000) as I work to re-loose those last 8kgs again. The RCA will incorporate every marginal gain known about that the UCI rules allow.

Saving 100gms by using Ti bolts and not worrying about my 8kg gut is a little on the silly side having limited resources. I sometimes need to ‘stand next to myself’ and just check some of the habits my life and my thinking are delivering and make some adjustments. Listening to and watching MGs podcasts and videos helps keep my thinking function motivated.

When Fattie’s mates or neighbors start telling him they will soon need to call him Mr Slim (or some such) he won’t just be using marginal gains. At 71kgs and commuting 200kms per week I found I could eat huge amounts of food and still enjoy drinking in moderation too! Win, win?

I enjoyed the weight weenie episode and have a few non-climbing question about weight.

What real world impact does weight have in an accelerating on a flat road?

If Force = Mass * Acceleration (f=ma) and Final Velocity = Initial Velocity + Acceleration * Time (Vf=Vi+at), solving for Acceleration gives f=m(Vf-Vi)/t. So if Vf and Vi are the same, a lighter rider needs less less time for the same force to accelerate or they need less force to accelerate in the same time.

Of course this does not incorporate air resistance, rolling resistance, etc. So is there much of a real world impact in a 150 vs 180 lb rider accelerating from 20 to 30 mph? Needing 4 vs 5 seconds to accelerate and respond to an attack can lead to huge differences in race outcomes. Or needing 800 vs 1,000 watts to respond in the same time.

Thanks in advance, JG