1kg off body = 1kg off bike?

**Timbuk2**

This is probably the stupidest question to darken the doorsteps of the Cycling forum, but here it goes:

Does losing 1kg of weight off your body (fat, not muscle) equate to having 1kg less on your bike? (Ignoring any gains in fitness that may have resulted in losing 1 kg).

I have a Peugeot road bike which I like a lot (despite it being very old) but I weighed it the other day and it was just below 12.8kg, which is quite heavy for a road bike.

I weigh 68 kg and I'm 5'9". So would I see the same performance gain if I reduced my weight by 1kg (67kg) as I would if I reduced my bike by 1kg (11.8kg).

Thanks for reading the idiotic question

Lumen

Short answer: pretty much the same, objectively.

Medium answer: pros and cons of each, and it depends exactly where you take the weight off, but 1kg from 81kg is not much.

Long answer...

If you enjoy the bike and are not racing competitively, then what's the point is splashing cash for the sake of numbers?

However, 13kg is a very heavy road bike, 8kg is achievable with a new build without going to extreme expense. The most noticable gains to the feeling of lightness would probably be from lighter wheels, so take them off and weigh them.

68kg is not much even for a 5ft9 rider, but depending on your current fat levels and build you could maybe drop this 10% to 62kg through careful diet.

The largest gains in power/weight come from combinations.

If you weighed 62kg, had an 8kg bike, and added 10% power (each of which is fairly easily achievable), you'd gain 27% power/weight, which is a massive improvement.

air

Weight lost from your wheels would be more beneficial than weight lost off your body, however there's probably not much to trim there (relatively speaking).
Otherwise, yeah 1kg off body = 1kg off bike & it's a lot cheaper to shave a few kgs off your body with the added benefit of improved power output as a side effect as mentioned by Lumen.

**Timbuk2**

Thank you Lumen, that was an excellent answer!

I'll concentrate on losing weight from my body then rather than spend a lot of money for the sake of ~5kg or so.

According to the BMI scale (which I don't believe in), my weight is 'normal' for my height but in reality I've slipped from a Kit Kat to a Kit Kat Chunky in the last 2 months (excuse: exams + laziness ).

thebouldwhacker

This reminds me of a guy. He had a top notch carbon Orbea but the guy was easily 20 stone, in this case I reckon body weight loss would be a better idea:D:D

air

To be fair though, there's nothing wrong with someone treating themselves to a bit of two wheeled retail therapy if he can afford it. It's no more pointless than a woman buying an overpriced handbag & helps the industry at least!
Having said all that an ultra lightweight setup wouldnt hold up too well to a guy of 20 stone on top!

Junior

Well yes and no, you can lose a kg but if your power output drops with this weight lost your 'weight loss' won't be as benefical.

Lumen

Junior wrote: »

Well yes and no, you can lose a kg but if your power output drops with this weight lost your 'weight loss' won't be as benefical.

I've read about this, but haven't experienced it myself. Perhaps it's only an issue for highly trained athletes?

Do you know anyone whose power has suffered due to weight loss?

kennyb3

can i ask what difference does 1kg in bike weight really make?

i ask cause i ride a 10.4kg defy 4 but train with a few lads that ride carbon bikes, is this putting me at much of a disadvantage?

Lumen

kennyb3 wrote: »

i ask cause i ride a 10.4kg defy 4 but train with a few lads that ride carbon bikes, is this putting me at much of a disadvantage?

No.

I think I worked out after the Kippure TT that 1kg was worth 8 seconds (over about 10-15 minutes). And that's an extreme hill with no descending.

lukester

Junior wrote: »

Well yes and no, you can lose a kg but if your power output drops with this weight lost your 'weight loss' won't be as benefical.

I thought this was only an issue for an athelete at the very edge of their ideal weight envelope, and is related to loss of muscle weight rather than fat.

I imagine most folk have a spare kilo or 2 they could lose and not notice any difference. If you're already at your minimum body fat level, you don't want to lose any weight, unless it's 'useless' muscle.

**Timbuk2**

kennyb3 wrote: »

can i ask what difference does 1kg in bike weight really make?

i ask cause i ride a 10.4kg defy 4 but train with a few lads that ride carbon bikes, is this putting me at much of a disadvantage?

When I asked about 1kg, I didn't mean losing just 1kg specifically. I used 1kg as a 'standard' to highlight that I was talking about the same weight drop from both body or bike. I wanted to avoid a non-specific title like "Weight Loss = Less weight on bike" or something similar.

Perhaps I should have said "x kg off body = x kg off bike"

Ryaner

From what I've read wheel weight loss bring the biggest gains. Due to spinning force (forgotten the correct term).
Beyond that, weight higher up will affect things more on the hills due to balance.

Also, for every 1kg of weight, it will slow you down 1.25% on an 8% incline from the tests I've read about. I find this accurate enough going on my speed up Howth hill and the weight I've lost of the past 6 months.

Junior

Lumen wrote: »

I've read about this, but haven't experienced it myself. Perhaps it's only an issue for highly trained athletes?

Do you know anyone whose power has suffered due to weight loss?

lukester wrote: »

I thought this was only an issue for an athelete at the very edge of their ideal weight envelope, and is related to loss of muscle weight rather than fat.

I imagine most folk have a spare kilo or 2 they could lose and not notice any difference. If you're already at your minimum body fat level, you don't want to lose any weight, unless it's 'useless' muscle.

Well some people at the high end of the scale when they lose weight they are actually slimming down muscle - so they can lose the 'engine' to create power. I was speaking in general terms, if you can shed 'weight' and increase fitness/power you'll find benefit. However if your not training right in the first place, working way above your heart rate zones and stuff, you might be losing the weight but in reality your not really getting the full benefit of what your putting in..

Diarmuid

Take a look at Wiggins or Millar in this years TdF to see the difference losing weight will do. It's probably the cheapest and best way to improve your performance in the mountains. On the flat, excess weight is less of an issue.

dave2pvd

Ryaner wrote: »

From what I've read wheel weight loss bring the biggest gains. Due to spinning force (forgotten the correct term).

Only really applies when accelerating. Disc wheels are heavy, but can be very fast. Why? Aero. Aero is the biggest variable outside of rider fit & fitness when trying to go fast. So don't worry too much about bike weight. Although, it's always a good idea to lose spare body weight.

Lumen

dave2pvd wrote: »

Aero is the biggest variable outside of rider fit & fitness when trying to go fast.

Whilst rider aero is critical, ISTR that a Zipp 808 is worth about 12W at 50kph over a completely ordinary wheel (Aksium). But that speed in the drops requires over 500W, so only about 2% gain for €2k and hassle (crosswinds, robustness).

Gaining 2% on a hard climb means losing less than 2kg, which is easy peasy. And since you can't wheelsuck as effectively on a steep climb, individual performance is more critical.

Aren't the climbs where most of the attacks happen in racing?

kennyb3

thanks lumen your a mine of information

Ryaner

dave2pvd wrote: »

Only really applies when accelerating. Disc wheels are heavy, but can be very fast. Why? Aero. Aero is the biggest variable outside of rider fit & fitness when trying to go fast. So don't worry too much about bike weight. Although, it's always a good idea to lose spare body weight.

Too true. Being 93kg, I usually concentrate on the hills and start off from stopped.