What difference does a light bike make?

There are a couple of things that exaggerate differences in bike set-ups.

Heavier-built bike with more travel waste a lot of energy, especially if you try and climb stood-up.

Human beings do not produce power in a linear fashion. At higher levels of exertion a small increase in power output will cause a large increase in lactate production. Similarly, over a long distance, minor differences in the bike will have an exaggerated effect because you are already operating very close to your physical limits.

If you are the slowest, or amongst the slowest in a group, its worth losing a bit of weight because you are likely to be pushing yourself to keep up, and be close to your physical limits. If you are the fittest in the group you might be able to ride a big bike, and climb all day at your mates pace, and never even hit your lactate threshold.

If you are riding close to your limit a lighter bike will have a big marginal effect on perceived exertion.

…and we've not even touched on the idea that heavier things go downhill faster yet.

???

I'm going to back pedal a bit here now. Actually even in road racing the lightest isn't always going to be the fastest every time.
Just thinking back to a small critisism about the road wheels I was just about to buy. I made it clear that these were for racing and someone said that they weren't very light.
Anyway UK early season road racing is pretty mucky, gravel, potholes muds etc I know from experience that at my level a set for beefier wheels/tyres will keep you able to ride quicker in those conditions. Come summer or Crits then I'd loose the extra 300g.

If you are riding close to your limit a lighter bike will have a big marginal effect on perceived exertion

What does that mean?

It's like a definite possibility 🙂

Around your lactate threshold, a slight increase in power output will cause a large increase in lactate production. Lactate production causes a big increase in perceived exertion and recovery times.

So, for a small marginal increase in power you have to sacrifice a large increase in perceived exertion.

When I read anti-weight weenie posts, I often wonder if the difference is that some people have seriously steep hills in their area and others don't.

(Let's assume we are not trying to get bikes so light that they are fragile flexi-flyers)

I see shandy, that's clearer. Are you talking about a 0.1% lighter bike + rider or a 10% lighter bike + rider though?

I remember reading a guidebook for touring cycles from the 1930s – it said a good weight for a road touring bicycle was 'around 30lbs', so we can't really complain about MTBs really 🙂

Its all relative, 10% will make a big difference, 0.1% will make next to none.

I only posted because it annoys me that so many people are critical of cutting weight off the bike. I can see why guys who just ride for fun would want to lose weight/rolling resistance, it increases their enjoyment of their bike.

A little bit of extra weight or rolling resistance can make things a lot harder if you are already working close to your limits or struggling to keep up with a group. I have noticed riding in groups that the guys who are gassed at the top of the first couple of climbs only get worse in comparison to the rest of the group. Pushing past the lactate threshold starts a vicious cycle of being unable to recover, having to push harder, etc. If they ride more regularly they see a dramatic improvement in their fitness and suddenly they can sit on the back all day without suffering worse on every successive climb, and enjoy the descents.

ive been misreading the thread title as

"what difference does a bike light make?"

impressed it made it to three pages.

LOL shandy you've just described nearly every ride with my mates 😕

As you've said, increasing your fitness will make a big difference. A bike 10lbs heavier than your mates can have a big effect too.

It can also be improved by having mates who enjoy the scenery and chill out at each stop, letting you recover, instead of ones who are champing at the bit to start racing the next section before you've even stopped wheezing…

There's a very easy way to settle this though- load some luggage on your bike, go for a 3 day ride with a bivvy bag, sleeping bag, food, cooking kit and stove, change of clothes, etc on panniers. Not one person will come back and say it makes no difference. The bike will ride completely different, it'll be harder to maneuvre, harder to slow, harder to hop over rocks or muscle round a tree at speed, and yes, harder to pedal up a hill- though actually the climbing impact is relatively minor compared with the feeling of riding a tank on anything technical.

And it won't go downhill faster either 😉 Unless wildly out of control of course.

bivvy bag, sleeping bag, food, cooking kit and stove, change of clothes, etc on panniers

Yeah… but that will add about 10lbs to your bike! We are talking about paying £100 for for 100g of weight loss here…

Well, I am. Sort of. I think this thread is slowly killing itself!

Just trying to get some sanity back for the people who think it makes no difference, or only makes a difference when you're climbing. (personally I don't notice a difference at all when climbing, I just climb faster and end up just as shattered… It's the rest of the time a light-but-tough bike pays off for me)

Once again, who has said it makes no difference or only when climbing (again other than the one obvious joke post). It's a discussion about whether the feeling of a lighter bike actually translates into actually going significantly faster.

It never gets easier, you just go faster. Have you not seen World Cup racers after a race? They're not exactly fresh faced!

"Once again, who has said it makes no difference or only when climbing"

Nobody has explicitly said it in that many words, but everyone fixates on it, and we have these (disputed) calculations that it only makes 0.005% of a difference, etc, while completely ignoring all other aspects of it, just because that's the most tangible difference. And then using this as "proof" that it's a waste of money, and quietly ignoring that even if they're accurate they tell only a small part of the story.

It's just as linear for speeding up (and slowing down) though isn't it…

The point being as ever that weight alone is just a small part of what determines how 'fast' you are and more importantly that perceived 'quickness' of a bike isn't the same as actually going faster.

Good example actually – Back in the day, I was pretty fit to say the least but had a crap, heavy road bike. I then got my student loan and bought a pretty spangly bike that was much lighter. The first couple of rides were a complete joy – I was flying up climbs, sprinting off the lights and so on. Then I went for a ride with my usual riding group and despite expecting to be lining them out and making them suffer, actually turned out to be essentially exactly the same speed as usual relative to the rest of the group – maybe just a tiny bit faster than previously but part of that was simply because I felt I had to be as I was riding the spangly new bike 🙂

bang on northwind.
personaly i have never got on a bike that came in at over 26pounds that excited me.
so i allways go for lighter.
current bike is around 23 and for me this feels right.
no one can tell me thats a load of toss as it is down to the way it feels to me.

Absolutely and no one here has ever said that you shouldn't ride a light bike if that's what feels right to you.

What has been said is that it's probably not as much faster as you feel it is…

It I swap from my winter road bike (Spesh Allez, PowerTap wheel, Tiagra kit, 21lbs) to my summer (Trek Madone, full Dura Ace, Race X Lite wheels etc, c16.5lbs) there is a phenomenal difference. It's not mental, the Allez is a dog, particularly on hills, and the Madone isn't.

I subscribe to the whole stiffer frame thing and what not, but I'm relatively confident that if I went out on the Madone with a 5lb bag I'd still go quicker up the hills than on the Allez.

How much do you weigh Nonk?

Lol at the over-excitement…

I'll make my position quite clear;

When you go out on a mountain bike ride, get fully togged up, Camelbak, the works, then pick your bike up and stand on the bathroom scales.

That weight, 90-100kgs is what you are dragging around the countryside, up hills, down hills, along the highways and byways.

Changing that weight by 1-2-3 kilos will have a very very small effect on your performance.

Spending money on lighter bike bits to drop 1-2-3 kilos is a very expensive, very inefficient way of attempting to make very small performance increases.

Like I said yesterday; imagine you have to take 100 kilos of gold up a hill. If someone offers to take 5 kilos up for you, you aren't going to be knocking off that much earlier…

Then again, there is a large part of the bicycle industry that depends on you buying stuff because you think it makes a huge improvement, so don't stop!

5 foot 9 ish and around 10stone.

njee20 that's light, classic build as well. Don't even know what mine weighs?

@crikey, I wouldn't dream of weaing a Camelbak. See we all see things so diferently. I would estimate fluid for a ride and the ammount if any of spares to carry.
And whilst I'll seek the lightest parts, I'll factor in comfort and many other things. I mentioned light wheels, on some road courses light wheels can feel so harsh so can minimal saddles and for that reason both can effect my speed over the race. Front suspension is another one. I can save loads by going rigid, but then the bike doesn't flow through the bumps as well.

I am guessing, I've not weighed it for ages, it may be 17 or more, but it was that neck of the woods I think. It's a pretty run of the mill spec, Bontrager carbon bar and stem, Alien seatpost, Toupe SL saddle, Keo Carbon Ti pedals.

It's old frame now too, the 2005 Madone SL, it was the lightest at the time, not even close now!

I'll get round to replacing it, but it's still a really nice bike to ride!

if only the uci would shift abit on that min weight limit eh?

I have spent a bloody fortune on bike bits over the years and have recently revised my thinking. Don't bother with XTR or equivalent – too expensive and makes very little difference. Also don't buy crap. Middle and higher so usually slx sometimes xt. Also there are cheap things that can make a real difference – tyres and tubes can save alot of rotational weight cheaply which does help.

I think it's surprising it's stuck where it has, but I don't think it's a bad thing, it's made the use of power meters and aero parts much more prevalent, which I think is good. It's forced innovation in different ways.

17 is about right; I've got a 2001 OCLV with Ultegra stuff and it comes in about 18lbs, still no slower than a 16.5lb Scott addict though..

i guess so.
i dont supose we would see all that stuff if it was loads lower.

but I'm relatively confident that if I went out on the Madone with a 5lb bag I'd still go quicker up the hills than on the Allez.

I imagine that you're right. Stiffer frame, wheels and faster tyres probably…

Nonk – 140lbs bike – 25lbs
5.6:1

Me – 85kg bike – 15kg
5.66:1

I wouuld agree, bikes over 15kg (33lbs) to me start to feel sluggish..
I feel a new thread coming on….

Same here brianbrian. Ultegra on the road bikes and XT on the mountainbikes (except for XTR shifters yum yum)I'm not a lightweight breakaway racer more of a plough through anything type i.e the Crits and TT guys muller me, but the tables (used) to get turned on rough country lane road races.
Hoping that's still the case come March 😐

You know in the days when people put a bike bottle or two on the frame? Could you tell the difference between full and empty bottles on the climbs?

I've always found it's the trend for heavier bikes to have worse climbing geometry and bigger tyres that slows me more than the actual mass of the bike.

I imagine that you're right. Stiffer frame, wheels and faster tyres probably

Tyres are often the same, if not similar, I doubt the wheels are stiffer (20/24 spoke RXLs vs handbuilt 32 spoke wheels on Open Pros with DT Competitions) and even if they are you're talking about minute amounts, as there's no real brake rub. I will agree on the stiffer frame, but we're talking bigger differences than that.

When the weather gets nicer I'll stick the PowerTap on the Madone and go and ride up a hill and see how long it takes compared to the Allez.

I've got a 2001 OCLV with Ultegra stuff and it comes in about 18lbs,

It's a whole chunk lighter than that, no common parts at all, I'll go back to my 16.5 estimate 🙂

I would hope (dunno why) that mine comes in under the 20lb mark.
PX Carbon Pro
FSA Carbon wing bars(heavy) FSA Carbon post & stem, FSA Carbon Team chainset 53/39 with LOOK Keos.
Ultegra 10 speed
Very very old Alex A-Class 430 wheels with heavy old Pavés

One of my mates had a bike shop and when the local roadies came in with new bling bikes, he would offer to weigh them. He always used a piece of foam to protect the paint.

I found out a few years later that the foam had a lead lining, psychology in action…

One of my mates had a bike shop and when the local roadies came in with new bling bikes, he would offer to weigh them. He always used a piece of foam to protect the paint.

I found out a few years later that the foam had a lead lining, psychology in action…

LOL – sneaky 😉