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Bike weight isn't as important as you think it is.
it's probably more important than *I* think it is 🙂 The only time I care is when I have to carry the ****er!
Juan, you insulted me by accusing me of poor reasoning. That's calling me stupid, and an insult.
You have no model, nothing at all, no attempt scientifically, mathematically, sensibly to suggest a way of quantifying the gains you think you can make from having a lighter bike...
I'll type it again for you.
When you are on a technical climb, there are many many points where you have to brake and accelerate. You also have to move the bike to the left and right quickly to avoid rocks and roots etc (whilst your centre of mass continues in a largely straight line). You also have to lift the bike up over certain obstacles. I don't know why you think this would not be easier with a light bike..? Your body needs to move less to get a light bike to move in response to it, which in turn saves energy.
Do you ride with a heart rate monitor? I do. On technical downhills where I do not need to pedal, my heart rate can be up in the middle of its range, around 160, without making a single pedal stroke. This is because handling the bike takes energy.
I would come up with a mathematical model but it's just too damn late and I need to go to bed and work tomorrow. But if you are lucky you'll get a model.
Btw, can I ask what bike you ride and how much it weighs?
Produce a sensible counter argument instead of 'muscling the bike around' and maybe the debate could go somewhere
Mmm or you could just listen to other people's experiences, rather than just assume we're gullible easily-led techno-weenies who think something's good just because it's expensive. That is what you think, isn't it?
Bike weight isn't as important as you think it is.
How important do I think it is then?
Now if light bikes where that good, why the same Nico schurter, choose to ride a "heavier" bike on a race that was longer?
Well there could be several reasons. Geometry and comfort for two.
I do not always take my lightest bike to races.
I think you are missing my point. What I am trying to say is that on technical climbs and singletrack light weight can make you go significantly faster, but there may be other factors which are more important in some cases. I am not saying you cannot win unless your bike is light, I am not saying that you will win if your bike is lightest.
Why else would XC racers most often use very light bikes?
Crikey wrote, "You have no model, nothing at all, no attempt scientifically, mathematically, sensibly to suggest a way of quantifying the gains you think you can make from having a lighter bike.."
That's correct- with the exception of "sensibly", which is all we're doing. All we have are real world observations- which of course are exactly as [i]scientific[/i] as models on a screen. We also have the ability to point out the obvious failings of your model, and the ability to point out the blindingly obvious. I can see why you'd consider that to be inferior to your inadequate model wth its innacurate results 😉
Why should we provide a model to show what anyone who has ridden a bike knows, that sometimes the rider and bike move differently? This is where the simplistic argument about rider + bike weight falls apart. How does that work in any of the situations I mentioned above which you're so studiously avoiding? Can a 30kg rider manual a 20kg bike in exactly the same way as a 40kg rider would manual a 10kg bike, assuming comparable geometry? Or sidehop it? Or unweight it over roots? Of course not- yet all nice straightforward examples of "muscling the bike about". So clearly, models or not, there is a real difference between rider weight and bike weight. So there goes one of the attempted rebuttals we've seen throughout this thread.
People who want to argue against the benefits of weight loss often end up hiding in maths, and don't bat an eyelid when their maths fail to reintegrate into the real world. It's also, I suspect, why they always fixate on power-to-weight and on climbing- they're easier to put into an equation. Not so easy that you can give us any results that actually work in the real world, but still, easier. And if it's not in an equation, then it's not scientific and it doesn't exist.
"regarding the benifits of a bike that is lighter by... Oh, you never said"
Er, actually I did. Several times.
[i]That is what you think, isn't it?[/i]
Wind your neck in, you'll go faster...
I think that people in general over-estimate the extent to which having a lighter bike affects their performance. I think the main effect is a placebo type one. I think that modelling bicycle and rider performance is very difficult, and requires a number of assumptions. I think that lightness in bike terms is a good thing, but I don't think that the average rider will gain much by lightening a bicycle by 2-3-4 kilos.
The beauty of cycling and cycle sport is that it really isn't about the bike; that's why you can't walk into a bike shop and pay £5000 and come out a better, faster rider.
I've been riding and racing for 20 odd years now, and I've been in the position where I could buy light kit. My current road bike is 16.5 lbs, but I was quicker on a 531 22lb bike.
As I said, there's a whole industry dependent on selling the latest performance upgrade to people on the basis of lightweight....
They wont go bust anytime soon.
[i]People who want to argue against the benefits of weight loss often end up hiding in maths, and don't bat an eyelid when their maths fails to reintegrate into the real world.[/i]
Ah, the old 'you dont get it, hiding in your laboratory, this is the real world' stuff...
Whatever, been there, done that, know that you can lighten your bike all you want and it wont make you any quicker.
Night boys.
well molgrips I can't find the bit where I say you are an idiot.
If you don't like people telling you your reasoning is not good maybe you should stop interacting with other people...
Plus I am waiting for you and njee to answer my other point.
P.S. if you found south well rocky I really need to create a charity groupt to buy you a plane ticket.
crikey wrote, "Ah, the old 'you dont get it, hiding in your laboratory, this is the real world' stuff..."
Well, no. I took your model, put the numbers into it and it gave us back answers which you agreed were clearly wrong, remember? You've kept on trying to use the model despite knowing it to be incorrect. But you have the nerve to talk of science.
But once again I see you've ignored all the rest of my post. A cynic might suspect you don't know how to respond to it, given the number of times you've done that...
I think that people in general over-estimate the extent to which having a lighter bike affects their performance.
I do not estimate the extent at all! I merely said the effect was significant.
Placebo effect? Not with me. I am a critical scientific thinker.
And I have not bought a lightweight component for three years. I built my race bike as an insurance replacement in 2007 and it's stayed exactly the same. It does not have the lightest of everything or the most expensive. It has disks and riser bars, and it's full sus.
I don't think that the average rider will gain much by lightening a bicycle by 2-3-4 kilos
Rider or racer? And are you talking about times here or riding pleasure? I would say that 4kg would make a significant difference do the handling speed of a bike and hence riding enjoyment (no-one likes riding a tank, do they?) and the overall position in say an MTB marathon.
Do you think you would not notice if I sneaked up and tied 9lbs of lead around your frame?
that's why you can't walk into a bike shop and pay £5000 and come out a better, faster rider.
Yeah you could. If you were riding a £500 stumpy and you bought a bike like my Heihei, I would bet you'd end up a good few minutes quicker up the Cwmcarn climb. Partly because of the weight, and partly because of the ride and handling characteristics.
For a while I had a 37lb Orange Patriot. Ask anyone who went riding with me, it was very slow up hills.
P.S. if you found south well rocky I really need to create a charity groupt to buy you a plane ticket.
I define rocky as a place where there are lots of rocks on the ground. I am absolutely sure it's not the rockiest place in the world, however there are plenty of rocks lying around so I will continue to call it rocky.
You insulted me here too:
so you just can see you talk shite
Ah, wouldn't this thread be so much better if we could put Juan in a sack- a heavy sack ideally so it does downwards faster-, tie it to some of those rocks he's so fond of and throw him in the sea?
Me plus 20lbs bike = 100kgs, me plus 30lbs bike = 105kgs, just in potential energy alone thats a 5% difference which is significant enough for me on the 500m of ascents I regularly take in on a ride around the chilterns...
Now wheres that maths book so I can add in the energy taken up in accelerating the wheels from 5 to 20 mph say 20 times in a 30 mile ride... no actually I can't be bothered, I'm not going to change anybodies view on the topic so might as well go to bed. Night all
It's funny how [s]people[/s] [s]rider[/s] [s]racer[/s] sorry race champion seems to be good at eluding questions. Plus saying you are talking shite is not an insult, saying to someone that is a twaàt is.
So I'll ask again molgrips how many races have you won, you must have wont some as you seems to be so fast.
I have been to wales and I wouldn't say there is lots of rock on the grounds. But as I perfectly willing to accept that the trail centre in the south of wales make an ergodic system of the riding in south wales.
I shall ad that if you're slow on an heavy bike but not on a light one, it's fitness. I know some pretty good riders, and to be fair they are as fast on a sub 13 kg carbone bike to go uphill as they are on a 16+ kg mini DH
Edit
I'm not going to change anybodies view on the topic so might as well go to bed. Night all
Bow to that...
Why should we provide a model to show what anyone who has ridden a bike knows
Because an awful lot of the stuff anyone who has ridden a bike knows is actually placebo effect or similar. Anybody want to discuss how much better a steel hardtail is at absorbing bumps than an alu one is?
When you are on a technical climb, there are many many points where you have to brake and accelerate. You also have to move the bike to the left and right quickly to avoid rocks and roots etc (whilst your centre of mass continues in a largely straight line). You also have to lift the bike up over certain obstacles. I don't know why you think this would not be easier with a light bike..? Your body needs to move less to get a light bike to move in response to it, which in turn saves energy.
Yes, but that doesn't actually use that much energy compared to propelling the bike up the trail - you won't slow down to half the speed if you continuously wiggle your bike from side to side. Meanwhile there isn't actually that much of that sort of thing on a typical trail - certainly nowhere near enough to justify your speed differences at Cwmcarn. You still haven't got back to me on why that's not more to do with differences in tyres and suspension setup.
On technical downhills where I do not need to pedal, my heart rate can be up in the middle of its range, around 160, without making a single pedal stroke. This is because handling the bike takes energy.
I find my heart rate goes up significantly when I get cut up by a car. That's undoubtedly to do with how much I'm wiggling my road bike about in anger.
Did you know that a lighter rider will go downhill *faster* than a heavier rider on the same bike, assuming that the bike setup is adjusted accordingly?
Go on.. Ask me how...
Actually, don't.
In the end the lighter rider came third behind the heavier rider and the bloke on the Halfords bike because his full-body spider man suit slipped down over his eyes.
In the real world you could probably collect enough data to exclude factors such as differing suspension design and rider ability to prove that lighter bikes are faster, but what would be the point?
Light bikes are fun. Sometimes a bit sketchy and fearful amongst rocks, but nonetheless fun.
as normal an interesting thread turns into , a slagging match,, especialy as the evening progresses, but it is fun to watch from the side lines,, and read those interesting well thought out arguments
we all know that it's the percentage of matching anodizing /paint that makes the bike fast
It's very disappointing that for some it's become so very personal.
It's not important, yet the vile language & insults being flung about makes you wonder quite why some of the guys here take it so personally.
Quite depressing re-reading some of the posts here.
Juan, I don't win races, I'm too fat. The fat's not in my brain though, so my analysis of the Physics involved is not affected 🙂 Plus, no-one ever passes me in races on the flat or downhill bits 🙂 Winning races has nothing to do with understanding bikes, does it?
Aracer - I haven't come up with a definitive reason why my light bike is so much quicker up Cwmcarn; I have some ideas, but I can't prove either way. I do think the acceleration and deceleration is the main issue however.
Ti29er - I do not really object to people having a different point of view. What I really object to is people telling me I'm some kind of brainless idiot who minces about shelling out tons of cash because some magazine tells me to on the basis that I think it'll make me into a super fast race winning wonder kid.
Please, I'm a reasonable thoughtful chap, so let's put our arguments forward without the constant veiled insults (Juan, you are getting insult confused with epithet).
Well said Ti29er, ade ward & bike whisperer.
Having slept on the issue, I'd just like to conclude by saying that on a long slow climb & with all other things being equal my 8.5st girlfriend is going to have to expend approx 8% more energy to get to the top hill if she used a 30lb bike instead of a 20lb bike.
And yes before you start flaming me for ignoring wind resistance rolling resitance etc, in reality it's the hills that most people find the hardest and at 5mph struggling uphill those factors are going to be fairly minimal on their effect on the percentage of effort required.
Maybe weight is not the be all & end all, but to ignore it & pretend it doesn't matter makes no sense to me
I haven't come up with a definitive reason why my light bike is so much quicker up Cwmcarn; I have some ideas, but I can't prove either way.
They do have different tyres and suspension systems though? Possibly also a different position/geometry?
Is the HeiHei your 21lb bike? Extremely light for one of those I'd have thought - what's the build?
Maybe weight is not the be all & end all, but to ignore it & pretend it doesn't matter makes no sense to me
but most of us are quite a bit heavier than that, so the figure would be closer to 5%, which may be too small to feel. I would estimate my energy levels vary about 30% from day to day. I don't think ayone is saying it makes [b]no[/b] difference, only that the differences are too small to be important, except in racing and psychologically, and probably not worth paying much money for.
I agree with Molgrips, although not his dogmatic, aggressive and over sensitive delivery. 😕 A lighter bike is easier to manoeuvre in technical situations.
I'm a distinctly average physicist, but this would be relative intertia between the bike and the rider, since the two components are not fixed and rigidly linked together.
Less intertia equals less resistance to acceleration/deceleration which is something you do all the time when manoeuvring the bike about. I don't think forward motion would have much of a role in this sort of activity, at least at the 'forces' level we've decided to examine it at here.
I guess there's a similar model between the rider and the bike during these events as there is to suspension - and it would be the same reason why its good to get unsprung mass as light as possible. i.e less inertia equals more responsive suspension.
Having read most of this thread, I think the answer to the OP is "yes".
Apologies for being over sensitive, I lost the required STW perspective and got annoyed last night...
Is the HeiHei your 21lb bike?
Yes, and to show I'm not a stupid weight weenie idiot, here's the build. It saves weight where it can do it without compromise:
Kona Heihei 2007 frame, Fox RP23 shock 19"
Pace RC39 80mm forks
Tune headset
Syntace F99 105mm stem
Easton monkeylite XC carbon bar low rise 24" width
USE alien carbon seatpost
Flite SLR saddle
ZTR Olympic rims
XTR hubs
Sapim laser spokes
Some lightweight skewers I forget what
Racing Ralph 2.0 with Stan's tubeless system including the rim strip
XTR cranks
XTR brakes 160mm centrelock rotors
XTR mechs front and rear
Dura Ace bar-end thumbshifters with Paul's components bar mounts
Xpedo ti pedals
Ritchey WCS foam grips
Of those things, people will laugh at the following:
Seatpost - I have confidence it won't break
Saddle - comfy enough for 3-4 hours in the saddle, but this is an XC race bike
Skewers - a possible concern, although they've been great so far, good cam action
Grips - cheap as chips and I find them as comfortable as any, so may as well save the weight
Stem - must admit I am a bit concerned about the 4 bolt stem and the bars, can't decide if there's a problem or not
Shifters - they actually work really well, cost WAY less than XTR and weigh loads less too.
Forks - they've been excellent, although I do somewhat wish I'd gone for the 100mm version of the same fork.
It comes up as 21.5lbs on my cheap fish-weighing scales (which I think may over-read slightly, not sure).
which may be too small to feel
May be? Well we are telling you it's not - at least the way I ride it's quite evident.
And so what if it's psychological? Most of us ride for fun, not performance - and if it feels really nice to ride a light bike (for whatever reason) then surely that's ok?
Considering my Fuel is 21lbs, your scales certainly don't over weigh, or if they do, mine do so even more 😉
and if it feels really nice to ride a light bike (for whatever reason) then surely that's ok?
I never said it wasn't OK 🙂
I have a few road bikes. The lightest is under 14lbs, and the heaviest about 19lbs, but the heavier one is far more reassuring to ride.
I have a few mountain bikes. The lightest hardtail is about 21lbs, and the heaviest 7 inch full susser is about 33lbs. They each have their uses, but for sheer fun and smiles, the 33lb full susser does it for me every time. Having said that, they are all built up with some of the lightest parts possible for their build, so as much as weight doesn't matter in terms of a 'horses for courses' bike, within a certain type, lower weight is usually an advantage if it does't compromise handling, robustness, safety or fun.
I use to have a 23lb carbon HT, a friend borrowed it. And from been at the back on his ancient heavy thing, he was suddenly mid-pack. And enthusing about how well it rode, and how easy it was to pedal up hills.
He then bought himself a s/h Boardman HT, mainly due to the (lack of) weight per £.
Some will say its the Placebo effect, but even my limited understanding of gravity/force/effort tells me otherwise.
Some will say its the Placebo effect, but even my limited understanding of gravity/force/effort tells me otherwise.
I think most of us have reached a similar conclusion, but arguing with some people seems a bit like banging your head against a brick wall.
But without the excitement.
They each have their uses, but for sheer fun and smiles, the 33lb full susser does it for me every time
Yep.. I never race on my Patriot, but I rarely take my race bike out to the hills.
Well at least the designers are obsessing over bike weights. So all middle aged men have to do themselves is just splash the cash.
I have to say the general rule of weight saving so far as I’m concerned has always been wheels before anything else, specifically the outer circumference; the Rims, Tyres and Tubes (if you use them) and this will have the greatest effect on handling and acceleration, look at it this way you have a 2 wheeled vehicle with 26” (or 29”) control and drive wheels, both of which are generating significant gyroscopic forces and both of which need to be spun up to speed and decelerated by the puny Biped in the saddle, the lighter they are the easier they are to accelerate, decelerate and turn, we live in the age of the sensibly Strong & Light Rim and reasonable weight Kevlar tyres, I think if anyone asked me what is the best way to spend ~£100 “lightening” a bike, my suggestion would always be look at rims and tyres first, obviously this takes total weight down a notch but effect of saving 1Lb on a wheelset is more marked than saving 1Lb of drivetrain, frame, fork, or finishing kit…
Overall weight of the machine is of course academic, because the heffalump sat on top will always be the heaviest component and the best thing to try and reduce the weight of…
Plus I think it’s worth considering the actual need for 5 litres of water, six mars bars, a full servicing tool kit, a Gortex jacket and liner and a sodding great pump when you’re only trundling round swinley for 2.5 Hrs on a sunny Sunday morning, the Camelbak has probably added more weight to most mountain bikers expeditions than their bike ever will, “compact and efficient” seems to be an alien concept to many these days.
As so many people frequently point out the fit of a bike is the most important thing, why you would compromise fit for marginal weight saving is beyond me, a badly fitting bike will fatigue you far quicker than a well fitted bike which is a couple of pounds heavier…
I won’t deny total weight can have a bearing on performance but it’s way down the list (whether on a flat out XC race machine or a 6” bouncy trail bike) above it you will find rider position, Wheel and Tyre choice, suitable equipment for the ride/race you’re doing and all of these allow more efficient use of the energy a rider has, a light bike so long as it ticks all of the other boxes will be a “better” more efficient machine but the cost of building a sub 22Lbs bike is relatively high, I can’t imagine anyone other than a “Very Serious” racer would require such a machine, and certainly not the average trail centre pootler…
the lighter they are the easier they are to accelerate, decelerate and turn
And the smaller they are.. 26ers are more manoevrable than 29ers. Not I do not say 'faster'... Moment of inertia is dependent on the fourth power of the distance from the centre of rotation (iirc) as well as mass.
Overall weight of the machine is of course academic
Only if you are slogging up a smooth fire-road or road climb. Not at all academic on singletrack.
why you would compromise fit for marginal weight saving is beyond me
I wouldn't.
I can’t imagine anyone other than a “Very Serious” racer would require such a machine
Require? We don't 'require' any of it.
So to sum up - light weight is quicker, but not at the expense of to much comfort or control (note none of the contributors here have said anything like that).
And who on this thread is an 'average trail centre pootler'?
We on this thread clearly care about our bikes in specific ways.. so I would assume we want more out of them than something to trundle about Afan on.
And who on this thread is an 'average trail centre pootler'?
Moi, when I’m at one, ‘a’ trudlin…
I think you’ve chosen to take umbrage at my post which was really just stating a few general rules (of my own concoction) essentially stating that total bike weight is not the primary key to “better performance” and reduced rider fatigue, it’s merely a contributor and comes in 4th or 5th place behind some other concerns, I wasn’t talking specifically about flat backed XC racers but I guess some of what I typed applies, and Racers aren’t the only people who buy bikes/parts or use this bike forum… I wasn’t really disagreeing with anything you’d written (not that I can really be arsed to read all of the diatribes in this thread up to this point) but if I’ve offended you I promise it wasn’t intentional…
Targeting any loss of weight at key areas and improving bike fit, yield more “Bang per Buck” (or GBP) than simply throwing £4.5K at Carbon and Ti and assuming the headline weight figure is all you need to worry about…
Cookeaa, wasn't offended - didn't mean to sound narky.
What you say is of course true and my aim is not to argue against it.
Just take exception to others telling me I'm an easily led idiot...
Light is good but not the only good thing.
I think the Camelback point is a good one.
Its so easy to carry stuff without really feeling encumbered by it, so that temptation is to throw anything you fancy in there. I think the backpack contents thread was done a while ago, and it was quite and eye-opener!
Ah! Here it is: http://www.singletrackworld.com/forum/topic/kitlists-and-multitools
Stuff in the camelbak is only wasted weight if you don't need it though. You could head out on every ride with no pump, no tubes, no tools and no water, would save alot of weight but wouldn't be a great idea!
I don't use a Camelbak...
I also don't carry a tube.
I think the Camelback point is a good one.
It's also why XC racers virtually never use them. I wouldn't if I could get someone to bottle me. I also wouldn't carry a tube since if you puncture, that's basically it. I used to take seal'n'flate, now I use tubeless.
Just ask randoms, there's always someone to bottle, the feed zone's full of them!
Presumably you carry what you generally need though? ie some water, some method of reinflating a tyre, a minitool, etc. (For a normal ride, not a race).
Yep, a water bottle (with a view to buying another bottle somewhere en route if appropriate), a multi tool with chain tool and a CO2 pump. Sorted!
Just ask randoms, there's always someone to bottle, the feed zone's full of them!
Mm, good idea. My wife did it once but didn't watch out for me coming, so I had to stop and look for her before taking the bottle. Ok so it was a 100km enduro but still 🙂
I was thinking some kind of stand arrangement like how they used to collect mailbags on wild west trains...
Gee used to do that, he had a little table. I tried it on occasion, but found it really difficult to not send them all flying! You must know someone who has a wife/girlfriend/boyfriend etc that comes along!