Weight & physics

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  • Weight & physics
  • DrP
    Member

    Probably- a light bike and heavy rider means the bike can ‘move more’ under you….
    A heavy bike will require more energy to manoeuvre, I would say.

    DrP

    trail_rat
    Member

    how ever if your riding any sort of distance you want to keep crap off your back and thus the bike is the best place for it.

    never understood the facination with camelbacks – most folk here could do their rides off one bottle yet carry a full 3 litre camelback with the entire world in it – because they can.

    just contributes to sore bums and backs

    ndthornton
    Member

    It will move your centre of gravity upwards slightly which is generally bad for stability. But I alaways use a camel back – I cant stand stuff hanging off the bike where it can bounce off, get damaged etc. It also adds more places for mud to collect which adds weight – is more difficult to clean – and reduces life. Also looks rubbish.

    Premier Icon endurobadger
    Subscriber

    lower centre of gravity.

    weight on the bike will make the bike less maneuoeueuoverable, but you more so. and vice versa, depends whether you mean the ‘bike’ or you and the bike.

    ndthornton
    Member

    yet carry a full 3 litre camelback

    Who says you have to fill it up?
    I rarely carry more than a litre – but its there if you need it.

    trail_rat
    Member

    so is my bottle…

    and if its a long ride i might carry two 😉

    Premier Icon aracer
    Subscriber

    Who says you have to fill it up?

    Some people on here certainly seem to think they need 3l for riding around a trail centre. Though what’s worse is that they also seem to think they need to take a full workshop tool kit with them.

    ndthornton
    Member

    I think bottle or camel back boils down to personal preference and riding type….but tools tubes pumps etc is really not going to last hanging off a bike in this country – especially if you leave it on the bike when you clean it. I have one of those under seat bags for the road bike but seems like a bad idea for anthing else.

    …and what about your lunch? shove it all in one bag and then add water
    simples – all in one place and protected

    If it’s on the bike then it’s either unsprung mass, or less well sprung mass, which will cause the bike to be less smooth over the rough stuff and have less grip when cornerning or braking. But when climbing it’s often more pleasant having the weight on the bike rather than on your back. What matters more to you? Uphill or downhill? Covering miles or shredding the gnarr? 😉

    TooTall
    Member

    My stuff is a smaller percentage of my body weight than it is of the bike, so it goes on me.
    As for the haters – some of us sweat like a fat lass in a chocolate factory and need way more hydration than fits on a bike frame.

    DrP
    Member

    In addition…

    It’s all down to your style of riding isn’t it?
    If you’re going for a country bimble along mostly fire tracks, then stick all the weight on the bike.
    If you’re ducking and weaving the bike down roots and rocks and through trees, I’d want the bike as maneuverable as possible, and accept the weight on my back.

    On the road bike I stick all I can on the bike – bottles and tools. Why – because I’m unlikely to be swinging that bike this way and that….

    DrP

    Premier Icon ahwiles
    Subscriber

    slight troll, with hint of seriousness:

    dehydration is good for you.

    you’ve got to lose a LOT (litres) of water before it reduces your performance by any measureable amount, and if you lose litres of water, you’re lighter, so can afford a little loss in performance.

    crispy1970
    Member

    Humor me because this question keeps bugging me and as a beginner I have not had enough trail time to work it out.

    When I go out riding I have a drink & bottle , seat wedge with tools and bits and a pump all attached to the bike.

    I understand the weight will be the same from an overall speed point of view but will it make the bike more manoeuvrable and easier to ride if this weight is shifted into a camel back?
    Cheers,
    Chris

    ndthornton
    Member

    ahwiles

    Agreed – Iv stopped taking water on my 22 mile commute to work to save weight as the distance is bordering on impracticle and need to save as much time as possible. I drink as much water as I can before setting off and then Im fine – dont get thirsty at all – just hungry. Its early morning and late afternoon so dont sweat much.

    TooTall
    Member

    you’ve got to lose a LOT (litres) of water before it reduces your performance by any measureable amount, and if you lose litres of water, you’re lighter, so can afford a little loss in performance.

    Guff. Far too many variables in ride / conditions / fitness etc for you to say that so broadly.
    My performance degrades badly on a day of cycling (or anything else) if I dehydrate. All experience (inc extended desert conditions with lots of others to observe) tells me hydrations is good. You do what you want but I’ve suffered extensive dehydration before and would rather manage to avoid that.

    Premier Icon prettygreenparrot
    Subscriber

    back to the OP. If you put the stuff in the camel bak then the bike becomes more manoeuvrable. But you get a bit top heavy.

    On the whole I prefer putting stuff in the camel bak rather than on the bike. Main reason is I keep the camelbak in the house and I can be sure I’ve got the things I want in it before setting off. Another reason is I used to find stuff would rattle around or drop off the bike (pumps, bottles, seat wedge bags…).

    On 3L of water and bottles and dehydration, use the water container you prefer and drink when you’re thirsty. This piece in the BMJ has a few things to say about sports drink myths. Unfortunately, it is a piece of ‘pay to view’ research so non-subscribers don’t get the full story.

    ndthornton
    Member

    xtended desert conditions

    Quite common round these parts 🙂

    Premier Icon The Pinkster
    Subscriber

    If it’s on the bike then it’s either unsprung mass, or less well sprung mass

    It’s only unsprung mass is it’s mounted on the wheel side of the suspension or you’re riding a rigid bike, in which case so is the rider. If it’s a full susser and it’s mounted on the frame side of the suspension then it’s sprung mass, no matter where it’s mounted, on rider or bike.

    DrP
    Member

    you’ve got to lose a LOT (litres) of water before it reduces your performance by any measureable amount, and if you lose litres of water, you’re lighter, so can afford a little loss in performance.

    Any evidence for this?
    As there is plenty of evidence to the contrary i.e 5% loss in total water, (which for a 70kg male is likely to be only 2-3L) can have performance impact.

    DrP

    Premier Icon D0NK
    Subscriber

    never understood the facination with camelbacks

    swapping bikes innit. I’ve got a ‘bak for proper rides and a tragically uncool bumbag for commuting/road. Aslong as I have my bag I’ve got the necessary tools, I’ve not left my multitool in that jersey pocket or my mini pump in that softshell. Not seen a saddlepack or similar that would fit on all bikes securely and not wag about like the saddlepacks of old used to (and wreck your paint job). I think it is easy to overpack with ‘baks, end up with the kitchen sink and twice as much water as you need but aslong as you are sensible you should be ok. I didn’t used to like riding with a pack, still don’t on road, but for long xc rides ‘baks are great. Wingnuts and newer camelbaks (i think) that sit on your hips seem to be a lot less strain on your back aswell, and more stable, I used to get a little backache with a mule and full bladder on long rides, not a problem with my wingnut.

    wobbliscott
    Member

    For MTB I think your best with a backpack or camelback as you move the bike around under you much more (or should be). On a road bike my preference is to have everything on the bike.

    crispy1970
    Member

    cheers for all your feedback

    chief9000
    Member

    ahwiles – Member

    dehydration is good for you.

    you’ve got to lose a LOT (litres) of water before it reduces your performance by any measureable amount, and if you lose litres of water, you’re lighter, so can afford a little loss in performance.

    Hydration is actually super important. A 2% drop, and over, in body weight (through dehydration) has a measurable effect on performance.

    My bike is too rad to hold a bottle.

    And it would get covered in cack almost instantly which I don’t want to put in my mouth.

    Premier Icon njee20
    Subscriber

    .

    but tools tubes pumps etc is really not going to last hanging off a bike in this country – especially if you leave it on the bike when you clean it

    Why? I often put a spare tube and co2 pump on the back of my seatpost, hose it off when I wash the bike, so it’s clean again. Why wouldn’t it last?!

    Premier Icon tenfoot
    Subscriber

    This regarding bottle use —–>

    And it would get covered in cack almost instantly which I don’t want to put in my mouth

    Premier Icon BigJohn
    Subscriber

    1) A lighter bike feels better, more responsive and gives a far mor enjoyable ride. That’s what we do it for (and spend a fortune on lightweight parts)

    2) A camelbak is a more convenient way to have a drink when you want to and will also carry your jacket when you get hot.

    3) If you’re going to mention physics you should refer to mass, not weight.

    Toasty
    Member

    Who says you have to fill it up?

    Regardless, an empty Mule weighs about the same as a full smallish bottle.

    3) If you’re going to mention physics you should refer to mass, not weight.

    I think it’s safe to assume the above is all on Earth.

    ndthornton
    Member

    [/quote]empty Mule weighs about the same as a full smallish bottle.

    Wow that would have to be a small bottle – yakult?

    Toasty
    Member

    MULE = 590g
    500ml + 100g bottle

    You could take a full 7 pack of Yakult for about the same if that’s what you’re after though.

    trail_rat
    Member

    100 gram bottle. With 500ml water in.

    Itll only be half full surely.

    750ml bottle weighs between 50 and 80 grams and throw in about 25 grams for a cage

    Job jobbed , i have fluids and you have an empty bag.

    Also camelbak list the mule as being 860 grams.

    Premier Icon Northwind
    Subscriber

    never understood the facination with camelbacks

    I’ll field this one- it’s because drinking from bottles covered in crap is rubbish. Carry more, in comfort, and cleanly, without weighing down your bike, or ever losing a bottle. What’s hard to understand?

    The thing about riding with the minimum of kit, is that sometimes it turns out not to be the minimum. You run short of water, or get one more puncture than you can deal with, or it rains and you have no jacket, or it doesn’t rain and you have nowhere to put your jacket… Camelbaks remove a lot of the ways that rides go wrong. Random passing Northwinds with camelbaks fix problems for people who’ve come out without kit they later want.

    Drinking on a ride isn’t just about avoiding negative performance issues from dehydration- it’s largely about not being thirsty. Hands up everyone here who only eats when they absolutely need to, rather than when they want to? Why drink differently?

    It’s only unsprung mass is it’s mounted on the wheel side of the suspension or you’re riding a rigid bike, in which case so is the rider. If it’s a full susser and it’s mounted on the frame side of the suspension then it’s sprung mass, no matter where it’s mounted, on rider or bike.

    The longest travel and best suspension on any bike is the rider’s arms and legs. Mass added to the rider’s torso is far more effectively suspended than having that mass on the frame of a downhill bike, let alone on a shorter travel full sus, hardtail or rigid bike.

    uselesshippy
    Member

    I’ve never lost my camelback on a rough descent.
    Lost a few bottles though.

    Premier Icon aracer
    Subscriber

    I’ve never lost my camelback on a rough descent.
    Lost a few bottles though.

    I regularly lose my bottle on a rough decent.

    Toasty
    Member

    I’ve never lost my camelback on a rough descent.
    Lost a few bottles though.

    I’ve never bought a £60 water bottle.
    Bought a …. etc 🙂

    Premier Icon epicyclo
    Subscriber

    buzz-lightyear – Member
    …And it would get covered in cack almost instantly which I don’t want to put in my mouth.

    You can get bottles with lids – the only sort I use.

    But the best place for fluids is inside you. I fill up before I go.

    trail_rat
    Member

    I’ll field this one- it’s because drinking from bottles covered in crap is rubbish. Carry more, in comfort, and cleanly, without weighing down your bike, or ever losing a bottle. What’s hard to understand

    Good cage. Means ive never lost a bottle even on the roughest descents – kilbo path or spooky gnar wood ! – except my aero bottle on my tt bike – that was user error.

    Bottle covered i crap . Do you aim for dog eggs ? – my mate did ride through once and covered his bike and the roof of his mouth in dog egg. Drinking from the bottle wS the least of his worrys.

    I cant think what you might have in your bag that i might want on a ride . Do you care spare mechs or handle bars – i may bend or snap those on a ride. Everything else is repairable with my multi tool , pump and tube. Which all go in the pockets of my jersey.

    But then i do notice on here that many folk are in the reactive maintainance camp so i can see why you would want to carry the kitchen sink on your back in that case.

    trail_rat
    Member

    Oh just minded – biggest revelation in drinkng bottles is camelback podiums. Pull it out , give it a squeeze and voila clean nozzle 🙂

    Premier Icon D0NK
    Subscriber

    I cant think what you might have in your bag that i might want on a ride …multi tool , pump and tube

    well:
    patches for when you get more than 1 puncture (more often than I’d like),
    universal mech hanger (pretty light so I can live with it),
    ducktape(mostly used as tyre boot for rips/tears),
    zipties (couple of grammes and a million* lot of uses),
    a second tube if its a long, middle of nowhere ride (flatting 2 tubeless tyres or destroying 2 tubes is pretty damn rare but it will leave you stranded),
    tubeless plug kit (quite possibly overkill with latex)

    then you’ve got an extra clothing, short blasts in summer or consistently cold winter days not much need but changeable conditions eg night rides where it starts off warm then the temp drops, or those typical UK rainy/sunny/windy days you may need something. Racers seem to manage with just lycra but they are going hell for leather throughout the race generating a huge amount of body heat, average stwer is a damn sight slower and stops for chats/lunch etc

    Bottle users get pretty adept at grab/swig/replace but it still doesn’t beat having a bite valve a few inches from your mouth

    But this is all personal choice, if you’re never more than a couple of miles form your house/car minimal tools and a bottle sounds reasonable to me.

    Bottle may be fine for you trail rat and not having a backpack on is certainly better ergonomics but lots of people like the versatility of packs and you can’t argue with them on that point.

    *will try to avoid hyperbole

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