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  1. #1
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    Heavier tires + lighter frame = same?

    If I added 500g to my tires by going very wide, but removed 1000g from my frame, will it be the same effort climbing? (Ignoring the benefit of added traction and improved small bump comp.)

  2. #2
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    Apparently rotational weight is the big pink elephant in the room (or is it white?)...

    I think it works like so... Getting it (RW) up to speed takes more energy, but once rolling it should carry/maintain more momentum.

    Just reduce your calories an loose some weight of your taint. According to most that'll benefit your riding more.

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  3. #3
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    Heavy wheels suck if you are wanting to climb fast, I'd rather have a heavy frame and light wheels, especially if it's a 29er.... the larger the diameter wheels, the more you will notice.

    When people ask me where to spend their money I always start with good wheels.

    NOW... that being said, I really LOVE my wide rims and bigger tires = lower pressures, better small bump control and traction. I ride my "big bike" almost always now... but when I want to go fast I go right back to my "XC" bike with the regular 2.1 tires and nice wheels.

    If you go the lighter wheel route... pay big attention to tire weights too... a poor tire choice can negate a light wheel set very easily. Make sure you are tubeless... if you are not tubeless you are not serious about saving rotational weight...
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  4. #4
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    I might add that I have a very good comparison base right now.... I have two Ripley frames with similar components... but one has race wheels and 120mm (Lefty) fork the other all mountain 140mm fork and wide rims and pretty heavy tires.

    The effect of the big wheels is very, very noticeable when trying to accelerate/climb.

    The difference between the two bikes is 3.3 lbs.... all in the fork and wheels
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  5. #5
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    Wheel/tire weight matters far more than anything for flat or climbing. Added weight there will have far more effect on the effort you need to put in to make your climbs etc. Not a simple swap in weight by any stretch.

    Add a bottles and such to your bike and ride it. Then strip all that. Divide the total weight of those items by 2 to know how much weight to add to your wheels. Ride again. Your legs and lungs will surely feel the difference on the first decent climb.

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  6. #6
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    On a smooth surface, heavier wheels will affect acceleration and manoevrability, but once up to speed, the effort to maintain that speed will be the same, its primarily limited by aerodynamics.

    Again on a smooth surface, at a steady speed, climbing will be affected by overall weight, rider + wheels + everything else, weight on the wheels won't matter more than weight on the frame. For every gram on the wheel that goes up at the back of the wheel, a gram comes down at the front.

    Once you get onto a rough surface, or when you are accelerating, a completely different set of factors comes into play, and lighter wheels will always be faster.

  7. #7
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    If you account for rotational weight as 2x static weight then weight is weight isn't it? Are we saying the same thing?
    Is there any difference between adding 3lbs to my frame versus adding 1.5lbs to my wheel in terms of climbing speed?

  8. #8
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    I just answered that above (just as others did)

    Weight IS NOT just weight. You CANNOT just say " oh I can make the best of my bike 3lbs lighter and add 1.5lbs for each wheel for the same effect". Does not work that way. Especially when it's in the case of tires.

    There is a reason why many pay most attention to tire weight then wheel weight behind that. Because in CLIMBING AND ACCELERATION that is the weight that matters the most.

    A couple lbs more on the rest of bike is the same as having a full hydropack vs no pack. Doesn't matter THAT much. Your not going to notice it a whole lot because you quickly adapt

    Add that same amount of weight to the wheels instead and you suddenly CANNOT MAKE CLIMBS you did before or your slower and more fatigued after making them.

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  9. #9
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    3lbs on the frame versus just 1.5lbs extra spread evenly to both wheels.

    Oftentimes you'll see people quantify rotational weight as 2 times that of static weight. You're saying that is false? Then how do we equate rotational weight to static weight? Climbing effort probably has a pretty tight relationship to total weight. I figured if you remove double the amount of weight from the frame that you've added to rotational weight you would come out the same. Maybe I'm just not communicating effectively here.

  10. #10
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    Rotational weight at the tire is roughly = 2x static weight on the bike when we are talking about acceleration. So if you can drop 1lb by getting lighter tires, that would roughly equal dropping 32oz of water from your pack or bottle.

    Now try accelerating withe that 32oz water bottle and then without it. If you can feel a real difference, I would be surprised. There is a difference though.

    A huge part of cycling is mental. If you think you will be faster, you will be faster.

    When talking about tires you have to take rolling resistance into account. It plays a much bigger role compared to the weight.

  11. #11
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    Don't forget wheel size also plays a part. More weight on a 24" wheel is a lot less noticeable than on a 29er.

    Going wider also means going taller, which increases not only gear inches but effects of tire weight.

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  12. #12
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    If you're adding 500g of tire to your bike, you're probably installing some really slow tires. The bike is going to be slow. Not because of the weight, but solely because of the slow rolling tires.

    If you add 500g of tire and remove 500g of wheel weight, its probably going to be slow. If you do it the other way around, saving 500g of tire and adding 500g of wheel, its going to be much, much faster almost always (save some weird bad tires).

    A couple hundred grams of tire is nothing. Rotating or not doesnt really matter, its really a completely inconsequential amount of weight. Rolling resistance is a huge deal though, and high resistance is generally associated with large, wide heavy slow rolling tires.

    Big tires are not faster up a climb. They easily may be faster over a whole course, but not over a climb.

  13. #13
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    This is my take on the rotational weight thing. As the day wears on the engine on my bicycle (Me) becomes more and more inefficient. A lighter wheel will allow me to use less energy to accelerate or climb as I become more and more tired. My 2000 gram wheels feel a lot differently than my 1500 gram wheels at the end of a long ride. If I had removed that 500 gram difference from anywhere else on the bike, I am not sure I could feel the difference as much. But as was mentioned above, a large part of cycling is mental and I could very well be mental.

  14. #14
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    One Pivot nailed it.

    The weight is a minor consideration compared to the almost certainly massive gain in Crr.



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  15. #15
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    There is another big consideration with wheel / tire weight, which is gyroscopic inertia and how the bike handles airborne. If you are doing trials or bmx behaviour, heavy tires are sluggish rather than nimble.

    Keep both wheels on the ground and ride on the flat, there the big gains are to be had from aero, not bike weight. 100g is equivalent to a protrusion an inch by 2mm, 1kg is equivalent to a pencil.

    It is curious how in mtb aero is generally ignored. Ride into a headwind and it's pretty obvious that it's like riding with the brakes on.

  16. #16
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    Quote Originally Posted by jacksonlui View Post
    If I added 500g to my tires by going very wide, but removed 1000g from my frame, will it be the same effort climbing? (Ignoring the benefit of added traction and improved small bump comp.)
    I have only experience comparing DT Swiss XMC 1200 running Nobby Nic 2.35 front 2.25 rear vs Easton Wheels with Nobby Nic 2.8. Weight difference is more than 500 grams (just the DT wheels are 1400 vs aroung 1800). Going uphill in the smallest cogs the difference was sizable, and the winner did not feel like the wide wheeled/tired bike. It was like comparing a tank to a sport car ... btw: you won't be able to remove 1000 grams from a frame!

  17. #17
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    I was speaking theoretically, what-if scenario trying to validate rotational weight at 2x versus static weight thats either sprung or unsprung. Maybe someone has already gone down this path of research.

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  18. #18
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    I kept it simple. Keep the rotating weight at a minimum for what I need (which as a big guy I'm limited), make sure they have only the traction I'm going to need, not way more which brings rolling resistance much higher.

    Taking almost a pound off my wheels (combined) I noticed a lot. Adding 2 lbs to my bike and me when going night riding I DONT NOTICE AT ALL. Same ride, same trail. But I ride a 29er so it's noticed. And I didn't realize my previous wheel weight till I actually weighed them after riding my new wheels and noticing a difference on my climbing. So no "mental" there.

    You can compensate if your bike has enough weight to loose that's not rotational for 500g of added wheel weight.

    But in real life, as pointed out, the wheel changes you'll notice far more than anything else especially on long rides and climbing. But I wouldn't worry so much about it. You'll adapt fairly quickly. And you'll notice even more when you jump back on a bike with lighter wheels. It's why my fat bike is great all year. Cause my 29er weighs nothing in comparison now.

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  19. #19
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    Quote Originally Posted by Davide View Post
    ... btw: you won't be able to remove 1000 grams from a frame!
    Certainly a 1700g aluminium frame can't be got down to 700g easily.

    However, in full suspension world dropping a kilo is perfectly feasible.

    In hardtail world dropping the front suspension can save a kilo or more moving to rigid carbon or ally forks. I have a set of steel forks rotting in my garden that weigh more than a set of downhill forks.

    Going from a 2.2kg steel frame to a 1200g carbon fiber frame is possible.

    I have found it is possible to routinely drop a kilo off a hardtail by using 1400g xc forks, 500g crankset / bb, 300g pedals and getting rid of the front mech/shifter/rings. The rest is shavings, but that can add up to another kilo easily.

    An inferior sealed square taper bottom bracket is often close to a kilo.

    A kilo is a lot to lose, certainly.

  20. #20
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    The rolling resistance and climbing will be the 2 most noticeable things. I added some big 2.4 ardents in place of liteskin rocket rons (adding 600 grams) for a trip i was taking and it was rather noticeable. I could feel the rolling resistance on the flats and the weight on the climbs, not to mention the lap times. The downhills were awesome though.

  21. #21
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    But you can enter corners and brake later and be more safe, you can make up the time on descents right? The big ardents will let u clear tech climbs while others have to push the bike. Unless you have a lot of fire roads to climb which would suck either way.

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  22. #22
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    Eh not really unless it's mostly a descending course. What you gain in the corners is not much compared to the time the rolling resistance of the knobbier tires adds over the full length of the course. Which is why racers use smaller less knob, less weight tires. For XC racing you have to compromise on the tires that will get you around the entire loop the fastest.

  23. #23
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    Yeah. I was referring to more aggressive terrain thats a little beyond xc. I think they call ot extreme xc which is basically trail or variations of all mountain. Pure xc is probably best served with one of the latest renditions of a long and slack HT

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  24. #24
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    The lightest tire ive ever run was a 2.35 ikon front and rear. I was much faster overall with the dhr2 front and minion ss rear. It was eye opening for me. I wonder what a rocket ron would feel like. Maybe if they go on sale one day I'd get it just to see the difference

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  25. #25
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    Quote Originally Posted by jacksonlui View Post
    But you can enter corners and brake later and be more safe, you can make up the time on descents right? The big ardents will let u clear tech climbs while others have to push the bike. Unless you have a lot of fire roads to climb which would suck either way.

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    I've literally never had a climb where I thought "Man, if only I had a knobbier tire, I'd make it up this hill."

    Body positioning and pedaling technique matter far, far more than the tire when it comes to producing climbing traction.

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  26. #26
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    Quote Originally Posted by Le Duke View Post
    I've literally never had a climb where I thought "Man, if only I had a knobbier tire, I'd make it up this hill."

    Body positioning and pedaling technique matter far, far more than the tire when it comes to producing climbing traction.

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    Really? In wet conditions and slightly muddy/soft terrain, knobs are the s**t for clearing some of the technical climbs on my trails. It's not a substitute for technique and body positioning, but it sure as hell helps.

  27. #27
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    Yeah. Tires can help make up for lack of skill for sure. Unfortunately i need that extra help. Ive always said pros can ride a kids' tricycle and still be faster.

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  28. #28
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    To be fair tho. Im comparing 2.35 dhr2 to rekon 2.8. The successes are primarily due to more grip and low pressure which is the same net effect. Im clearing stuff ive always had trouble on consistently and its probably not the knobs. However i do like how the minion knobs help on corners. That i can compare between several minion tires versus ikons and NN which have smaller or unsupported knobs. Rekon has the knobs and traction which is why i went with a plus tire. Not sure if going heavier with bigger tread will help but id imagine more cornering traction and better braking performance. At some pt the returns are diminishing and it varies by person's skill and terrain. Thats why its better just to try than go exactly with what others recommend although its great as a starting reference for your journey to that ultimate biking machine.

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  29. #29
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    Quote Originally Posted by Crossmaxx View Post
    Really? In wet conditions and slightly muddy/soft terrain, knobs are the s**t for clearing some of the technical climbs on my trails. It's not a substitute for technique and body positioning, but it sure as hell helps.
    Well...hopefully you won't be taking a semi slick out on a muddy ride.

    In So Cal...it's dry and dusty. At least when it comes to climbing...you can get away with pretty minimal tread for most areas. I have found that body position (when to load and unload your weight) does more for climbing traction than the type of tire you run.

  30. #30
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    Yeah. Im in san diego. I like the big corner knobs for the loose and dusty corners. Ive wiped out too many times than I'd like to admit

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