Wheel Upgrade...will I notice the difference up hills?

I've got 2 sets of wheels for one of my bikes, a set of Bontrager Race that I use for commuting and winter training and a set of Race X-Lites that I use as "best" wheels.

The Race X-lites are also around 400g lighter (iirc) than the Race - I've no idea how much of that is a saving in the rim or in the hub, though,

In practice, the RXLs spin up much quicker than the Rs when getting away from junctions and so on and "feel" much quicker overall, but there's also other factors at work, such as newer bearings and racier tyres on the RXLs.

Simple answer: Yes, but it may be all in the mind. I upgraded recently and notice the difference, it may be only perceived and not real but it's there all the same.

I went from a 2.1Kg set to 1.6Kg. I noticed the difference in acceleration when trying to put a bit of pace back into a climb, usually around the 7-8 minute mark... So I get marginally quicker times, probably as much because I feel the reward at those brief moments of acceleration and psychologically that helps keep me +ve over the duration of a 15-20 minute climb. I am still piss poor at climbing compared to many of the local club riders though! But that's fine, I am no racer.

I am a real wheel-whore and love expensive wheels, but in reality they don't make much difference.

The thing with lighter wheels accelerating  quicker is that they also decelerate more quickly, a heavier wheel will hold onto that speed for longer, so it is all swings-and-roundabouts. That feeling of a lighter wheel being more nippy is real but very insignificant in the context of a whole ride.

Lighter wheels and tyres certianly make a bike feel faster, almost certainly because they accelerate better. How much this equates to in reality I don't know but there's nothing like the feel of a good set of wheels/tyres. I remember when I built myself a set of tubular wheels back in the 80s. The difference in feel of my bike with those wheels over my stock 700cs with 23mm tyres was very noticeable both in terms of speed and ride quality. I suspect that now as rim and tyre technology have improved that the differences are less. However I do like to keep wheels and tyres as light as is reasonble. My personal preference for tyres is GP4000s 25s and my winter bike has a set of Ulteegra wheels (1600g) and my summer bike at set DT Swiss wheels (1400g). Don't forget to experiment with tyre pressures. Experience has taught me that on the sort of roads I ride on it is easy to over-inflate tyres to the point where the ride becomes harsh and slower. Get the pressures right and the bike glides over the road surface. I weigh around 70 kg and generally run my tyres at around 60/70 psi front/rear.

I swapped out some DT's for a pair of Racing 3's. The Fulcrums were marginally heavier but felt way better on the road due to the stiffness. You could even say a bit harsh but I'll take that in return for performance.

So maybe weight isn't the big issue,but I've been riding a bike that's had a 2kg and 1.6kg wheelset on it. It is definitely slower and harder work uphill with the heavier wheelset.

I know its claimed that the lower weight really only counts on acceleration but cyclists do accelerate quite frequently on climbs .

New bits make you go faster, new, shiny bits even faster and new, shiny, expensive bits make you go faster still.  If you can always upgrade.  She deserves it.

I think some physics revision is needed...

Rotational mass and iniertia are insignificant!

http://www.biketechreview.com/reviews/wheels/63-wheel-performance

http://road.cc/content/feature/194441-cycling-myths-busted-da-vinci-dead...

Rotational mass and inertia are only of any significance when accelerating very quickly (like a sprint from standing start). Once you start moving above about 15mph then aerodynamics is by far the most important factor.

Even on climbs, weight isn't as important as it is made out to be. Yes, when you are going slowly, on a steep gradient, weight is more important than aerodynamics. But, as soon as it gets flatter or you are moving quickly, then aerodynamics is back to being the dominant force.

Losing weight off the bike isn't very important, in terms of physics  (however, I do agree it can make a bike feel better). If you weigh 75kg and have a 10kg bike losing 500 grams off the bike has a 0.5% reduction on total weight.

Just switching from riding on the hoods to the drops can give a reduction of 0.02 in CdA, which would be a reduction of aerodynamic drag by around 6% (this would be around 0.5mph increase at 190 watts).

So, whilst I agree that some super lightweight wheels will save you a few seconds on a hill climb, just switching from hoods to drops can increase your speed by 0.5mph over your entire ride.

If you really want to get faster, get flexible, get low.

As I said right at the beginning though, Campag Zondas are a lovely lightweight set of wheels that look awesome too! They "felt" better when I upgraded to them - I won't suggest they will make any significant time gains though Fulcrums are nice too.

I would suggest that your faster times are due to 5% weight and 95% improved rolling resistance/aerodynamics.

400g wheel weight difference = 0.7 mph average speed gain over 30 miles and 1 "extra" gear

400g tyre weight reduction = another 0.5mph average speed gain over 30 miles and 1 "extra" gear

So yes, reducing rotational mass has a noticeable effect. Buy cheaper lighter wheels if you can. I got some Prime wheels...good so far

Try spinning a wheel with your hand. Pretty easy, isn't it. Rotational inertia is fairly minimal, you won't be saving much.
Much as it's nice to save a bit of weight, half a kilo really won't make much difference, generally. But something a bit more aero will, you won't really notice it, but you might realise you go a little faster in Strava segments? Aero wheels will probably be about the same weight as what you were looking to purchase anyway.

I bought an RS11 wheelset for £80 and a set of RS31 with 30mm depth rims for a litle over £100, both have different bladed spokes (RS11 seems more aerofoil shaped, RS31 spokes seem flat and square-edged). Bargain wheels but I've never used either set in over 3 years, after lots of researching I realised spending a bit more on aero wheels was much wiser. I'll probably keep the RS31 for the cheaper carbon bike when the RS501 go in the bin or onto the cheap Longforme Alu frame and carbon fork bought for just over £100.

I choose "free speed" all day long, unless you traverse mountains on a daily basis?

I've not seen any aero tests but OVAL wheels look fairly aero, they might be affordable. Otherwise I recommend importing a couple of FLO30 wheels. $498. Postage and import duty really add to the price though.
http://www.flocycling.com/wheels_rear_flo_30.php

Thanks PR and CRX, my top machine is £1800 worth sourced at a third of that hence my thoughts on what I'd spend on a gadget.

The HR made an unbelievable difference to my MV training and taught me a lot. How long I could work in which zone, what gradient tends to put me there etc. Allowed me massively to pace the giant and even since I've pretty much ignore the speed and average speed, I work on whether I've spent the time.

My smart(ish) turbo has calculated power so I might start having a play, with cheapening tech a one arm pm may start to drop to 'acceptable' levels

weight before = 70kg + 8.1kg = 78.1kg

weight after = 70kg = 7.7kg = 77.7kg

percentage saving = 0.512%

actual effect = marginal

placebo effect = priceless

The gains are minimal, but if you want better looking wheels and don't mind splashing the cash, go for it!

£300 will get you some pro-lite Bortola wheels (17.3mm internal), or a set of DT Swiss 370 straight pull (28/24) mounted to DT swiss 460 rims (18mm internal) shimano variant is 1620g.
Less weight will make a difference but it's often difficult to notice how much, better tyres, change in pressures, better bearings can all add a little, marginal gains and all that.
And all defeated because the wind changed direction.lol

I went from RS010s to the Zonda C17s, I did notice a difference, improved times up hills and no stopping half way up some pretty steep ones. Could all be in the mind though! You will notice the difference in when you select your usual low gear and you end up lifting the front wheel off the road! They also give a slight buzz which is always enjoyable to hear. 

I’m just under 90kg, have done a around  1000 miles on them with no problems. My choice was between them and the Fulcrums too, but the Zonda’s looked classier and I know a few people who have had problems with the Fulcrum hubs. 

I don't know if you will feel any difference.  If you forget your water bottle one day, does the ride feel any different?  As others have said, the way the more expensive wheels are bit and what they are made from may have more effect in what you feel. 

I switched from some stock alloy wheels to carbon and then back to these https://www.cycledivision.co.uk/cero-ar30-evo-wheelset-2100 they were the same weight as my carbon wheels, same depth, tubless compatible and better braking!

Tbh, you won't notice a MASSIVE difference uphill - really that's down to raw power.-correct

Work out the 400g saving in percentage terms of your weight + the bikes overall weight, that will give you an indication of how much you'll notice the difference.

Now, the placebo affect will be enormous because you've spent some money on upgrading.

No, you won't notice a difference that is due to the weight. You may notice other improvements though.

No, It's rhetoric. The benefits are small.

Spend the cash on a power meter instead. WAY more useful.

On a long climb (30 mins plus) wheels may save seconds.

The power meter can save you MINUTES.