Wheel Upgrade…will I notice the difference up hills?

jimbobule wrote:

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

Where did you get those stats from?

I assure you that saving those 800 grams will not make you 1.2mph faster… Especially if you are going uphill.

If you average say 18mph, then averaging 19.2mph will require nearly 13.8% more power to overcome the extra drag (doesn’t even include the extra rolling resistance you need to overcome)… or equivalent reduction in drag. Where would generate such an impressive increase in power from? It’s certainly not from the wheels.

steve_s1 wrote:

steve_s1 wrote:

Appreciate all the comments…lot’s to consider.

Regarding the weight saving, I know it’s a small % of overall weight, but my understanding was that weight saved on wheels is more significant than elsewhere because it’s rotational mass…but my physics is a bit rusty, so not sure if this true or not!

 

Rotational mass only has an effect when accelerating when the speed of the wheel is changing; ie, when you accelerate. I once worked out the difference for a 70kg rider on a 7 kg bike accelerating from standing (no air resistance when not moving, so all power goes into acceleration, making these effects as big as they could ever be) if you took 400g off EACH rim. It came out at about 0.8%.

The only other improvement you can (theoretically) expect to see is climbing, but the fact that the weight is at the wheels doesn’t have any special effect if you’re at a constant speed, and as someone else has said, the percentage weight saving is tiny.

Your best bet, for going faster (and looking bling), is some deeper wheels. The aerodynamic benefit will help you whenever you’re moving, not just when you’re going uphill or accelerating

steve_s1 wrote:

Appreciate all the comments…lot’s to consider.

Regarding the weight saving, I know it’s a small % of overall weight, but my understanding was that weight saved on wheels is more significant than elsewhere because it’s rotational mass…but my physics is a bit rusty, so not sure if this true or not!

 

 

Rotational mass is certainly important, but mostly when you’re accelerating it by increasing your speed.  On a climb you’ll *mostly* be at a steady speed, so you won’t notice it as much as you would, say, in sprinting off the front of the pack.

Thanks PR and CRX, my top
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 🙂

alansmurphy wrote:

Plasterer’s Radio wrote:

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.

 

Do you think so? I only started using HR a year or so ago and am now a convert, speed is just an output, controlling the ability to push a much better measure. It’ll be hard to convince me to spend so much on a piece of tech, why does it make such a difference?

 

Speaking honestly, I would rather have an £1K boggo bike with a PM than a £3K bike without. 400quid or so gets you a good PM and isn’t THAT much if you ride your bike lots but people do like to see something tangible for their money. Bling wheels or Dura-Record on an otherwise mundane componant. Fast riding is largely about the ENGINE….meaning you the rider.

They are not just for racers. Audax riders, sportive riders etc can all benefit. I have. HRMs are OK but a PM offers much more.

Search power meters in youtube. DurianRider videos are funny too but he is marmite too!

alansmurphy wrote:

Plasterer’s Radio wrote:

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.

 

Do you think so? I only started using HR a year or so ago and am now a convert, speed is just an output, controlling the ability to push a much better measure. It’ll be hard to convince me to spend so much on a piece of tech, why does it make such a difference?

 

 

A power meter is a good tool, but when used with a HR they work very well together.  You learn quickly at particular heart rate you can make at a certain power figure.  This is easy to measure and see when doing indoor training with both devices.  I now only use HR when outside and so know when at a  particular HR, I’m in, lets say sweetspot zone.  Obviously seeing a power number is more accurate, but HR and feel once experienced is nearly as good and will do if you’re climbing an alpine route.

£300 will get you some pro
£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