Reducing front wheel weight

[mattobrien]

I think that @Justinslow has hit the nail on the head regarding spinning weight, the less weight the easier it is to spin.

It is correct that a heavy spinning weight will help maintain momentum when power ceases to be applied, but I for one don't cease to apply power. The only time I do that is when I want to slow i.e. brake for a corner, and as a light weight is easier to slow due to lack of momentum then I want light wheels. They are easier to spin up and easier to slow down.

I agree that holding a speed is regardless of weight and that is why aero is more important than weight for a TT bike. But seeing as much of my riding is not in a TT style I'll opt for as light wheels as I can afford as well as reducing the weight of everything else too.

And to declare an interest, I have mid depth, light wheels. Could go light for a shallower depth, but prefer the look of the bike as it is. Would possibly like slightly deeper rims, for aesthetics, but they are made currently by my chosen rim manufacturer.

 

[Tenacious Sloth]

It must be frustrating being @Yellow Saddle, knowing everything, but being surrounded by dopes and duffers like us.

There is a lot of thruth in this, although I suspect it is meant tongue in cheek.

Personally, I value having people like YS on the forum as he has probably forgotten more about bicycles than most of us will ever know, a lot of it gained through personal experience.

My somewhat limited experience of the relative merits of different wheels tells me that shaving a kilo off the weight of my wheelset (this included much lighter tyres) definitely made a big difference to my ability to go up hills. Much more of a difference than carrying a kilo less in my seat bag. This may or may not be backed up by physics but to me it made the investment in new wheels worthwhile, as struggling up steep hills can really take the shine off a ride, particularly a group one.

There are a few too many shrinking violets on this Forum and this thread is starting to develop a "school playground" vibe. Let's just all man-up and keep on track.

And please, no more "will these wheels make me faster" threads for a while.

Let's use the search function.



Graham

 

[Justinslow]

I think that @Justinslow has hit the nail on the head regarding spinning weight, the less weight the easier it is to spin.

Thanks for the credit, but I don't think it was me making such grand claims for "spinning" weight!

I think my main point is- yes if you are a "performance" cyclist- lighter better kit will make you quicker, assuming you don't always ride on pan flat surfaces!
If you can't exploit the lightweight kit because you are not fit enough or your power to weight ratio is poor then it will make tiny improvements at best.

Getting fit and training properly will in my opinion reap the best rewards (obviously) but better/lighter kit helps along the way.

 

[shouldbeinbed]

Why do Bromptons accelerate so quickly?

The awesomeness of the rider that picked the nippy wee beast

 

[shouldbeinbed]

Do they?

Surprisingly so for their appearance and appreciably so vs the other folders I own(ed) at the same time and with the same lump/engine/whatever I am powering them.

 

[Justinslow]

By the way anyone see the gadget show last night, £600 Allez v £6000 custom built Venge. Conclusive proof.

 

[Tenacious Sloth]

Why do Bromptons accelerate so quickly?

Is it because they have smaller diameter wheels and so would have less inertia to overcome?

[Dons tin hat and waits to be blinded by science]

Graham

 

[winjim]

I think a lot of what people report as faster acceleration might come down to the instantaneous feel of the bike, if that makes sense. So when I stand on the pedals on my light bike, I feel the bike surge forward from underneath me. Of course inertia is preventing my body mass from accelerating at the same rate so half a second or so later I have to drag myself forward to catch up with the bike so to speak, but I don't really account for that in the "feel" of the bike. On my heavy bike, it doesn't leap away from me so quickly, so there's no lag between the bike accelerating and my body mass accelerating.

So on my light bike it feels like I'm accelerating 8kg, on my heavy bike it feels like I'm accelerating 75kg. So it feels like a big difference when in fact it's not.

 

[Profpointy]

in fairness to YS 80%+ of what he says is actually spot on!

 

[Justinslow]

in fairness to YS 80%+ of what he says is actually spot on!

Which is why I tagged him in on the thread, it's a shame about the other 20%..........

 

[PhilDawson8270]

I think YS is correct in this thread, but I think his presentation of his arguments are a bit unclear.

Rotating mass has further benefit in reduction than just weight saving. Ability to spin up, etc. However, when coasting, the lighter wheel will also slow down quicker.

Saving weight obviously will have performance benefits, I don't think that can be disputed. Same power with less weight will accelerate quicker, and make it easier to climb, but it will descend slower too.

I think the point @Yellow Saddle is trying to make is that the difference is going to be negligible for the majority. Of course, pro's will want to save as much as weight as they can on the bicycle, as they are pretty damn light themselves. Unless you're extremely slim, what's the point in spending £xxxx on reducing 400g on a wheel. When you could lose 1kg of bodyweight for free, and get the same net effect.

Of course, if somebody wants a new wheel, it's their money. They can buy what they like. Hell, I've bought plenty of stuff that I didn't need, but I wanted. Doesn't mean it's technically the "correct" choice for performance.

Same as aero, what's the point in deep dish aero wheels, unless the rider has already done everything they can to minimise their own drag. Correcting your body posture will give a bigger benefit than deep dish wheels.

If you have a 90kg rider, saving 500g on a wheel isn't likely to be of a significant performance increase unless covering large distances. The OP says he's a newbie, if he is a newbie to cycling or the forum, it is unclear. However, for most of us, 500g can be saved for free, the performance gain can be made by training, for free.

Obviously reducing mass will increase performance, silly to say otherwise. But it's not the best option, nor the biggest net gains, until the rider (the biggest source of mass, and drag) are addressed.

 

[User6179]

I think that @Justinslow has hit the nail on the head regarding spinning weight, the less weight the easier it is to spin.

I agree but most of the weight saving on expensive wheels is at the hub , not at the rim where it matters , take Mavic Open Pro verses Mavic Ksyrium Elite, you only save about 30 grams per rim .

 

[PhilDawson8270]

Let me try again.

Weight that is not engine - is one of the better places to look at reducing weight.

With the human engine, one can get to the point of power loss when trying to reduce weight. Anorexia is an extreme example. Feeling weak below a certain weight is more common. There are some skinny riders that are not that good going uphill or in the flats and I would probably be one of them.

One of the best places to look at reducing weight, is in the components that carry the most of it. It's easier to save 2kg on something that weighs 90kg, than save 2kg on something that weighs 4kg

 

[PhilDawson8270]

F1 cars follow the same laws of physics as a bike. Therefore it is reasonable to use them as an example. However, if you don't like comparing to F1 cars, then why not road cars. Arial Atoms are faster than all cars with comparable power. Their reduced weight being the key difference.

F1 cars, at high speeds weigh more than my Honda Civic. If you could stick an F1 car on a scale while it is traveling at top speed, you'd expect to see closer to around 2200kg (vs it's static mass of 790kg ish)

 

[Tanis8472]

No they don't