Best lightweight climbing clinchers?

singleton

ugo.santalucia wrote:

I blame the aero brigade, mainly led by the British school of thought that is all about the aerodynamics. You go on an Italian forum and it's all about the weight.

It's also the tri folks who focus on aero.

I've done a number of trithlons and there is a huge focus on aerodynamics there. Most tri's are non drafting and you need to keep something back for the run - so aero is preceived as the easiest way to get free speed unless it's very hilly.

darkhairedlord

a quick calc shows that accelerating from 15-20 kmh with rim/tyre combination lets say 0.5kg lighter will require 3 Joules of energy less than the heavier pair. Accelerating the bike and rider of say 80kg all up will require 540 Joules not including rolling resistance, aero effects etc. So on the whole it doesn't make much difference but it does FEEL different, especially out of the saddle.

cmcdonnell

If in doubt you won't go far wrong with campagnolo neutrons. Mine are bombproof, reasonably light and great braking. Shamals are better still but a bit pricier. Never got in with Mavics, can't put a finger on it but have sold every set I ever bought. No issues with my Bora 50c's on descents but not ridden them in the wet. I kinda fancy some Bora 35c's for climbing. Some rave over the Hyperions but I've never tried them.

meanredspider

ugo.santalucia wrote:

how come it is easier to cycle at 10 mph in a 20 mph head wind than it is to cycle at 30 mph in zero wind?

That one's pretty easy: a 20mph head wind isn't 20mph over the whole of your bike and body - the wind speed will be much lower near the ground. When you're travelling at 30mph, that's 30mph over your whole body and bike.

Weather report wind speed is measured at 10m

Reference FYI: http://belfortinstrument.com/height-win ... ts-ground/

In fact - if the weather is reporting 20mph, in open ground you're only seeing around 14mph on your body and less still near your feet.

Riding with a power meter is really interesting from an aero point of view - seeing how much it drops when you suck somebody's wheel (to about 80% or less) and how much more it drops when following a small bunch (say 6 riders) (70% in rough numbers) at around 20mph.

Riding for a couple of years in N Holland has made me far more aero aware. Flat and often zero natural cover, you're exposed completely to the effects of the air.

Where weight is painful is where you lose the kinetic or potential energy you have to put into the system. Going up hill you're putting energy into kinetic energy which you mostly get back in the inertia. The potential energy doesn't get fully paid back though because you lose it aero losses on the higher speed descent or in braking for corners.

ugo.santalucia

meanredspider wrote:

ugo.santalucia wrote:

how come it is easier to cycle at 10 mph in a 20 mph head wind than it is to cycle at 30 mph in zero wind?

That one's pretty easy: a 20mph head wind isn't 20mph over the whole of your bike and body - the wind speed will be much lower near the ground. When you're travelling at 30mph, that's 30mph over your whole body and bike.

Weather report wind speed is measured at 10m

Reference FYI: http://belfortinstrument.com/height-win ... ts-ground/

In fact - if the weather is reporting 20mph, in open ground you're only seeing around 14mph on your body and less still near your feet.

Riding with a power meter is really interesting from an aero point of view - seeing how much it drops when you suck somebody's wheel (to about 80% or less) and how much more it drops when following a small bunch (say 6 riders) (70% in rough numbers) at around 20mph.

Riding for a couple of years in N Holland has made me far more aero aware. Flat and often zero natural cover, you're exposed completely to the effects of the air.

Where weight is painful is where you lose the kinetic or potential energy you have to put into the system. Going up hill you're putting energy into kinetic energy which you mostly get back in the inertia. The potential energy doesn't get fully paid back though because you lose it aero losses on the higher speed descent or in braking for corners.

OK, how do you explain that riding at 20mph in no wind is more effort than looking at your bike from the window of the cafe' when it's blowing 20 mph of real wind?
It'a paradox of course, but the point is that the 90% figure is a number like another... it can be 10, it can be 60 and it can EVEN be 90%... but it's never always 90% as the aero brigade wants you to believe.

And why a 3 mph head wind doesn't slow you of 3 mph (or should I say 2.7 mph)?

meanredspider

ugo.santalucia wrote:

OK, how do you explain that riding at 20mph in no wind is more effort than looking at your bike from the window of the cafe' when it's blowing 20 mph of real wind?
It'a paradox of course, but the point is that the 90% figure is a number like another... it can be 10, it can be 60 and it can EVEN be 90%... but it's never always 90% as the aero brigade wants you to believe.

And why a 3 mph head wind doesn't slow you of 3 mph (or should I say 2.7 mph)?

I think the second one is easier to answer: you just put more effort in and use up more energy. I always find a power meter more inspiring in wind because, as you're head down and ploughing forward and only seeing 12mph on your speedo, you feel happier if the PM says 300W.

Agree though, it's never always 90%

ugo.santalucia

meanredspider wrote:

I think the second one is easier to answer: you just put more effort in and use up more energy. I always find a power meter more inspiring in wind because, as you're head down and ploughing forward and only seeing 12mph on your speedo, you feel happier if the PM says 300W.

Agree though, it's never always 90%

To achieve an axtra 3 mph average you need more than just more effort.
The fact that aerodynamics work with the cube of speed and other forces don't already tell you it cannot always be 90%. I think most calculations are based on unrealistic average speed, like 20-30 mph.
I know with Strava everybody is a hero these days, but the real average (which is the distance from A to B divided by the time your watch says it took you to get there) is hardly more than 15-16 for the vast majority of people

Grill

My watt savings as a result of decreased CdA are measured at 30mph.

In regards to wheels, I climbed just as fast with my 1690g Aero 72's as I do with my 1430g Enve 4.5's.

Weight just isn't a big deal unless you're at the sharp end of the stick or competing in HC's.

pblakeney

Grill wrote:

My watt savings as a result of decreased CdA are measured at 30mph.

In regards to wheels, I climbed just as fast with my 1690g Aero 72's as I do with my 1430g Enve 4.5's.

Weight just isn't a big deal unless you're at the sharp end of the stick or competing in HC's.

The best advice from what I have read so far is........
Spend the money on a cycle holiday for training instead. 8)

ugo.santalucia

PBlakeney wrote:

Grill wrote:

My watt savings as a result of decreased CdA are measured at 30mph.

In regards to wheels, I climbed just as fast with my 1690g Aero 72's as I do with my 1430g Enve 4.5's.

Weight just isn't a big deal unless you're at the sharp end of the stick or competing in HC's.

The best advice from what I have read so far is........
Spend the money on a cycle holiday for training instead. 8)

Indeed...

Weight savings matter when they are significant, like everything... 200 grams are not a lot in the grand scheme of things

singleton

ugo.santalucia wrote:

Indeed...

Weight savings matter when they are significant, like everything... 200 grams are not a lot in the grand scheme of things

Yes, but assuming that someone already has a bike, then saving 1kg on your overall build involves saving 200g in multiple different places.

FatTed

Ugo You say stay away from carbon clinchers, is that just for rim brakes or disc brakes as well?

ugo.santalucia

FatTed wrote:

Ugo You say stay away from carbon clinchers, is that just for rim brakes or disc brakes as well?

I just said that carbon is not an everyday choice for riding in the mountains, because it might not brake as well... if you have disc brakes, no such problem