preview: Al33 kickstarter launch (new 33mm deep toroidal shaped aluminum rims (465gram) + wheels)

[Tomstr]

Do you have a link by any chance?

[jlaitinen]

Here's a link to the blog. Seems that the AL33's best Zipp 303's in most yaw's http://www.novemberbicycles.com/blog/2017/2/9/wind-tunnel-testing-the-al33-xr31tfsw3-and-other-alloys.html

[glepore]

At low yaw, not just the Al33 but also the Kinlin. Given the superior braking, I see a pair of these in my future.

[Kurets]

Where will these rims be available as rim only?

[Svetty]

Unless or until these are widely available from regular production runs - and not low number pre-production 'specials' - they remain vapourware to all intents and purposes IMO.....

[mpulsiv]

For those of you that still haven't seen the numbers from the wind tunnel. There's a delta of ~ 3 watts of drag at 10 degrees of yaw angle between Zipp 303 and Al33. "10g of drag roughly equals 1 watt, and 1 watt roughly equals 3 seconds in the mythical 40k. Not good enough for real science, but good enough to become a hyper-aware wheel consumer." Do you really need $2000 Zipp 303 wheels when Al33 would do? We are talking about ~0.3 watts (at 10 degrees of yaw angle) and ~0.1 watt (at 10 degrees of yaw angle). In 40k, this roughly translates to ~1.5 seconds. Am I missing something here?

Source http://www.novemberbicycles.com/blog/20 ... lloys.html
FLO claims that 80 percent of the time cyclists experience between zero and 10 degrees of yaw. Source http://flocycling.blogspot.com/2016/03/ ... tep-2.html

[antonioiglesius]

I have a dumb question: the Zipp 303 rim is 45mm, while the Al33 is 33mm? Taking this into account, in terms of aerodynamics, the Zipp is substantially better than the Al33? And my impression is that rim widths of around 30mm and below are not normally considered aero in the sense that we don't think about using them when we have long flat straight routes? 30mm is more in the realm of climbing wheels?

(Later) Sorry, I had cross-wind effects on deeper rims at the back of my mind which led me to think the 45mm Zipp was doing well in spite of its greater depth. Which doesn't make sense in this case.

[AJS914]

I have a dumb question: the Zipp 303 rim is 45mm, while the Al33 is 33mm? Taking this into account, in terms of aerodynamics, the Zipp is substantially better than the Al33? And my impression is that rim widths of around 30mm and below are not normally considered aero in the sense that we don't think about using them when we have long flat straight routes? 30mm is more in the realm of climbing wheels?

If you believe the chart (I do), the 303 isn't much better. Factor in the fact that 85% of our riding is between 0 and 5 degrees of yaw where the 303 doesn't provide much benefit at all. Forget the Ai33, between 0 and 5 degrees none of these wheels are that much better than each other.

To sum it up, for my own riding, I don't need the extra 1.5 seconds (40K TT, 30mph) so I'll keep my money in my pocket.

[mpulsiv]

I have a dumb question: the Zipp 303 rim is 45mm, while the Al33 is 33mm? Taking this into account, in terms of aerodynamics, the Zipp is substantially better than the Al33? And my impression is that rim widths of around 30mm and below are not normally considered aero in the sense that we don't think about using them when we have long flat straight routes? 30mm is more in the realm of climbing wheels?

(Later) Sorry, I had cross-wind effects on deeper rims at the back of my mind which led me to think the 45mm Zipp was doing well in spite of its greater depth. Which doesn't make sense in this case.

Depth is no longer the pivot point, ever since FLO 30 was released. Back in 2013, if I'm not mistaken. It's all about the rim profile. This is not the first wind tunnel chart where well designed 30mm aluminum wheel perform that well. There are 3 wheelsets between $500-$750 (Aforce Al33, FLO30, Boyd Altamont) to give someone (Zipp) run for their money.

[thp]

They supposedly have finished some builds for customers. Hopefully its for someone here so we can get real evidence these exists.

[nobuseri]

As soon as I get mine, I will post some weights/pics.

[Ltyarbro42]

Just thought I'd let you guys know they have these over at Prowheelbuilder now. Right on time after I gave up waiting and bought another set

[antonioiglesius]

[bm0p700f]

So the even cheaper Kinlin is even better at yaw under 7 degrees I'll stick with those then. It is possible the design of 30mm ish deep rims has been optimised and there are no more gains to be had.

It is obvious when moving at a normal pace your yaw angle is going to be low most of the time so the Kinlin rim wins. Therefore the AL33 will win on really windy days where you probably wont venture out side anyway and if you did you would not worry about speed but will make an extra effort in staying upright.

[glepore]

Yes but the Kinlin lacks the ceramic brake track....


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