Anything Better Than Zipp's!!??!!??
Comments
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dennisn wrote:Jeff Jones wrote:
Rotational inertia has a tiny effect on your speed. See http://www.biketechreview.com/archive/wheel_theory.htm for an explanation/experiment.rjsmith wrote:It about Inertia. Weight on the wheels makes more of a difference than the weight of a waterbottle. Each to their own of course but the lower inertial mass of a shallower rim will do hills better.
Not many people (hats off to those who do) road race by doing race long solo breaks. Most of the time you are part of a bunch, subject to various accelerations and decelerations of others. Here again, the lower inertial mass helps with this.
Don't get me wrong, I love riding aero wheels and do most of the time (English RRs tend not to be hilly enough to worry too much about rim depth), but there are times when I feel a shallower wheel will help.
He summarises: in terms of powering your bike, aero is 10 times more important than wheel mass and 100 times more important than wheel inertia.
It would appear that everyone has an answer to these questions about aero, weight, looks, etc., etc. My advice. Forget all this crap and buzzword bullsh#t. Go out and buy
a set of handbuilts with Chris King hubs, 28 spoke front, 32 rear, DT revolution spokes,
tubies would be my choice, Mavic rims, Continental Sprinter tires and ride the hell out
of them. They will last a whole lot longer and cost less than some of the stuff being
pushed on this thread as "must have", "can't win without", "most aero", 'lightest".
Go with the dependable, easy to repair, stuff. When you become a pro you will be given all these
other things.
Dennis Noward
Or you could just wait till the end of a reasoned debate, ignore everyone else's opinion and state that modern life is rubbish...0 -
Having gone through the whole post. It seems clear to me that you should get the Mavic Cosmics, cheaper and stronger than the Zipps. IMHO they are also the best looking.
Actually judging by these posts, the general opinion seems that if can have just one wheel, the Cosmics are the one. May get some myself now.0 -
aracer wrote:
If I want easy to use and repair, why tubs?dennisn wrote:tubies would be my choice...
Go with the dependable, easy to repair, stuff.
No problem for me. I use "Tufo" tape, instead of regular glue, and it's a snap.
As for flats I just don't seem to have the problems that lots of people write in about.
You know, 3 flats in a day, stuff like that. As for tires I have begun switching over to
"Tufo" tubeless tubulars and most flats(very few) that I get with them are very easy
to fix with their version of "tire slime". Even on the road. As far as "Conty Sprinters"
go I have used them for years with very few flats. If I do have flats with them I save them
up until I have 4 or 5 and send them to my parents in Florida. They live close to a guy
who opens them up, puts in a new tube, sews them back up, and only charges about 10
dollars. They make great spares and trainer tires.
Dennis Noward0 -
Still sounds like a lot more trouble than clinchers to me - you just put the tyre on and pump up, no messing about with adhesive tape, and when you get a flat just put in a new tube and its a simple home job to fix the old one. Exactly what benefit do you get that's worth that extra hassle - and how much more important is that benefit than all the benefits of light, aero wheels you're dismissing?0
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aracer wrote:Still sounds like a lot more trouble than clinchers to me - you just put the tyre on and pump up, no messing about with adhesive tape, and when you get a flat just put in a new tube and its a simple home job to fix the old one. Exactly what benefit do you get that's worth that extra hassle - and how much more important is that benefit than all the benefits of light, aero wheels you're dismissing?
As far as light goes, tubie rims are lighter than their clincher counterparts.
Aero is not even a consideration for me. Doesn't even come into play, except at
higher speeds than this old bastard can maintain, for any length of time, to make it
worthwhile. Plus I don't race. I don't use overly expensive tubies and when they flat
I try "slime" first. If that doesn't work and they have enough tread on them they go out for repair. If not it's into the trash. Truthfully I don't have that big a problem with flats but
it does seem, at least to me, that clinchers flat out more than tubies. Plus I'm old and
set in my ways. I will confess to using "Tufo" tubular clinchers at times. They work just fine. Yea, tubulars are a bit more trouble than clinchers but I've used them for so long
that I'm hooked.
Dennis Noward0 -
Jeff Jones wrote:Rotational inertia has a tiny effect on your speed. See http://www.biketechreview.com/archive/wheel_theory.htm for an explanation/experiment.
He summarises: in terms of powering your bike, aero is 10 times more important than wheel mass and 100 times more important than wheel inertia.
Sorry, but this reference is hardly reliable in itself as evidence. The guy does only two rides (since he uses one ride for the training portion and uphill part) for all his data. the sd on the figures is large as well.
The guy also say things like "Quite simply, inertial forces are a function of acceleration". Really!? Try pushing a lorry from rest and then a car from rest, with the same acceleration. See which one is most reluctant to move!
The whole paper would be ripped to shreds by any A Level Physicist.
But don't get me wrong, I agree with the (rather obvious) findings that rider aero profile, wheel aero profile and then rider weight is the order generally which one would choose wheels. But an aero wheel won't make any difference when climbing a hill at 10-15 mph. I'd rather have a lighter wheel. You don't see the Pros use their deep sections very often in the mountain stages (unless they have the aforementioned Carbonsports wheels).
I did say that most English races I would still ride deep sections anyway!
Back to the topic - the Dalkiia wheels (at about £540 a pair) look good value. 60mm rim, clinchers. Weigh about the same as Cosmics. Depends if you love or hate the transfers really.0 -
ick dalkia transfers are just a bit ming.
can't think of a bike that they would match!
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http://itgoesfasterwhenitmatches.blogspot.com/0 -
Have you actually read that page properly? He's simply using the data from his rides as typical ride profiles to enter into his equations. Given that I don't see anything wrong with what he's doing - he uses one ride for 2 lots of calculations since the whole of it approximates a typical hilly ride, and just the uphill bits approximates a hill climb. I don't see anything wrong with that for what he's doing. Of course the sd is large - that's because they are real figures from a real ride, and speed / power varies a lot, which is the whole point.rjsmith wrote:Jeff Jones wrote:Rotational inertia has a tiny effect on your speed. See http://www.biketechreview.com/archive/wheel_theory.htm for an explanation/experiment.
He summarises: in terms of powering your bike, aero is 10 times more important than wheel mass and 100 times more important than wheel inertia.
Sorry, but this reference is hardly reliable in itself as evidence. The guy does only two rides (since he uses one ride for the training portion and uphill part) for all his data. the sd on the figures is large as well.
I presume that A level physicist wouldn't be you, since you seem not to have heard of F=maThe guy also say things like "Quite simply, inertial forces are a function of acceleration". Really!? Try pushing a lorry from rest and then a car from rest, with the same acceleration. See which one is most reluctant to move!
The whole paper would be ripped to shreds by any A Level Physicist.
Now that's where you're wrong. Since aero drag is proportional to the cube of speed, to convert from the 50kph figures in http://www.rouesartisanales.com/article-15505311.html to 15mph/10mph, simply divide by 9 or 30 (50/24 cubed or 50/16 cubed). That gives 1.9/0.5W of drag for the 808 (the most aero), 2.7/0.8 of drag for the LW Obermayer (the lightest) and 3.9/1.1W of drag for the R-Sys (the least aero). Not much difference admittedly, but now lets look at the difference a light wheel makes. Weights are ~700g for the 808, ~450g for the LW, ~600g for the R-Sys. Now if we're climbing at 20m a minute (which is quite a rate, particularly at 15mph), the power requirements for lifting the wheels are 2.3W 808, 1.5W LW, 2.0W R-Sys. Add them together and you get 4.2/2.8W for the 808, 4.2/2.3W for the LW, 5.9/3.1W for the R-Sys for aero and gravity. So the heaviest and most aero 808 is the joint fastest at 15mph, and still faster than the R-Sys at 10mph!But an aero wheel won't make any difference when climbing a hill at 10-15 mph. I'd rather have a lighter wheel.0 -
Hey aracer, totally respect your opinion mate. Your are basing your aguements on cycling up a hill in velodrome conditions with no real world factors such as the many repeated accelerations (who pedals supersmooth or with no sidewinds etc etc). I'm sorry but I am not riding double disk wheels uphill whatever you say.
Yes, you are right, I am not an A level Physics student. But with my Physics degrees I've just been teaching them for 15 years and road racing for more than that. So maybe you could argue without insults, like the way a good forum should be? Disagree by all means, but don't lower yourself mate.0 -
Not at all - the wheel aero figures I'm using are based on a variety of wind angles, so account for crosswinds. In any case, given the 808 performs even better relatively in crosswinds than it does in a head wind - to the point it almost sails itself along - a crosswind wouild only increase it's advantage over the lighter non-aero wheels. Also acceleration has much less effect than people seem to think on cycling performance. For example if you accelerate from 9mph (4m/s) to 13.5mph (6m/s) once every two minutes (which is a huge amount of acceleration), for a 700g wheel with a 400g rim that's only an additional 0.09W average required for the acceleration - though of course that was all covered in the paper you seem to be dismissing as incorrect. If you're just concerned about accelerations due to varying pedalling rather than the slope changing though, the heavier wheel actually has an advantage since it will smooth out the changes in speed!rjsmith wrote:Hey aracer, totally respect your opinion mate. Your are basing your aguements on cycling up a hill in velodrome conditions with no real world factors such as the many repeated accelerations (who pedals supersmooth or with no sidewinds etc etc).
Sorry - are you taking my suggestion that you haven't heard of F=ma as an insult - I certainly wasn't intending to insult you? I presume as a physics graduate you are well aware of it, in which case you do realise that in that equation the force is a function of acceleration just as he says? I'm kind of surprised that with your background you don't understand the point he is making with that statement, which is completely correct. Meanwhile I can't see any other incorrect physics in that paper, for all your claims about it being ripped to shreds.Yes, you are right, I am not an A level Physics student. But with my Physics degrees I've just been teaching them for 15 years and road racing for more than that. So maybe you could argue without insults, like the way a good forum should be? Disagree by all means, but don't lower yourself mate.0 -
Wait a minute. Sex is better than Zipps.
Dennis Noward0 -
