26 replies to this topic

[marinhousehold]

I am thinking of buying racing wheels as a christmas present to my self.
what should I be looking for? and how much do they really help?
any help would be appreciated.

[Plazbot]

Before I get on my high horse can we get a tad more info?

Male/Female?
Race distances?
You going to Kona?
Budget?
Weight? (ballpark)
Clincher or tubular?

[rohan]

Plazbot, on Dec 15 2008, 10:16 PM, said:

Before I get on my high horse can we get a tad more info?

no, why don't you just ride in on the horse and ask questions later.
-----
now for my high-horse... i am skeptical of the claimed benefits of gear.

my favorite example is this....
http://www.nytro.com...cles.asp?ID=119
now if i extrapolate those results out to 90.1km and apply it to my case, then if i had all the right bits they mention i could beat mitch anderson on the bike leg of a half ironman. (in the same race i have ridden 20 mins slower than mitch who had the fastest bike time of the day).

this is despite me being just an OK cyclist and only riding 175km per week average in the lead in to the event, and him being a pro athlete.

hijack over.

[Plazbot]

That is a prettty disappointing list and very irresponsibly misleading for them to have on their web site. I wont go into anything more than to say that drag is not linear.

For some general on topic stuff though, I think the things to focus on the most are spokes and tyre/tube combos. All tyres are not created equal and that is where the vast amount of savings are to be made by many. Most wheel tests play around with their results based on yaw angles of 10-15 degrees. Even the Zipp tests have all of their wheels in zero wind testing pretty close to the same. What is consistent though is that your spokes are smashing into the wind pretty quickly and a thin bladed spoke with be the faster option.

Tyres
http://www.biketechr...FM_tire_crr.htm

Drag
http://www.zipp.com/_media/pdfs/technology...onary_speed.pdf
page 3 is the graph I was talking about with the yaw angles.


Helmets
http://www.bikeradar.com/road/news/article...URCE=BRROADHOME

[miners]

supporting Plaz's info (and yes it's been done to death both at Trannies and at Twits), but the aero helmet is going to give you the best advantage for your $ if you're looking at speed.

But everyone loves race wheels. Forget about whether they'll improve your speed or not, it's all about looking good and generating that thrumming sound you can feel in the bottom of your belly when you accelerate out of a corner.

For the most part, one deep-dish wheel won't be any faster than another. Often it does come down to tyre/hub choice in providing any sort of difference. So in what to pick - Zipp are most popular, but expensive. Corimas also expensive. You can get HEDs, Eastons, and American Classics a little cheaper. There's a heap of re-badged wheels that come out of the same Taiwanese factory at variously cheaper prices than these.

A few mates up here are currently riding on these XLR8, which appear to be some of the cheapest of the deals going round.

Edited by miners, 16 December 2008 - 10:54 AM.

[JustinS007]

rohan, on Dec 16 2008, 10:19 AM, said:

i am skeptical of the claimed benefits of gear.

Amen.

Unless the 'rider' is already as aerobically fit and as lean as they can ever be then I think it's a heck of a lot easier to do a bit more training and lose 1kg. In fact the 1kg weight loss alone will probably do more for time than aero wheels that are 250g lighter than what's already in place.

J.

[Plazbot]

Triathlon is a running race anyway.

[miners]

I take Rohan's point in that the advertising spin is ridiculous - I've always thought Oakley and Nike were some of the worst perpetrators of this, but Zipp are right up there

but the point is, race wheels won't make you slower. There will certainly be a difference - much the same as there'll be a difference if you lose a kg, or if you improve your bike position, or wear tight-fitting lycra .v. a cotton t-shirt.

Race wheels look better, they sound better - and really that's all that matters, particularly at Christmas time

[rohan]

miners, on Dec 16 2008, 04:02 AM, said:

Race wheels look better, they sound better - and really that's all that matters, particularly at Christmas time

but most importantly, make sure you get the stickers on them that match your bike color scheme.

[miners]

rohan, on Dec 16 2008, 01:22 PM, said:

but most importantly, make sure you get the stickers on them that match your bike color scheme.

yes, a common mistake

also try to get reasonably compatible fonts for the frame and wheel graphics

here's one example where some bloke has made a more than half-decent attempt (courtesy of someone from trannies at one point or another)



And your army-surplus bike would equally qualify I think Rohan

[JustinS007]

miners, on Dec 16 2008, 02:57 PM, said:

here's one example where some bloke has made a more than half-decent attempt (courtesy of someone from trannies at one point or another)

I reckon the 5'6" owner that weighs 96kg has over capitalised here, but never-the-less that IS a trick looking ride!

J.

[thomo]

rohan, on Dec 16 2008, 02:22 PM, said:

but most importantly, make sure you get the stickers on them that match your bike color scheme.

miners, on Dec 16 2008, 02:57 PM, said:

yes, a common mistake

also try to get reasonably compatible fonts for the frame and wheel graphics

here's one example where some bloke has made a more than half-decent attempt (courtesy of someone from trannies at one point or another)



And your army-surplus bike would equally qualify I think Rohan

Here you go.

[Colin]

rohan, on Dec 16 2008, 10:19 AM, said:

my favorite example is this....
http://www.nytro.com...cles.asp?ID=119
now if i extrapolate those results out to 90.1km and apply it to my case, then if i had all the right bits they mention i could beat mitch anderson on the bike leg of a half ironman. (in the same race i have ridden 20 mins slower than mitch who had the fastest bike time of the day).

this is despite me being just an OK cyclist and only riding 175km per week average in the lead in to the event, and him being a pro athlete.

45min of difference may require double the power output, so the 20min of difference is not really that close mate.

Your other misinterpretation here is that you can add all the time savings....they don't make that clear, but you can't, otherwise theoretically you could have many saving factors at a certain speed that would give you zero total time, perhaps even negative

Plazbot, on Dec 16 2008, 11:24 AM, said:

That is a prettty disappointing list and very irresponsibly misleading for them to have on their web site. I wont go into anything more than to say that drag is not linear.

Actually that is quite a good list...nothing wrong with it. They also make it quite clear that drag is proportional to square of speed. See below:

"How Important Is Aerodynamics Vs. Weight


To understand how important aerodynamics is to bicycling you must understand the relationship between speed and drag. The faster you go the more drag you create. However to travel twice as fast the drag is not simply doubled, it is quadrupled because drag follows a square law. So, if you go 3 times as fast you create 9 times as much drag.
How does all this theory really apply to cycling?

The power required for the average size (5' 9") person to:

maintain 20 mph = 1/4 hp or 186.5 Watts.
maintain 26 mph = 1/2 hp or 373 Watts.

As you can see it takes twice as much energy to go only 6 mph faster. "

JustinS007, on Dec 16 2008, 12:32 PM, said:

In fact the 1kg weight loss alone will probably do more for time than aero wheels that are 250g lighter than what's already in place.

Not sure how you know that is "fact", unless you have tested it. My 'guess' is that 250g off the wheel is more effective than 1kg (or even more) off the body on a flat fast course, because the latter is static weight whilst the former has inertia, meaning that you constantly have to apply force to it. In the absence of inclines and other resistance dependent on weight, additional static weight requires no more energy to keep a constant speed once you have accelerated, whilst heavier wheels will require more than lighter wheels.

On a flat course the bigger muscled , stronger riders will go faster if the aero drag is same as weaker , lighter rider.

On a hilly course, the lack of weight (static and dynamic) will play in favour of lighter rider with the drag being less of a factor too.


At the end of the day, the wheels will make a difference, less so if you are a slower rider, but the original poster is still none the wiser after much technical debate.

[rohan]

Colin, on Dec 16 2008, 06:32 AM, said:

45min of difference may require double the power output, so the 20min of difference is not really that close mate.

Your other misinterpretation here is that you can add all the time savings....they don't make that clear, but you can't, otherwise theoretically you could have many saving factors at a certain speed that would give you zero total time, perhaps even negative

not sure where your 45mins difference comes from?

my point is that my 20min time difference over 90km is a world away from pro. (2;06-mitch vs 2;26-me for 90.1km)

yet, the nytro site does add all the time savings (note the 10;55, possible saving over 40km listed at the bottom of the table)... so that's not a misinterpretation on my part. it's their poor logic.

my point is, if i follow the spin (BS) on their website then i should theoretically be able to ride faster than mitch, basically just by purchasing stuff.

[rohan]

Colin, on Dec 16 2008, 06:32 AM, said:

but the original poster is still none the wiser after much technical debate.

you're making erroneous assumptions about the purpose of internet forums...

i hear the mitch camp are quaking in their boots. worried that i might be thinking of buying a new bike specced by nytro.

anyway, have you done an ironman?

[Plazbot]

Just on the 250g point, it is not all that far off a rule of thumb from my cycling mates of 1 on the wheels = 2 on the bike = 4 on the body so the 250g on this would run into the 1 kilo weight issue. For triathlon racing on the bike, weight is far from the limiter. Position is king and by a very very long way.

As far as info for the original poster, I am guessing they have a life unlike me and have not checked back to answer the list of questions I posed.

Oh and Colin, just take it all with a grain of salt.

For Rohan re your 2:26 v a 2:06

I made an assumption that you and your bike combined weigh 85 kilos (70 for you plus 15 for your bike, botles, spares, kit, shoes etc etc)

and for you just using a fairly generic drag number (it does not matter as it is like with like)

2:26 requires an average of 220 watts
2:06 requires an average of 328 watts

You would have to liken it to the difference between a 2:40 and a 2:20 marathon. It might not look like much on paper but it is enormous in practice. 328 watts average for a little fella is enormous.

Edited by Plazbot, 16 December 2008 - 05:05 PM.

[Kandingo]

if you are doing a fun run race wheels will be very helpful
if you are doing a tri...my opinion only --- 1-2 minutes for 40km ...4-8 for IM...I have zero tech data
I generally ride 50mm clinchers at 110psi..not pumped to 3000psi like some others...waiting for someones bike to float away at a race !!
my wheels cost $750 for pair and have done 20+ races on some dodgy roads at reasonable speeds
1 pair Zipps = 3 pairs of mine...my choice was easy

race wheels 98% cosmetic

[Colin]

rohan, on Dec 16 2008, 05:30 PM, said:

not sure where your 45mins difference comes from?

Nowhere...I was just using it as a relative measure vs 20min over 90km. 30km/h =3hrs and 40km/h =2:15, therefore approx double power output.

Plaz kindly worked it out a bit better, 20min on a bike over 90km is a lot.

Plazbot, on Dec 16 2008, 05:53 PM, said:

Just on the 250g point, it is not all that far off a rule of thumb from my cycling mates of 1 on the wheels = 2 on the bike = 4 on the body so the 250g on this would run into the 1 kilo weight issue.

Would like to see some real dat on this over a flat course because it doesn't conform to physics. And btw , weight on the body is the same as weight on the bike..static, and one could even say weight on the body is better for a cyclist, if that weight comes with extra strength too...which is the case usually for regular, fit cyclists...i.e.the extra muscle brings the weight.

A lot different from running. In cycling, a big bloke is more likely to thump a little bloke over a flat time trial course , which is what we are talking about, even if that big bloke has a big paunch.
Whereas in running, you can pretty much see from build that someone with a paunch, too big , too heavy etc won't beat a little bloke for the same training, because every step has to carry, accelerate the weight unlike cycling.

...with a pinch of salt of course.

[Colin]

Oh, and just so I can give an answer to OP.

Get a lighter wheel...it is likely to save you energy.

Thinner spokes may have less drag, but turbulence has to be factored in.

Less spokes may create less turbulence and drag.

As an aside when driving down to C2K the other day. Just by having a mountain bike behind my ute (with tonneau) on bike rack, my freeway (diesel) consumption at that speed (110km/h) went from 8.4L/100 to 11.2L/100 , 33% more despite also carrying less weight and passengers in total. In fact I have never got worse than 10L/100 even in Sydney traffic.

What relevance is this? Well the bike wasn't exactly being pushed (or pulled) against the wind, but created a disturbance immediately behind the tail of ute, where it is said there is some sort of high pressure pocket, which kind of pushes car forward. Either way, it had a biger affect than possibly having it on roof racks.

So drag(or turbulence) on a bike may also not just be affected by what is facing the wind, but also by what may be behind and other sort of odd shapes.


cheers

Edited by Colin, 16 December 2008 - 09:03 PM.

[Mick]

Maybe try these, should turn a few heads

Attached Files

•  Wheels.jpg   127.39K   23 downloads

[Plazbot]

http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...em=120350553935

These are OK. I would set myself a limit at $800.

Tyres I would put on them would be
http://www.probikeki....php?code=Y1219

Glued with (3 coats wheel, 2 coats tyre)
http://www.probikeki....php?code=Y1217

[marinhousehold]

Plazbot, on Dec 17 2008, 06:22 AM, said:

http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...em=120350553935

These are OK. I would set myself a limit at $800.

Tyres I would put on them would be
http://www.probikeki....php?code=Y1219

Glued with (3 coats wheel, 2 coats tyre)
http://www.probikeki....php?code=Y1217

If I can be so naive and ask, why these wheels?
If it helps I am male, around 87kg, not going to know but to port mcquarie in April.

[marinhousehold]

Also another question:
are zipp wheels all they are cracked up to be?
Is just that they seem really expensive and I just wanted to know if they rae the best wheels on the market? or if they are just the best marketed wheel on the market?

[Plazbot]

Zipp wheels probably are the best wheels on the market. Quality control, warranty, performance, longevity. Are they 3-5 times better than others? No way. Probably a percent or two here and there (percent of the gain over the worst option). All of the gains can be lost via poor tyre choice. Berkel just won IMWA on a Token disc/front combo that you can get for around $1000. Macca won kona on a GZ rear which is the same generic rim and spoke that Token/Edge/CarbonR and all the other generics use.

[miners]

marinhousehold, on Dec 17 2008, 11:13 AM, said:

If I can be so naive and ask, why these wheels?
If it helps I am male, around 87kg, not going to know but to port mcquarie in April.

I'm a fan of HED (so to speak), so take these comments with a grain of salt, but HED are arguably the best quality wheels per $ outlay on the market (imho). Lots of independent testing, quality control is good, heritage is good, wide range of wheel/rim options (which include carbon fairings as well as structural rims), quite a lot of Pro contracts, etc.. Zipp of course make great quality stuff, and they're certainly the most popular of the wheel brands, but you pay for it too.

The HED stingers (Plaz's link) are a very well respected wheel-set. Remember though that if you go to tubular rim set-ups, you bring in a whole new range of logsitics to think about. New brake pads, need to learn gluing techniques, more expensive tyres (generally), and you need to carry spare tyres, not tubes with you on long races etc...

If you're doing some research (you should), perhaps go trawl some of the threads at Transitions to find other topics related to wheel choice. There's some valuable stuff over there.

what did you mean by your last comment btw? Are you lining up at Port in April? If so, wheel choice won't be strongly dictated by that course. It has a mix of everything, and weather could do anything - and as a consequence, you'll see the full range of wheel types on show there on the day (discs, tubbies, deep-rims, tri-spokes, training wheels etc...)

[marinhousehold]

yes I am competing at port, I figured that the bike course is rather tough.
I am looking at clenchers only because I feel more comfortable with changing them and with what i need to carry if I have a puncture.
I will keep an eye on HED wheels, zipp are a out of my price range at the moment.
Thank you for the hewlp, will let you know what I decide to go with.

[miners]

marinhousehold, on Dec 20 2008, 05:25 PM, said:

yes I am competing at port, I figured that the bike course is rather tough.
I am looking at clenchers only because I feel more comfortable with changing them and with what i need to carry if I have a puncture.
I will keep an eye on HED wheels, zipp are a out of my price range at the moment.
Thank you for the hewlp, will let you know what I decide to go with.

The course is hillier than Busselton, but it's not super tough. An undulating 9-10km through town, then 10km of flat road out to Lake Cathie, a little hill in Cathie, then another 10km or so of undulating road to & back from the turn-around. There is one nasty-ish (but short) hill when you come back into town which you may have heard of (Matthew Flinders Drive), but for most of the track in town it's primarily just undulating.

A well known Trannie, Pee Pee sells HED wheels from his Pedals Plus store if you're in Sydney. He's a great bloke to deal with

Edited by miners, 21 December 2008 - 08:37 PM.