BayAreaUser

So, I may not have mentioned this before, but i signed up for a triathlon in a little over a month. I've been training for a while and now just sort of want to work on a few details.

Getting a triathlon Specific bike is out of the question now.

1) I don't have a TT bike, so i'm simply gonna have to settle for clip ons.
Apparently FSA, K-force bars take on clips on so i'll give those a try, or simply swap the bars for an aluminum bar I have laying around. Does anyone have any experience with mounting clip ons on carbon bars?
So far i've been training with riding on the drops and getting as low as possible, which i can do and sustain for 8-12 miles, but it gets really uncomfortable after that and my fingers go numb.


2) I will have a set of Soul 2.0 wheels on the bike- if they ever get here. At this point, if they don't ship this week, I was told they were ready and paid for two weeks ago, i will cancel the order. They are super shallow and originally intended to be used as my everyday set.
Will getting/borrowing/renting a set of deeper rims really make a difference?
How deep is enough to justify the cost of the getting them? Would i feel the difference with william 38s or should i go with 58s?

Would the 58's be aero enough to justify the increase in almost half a pound in weight? how do the 58s compare to the Reynolds dv46c ul. I could get those for almost the same price and they lighter than the w-38s and w-58s?

For those of you that switch back and forth between narrow and deeper wheels, can you feel the difference in top speed?


Thanks. Off to the pool I go =)

datlas 

There are aerodynamic studies that will show how much exactly these wheels save you in time, I suspect some sage BF member will post the link.

My understanding is that these make a bigger difference the faster you are.

In other words for schmucks like you and me, it probably makes a minimal difference.

For faster guys who can maintain 25MPH for an hour, they make a bigger difference. And even then not a huge difference but a decent amount.

achoo

I would NOT mount clip-on aerobars to a carbon bar. The carbon bar is designed to be clamped by the stem. It's almost certainly not designed to be clamped on to by aerobars. If you can't find a torque spec for clip-on aerobars for your carbon bar, I'd venture to say it's safer to use the aluminum bar.

As far as aero wheels, I do feel a difference starting at about 23-24 mph. I can't hold that speed long enough to be any good at this sport, but I do feel the difference. I also feel a significant difference on descents, where the "wall of wind" seems to come a few MPH later with deeper-rimmed wheels.

datlas 

I know those aero bars are popular but a friend of mine is a pretty damn good cyclist and triathlete (he can do a sub 3 hour marathon, for example) and he HATES aero bars and uses regular road bars (and non aero wheels).

He says he has no problem passing tri-geeks with aero bars and deep section wheels.

It's all about the motor, the aero schwag probably makes a difference at the elite level for sure, but unless you are there I don't think you will get much bang for your bucks.

Val23708

aero stuff can save you over 100 wats in some cases. motors being equal, aero equipment will matter quite a bit. heck shoe covers will give you 10 seconds on a 10 mile TT. Aero helmet might be close to 30 seconds. Depending on the wind, deep wheels could give you more than 60 seconds. Of course the most important is TT/tri geometry which nets the largest benifit in aerodynamic savings.

Of course, ride with what you train with. If you want to use aero bars, then train with them or else you're probably better off in the drops.

echappist

Sorry to be nitpicking, but I have a hard time believing this given we are talking about TT's and triathlons. 50 watts between a standard road bike with box sections vs the Shiv with 808, maybe. But 100W sounds highly inflated. Most of your aero gains are due to profile differences, which is to say that getting in a good aerodynamic position that allows you to produce adequate power is far more important than the effects of deep dish wheels and tube shape combined.

Now, if we are talking about a sprint at 40+mph, you are right (but we are talking about a difference of 150W when the power output is 1300W), but i don't think anyone will be able to sustain that sort of power for long in a TT.

StanSeven

Moderately aero wheels (around the 58 you are talking about) will save around 60 seconds over a 40K course.

Val23708

I was including a TT geometry frame in that total, which of course is where you get the largest gain.

Velo Gator

Depends.

What is your ability level? What are your triathlon goals? If you're a fat guy who just wants to finish a sprint tri, save your money. If you need a bike spilt to Kona qualify, your needs might be different.

I can get into a decent aero position with clip ons on my bike, but I think that partially because the geometry lends itself to it. I use aero wheels because my bike came with pretty basic wheels and I had the money to upgrade.

Zen Cyclery

Heres the link https://www.rouesartisanales.com/arti...#more-15505311

rapnjoe

Aero helmet vs aero wheels
Copied and pasted from VeloNews

Training Center: Which gives more bang for the buck: an aero helmet or aero wheels?
By Sean Madsen, Boulder Center for Sports MedicineUpdated: Nov 15th 2010 11:51 AM ESTHave a question for VeloNews Training Center?
Send it to TrainingCenter@competitorgroup.com
Dear VeloNews Training Center,

I have a big time trial coming in a few months. I don’t have a huge budget for new equipment, but I’m considering investing in either an aero helmet or aero wheels. Which will help me the most?
-Todd

Time trial equipment is certainly expensive, but can afford the rider a quantifiable improvement in race performance. Prioritizing equipment can be a daunting task, especially given the marketing hype surrounding aerodynamics. To help in the decision making, let’s look at the scientific studies that have been performed in wind tunnels and real world settings.

Many studies have illustrated the primary resistance that a cyclist must overcome, especially at high speeds, is wind resistance. (Grappe et al., 1997; Kyle and Burke, 1984) Moreover, these same studies have pointed out that the body accounts for the majority of the aerodynamic drag, usually about 70 percent. If the body is the primary source of aerodynamic drag, then making changes to the body position can cause substantial changes in drag (Broker, 2003; Garcia-Lopez et al. 2008; Juekendrup and Martin, 2001). These same studies have also pointed out that optimizing aerodynamic drag does not necessarily result in optimized metabolic cost and respiratory capacity. So there is a balance between aerodynamics and power generation. All of this leads to the conclusion that the most important use of your money is actually getting positioned properly on your bike!

Since you asked an equipment question, let’s delve into that a little more. Wheels and helmets are two distinct ways to change your aerodynamic picture. The body represents the majority of the drag (70 percent) the bike must then be the rest (30 percent). Aero wheels can reduce the drag of the bike by 49 grams of force (Greenwell et al., 1995). An aero helmet can deliver much more of an aerodynamic advantage. A properly positioned aero helmet affects the drag coming from the body. The 2007 Sidelko study and the 2008 Chabroux study each showed large variations in drag reduction across all tested yaw angles, in three different helmet positions. A recent paper from MIT (Sidelko, 2007) shows even the worst performing helmet reduced drag by 113 gmf! The best performer reduced drag by 175 gmf.

Interestingly, increasing yaw angles tended to produce even better savings. These kinds of studies are actually making manufacturers look at improving their non-time trial helmets, to see what advantages can be made. Positioning of the helmet is critical. The 2007 Sidelko study and the 2008 Chabroux study, both showed large variations in drag reduction across all tested yaw angles, in 3 different helmet positions. Indeed, when the rider is looking down at the front wheel, and the tail of the helmet is straight up (think shark’s fin) half of the helmets tested were actually worse than a typical road helmet! This stresses the importance of being properly positioned on your bike.

There are other considerations with helmets, mainly heat transfer (cooling). Many Ironman Kona racers use a standard road helmet due to the hot conditions. As we all know, the metabolic cost of dehydration and over-heating will far outweigh any aerodynamic gain.

Looking at the published literature regarding both helmets and wheels, either can contribute to reducing your aerodynamic drag in a time trial or triathlon. Clearly it seems the best equipment for your dollars comes from an aero helmet, however the best use of your resources is to be properly positioned on your bike.

BikeNube

depends on effort duration.

Silvercivic27

That's it. I'm wearing an aero helmet with box rims on my next C group ride so I can be the first in line for coffee.

StephenH

Can you get the full results from a previous version of the event you're entering? If so, take those time reductions quoted up there, and see what that does to your potential ranking. If there's a 1,000 entries and you move from #600 to #590, is that something you really want to pay a lot of money for?

clink83

Uh, no. A proper aero setup has a *huge* effect on speed, no matter what your fitness level is.

You don't need aero rims though. You didn't say what distance your Tri is at either.

merlinextraligh

The 58's will definitely be fast enough to justify the weight. In almost all TT situations, except a pure uphill TT aerodynamics trump wieght.

That said, the question is whether they justify their cost.

We're talking about around a .2mph to .4mph improvement at 25mph over conventional box shaped rims. So the question is whether 45-60 seconds in a 40 K TT is worth the cash.

The cheapest answer to go the fastest would be a disc cover for the rear, and a used HED3 for the front. For $300-400 that will be faster than the Williams 58's.

coachboyd

Aerodynamics can be a cumulative thing (much like weight on a bike). It's not any one thing that will make you that much faster but a combination. Yes, the 58's will be a good choice for triathlons and would be a much better option than the 38's (it'd be better if they had aero spokes as those are just as important as rim shape).

The combination of time trial bike, helmet, position, wheels can all add up to make quite a difference. When I am on my road bike doing intervals on a flat road at 330 watts I tend to average about 24mph (road bike, alloy wheels, jersey and road helmet). Fully kitted out in time trial equipment (skinsuit, tt helmet, deep wheel on front, disc in back) on that same section of road I am right around 29mph for 330 watts.

Granted if it were a triathlon there's no way I would be able to run afterwards, but the combination of all these things can add up to some serious time savings.

zatopek

With respect to deep profile wheels, I've used quite a number of Al clincher wheels with rim depths up to 30mm. When I ride my 50mm Spinergy PBO Stealth CF wheels, I am able to maintain speeds above 25 mph more easily. Under 25 mph, I don't feel or notice any advantage to these wheels. And, in heavy cross winds, above 20 to 25 mph, the 50mm rim depth is a liability as I get pushed around a good bit. Still, those Spinergy wheels look pretty cool and have a very smooth and forgiving ride quality.

datlas 

This is the key, and what I alluded to in post #2.

If you are a strong cyclist and capable of maintaining 24-25MPH for an hour, then these make a LOT of sense.

However if you are a schmuck like me and are only able to maintain say 19 or 20MPH for an hour, I suspect these wheels don't make nearly as much difference.

Ditto for the shoe covers and aero helmets.

I do agree that an aerodynamic profile/setup on bike will matter even at lower speeds like 20MPH.

merlinextraligh

The mathematics of this works out to be a bit ironic. The speed advantage of aerodynamic equipment increases as speed increases. So the 25mph time trialer, does get more of a speed increase than the 20mph time trialer.

However, the amount of time to be saved in a time trial is higher at slower speeds. This is true because it takes the 20 mile an hour time trialer longer to complete the course, making a percentage change in speed have a larger absolute time savings. So a 20 mph time trialer saves more time from a given aero improvement than a 25 mph time trialer.

Phantoj

Almost no one rides box section rims anyway, so the comparison would be better against a typical cheap semi-aero rim profile wheel.

Rutnick

I have 30mm alloy clinchers, reynolds assaults, 30mm carbon tubulars and 50mm carbon tubulars.

You know what i noticed more about carbon deeper dish wheels? comfort and cornering. They feel more comfortable and I think the cornering is better with the same tires.

Rutnick

I do...which do you want? 36 spoke or 24/28?

kleinboogie

Some carbon bars are designed for clip ons, FSA for example. I did it once and never again because the aluminum clamp of the clip-ons gouges the clear coat and stickers of the handlebar. I wasn't happy. So I just bought some aluminum TT bars instead.

Aero will trump weight once they're up to speed like in a TT or Tri. Getting them there is where the work is. If you're doing something where you need to surge regularly (crit, climbing, breaks, etc.) then rotational weight is a factor. Carpediemracing has begun to talk about this in crits and I'm inclined to agree based on my limited racing experience. In a TT I don't care, I want as aero as I can get without being blown across the road by a crosswind. In a crit I want to get the wheels up to speed as quickly as possible.

My TT frameset is delayed somewhere in China so I have a full TT cockpit on my Supersix with 404's and a disc cover in the back. 38mm and 80mm tubulars are on a boat. Not aero at all but can't do much until the frameset comes.

Cost vs. benefit is something people with limited funds talk about. For others the question isn't is it worth it, money doesn't become the hurdle. The questions are is there a better one and do I need a spare? Once you've reached your current limitation (physically, equipment, nutrition, etc.) then those seconds become your primary focus. The reason is because people will pay through the nose to have an edge over their buddies or competition. Any competitive, real or imagined, sport operates on this principle. It's just human nature.

When people say don't buy that thing that may make you faster all I hear is, "Be slow." No thanks. Cheers

merlinextraligh

1) Conventional rim is just an easy benchmark.

2) My point was that the difference is pretty small to start around .2mph to .4mph. If you already have a wheel more aero than a conventional box rim , its going to be smaller.

3) I believe, The OP has Soul 2.0 wheels with a rim height of 25mm, so those are not going to be a whole lot more aero than a conventional rim.