Mostly flat bike course - wheel setup

Disc, however you make it happen, my man.

As I understand it, the wheel cover goes on and off for races....  but I could be wrong.  

And if someone comes along and suggests mostly flat wheels for mostly flat courses.... don't listen.

As has been mentioned, a wheel cover can be put on/taken off quite easily, so there wouldn't really be a need to buy a new wheel for this purpose.  

A rear disc or wheel cover is almost always the best choice for any tri.  I'll leave it at that.  For the front, I would say get it as deep as you can but know the associated "risks."  An 80mm front might not be the best in a really windy situation depending on your body type (a smaller rider will have a harder time controlling a 80mm in the wind, while a bigger rider may have no issues).  Generally speaking, a 50mm front will be the most versatile depth.

If you are an averaged size and are looking for a wheel you can use in any condition, I'd get the 50mm front and wheel cover/disc rear.

Hope that's a little helpful.

Drew 

Deep front wheel first. And I'm talking deep enough that you won't fit through the wheel... (if it had no spokes )
Disc or a cover next.

This would make for an amusing bike fit.

As always.....you guys are great.  Thanks.

I'll be on the lookout for a front clincher in the 50 (or +) MM range.  I've got some time.

if your budget is 500-600...you could do this:

85 mm front

https://williamscycling.3dcartstores.com/Wheel-System-85-Tubular-Front-_p_53.html

disc cover for the rear

now this is a tubular just an fyi...but you get the idea.

Shane I always have been on board with deeper front and disc is always better too. HED has a compelling note on it's site whether a 60 or 90mm front would be better depending on rider speed and wind conditions. Basically in a crosswind a faster rider sees less of a yaw so the deeper is still best MOST times and for slower riders it can stall out in more conditions. I'd post a link but I'm on my phone....sure you've seen it though. Have you beaten that topic to death elsewhere?

Like I said....I don't know much about wheels, at all.

My question on tubulars is......what happens if I flat on a tri course with a tubular?  I can change a tube, OK (now).  I have no idea what's involved in repairing a tubular.

William makes a nice wheel and so does synergy sports.

I will say that the front wheel advice is a little off.   Deeper is not always better.  There are some good articles on the HED website and synergysports website that state that the deeper front you go the faster you need to go in order to reap the benefits of the deeper profile.  Synergysports.com says that you need to average >26mph to push a 95mm front.  

Rear disk is awesome buy for the money if you can not get a disk or really deep profile. 

This is what I did.

I went onto ebay and looked for a rear wheel that was fairly light and bought a wheel cover.  I only use thst wheel for the wheel cover becasue then I don't have to fool with putting it on and off (not that it is hard, but as you and I have discussed before, I would like to spend the bulk of my free time either training or doing something else important). 

Right now you can get a decent wheel for right around $100 - probably less if you shop around.  Wheelbuilder wheel cover is going to run you another $100 after taxes and what not. 

I got a HED JET 60 for $325 last year from ebay. 

Now, you can certainly save some coin and just place on and remove the disc if you like, but this is what you have to remember.  That disc cover is going to be made for the wheel you order it for.  The ordering process asks you about the number of spokes, wheel type and wheel size.  Once yopu make that determination you have to shop for another rear wheel to use with it, if you choose to do so, with that in mind. 

BTW - there are quite a few HED Tri Spokes out there on ebay right now, not sure how they are running. 

No personal experience here, but I am going to be switching to tubulars for races (based on experiences of others).  There seems to be some risk/reward trade-off on the flat tire potential.  I believe there is a product that can be used to seal most punctures if you have a flat in a race.  That will probably be my strategy.  Actually changing a tubular involves gluing or taping a new tire on the wheel.

It appears compelling at first glance but IMO the reasoning is flawed.  If I get a chance later today I will do a quick analysis and post my thoughts on it.

Shane

When I ran tubulars, my flat strategy was:

1)  Pitstop - in the event of a flat, I would hit the tire with Pitstop and if it worked great; if not, I was done (short course)
2)  If I was racing long course, I would carry a pre-glued and stretched tire, a razor blade and CO2.  If the Pitstop didn't work, cut the tire with the razor blade, rip it off and put the new tire on.

IMO tubulars are not worth the additional hassle; good clinchers with latex tubes perform as well as good tubulars that are well glued.  Further, to well glue a tubular you are going to need to do it yourself and it is going to be very hard to remove on the side of the road.

Shane

I had a chance to sit down and run some numbers; I had orginally started with Hed's data but even their numbers show the S6 being a slower wheel at 20* of yaw despite what was written in the article you mention.  However, I worked with their assumption that the S9 stalled at 15* and that the S6 did not stall until some point past 20*.

I decided to work with a 16km/h wind as at ground level that would be a pretty brisk day and started by modelling the yaw angles experienced by cyclist who can put out a consistent 200W (85kg rider and bike, .005 Crr, 1.22 rho, .28 CdA) and found that it was pretty much a bell curve with a range of 0 to 25 degrees.  I then found the range for a 150W, 250W and 300W cyclist and found 0-27, 0-23 and 0-21 degrees respectively.

To make the calculations quicker, I just grabbed Zipp's projected time savings and used the 404 and 808 savings for a 40kmTT which were 70 seconds and 80 seconds respectively.  At some point I may go back and pull the drag deltas from the Hed graph and revist the time savings as both wheels perform better in the most common yaw angles.  In my analysis, the 7-15 degree yaw angles are what these cyclists would experience >70% of the time.

I also assumed that a stalled aero wheel would perform no worse than a standard wheel (which is reasonable based upon data that I have seen on stalled wheels).

I then used a Gaussian distribution to model the expected wind direction with the different ranges.  Based upon this, I found the following (all savings are over 40km):

150W rider - S6 faster than S9 by 10 seconds
200W rider - S6 faster than S9 by 3 seconds
250W rider - S6 slower than S9 by 3 seconds
300W rider - S6 slower than S9 by 7 seconds

So while this supports their assertion that the deeper front is not always the fastest option, I believe that it also shows they have overstated the effect; claiming that only the top 20 in a state TT would be faster with the S9 is likely untrue.

Shane

Edited by gsmacleod 2010-10-01 6:12 PM