Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

"The 33"-Road Bike Racing We set this forum up for our members to discuss their experiences in either pro or amateur racing, whether they are the big races, or even the small backyard races. Don't forget to update all the members with your own race results.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-15-14, 11:39 AM   #426
Ygduf 
\_(ツ)_/
 
Ygduf's Avatar
 
Join Date: Jun 2008
Location: Redwood City, CA
Bikes: aggressive agreement is what I ride.
Posts: 9,388
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
TY. now to find a flat road.
__________________

strava.com/athletes/ygduf
Ygduf is offline   Reply With Quote
Old 08-15-14, 11:41 AM   #427
echappist 
fuggitivo solitario
 
Join Date: Jun 2009
Location: Arlington, VA
Bikes:
Posts: 8,789
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 72 Post(s)
Quote:
Originally Posted by Ygduf View Post
Aero "savings" are often listed in grams of drag.

What is a reasonable amount of "grams of drag" at like 40km/hour for a cDA of 3?
back of hand mnemonic

at 30 mph, 50 grams = 5 watts = 0.005 m^2 (CdA) = 0.5 sec/km

actually it's more like 45 grams, but this is back of the envelope
echappist is offline   Reply With Quote
Old 08-22-14, 06:59 AM   #428
Grumpy McTrumpy
gmt
 
Grumpy McTrumpy's Avatar
 
Join Date: Sep 2008
Location: Binghamton, NY
Bikes:
Posts: 12,452
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
The aerolab data from last night indicated a CdA below .2 for the first time ever. It's not easy to estimate Crr, but I tend to err on the side of too much, choosing a number that is higher than what I measure on my rollers, but not so high that it puts things way out of proportion. CdA worked out to be .1991

Additionally, I have to estimate transmission efficiency which I tend to keep around .965

The change? Replacing the long Uvex with a Giro Selector has lowered the CdA by a measurable amount, so far as I can tell. (~.0039)
Grumpy McTrumpy is offline   Reply With Quote
Old 08-22-14, 04:28 PM   #429
aaronmcd
Senior Member
 
aaronmcd's Avatar
 
Join Date: Aug 2013
Location: SF Bay Area, CA
Bikes: Cervelo S5
Posts: 2,458
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
Is it tacky to use electrical tape to hold the aerobar plugs in if they like to come out (clip ons, so no bar end shifters)?
aaronmcd is online now   Reply With Quote
Old 08-22-14, 04:45 PM   #430
Ygduf 
\_(ツ)_/
 
Ygduf's Avatar
 
Join Date: Jun 2008
Location: Redwood City, CA
Bikes: aggressive agreement is what I ride.
Posts: 9,388
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
do what you got to do.
__________________

strava.com/athletes/ygduf
Ygduf is offline   Reply With Quote
Old 08-22-14, 10:28 PM   #431
aaronmcd
Senior Member
 
aaronmcd's Avatar
 
Join Date: Aug 2013
Location: SF Bay Area, CA
Bikes: Cervelo S5
Posts: 2,458
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
I have two random questions.

While racing a time trial, a hill causes the racer's velocity relative to wind to fall below x, reducing the effect of aerodynamic drag and prompting the racer to optimally leave the aerobars for more power. Solve for x.

Also, here is a random theoretical question:
My TT on Sunday is uphill out and downhill back. But say a time trial is the reverse - starting with a descent and finishing with a climb. Should one carry an aero bottle, filled with water and installed with a release valve on the bottom in order to use gravity for an advantage on the first half, and dump the water for the climb?
aaronmcd is online now   Reply With Quote
Old 09-25-14, 09:50 AM   #432
MDcatV
Senior Member
 
Join Date: Dec 2006
Bikes:
Posts: 6,760
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
aero question: watching world championships, the announcers reiterated a number of times that the riders need a rounded back or hunchback for better aerodynamics as opposed to a flat back. is this an across the board truth? rider specific? complete hogwash?

they also said one of the riders lost 6 kg in the 4 weeks leading up to the event so they could climb better. That's 13 pounds in old money, which for a prof cyclist doesnt sound very realistic to me, so my confidence in the proclamations of the announcing crew is low.
MDcatV is offline   Reply With Quote
Old 09-26-14, 07:22 AM   #433
echappist 
fuggitivo solitario
 
Join Date: Jun 2009
Location: Arlington, VA
Bikes:
Posts: 8,789
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 72 Post(s)
if the said announce is a certain Mr. Liggett, well, you have your answer there

now that said, at a certain back angle below horizontal, you actually incur more drag the lower you go. but that's still a bit to go from flat back

Last edited by echappist; 09-26-14 at 11:23 AM.
echappist is offline   Reply With Quote
Old 12-29-14, 04:27 PM   #434
revchuck
Senior Member
 
Join Date: Oct 2010
Location: South Louisiana
Bikes: Cannondale CAAD9
Posts: 5,677
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 36 Post(s)
Going to get fitted to my new (to me) first ever TT bike. Is there any relationship between the saddle I use on a road bike and the saddle on a TT bike? Should I just bring the loose saddles I have in my spares box, or will I likely need something entirely different?
revchuck is offline   Reply With Quote
Old 12-29-14, 05:20 PM   #435
shovelhd 
Senior Member
 
shovelhd's Avatar
 
Join Date: Jun 2010
Location: Western MA
Bikes: Yes
Posts: 15,479
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Most guys I know use a TT or triathlon specific saddle.
shovelhd is offline   Reply With Quote
Old 01-06-15, 09:25 AM   #436
island rider
Senior Member
 
island rider's Avatar
 
Join Date: Feb 2009
Location: FFLD CTY, CT
Bikes:
Posts: 1,960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
With all the aero advantages on new Tri specific (Non-UCI) bikes, is there any reason a Cat 4 -3 for whom participation in a national event is extremely unlikely shouldn't buy a Shiv or something like it and benefit from those gains?
island rider is offline   Reply With Quote
Old 01-06-15, 09:49 AM   #437
shovelhd 
Senior Member
 
shovelhd's Avatar
 
Join Date: Jun 2010
Location: Western MA
Bikes: Yes
Posts: 15,479
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Who gives a ****. Buy what you want and **** what anyone else thinks.
shovelhd is offline   Reply With Quote
Old 01-06-15, 10:10 AM   #438
furiousferret
Senior Member
 
furiousferret's Avatar
 
Join Date: Jan 2006
Location: Redlands, CA
Bikes:
Posts: 4,485
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
Quote:
Originally Posted by island rider View Post
With all the aero advantages on new Tri specific (Non-UCI) bikes, is there any reason a Cat 4 -3 for whom participation in a national event is extremely unlikely shouldn't buy a Shiv or something like it and benefit from those gains?
The Shiv TT is not much of a gain in the tunnel, unless you have the one with a fairing that covers the front brake. The real deal breaker for me would be that water bladder, since you can drink and stay aero that could add up to a ton of time saved in a long tt. So long as you race with it empty I would not care (that's coming from another competitor's perspective).
furiousferret is offline   Reply With Quote
Old 01-06-15, 10:32 AM   #439
island rider
Senior Member
 
island rider's Avatar
 
Join Date: Feb 2009
Location: FFLD CTY, CT
Bikes:
Posts: 1,960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Quote:
Originally Posted by furiousferret View Post
The Shiv TT is not much of a gain in the tunnel, unless you have the one with a fairing that covers the front brake. The real deal breaker for me would be that water bladder, since you can drink and stay aero that could add up to a ton of time saved in a long tt. So long as you race with it empty I would not care (that's coming from another competitor's perspective).
That's the thing, not the Shiv TT, the Shiv Tri. It's not UCI legal, but most races up to the national level don't require UCI compliance and/or specifically allow bikes like this.
island rider is offline   Reply With Quote
Old 01-06-15, 12:53 PM   #440
Grumpy McTrumpy
gmt
 
Grumpy McTrumpy's Avatar
 
Join Date: Sep 2008
Location: Binghamton, NY
Bikes:
Posts: 12,452
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
I have one of those nosecone Shivs. I've gotten it down to .2 CdA on calm days according to Aerolab.

If I were going to Nationals I guess I would find a new frame but I'm hoping they relax some of the UCI guidelines and legalize it. They have already relaxed a bunch of guidelines and this model was originally designed to meet UCI specs until the McQuaid regime killed it (after it had won worlds with Cancellara).

I don't intend to go to Nats until I have seen TTs in the 29mph range (or possibly if they choose to have it in Pennsylvania again).
Grumpy McTrumpy is offline   Reply With Quote
Old 01-06-15, 04:12 PM   #441
tetonrider
Senior Member
 
Join Date: Aug 2007
Bikes:
Posts: 3,524
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Quote:
Originally Posted by island rider View Post
With all the aero advantages on new Tri specific (Non-UCI) bikes, is there any reason a Cat 4 -3 for whom participation in a national event is extremely unlikely shouldn't buy a Shiv or something like it and benefit from those gains?
Quote:
Originally Posted by furiousferret View Post
The Shiv TT is not much of a gain in the tunnel, unless you have the one with a fairing that covers the front brake. The real deal breaker for me would be that water bladder, since you can drink and stay aero that could add up to a ton of time saved in a long tt. So long as you race with it empty I would not care (that's coming from another competitor's perspective).
the nosecone shiv only proved to be more aero than the UCI-legal shiv TT at yaw > 7*. it is slightly slower than the shiv TT between 0 & 7.

the newer model shiv (tri) was designed to allow triathletes to store more $hit in their frame rather than hanging off of it, as well as to be easier to work on and to fit more people (it's a much taller frame vs the shiv tt long & low, so it appeals to a lower common denominator). it's slower than the shiv TT from 0-7 and slower than the nosecone shiv >10. they viewed it as a win because it added features that many customers wanted while doing a pretty good job with aerodynamics. the UCI-legal thing doesn't matter to a large set of customers.

for a rider actually doing TTs (not ironman triathlons @ 20mph), >10 yaw -- even >7* yaw -- is not all that common. (yes, yes, there are examples to the contrary, but a rider going 27, 28, 30mph needs to experience pretty high winds at actual ground speeds, which is not as common as we tend to think.
tetonrider is offline   Reply With Quote
Old 01-06-15, 04:17 PM   #442
tetonrider
Senior Member
 
Join Date: Aug 2007
Bikes:
Posts: 3,524
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Quote:
Originally Posted by Grumpy McTrumpy View Post
If I were going to Nationals I guess I would find a new frame but I'm hoping they relax some of the UCI guidelines and legalize it. They have already relaxed a bunch of guidelines and this model was originally designed to meet UCI specs until the McQuaid regime killed it (after it had won worlds with Cancellara).

Quote:
Originally Posted by Grumpy McTrumpy View Post
I don't intend to go to Nats until I have seen TTs in the 29mph range (or possibly if they choose to have it in Pennsylvania again).
USAC made an exception for the nosecone shiv. not sure if it was for 1 year only, but you might want to look into that.
i kinda understand this logic and also kind of don't. i've had a bunch of friends not show up to nationals because they wanted to wait until they felt like they could win and failed to realize that by not showing up they had no idea of how far they truly were from their goal. IMO, it is helpful to go out and ride vs the best guys on the same day, same course, same conditions. a good a$$-kicking is supremely motivating.

the guys who save it until they are ready sometimes waste some time in learning that lesson.

no one is ever really "ready".

masters nationals in 2016 in NC, grumpy. close enough to PA for ya?
tetonrider is offline   Reply With Quote
Old 01-06-15, 05:13 PM   #443
Grumpy McTrumpy
gmt
 
Grumpy McTrumpy's Avatar
 
Join Date: Sep 2008
Location: Binghamton, NY
Bikes:
Posts: 12,452
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
maybe.

depends on my form. Plus, TT frames aren't cheap
Grumpy McTrumpy is offline   Reply With Quote
Old 01-06-15, 05:15 PM   #444
Grumpy McTrumpy
gmt
 
Grumpy McTrumpy's Avatar
 
Join Date: Sep 2008
Location: Binghamton, NY
Bikes:
Posts: 12,452
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
As far as the asskicking goes, I don't have to go to NC for that. Several of the nearby stage races tend to feature National champs from different countries, plus people who finish close to them.
Grumpy McTrumpy is offline   Reply With Quote
Old 01-07-15, 12:10 AM   #445
tetonrider
Senior Member
 
Join Date: Aug 2007
Bikes:
Posts: 3,524
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Quote:
Originally Posted by Grumpy McTrumpy View Post
maybe.

depends on my form. Plus, TT frames aren't cheap
i checked to be sure; as of last year they were still allowing the nosecone shiv as an exception to the 3:1 rule. see bottom of page 1.

the TT course in SLC is a very cool one, if you are so inclined. there are some hills.

just saved you a few grand, so maybe you can use that for travel. ;-)
tetonrider is offline   Reply With Quote
Old 01-07-15, 09:51 AM   #446
island rider
Senior Member
 
island rider's Avatar
 
Join Date: Feb 2009
Location: FFLD CTY, CT
Bikes:
Posts: 1,960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Quote:
Originally Posted by tetonrider View Post
the nosecone shiv only proved to be more aero than the UCI-legal shiv TT at yaw > 7*. it is slightly slower than the shiv TT between 0 & 7.

the newer model shiv (tri) was designed to allow triathletes to store more $hit in their frame rather than hanging off of it, as well as to be easier to work on and to fit more people (it's a much taller frame vs the shiv tt long & low, so it appeals to a lower common denominator). it's slower than the shiv TT from 0-7 and slower than the nosecone shiv >10. they viewed it as a win because it added features that many customers wanted while doing a pretty good job with aerodynamics. the UCI-legal thing doesn't matter to a large set of customers.

for a rider actually doing TTs (not ironman triathlons @ 20mph), >10 yaw -- even >7* yaw -- is not all that common. (yes, yes, there are examples to the contrary, but a rider going 27, 28, 30mph needs to experience pretty high winds at actual ground speeds, which is not as common as we tend to think.
I've just got TT bike money set aside and burning a hole in my pocket. I just sold my last one and need a replacement. I have no vested interest in going with one versus another so I'm looking for reasons.
island rider is offline   Reply With Quote
Old 01-09-15, 12:00 PM   #447
Racer Ex 
Resident Alien
 
Racer Ex's Avatar
 
Join Date: Jul 2007
Location: Location, location.
Bikes:
Posts: 12,522
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Quote:
Originally Posted by tetonrider View Post
i checked to be sure; as of last year they were still allowing the nosecone shiv as an exception to the 3:1 rule. see bottom of page 1.
They have a rulebook? Really? Then why do these officials make s*** up as they go along?

Quote:
Originally Posted by tetonrider View Post
the TT course in SLC is a very cool one, if you are so inclined. there are some hills.
And bison. If you hit and kill one you get to keep the tenderloin.
Racer Ex is offline   Reply With Quote
Old 01-09-15, 12:03 PM   #448
Racer Ex 
Resident Alien
 
Racer Ex's Avatar
 
Join Date: Jul 2007
Location: Location, location.
Bikes:
Posts: 12,522
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Quote:
Originally Posted by aaronmcd View Post
While racing a time trial, a hill causes the racer's velocity relative to wind to fall below x, reducing the effect of aerodynamic drag and prompting the racer to optimally leave the aerobars for more power. Solve for x.
Trick question. The answer is a well trained TT specialist never leaves the aero bars because there is no positional differentiation in power.
Racer Ex is offline   Reply With Quote
Old 01-10-15, 07:49 PM   #449
revchuck
Senior Member
 
Join Date: Oct 2010
Location: South Louisiana
Bikes: Cannondale CAAD9
Posts: 5,677
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 36 Post(s)
Helmets

I was gifted an older Lazer TT helmet with the long-ass tail on the back. I frankly question my ability to use it properly, since I'm not sure I can bend my neck that much for a half hour or so. I'm considering getting myself a Specialized Evade to use instead on the assumption that a shorter tail will screw me up less when my head's not in perfect position. Another fact bearing on the problem is both my new-to-me TT bike and my new road bike are flat black, and the Evade is available in...wait for it!...flat black.

Opinions?
revchuck is offline   Reply With Quote
Old 01-11-15, 12:07 AM   #450
valygrl
Senior Member
 
Join Date: Jul 2003
Location: Boulder, CO
Bikes:
Posts: 8,321
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Quote:
Originally Posted by Racer Ex View Post
Trick question. The answer is a well trained TT specialist never leaves the aero bars because there is no positional differentiation in power.
My coach told me to stand for steep hills and going to the bullhorns is ok below 15 mph because you can breathe better. I take it you disagree?
valygrl is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 08:08 PM.