Orwell/Lucan/Usher/UCD/Tiernans league race 15/4/10 TT

sy

Well done to all Boardsies in yout TT results. Impressive times for guys and gals who are just starting out.

Special congrats to niceonetom, my first impressions are usually correct

@Lumen, getting closer to that Bradley Wiggins look and I like the wheels

Lumen

el tonto wrote: »

I'm not talking about dropping 35kg, just illustrating that weight apparently does make a difference.

Sorry, I wasn't suggestion you could or should. I just think there are limits of usefulness as far as comparing dramatically difference sized riders, so for all practical purposes (i.e. "what can I do to make me faster") on a flat TT weight makes no difference.

Another way to think of it is that if you are 50% heavier than another rider, all the gradients (up and down) are effectively 50% greater. If it's only 1 or 2% that's not going to mean much greater aero losses on the descents (which is where heavier riders are less efficient - on the uphills you are actually more efficient because your lower speed means less aero drag).

Home:Ballyhoura

el tonto wrote: »

It's amazing the amount of number crunching a TT generates. I just spent half my lunch trying to work out my power output by comparing my time to Lumen's and then using this tool to see how much faster I'd go if I dropped some weight.

Beasty wrote: »

So what was the answer?

(I presume not a lot on flat courses)

el tonto wrote: »

Hard to say exactly, but probably between 30 seconds and a minute. Unfortunately none of these power/speed calculators have a field to input how many cigarettes you smoke a day and what difference that would make.

All I will say is take whatever savings you can get! I won my last two local time trials by 2 seconds and 1 second respectively! That could be the difference between wearing overshoes or not, so anyone undecided about whether or not the savings of aerobars or similar are worth it or not, they are. Every second counts in TTs, well at least the last few I have done anyway and luckily they went in my favor! I'm getting to like the TTs these days now that I got my Stealth, I'm absolutely delighted with it.

cdaly_

blorg wrote: »

Of course few courses are perfectly flat, last night's certainly wasn't.

On that subject, is it worthwhile reaching off the aerobars to change gear for every little up and down? I found this morning that there were times where I was spinning up to 115rpm for maybe 5 sec or so on little descents with a climb coming up straight after. Any point in shifting up for those 5 sec and then shifting down again? My steady state was around 85-95rpm.

blorg

cdaly_ wrote: »

On that subject, is it worthwhile reaching off the aerobars to change gear for every little up and down? I found this morning that there were times where I was spinning up to 115rpm for maybe 5 sec or so on little descents with a climb coming up straight after. Any point in shifting up for those 5 sec and then shifting down again? My steady state was around 85-95rpm.

I don't think quickly reaching to shift has much of an aerodynamic penalty and it is worth it if it puts you in the right gear. You get to the point where you can just flick your right hand over and change quickly. I wouldn't be shifting every five seconds though, if you look at the course profile I think I would have shifted 2 or 3 times max per climb. I'd be looking at it the other way, if it is that short I'd just power over the climb in the harder gear staying in the aero bars. 115 RPM should be perfectly sustainable for short periods as long as you are still putting the power down. If you are just free spinning then I would shift, yes.

To an extent doing even a slightly undulating course fixed takes all this out of your mind. The only issue is you are stuck putting in an effort for little return on the descents.

Lumen

blorg wrote: »

To an extent doing even a slightly undulating course fixed takes all this out of your mind. The only issue is you are stuck putting in an effort for little return on the descents.

Or just stick your 20 gear bike in the single most appropriate gear for the whole course and benefit from the amazing efficiency of the freewheel.

DirkVoodoo

Is it a requirement to have a geared bike for a TT? Do you think you would have been faster on the planet x track bike?

Lumen

DirkVoodoo wrote: »

Is it a requirement to have a geared bike for a TT?

Assuming you mean "non-fixed"...

UCI rules wrote:

The use of a fixed gear in competition is prohibited

Cycling Ireland rules wrote:

The Technical Race Regulations referred to hereafter will apply to all races held under the jurisdiction of Cycling Ireland with the exception of those races on the UCI International Calendar which will be governed by the UCI Regulations (available on www.uci.ch). Where there is no specific Cycling Ireland Rule, the Rules of the UCI will apply where appropriate

Since there is no specific Cycling Ireland Rule about fixed gear bikes, I'd say they are not allowed under a strict interpretation.

DirkVoodoo

Lumen wrote: »

Assuming you mean "non-fixed"...

Yes, non-fixed. Singlespeed with a biggish gear.

Diarmuid

el tonto wrote: »

Did I miss some old post? What;s the history behind this?

Lumen

DirkVoodoo wrote: »

Yes, non-fixed. Singlespeed with a biggish gear.

Singlespeed is fine. Fixed is not. That's my reading of it anyway.

Chips Lovell

If I recall correctly someone placed in the national TT championships two years ago riding a fixed gear.

petethedrummer

el tonto wrote: »

If I recall correctly someone placed in the national TT championships two years ago riding a fixed gear.

Someone posted a pic of Paul Healion time trialling on a fixie.

Also, well done Tom. Nichezean said you were going strong the other day....seems he wasn't lying.


Edit.....

Last pic http://www.irishcycling.com/publish/exec/view.cgi?archive=10&num=3177

from this thread: http://www.boards.ie/vbulletin/showthread.php?t=2055324173

And I thought the internets was ruining my long term memory.

Home:Ballyhoura

niceonetom wrote: »

I now understand the appeal of aero too. I'm already looking at my time and involuntarily calculating what it would be if I had the hat, or the disk, or spent some time in a windtunnel... sigh. Buying seconds seems so much more appealing than actually getting stronger.

Have you already got a TT bike?

godihatedehills

el tonto wrote: »

If I recall correctly someone placed in the national TT championships two years ago riding a fixed gear.

Just out of interest, what's the advantage of riding fixed in a TT?

mloc123

godihatedehills wrote: »

Just out of interest, what's the advantage of riding fixed in a TT?

Less power lost through tranmission maybe? unless the course is pan flat though I don't see it being an advantage.

niceonetom

Home:Ballyhoura wrote: »

Have you already got a TT bike?

No. I was using my planet-x road bike with clip on aerobars and a different saddle position (higher and further forward), normal helmet and kit and traditional 32spoke wheels.

mloc123 wrote: »

Less power lost through tranmission maybe? unless the course is pan flat though I don't see it being an advantage.

Then there's the drag from derailleurs to be considered.

mloc123

niceonetom wrote: »

No. I was using my planet-x road bike with clip on aerobars and a different saddle position (higher and further forward), normal helmet and kit and traditional 32spoke wheels.



Then there's the drag from derailleurs to be considered.

Don't forget the zen and oneness with the bike...

blorg

I think riding a TT fixed removes the option of changing gear which is one less thing to think about, you can just concentrate on the riding. I don't think it necessarily needs a pan flat course but you wouldn't want extreme gradients. The big problem with TTing fixed is that you will lose time on descents, without any real recovery either.

My track bike is basically a TT frame; I don't have a geared TT bike yet. I have I think a pretty good position on it with 90 degree elbows. On the other hand I can put my aero wheels on the road bike which I can't with the track bike (I could put the front on but the back is what matters.)

mloc123

blorg wrote: »

(I could put the front on but the back is what matters.)

I think a good aero front wheel is recommended over a rear one, if you only had money to buy one.

blorg

mloc123 wrote: »

I think a good aero front wheel is recommended over a rear one, if you only had money to buy one.

I'm pretty sure it is the other way around. Wherever you see wheelsets with different profiles the rear is always deeper.

Lumen

blorg wrote: »

I'm pretty sure it is the other way around. Wherever you see wheelsets with different profiles the rear is always deeper.

Only because depth on the front affects steering.

blorg

Right, looks like I had that one the wrong way around so. Peculiar as there are wheelsets like my Easton EA90SLs that are deeper in the back than the front, but neither is deep enough to affect handling one way or the other (21/25mm.) I suspect that is mostly marketing.