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Should triathletes be allowed on bikes?

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Re:

11 Jan 2017 20:30


I haven't read the thread but there are things that running single chainring enables which can result in quite a few watts saving for those interesting in TT riding. The gains are more to do with being able to narrow Q-factor than the actual removal of a ring from an existing set up, the latter having a very limited benefit - I guess it might cough up a watt or two. Ruin aero? No. Potential tiny gain, yes. Narrowing Q factor though can be somewhat more worthwhile for aero gains.

I'd still run a chain guide for the front though if not riding a fixed gear.
User avatar Alex Simmons/RST
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Re:

12 Jan 2017 01:23


Gold...
"Also, it should be noted a rider would likely influence these numbers as the movement of legs, crank, shoes, pedals, etc. would all alter the airflow through the drivetrain area. Still, the results are worthy of further discussion and testing. "
Probably find it to be even more aero without the rider then... ;)
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Re: Re:

12 Jan 2017 16:13

Archibald wrote:

Gold...
"Also, it should be noted a rider would likely influence these numbers as the movement of legs, crank, shoes, pedals, etc. would all alter the airflow through the drivetrain area. Still, the results are worthy of further discussion and testing. "
Probably find it to be even more aero without the rider then... ;)


:D

Alex Simmons/RST wrote:
I'd still run a chain guide for the front though if not riding a fixed gear.


Really? Why? My Monstercross has no chainguide and a 4 year old, normal, non-single ring specific chainring and a non-clutch, Deore mech on it and I hardly ever drop my chain when riding MTB trails. What are people doing on a TT that's causing them to drop their chain?
Vincenzo Nibali:
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Reduce your carbon footprint, ride steel.
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Re: Re:

13 Jan 2017 01:48

King Boonen wrote:
Archibald wrote:

Gold...
"Also, it should be noted a rider would likely influence these numbers as the movement of legs, crank, shoes, pedals, etc. would all alter the airflow through the drivetrain area. Still, the results are worthy of further discussion and testing. "
Probably find it to be even more aero without the rider then... ;)


:D

Alex Simmons/RST wrote:
I'd still run a chain guide for the front though if not riding a fixed gear.


Really? Why? My Monstercross has no chainguide and a 4 year old, normal, non-single ring specific chainring and a non-clutch, Deore mech on it and I hardly ever drop my chain when riding MTB trails. What are people doing on a TT that's causing them to drop their chain?

Racing Triathlons :D ;)
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Re: Re:

13 Jan 2017 04:25

King Boonen wrote:
Alex Simmons/RST wrote:
I'd still run a chain guide for the front though if not riding a fixed gear.


Really? Why? My Monstercross has no chainguide and a 4 year old, normal, non-single ring specific chainring and a non-clutch, Deore mech on it and I hardly ever drop my chain when riding MTB trails. What are people doing on a TT that's causing them to drop their chain?

Ask David Millar. He ran a naked single ring in 2003 TdF prologue and dropped the chain with 500m to go. Lost by 0.1 sec to Brad McGee:
https://www.youtube.com/watch?v=U7Tx6MV_XyM
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Re: Re:

13 Jan 2017 14:33

Alex Simmons/RST wrote:
King Boonen wrote:
Alex Simmons/RST wrote:
I'd still run a chain guide for the front though if not riding a fixed gear.


Really? Why? My Monstercross has no chainguide and a 4 year old, normal, non-single ring specific chainring and a non-clutch, Deore mech on it and I hardly ever drop my chain when riding MTB trails. What are people doing on a TT that's causing them to drop their chain?

Ask David Millar. He ran a naked single ring in 2003 TdF prologue and dropped the chain with 500m to go. Lost by 0.1 sec to Brad McGee:
https://www.youtube.com/watch?v=U7Tx6MV_XyM


So one data point 13 years ago? Doesn't seem very relevant.

42x16ss wrote:
King Boonen wrote:
Archibald wrote:

Gold...
"Also, it should be noted a rider would likely influence these numbers as the movement of legs, crank, shoes, pedals, etc. would all alter the airflow through the drivetrain area. Still, the results are worthy of further discussion and testing. "
Probably find it to be even more aero without the rider then... ;)


:D

Alex Simmons/RST wrote:
I'd still run a chain guide for the front though if not riding a fixed gear.


Really? Why? My Monstercross has no chainguide and a 4 year old, normal, non-single ring specific chainring and a non-clutch, Deore mech on it and I hardly ever drop my chain when riding MTB trails. What are people doing on a TT that's causing them to drop their chain?

Racing Triathlons :D ;)


It's probably this :D
Vincenzo Nibali:
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Reduce your carbon footprint, ride steel.
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Re: Re:

14 Jan 2017 00:21

King Boonen wrote:
Alex Simmons/RST wrote:
King Boonen wrote:
Alex Simmons/RST wrote:
I'd still run a chain guide for the front though if not riding a fixed gear.


Really? Why? My Monstercross has no chainguide and a 4 year old, normal, non-single ring specific chainring and a non-clutch, Deore mech on it and I hardly ever drop my chain when riding MTB trails. What are people doing on a TT that's causing them to drop their chain?

Ask David Millar. He ran a naked single ring in 2003 TdF prologue and dropped the chain with 500m to go. Lost by 0.1 sec to Brad McGee:
https://www.youtube.com/watch?v=U7Tx6MV_XyM


So one data point 13 years ago? Doesn't seem very relevant.


For a race that significant, I think it is. And if, as people here are so keen to point out, having such a device present no performance disadvantage but may indeed save a race, then why not?
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Re: Re:

16 Jan 2017 12:08

Alex Simmons/RST wrote:
King Boonen wrote:
Alex Simmons/RST wrote:
King Boonen wrote:
Alex Simmons/RST wrote:
I'd still run a chain guide for the front though if not riding a fixed gear.


Really? Why? My Monstercross has no chainguide and a 4 year old, normal, non-single ring specific chainring and a non-clutch, Deore mech on it and I hardly ever drop my chain when riding MTB trails. What are people doing on a TT that's causing them to drop their chain?

Ask David Millar. He ran a naked single ring in 2003 TdF prologue and dropped the chain with 500m to go. Lost by 0.1 sec to Brad McGee:
https://www.youtube.com/watch?v=U7Tx6MV_XyM


So one data point 13 years ago? Doesn't seem very relevant.


For a race that significant, I think it is. And if, as people here are so keen to point out, having such a device present no performance disadvantage but may indeed save a race, then why not?


Not really. Drive-chains have progressed a lot in the last 13 years. If the only occasion that you can mention is 13 years ago I think we can say that it's no longer relevant. I know that single ring set-ups still aren't used that much.

Unsure if we mean the same thing when we say chain guide. I mean something like this:

http://www.tweekscycles.com/Product.do?method=view&n=3511&g=268345&p=268347&d=124&c=4&l=2&utm_source=Google&utm_medium=Base&utm_campaign=Chain%20Guides&gclid=Cj0KEQiA-_HDBRD2lomhoufc1JkBEiQA0TVMmkhE42hOLJu0TmzVOT7X_c9pgShm-mZcbf3v6zPLsDAaAt1W8P8HAQ

I would think that would have enough of an effect to put people off but I don't know.

Anyway this is getting off the actual point that people dropping to 1x because they think that the second ring is going to cause drag is mental.
Vincenzo Nibali:
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Reduce your carbon footprint, ride steel.
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16 Jan 2017 20:04

and yet roadies go nuts for ceramic bearings everywhere which will save less drag than this has the potential to. As I said before, there is definitely aero as well as potentially rider efficiency merit in narrowing Q factor, which becomes easier to achieve with a single ring up front.
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16 Jan 2017 23:11

But that isn't the discussion of the thread from slowtwitch and don't get me started on ceramic bearings. What about loses in pedalling efficiency through larger ratio differences in gears?
Vincenzo Nibali:
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Reduce your carbon footprint, ride steel.
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Re:

17 Jan 2017 04:52

King Boonen wrote:What about loses in pedalling efficiency through larger ratio differences in gears?

Have a reference for that? It takes quite a large change in pedal speed for there to be much impact on efficiency. Certainly more than difference from changing one cog tooth, which represents a 6-7% change in gear or roughly 6-8 rpm.
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Re: Re:

17 Jan 2017 11:15

Alex Simmons/RST wrote:
King Boonen wrote:What about loses in pedalling efficiency through larger ratio differences in gears?

Have a reference for that? It takes quite a large change in pedal speed for there to be much impact on efficiency. Certainly more than difference from changing one cog tooth, which represents a 6-7% change in gear or roughly 6-8 rpm.


Nope, that's why I put a question mark.

If you're running 1x then surely you're going to want to run a 10T and I'd guess you wouldn't want smaller than a 48T at the front. As far as I know that means you have to use a 10-42 (11-speed) which gives steps of 20%, 16.7%, 14.3%, 12.5%, 16.7%, 14.3%, 16.7%, 14.3%, 12.5% and 16.7% (thanks Sheldon!). This would mean the smallest changes in gear are pretty much double the 6-7% you mention. Do you think that's likely to impact pedalling efficiency?
Vincenzo Nibali:
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Reduce your carbon footprint, ride steel.
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Re: Re:

17 Jan 2017 20:42

King Boonen wrote:
Alex Simmons/RST wrote:
King Boonen wrote:What about loses in pedalling efficiency through larger ratio differences in gears?

Have a reference for that? It takes quite a large change in pedal speed for there to be much impact on efficiency. Certainly more than difference from changing one cog tooth, which represents a 6-7% change in gear or roughly 6-8 rpm.


Nope, that's why I put a question mark.

If you're running 1x then surely you're going to want to run a 10T and I'd guess you wouldn't want smaller than a 48T at the front. As far as I know that means you have to use a 10-42 (11-speed) which gives steps of 20%, 16.7%, 14.3%, 12.5%, 16.7%, 14.3%, 16.7%, 14.3%, 12.5% and 16.7% (thanks Sheldon!). This would mean the smallest changes in gear are pretty much double the 6-7% you mention. Do you think that's likely to impact pedalling efficiency?

Why would you use such a ridiculous rear cogset for a relatively flat terrain TT event?

More likely you'll use a straight block from 11T and up and choose a front ring to suit your speed/power level on the course.
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18 Jan 2017 09:30

No one said it was a flat TT, I picked a set up that would mimic a fairly typical gear spread allowing someone to ride their bike wherever they needed. If you don't need the 39T in the first place you might as well have dumped it to save the weight anyway. While this is interesting it's massively off-topic from even the post that lead to it which was specifically about the drag of the second chainring, so I think that's the last I'll say on it.
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Reduce your carbon footprint, ride steel.
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Re:

20 Jan 2017 02:58

simo1733 wrote:Wow.They're a different breed.
I had a guy on a TT bike abuse the hell out of me because I drafted him for a couple of kms.
I told him to buy a car.
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Re: Re:

20 Jan 2017 15:54

sienna wrote:
simo1733 wrote:Wow.They're a different breed.
I had a guy on a TT bike abuse the hell out of me because I drafted him for a couple of kms.
I told him to buy a car.

I've never understood why people get bent out of shape from being drafted. I take it as a compliment if someone can't pull through. They can sit there as long as they like. Why would I care?
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20 Jan 2017 22:30

I think it's common courtesy to ask if it's OK to sit on someone's wheel. Plenty of people have been brought down by some hubbard from behind. You ride up and say hello, introduce yourself and you might even make a new friend. Why is that not a reasonable thing to expect?

What would you think if someone walked right behind you for ten minutes, following your every move?
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Re:

20 Jan 2017 23:05

Alex Simmons/RST wrote:I think it's common courtesy to ask if it's OK to sit on someone's wheel. Plenty of people have been brought down by some hubbard from behind. You ride up and say hello, introduce yourself and you might even make a new friend. Why is that not a reasonable thing to expect?

What would you think if someone walked right behind you for ten minutes, following your every move?

Agreed. I just pull over as far left as I can and force them to have a conversation with me. If they can only stay with me because they were drafting they figure it out pretty quickly.
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Re:

22 Jan 2017 14:40

Alex Simmons/RST wrote:I think it's common courtesy to ask if it's OK to sit on someone's wheel. Plenty of people have been brought down by some hubbard from behind. You ride up and say hello, introduce yourself and you might even make a new friend. Why is that not a reasonable thing to expect?

What would you think if someone walked right behind you for ten minutes, following your every move?


It's not quite the same. Someone drafting on a bike is there for a reason that isn't "follow your every move and be creepy". They'll only follow you while they're getting a benefit, and while you're going the same way they would have been going anyway. But sure, it's better to introduce yourself and be social. It's absolutely reasonable to expect. But I don't get bent out of shape if they don't.

(I don't really have concerns about being brought down from behind by a drafter. If they touch my rear wheel, it will likely end much more badly for them than for me.)
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01 Feb 2017 16:11

Drafting is for weaklings and losers anyway :)
Vincenzo Nibali:
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Reduce your carbon footprint, ride steel.
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