Racer Tech Thread
#1451
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There's a study out there where athletes (NFL, NBA, etc) from other sports trained for two weeks in very short duration. Most of them had better 5 second and peak power than pro road cyclists; the problem is the endurance part of road racing cannibalizes your muscles.
#1454
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you seem to be blaming the venge and think that maybe Cav (or specialized) haven't tested it with big sprints?
Originally Posted by doge
Most every track sprinter is faster with more power than Daniel. Most every pro tour rider is not. Look at other sports and check out teen power and strength. They (the pro tour riders) know this inc. Sagan, Cav and others Daniel has ridden with. If it makes you feel better there are many USA crit riders more powerful than Cav and Daniel, they just can't finish the distance Cav does and cannot handle the speed. It is not a valid comparison.
Originally Posted by doge
Last month Daniel was gapped at Paris Roubaix and had to close it with a time that matched Niki Terpstra KOM time bridging back on - a pro level "KOM" 30+ mph in Paris Roubaix. There was no power meter. His finish was the best 17 year old USA finish ever. It is totally valid that he is stronger and faster than a guy riding some 100+ miles. Winning races and being the most powerful rider at the end are different. This was about pulling a wheel out, but the power numbers are real.
see above.
still gonna guess he's not doing 2000 @ 140 for anything more than a fraction of a pedal stroke (if that)...but not at all doubting he has a good jump and a good sprint.
surely he can hop on a bike with a power meter for $h!ts and grins with a sprint like that, just to throw down a #, no?
unless you've got a venge with a defect (possible), i'm going to bet it is not a Venge problem...that the bike/frame cannot handle ANY 140# rider's sprint.
#1455
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The more we hear about how good Daniel is, the better I feel about beating him for my lone and probable sole p12 road race win!
Sure he flatted, but that's what you get trusting a ****ty mechanic to build a bike with weird sub-standard parts. How many races will he lose to mechanicals?!
Sure he flatted, but that's what you get trusting a ****ty mechanic to build a bike with weird sub-standard parts. How many races will he lose to mechanicals?!
#1456
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Was going to post pretty much exactly what Teton said.
Yes, doge, it's negligent to have your kid race this frame/wheel/skewer setup until this is figured out.
Yes, doge, it's negligent to have your kid race this frame/wheel/skewer setup until this is figured out.
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Most likely it is one partial stroke pulling the wheel out.
As this is a tech thread the physics and math are not that hard. I rider moving the crank 10cm with a force of 120kg (so say 50 up 70 down) at 90 rpm is putting out 1,700W.
I used that 120kg number for easier math before I got a piece of paper.
120kg*9.8N/Kg then the 10cm arc is 1/10 revolution (2*crank arm*PI) ~1176N*.1m/.06667sec=1763W
Which is why I brought up leg press.
On the leg press (1,000lbs * sin 45 degrees) 707lbsf or 321kg. Over a similar distance and speed (which he does) that is 4700W
As this is a tech thread the physics and math are not that hard. I rider moving the crank 10cm with a force of 120kg (so say 50 up 70 down) at 90 rpm is putting out 1,700W.
I used that 120kg number for easier math before I got a piece of paper.
120kg*9.8N/Kg then the 10cm arc is 1/10 revolution (2*crank arm*PI) ~1176N*.1m/.06667sec=1763W
Which is why I brought up leg press.
On the leg press (1,000lbs * sin 45 degrees) 707lbsf or 321kg. Over a similar distance and speed (which he does) that is 4700W
#1458
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If he's that strong, and riding at that high of a level, surely you can just call up Specialized and have them send a new frame. Even I could probably have my LBS get a new frame at this point, and I'm lower than nobody. I'm sure they'd rather that, then a bunch of people on a hugely read forum wondering if there's something wrong with the Venge. Have you contacted Specialized at all? In my experience they're one of the easiest to work with (I'm a bit of a fanboy, admittedly, most of my bikes have been Specialized).
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Lowering Handlebars vs. Going to Narrower Bars for Increased Aero Benefits?
The impetus for this question is an article somewhere - probably VeloNews - that said that Tom Boonen had gone from 46(?)cm bars to 39cm bars based on wind tunnel data. I'm built like he is...well, except for the legs.
Tall and wide.
As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?

As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?
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#1460
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I can get pretty low on my bike, being able to touch the stem with my chin. What I will say and it will be confirmed by others is there is a power loss. The hip angle has an optimal point, and I'm not sure that can be changed. Its still good to get as low as you can, but there are tradeoffs, and make sure you can still ride in the optimal angle.
#1461
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[QUOTE=Flatballer;17781093Have you contacted Specialized at all? In my experience they're one of the easiest to work with (I'm a bit of a fanboy, admittedly, most of my bikes have been Specialized).[/QUOTE]
nah it's much more logical to take a dremel to the dropout.
in all seriousness, spec was pretty solid with my warranty claim as well.
nah it's much more logical to take a dremel to the dropout.
in all seriousness, spec was pretty solid with my warranty claim as well.
#1462
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The impetus for this question is an article somewhere - probably VeloNews - that said that Tom Boonen had gone from 46(?)cm bars to 39cm bars based on wind tunnel data. I'm built like he is...well, except for the legs.
Tall and wide.
As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?

As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?
I switched to 40cm bars and am considering 38s, even though I am fairly wide compared to some guys who look like a throwing knife on the bike (@shovelhd for example). I really like them, and I do think I am pretty aero, but of course you'll have to see how it works for you.
#1463
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Most likely it is one partial stroke pulling the wheel out.
As this is a tech thread the physics and math are not that hard. I rider moving the crank 10cm with a force of 120kg (so say 50 up 70 down) at 90 rpm is putting out 1,700W.
I used that 120kg number for easier math before I got a piece of paper.
120kg*9.8N/Kg then the 10cm arc is 1/10 revolution (2*crank arm*PI) ~1176N*.1m/.06667sec=1763W
Which is why I brought up leg press.
On the leg press (1,000lbs * sin 45 degrees) 707lbsf or 321kg. Over a similar distance and speed (which he does) that is 4700W
As this is a tech thread the physics and math are not that hard. I rider moving the crank 10cm with a force of 120kg (so say 50 up 70 down) at 90 rpm is putting out 1,700W.
I used that 120kg number for easier math before I got a piece of paper.
120kg*9.8N/Kg then the 10cm arc is 1/10 revolution (2*crank arm*PI) ~1176N*.1m/.06667sec=1763W
Which is why I brought up leg press.
On the leg press (1,000lbs * sin 45 degrees) 707lbsf or 321kg. Over a similar distance and speed (which he does) that is 4700W
the single leg strength is not that out of the ordinary, and 2000w @ 120rpm does not require a force of 120kg. i could be wrong, but i raise an eyebrow that your boy is simultaneously pulling up with 110lbf while also managing to push down with 154lbf......more than his body weight. i think some f your assumptions/calculations might be off.
as for your 4700w..... it's not happening on his venge, i'm sure, and i'd bet a good bit of money the frame can handle more than any junior rider can throw at it.
seems like defect or hub issue or installation error (repeated!) are more likely culprits than "boy too powerful."
The impetus for this question is an article somewhere - probably VeloNews - that said that Tom Boonen had gone from 46(?)cm bars to 39cm bars based on wind tunnel data. I'm built like he is...well, except for the legs.
Tall and wide.
As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?

As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?
that said, it is free, so get out there, ride a bit, and take some photos.
#1464
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If he's that strong, and riding at that high of a level, surely you can just call up Specialized and have them send a new frame. Even I could probably have my LBS get a new frame at this point, and I'm lower than nobody. I'm sure they'd rather that, then a bunch of people on a hugely read forum wondering if there's something wrong with the Venge. Have you contacted Specialized at all? In my experience they're one of the easiest to work with (I'm a bit of a fanboy, admittedly, most of my bikes have been Specialized).
#1466
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Or putting oddball threadlock spacers between the dropouts and the hubs.
Why not just try out a basic stock hub with a basic stock skewer cinched down tight? That could at least rule out the hub as a culprit. My one time incident was likely a user error fluke and hasn't been repeated. Granted, I'm not dropping 2,000 watts on the regular, but I have put it through the ringer since the incident with no additional issues.
Why not just try out a basic stock hub with a basic stock skewer cinched down tight? That could at least rule out the hub as a culprit. My one time incident was likely a user error fluke and hasn't been repeated. Granted, I'm not dropping 2,000 watts on the regular, but I have put it through the ringer since the incident with no additional issues.
#1467
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The impetus for this question is an article somewhere - probably VeloNews - that said that Tom Boonen had gone from 46(?)cm bars to 39cm bars based on wind tunnel data. I'm built like he is...well, except for the legs.
Tall and wide.
As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?

As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?
Narrow is really like you pulling your elbows in. Virtually no change in your torso or hip angle. The only thing would be out of saddle stuff - the bike will feel a bit more twitchy, the front wheel will feel like it's a 800c, not a 700c, because slightly less leverage on the bars.
From an adaptation point of view going narrow is very straightforward.
If you're not very low now then going lower usually brings the better return. In other words for most Cat 5s the first thing I'd do is to lower them. Once their torso/hip angle stuff is sort of settled then you really have to leave that alone. Narrow becomes the next thing to do.
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#1468
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narrower is generally more aero as bars are often the widest part of the bike. that is easy to say with some degree of confidence. lower may or may not be more aero. the thing about lower is that the angle of the low back tends to remain fixed (based on a rider's flexibility and physiology), regardless of bar position, and the arms either bend or straighten to compensate. i know nothing about your position, but just consider that you could drop your bars and all that may happen is your arms go straight (which often means your head is HIGHER as your neck/shoulders can't relax) and the back doesn't change.
that said, it is free, so get out there, ride a bit, and take some photos.
that said, it is free, so get out there, ride a bit, and take some photos.
Lower really affects breathing, back, neck, maybe other stuff.
Narrow is really like you pulling your elbows in. Virtually no change in your torso or hip angle. The only thing would be out of saddle stuff - the bike will feel a bit more twitchy, the front wheel will feel like it's a 800c, not a 700c, because slightly less leverage on the bars.
From an adaptation point of view going narrow is very straightforward.
If you're not very low now then going lower usually brings the better return. In other words for most Cat 5s the first thing I'd do is to lower them. Once their torso/hip angle stuff is sort of settled then you really have to leave that alone. Narrow becomes the next thing to do.
Narrow is really like you pulling your elbows in. Virtually no change in your torso or hip angle. The only thing would be out of saddle stuff - the bike will feel a bit more twitchy, the front wheel will feel like it's a 800c, not a 700c, because slightly less leverage on the bars.
From an adaptation point of view going narrow is very straightforward.
If you're not very low now then going lower usually brings the better return. In other words for most Cat 5s the first thing I'd do is to lower them. Once their torso/hip angle stuff is sort of settled then you really have to leave that alone. Narrow becomes the next thing to do.
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Demain, on roule!
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Demain, on roule!
#1469
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there are lots of trade-offs and individual anatomy and flexibility comes into play. you can train yourself to change, of course.
can't tell you what is right or wrong, but i think you have the basics.
many people think lower is better (PRO!), but it is not always faster.
#1470
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The impetus for this question is an article somewhere - probably VeloNews - that said that Tom Boonen had gone from 46(?)cm bars to 39cm bars based on wind tunnel data. I'm built like he is...well, except for the legs.
Tall and wide.
As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?

As a long-time pro, he may be maxed out in terms of going lower, which might be the reason he went in another direction. I can still go a good bit lower on my bike. Going lower is cheaper - just relocate that last spacer under the stem, maybe going to more than a -8 degree stem. Just wondering if going narrower might be a better idea. Thoughts?
Short answer is no; save your money, train hard/er.
#1471
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That was never my assertion (see repost two below) and I avoided the power discussion twice and you keep bringing it up. And the technical discussion devolved as I said it would. Its like asking what power is needed to break a chain. No power, just force because once the chain breaks there is no power. Likewise a jump on the bike in whatever contortion a cyclist makes puts out a whole bunch of force. But watts is power and not a useful measure for finding what will snap something. Force (chain tension), the angle of the chain, angle of the dropouts, forces down and side to side on the wheel and low sheer friction between the dropouts and hub face. I really can only affect the sheer friction.
My post #1394 covered the two above:
I did confirm those are steel plates on the dropouts.
I mentioned it here, sent a few emails, and gathering data. I have the model Cav was riding available an want to see if the dropout plates are the same. The issue is how to prevent it. It happened to @hack. Yes call Specalized, - Tyler x7743 real nice guy. I emailed Extralite Sunday night. We have no special channels - cycling is not that glamorous.
We knew Daniel was not going to win that race before it started - unless Adam had flatted earlier :-)
Max UCI distance for juniors - in any UCI race is 140k. PR juniors is about 70 miles. the last section is shared with the pros. They start about half way.
It is a fraction needed to move an axel 1 inch. It’s not really Watts - its force. I think all those in that race jumping on a pedal and pulling up with the excitement of seeing the finish put out more than that. I admit - I think that after running the calculations.
This is the kind of information I was looking for:
In a stopped static situation the wheel will come out when not tightened and downward force is put on the front pedal holding the front brake.
Two times this happened coming out of the corner final sprint finish in sight - VOS and DPGP. Once following an attack coming from <20. The high watt high RPM (Cav like) was not a factor.
Yesterday he had the proper skewers I don't think it is a power thing for sure or leaning the bike. There is a bunch of bike twist going on but at 140# he's just not hitting the components with what they have not been designed for. There is an issue I don't get. This only happens on this frame. He road the KCNC all last year and won lots of Cat 3 and Cat 2 sprints. That's why I think it is the hub axil face combo with the steal drop-out plates on the Venge. I know Cav uses the Venge, but I figure he has serrated hub faces.
I am trying to figure it out. So for now - serrated washers.
I am trying to figure it out. So for now - serrated washers.
This is the kind of information I was looking for:
I can't really say how it happened to me, but it did. It was right after a hard jump for a 200m sprint. First two pedal strokes were solid then the rear just felt wobbly and soft. I coasted until the others riders came past and checked it out. The rear skewer was really loose (even though it had been tightened that morning) and the wheel was kind of just floating in the drop out. I cinched it down to what felt like normal, check it periodically, but haven't had an issue since. Maybe something happened earlier in the day or the quick release got hit and I didn't know it ... dunno, but it wasn't a fun experience.
Two times this happened coming out of the corner final sprint finish in sight - VOS and DPGP. Once following an attack coming from <20. The high watt high RPM (Cav like) was not a factor.
Last edited by Doge; 05-06-15 at 11:32 AM.
#1475
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From what i've read, the dropout aluminum sleeve/shield/whatever can be replaced and that is what specialized will prob do for you in this instance. Keep pestering them or hit up your dealer ... seems your kid and team should have a bit more clout than the average Joe and you could get this resolved ASAP.