Ask your small, random, track-related questions here
#4126
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Many roadies who come to the track experience a lot of early success in the beginner and intermediate races based on their fitness. This (unfortunately) solidifies their impression that "Track racing is easy-peasy." Only when they are matched with racers of similar fitness but who specialize in track do they start losing.
That's why I said scratch race may be a mixed bag of results.....I think he would get crushed in a proper match sprint race, but could do very well in another sprint like event without bringing too much endurance into it....the scratch race. Don't know if he would be 1st or not, but I suspect he could podium...the times would be very close either way.
As Carleton pointed out - Cav is a two-time world champion in the madison (with two different partners). He won one of them more endurance style (1 point, but had a lap over the field) with 2nd and 3rd taken by pro 6-day racer pairs and the second one with a well known endurance rider (Wiggins) as a partner, which they won on points from sprints and had a lap along with the other leading teams (which also included many 6-day pros). I wouldn't bet much against Cavendish in any kind of track endurance race against anybody.
#4127
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Parts ID help needed
Not sure what the technical name is for this part, but I need to order a new one and figured someone here would know what it is and where to get a replacement. It is on a Dura Ace rear track hub, basically, it's the inside track nut on the rear axle. It has serrations on it that are in contact with the inside of the drop out and they are worn down, resulting in a pulled wheel under heavy acceleration. I have attached a few pictures so you can see the nut. It looks like it's separate from the nut behind it and can be replaced like the outter track nuts.
#4128
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It's called the "grip nut" and yes, they do wear down and cause slipping. This also leads to the bearing cones being tightened when the wheel is tightened leading to seizing, and thus constant adjustment with the cone wrenches.
This is normal wear and tear. One the same order get more track nuts as well. Make sure that you order the correct pitch nuts. Front/rear Dura Ace threading is different.
This is normal wear and tear. One the same order get more track nuts as well. Make sure that you order the correct pitch nuts. Front/rear Dura Ace threading is different.
#4129
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If you want the actual part numbers to order the parts yourself, I'd ask over in Bike Mechanics and ask for part numbers.
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Shimano Code Y23U06000. Try asking your LBS to order it.
https://wheelsmfg.com/tech/PDF/hub/hb-7600.pdf
https://wheelsmfg.com/tech/PDF/hub/hb-7600.pdf
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Thank you. My local bike shop said they would order them if they had a part number, but they weren't familiar with track hubs and understood if I got them from a shop that specializes in track stuff and had them in stock.
#4132
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Track hubs aren't that much different than any others. Especially the axles, nuts, and bearings, etc...
It's a Shimano loose ball bearing hub. If they can't work on that, I wouldn't trust them with bigger stuff.
#4133
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Is this your hub?
https://bike.shimano.com/media/techdo...9830672572.pdf
If so it shows rear hub part numbers.
https://bike.shimano.com/media/techdo...9830672572.pdf
If so it shows rear hub part numbers.
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Does anyone have any good data regarding the gains from using aero tubing vs round tubed frames?
Round tubes can come in steel, aluminum, or carbon. Here is Andy Lakatoh's round-tubed carbon Parlee that he used in 2011:
Round tubes can come in steel, aluminum, or carbon. Here is Andy Lakatoh's round-tubed carbon Parlee that he used in 2011:
Last edited by carleton; 07-11-17 at 01:02 AM.
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I've seen data on tube shape in wind tunnels. Specialized produces a lot since they have their wind tunnel and like to use the data to sell the bikes.
That said, everything I have read shows that aeroframes can reduce drag and the watts needed to propel the bike. However, most of the data is presented in the number of seconds saved over a 40k TT.
I haven't seen any data as to how that translates to a sprint, scratch, crit... Still, any energy savings is likely to be beneficial. In many cases, it is the accumulated savings from an aero helmet, wheels, frame... that make the difference.
That said, everything I have read shows that aeroframes can reduce drag and the watts needed to propel the bike. However, most of the data is presented in the number of seconds saved over a 40k TT.
I haven't seen any data as to how that translates to a sprint, scratch, crit... Still, any energy savings is likely to be beneficial. In many cases, it is the accumulated savings from an aero helmet, wheels, frame... that make the difference.
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Here they did a test that's not scientific, but pretty decent. How aero is aero? - BikeRadar USA
The difference for the frames between the road helmet and the aero helmet are .0235 and .0224, so using their data the frame is worth about .023CdA
The difference for the frames between the road helmet and the aero helmet are .0235 and .0224, so using their data the frame is worth about .023CdA
#4137
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Just as with most things I think there's more to the equation. I remember back 6/7 years ago because I was looking at them, I saw that Cervelo's non aero tubed R5 tested to be just as aero as the aero tubed S series bikes.
But the Specialized Win Tunnel test
is the best comparison that I've seen that isolates the frame. 50s over a 40km TT is a lot. Also consider that those tests usually mean an average speed of 40kph. So at track speeds where aero matters (TT and off the front efforts that are usually high 50-60+kph) the difference can be higher as the faster you go the more that aero matters. No doubt the data is out there in the hands of the likes of BT, British Cycling, Look etc, but I doubt we'd get to see it
But the Specialized Win Tunnel test
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I've seen data on tube shape in wind tunnels. Specialized produces a lot since they have their wind tunnel and like to use the data to sell the bikes.
That said, everything I have read shows that aeroframes can reduce drag and the watts needed to propel the bike. However, most of the data is presented in the number of seconds saved over a 40k TT.
I haven't seen any data as to how that translates to a sprint, scratch, crit... Still, any energy savings is likely to be beneficial. In many cases, it is the accumulated savings from an aero helmet, wheels, frame... that make the difference.
That said, everything I have read shows that aeroframes can reduce drag and the watts needed to propel the bike. However, most of the data is presented in the number of seconds saved over a 40k TT.
I haven't seen any data as to how that translates to a sprint, scratch, crit... Still, any energy savings is likely to be beneficial. In many cases, it is the accumulated savings from an aero helmet, wheels, frame... that make the difference.
But, those folks are in aerobars and grind away at 90RPM. In talking with Mr. Tiemeyer he explained to me that the legs make a lot of turbulence...which I think was the reason they got rid of the top tube in the GT Superbike.
I remember seeing one chart that listed the best bang for the buck aero equipment upgrades. Front wheel, helmet, skinsuit, shoe booties were high up on the gain/$ ratio and rear disc, frame, and ceramic bearings were low. I'll see if I can find it.
So, to compare
- Aerobars
- 40kph/25mph
- 80-100 RPM
with
- Drop Bars
- 65kph/40mph
- 130-145 RPM
is tough. Lots more turbulence being churned up with the legs.
Here they did a test that's not scientific, but pretty decent. How aero is aero? - BikeRadar USA
The difference for the frames between the road helmet and the aero helmet are .0235 and .0224, so using their data the frame is worth about .023CdA
The difference for the frames between the road helmet and the aero helmet are .0235 and .0224, so using their data the frame is worth about .023CdA
Just as with most things I think there's more to the equation. I remember back 6/7 years ago because I was looking at them, I saw that Cervelo's non aero tubed R5 tested to be just as aero as the aero tubed S series bikes.
But the Specialized Win Tunnel test https://www.youtube.com/watch?v=XE_GKePa3CQ is the best comparison that I've seen that isolates the frame. 50s over a 40km TT is a lot. Also consider that those tests usually mean an average speed of 40kph. So at track speeds where aero matters (TT and off the front efforts that are usually high 50-60+kph) the difference can be higher as the faster you go the more that aero matters.
But the Specialized Win Tunnel test https://www.youtube.com/watch?v=XE_GKePa3CQ is the best comparison that I've seen that isolates the frame. 50s over a 40km TT is a lot. Also consider that those tests usually mean an average speed of 40kph. So at track speeds where aero matters (TT and off the front efforts that are usually high 50-60+kph) the difference can be higher as the faster you go the more that aero matters.
It's also possible to get the aerodynamics wrong. I have a budget 5-spoke and wonder if it's any faster than other options knowing that just because it's 5-spoke doesn't make it faster.
Remember Aerospokes? (this isn't the one I have)
They are inexpensive, easy to find, yet they are rare on the competitive track racing scene. I think these were proven (or at least believed) to be pretty slow.
Early Team GB Superbikes used custom wide (38-40cm?) handlebars. But then there are pics with Hoy using 34cm Nittos in comp. Then Alpina started making the 33cm Sprint bars around the same time that 35 and 37cm Scattos came out.
I wish I had access to a wind tunnel or some college students did a proper experiment but at 130RPM in narrow drop bars as opposed to 90RPM in aerobars. 2 track bikes (one aero one round), same rider, same wheels, same bars, same position, simulating a flying 200 or scratch race finish, 130rpm, 30mph and 40mph.
I'm curious to know if the gains are on the order of 10%, 1%, 0.1%, or 0.01%.
Last edited by carleton; 07-11-17 at 07:54 PM.
#4139
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Here's one that's been bouncing around for years. Source: https://speedissafety.blogspot.com/2...-for-buck.html
Aero frame is the least effective of all. Ironically, it's one of the most expensive.
Same data:
Basically, it's because the air around the frame is so "dirty" from:
- The front wheel chopping it up.
- Bars and arms splitting it up.
- Your chest acting as a big scoop pushing air down into your legs.
- Legs whipping it up.
that a super slick frame has a really difficult job trying to clean it all up.
Aero frame is the least effective of all. Ironically, it's one of the most expensive.
Same data:
Basically, it's because the air around the frame is so "dirty" from:
- The front wheel chopping it up.
- Bars and arms splitting it up.
- Your chest acting as a big scoop pushing air down into your legs.
- Legs whipping it up.
that a super slick frame has a really difficult job trying to clean it all up.
#4140
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@brawlo, I found this from 2012:
Olympics track cycling: Will technology win the war for GB? - BBC Sport
So, you are right.
My google-fu is pretty good, but I can't seem to find any pics, much less videos, of sprinters in a wind tunnel with drop bars.
With the Flying 200 being faster and the margins for making the cut getting smaller than ever, I'd imagine that they are all in the wind tunnel cranking it up to 45mph/75kph!
EDIT:
another:
https://www.telegraph.co.uk/sport/oly...g-success.html
It's worth noting that Hoy or Pendleton didn't ride any events with aerobars in 2012. They only did F200M, Sprints, Team Sprint, and Keirin...all in drop bars. So, it's safe to say that all of that wind tunnel time was in drop bars.
Extensive use of wind tunnels has helped show the top British riders how they can make small tweaks to their position on the bike in return for sizeable gains in time and aerodynamics.
"The riders are totally involved in the process and they understand the value of it," says Boardman.
"They've all been to the wind tunnel to look at their position. A tiny change to their elbow can mean more than changing the entire bike. But they won't make changes lightly, so we take them to the wind tunnel to prove to them the benefits.
"When they see the difference, they'll force themselves into a more uncomfortable position if it seems faster, then make an informed decision about where to draw the line between efficiency and aerodynamics."
"The riders are totally involved in the process and they understand the value of it," says Boardman.
"They've all been to the wind tunnel to look at their position. A tiny change to their elbow can mean more than changing the entire bike. But they won't make changes lightly, so we take them to the wind tunnel to prove to them the benefits.
"When they see the difference, they'll force themselves into a more uncomfortable position if it seems faster, then make an informed decision about where to draw the line between efficiency and aerodynamics."
So, you are right.
My google-fu is pretty good, but I can't seem to find any pics, much less videos, of sprinters in a wind tunnel with drop bars.
With the Flying 200 being faster and the margins for making the cut getting smaller than ever, I'd imagine that they are all in the wind tunnel cranking it up to 45mph/75kph!
EDIT:
another:
"Chris Hoy's done eight-hour days sitting in a wind tunnel, helping us develop things and improving his own position and committing for four years to change his own position to make himself smaller, because that makes the biggest difference.
"Vicky Pendleton has done the same. They've all been through.
"The rest of the world has known since Beijing – well, they should've known forever – aerodynamics is a massive part of our sport.
"They're doing 50 to 70kph depending on the event, so why aren't wind tunnels a standard component in training? It's ridiculous.
"Vicky Pendleton has done the same. They've all been through.
"The rest of the world has known since Beijing – well, they should've known forever – aerodynamics is a massive part of our sport.
"They're doing 50 to 70kph depending on the event, so why aren't wind tunnels a standard component in training? It's ridiculous.
It's worth noting that Hoy or Pendleton didn't ride any events with aerobars in 2012. They only did F200M, Sprints, Team Sprint, and Keirin...all in drop bars. So, it's safe to say that all of that wind tunnel time was in drop bars.
Last edited by carleton; 07-11-17 at 08:59 PM.
#4141
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And Joe Public isn't going to see any of that research , probably ever
#4142
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Check through the Journal's topic I created a few years ago. There was a link to a huge Thesis by L Underwood (The University of Canterbury NZ) called Aerodynamics of Track Cycling. Been a while since I've read through it so not sure if it has what you seek, but would be a great place to start.
#4143
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Check through the Journal's topic I created a few years ago. There was a link to a huge Thesis by L Underwood (The University of Canterbury NZ) called Aerodynamics of Track Cycling. Been a while since I've read through it so not sure if it has what you seek, but would be a great place to start.
I just skimmed through maybe 20 of them. A few mention frontal area but no mention of bike aerodynamics that I saw.
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I know Carleton's take on this, and I've done some searches on this, but what is everyone else's thought on having power on your track bike?
I have some extra cash and a hook up to get a discount on an SRM. I have SRMs on both my road bikes and have been training with power for close to 10 years now. I'm just newer to the track.
I get the argument that cadence, speed, and time are the most important factors, but sometimes it's hard to get accurate time data when out training, and part of me is craving to see my power numbers. At the same time, I have been told by a couple people, Carleton among them, that having power on the track is a nice luxury, but if you're doing your intervals at home on the road bike with a PM, then I should be good.
Thoughts?
I have some extra cash and a hook up to get a discount on an SRM. I have SRMs on both my road bikes and have been training with power for close to 10 years now. I'm just newer to the track.
I get the argument that cadence, speed, and time are the most important factors, but sometimes it's hard to get accurate time data when out training, and part of me is craving to see my power numbers. At the same time, I have been told by a couple people, Carleton among them, that having power on the track is a nice luxury, but if you're doing your intervals at home on the road bike with a PM, then I should be good.
Thoughts?
#4146
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#4147
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Now I have a mix of wired and wireless SRM's on my TT bike, CX bike and wired track SRM's on both track bikes! If familiar with power training and metrics and will effectively review and use the data why not? Especially if you can get it for a good price!
#4148
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I know Carleton's take on this, and I've done some searches on this, but what is everyone else's thought on having power on your track bike?
I have some extra cash and a hook up to get a discount on an SRM. I have SRMs on both my road bikes and have been training with power for close to 10 years now. I'm just newer to the track.
I get the argument that cadence, speed, and time are the most important factors, but sometimes it's hard to get accurate time data when out training, and part of me is craving to see my power numbers. At the same time, I have been told by a couple people, Carleton among them, that having power on the track is a nice luxury, but if you're doing your intervals at home on the road bike with a PM, then I should be good.
Thoughts?
I have some extra cash and a hook up to get a discount on an SRM. I have SRMs on both my road bikes and have been training with power for close to 10 years now. I'm just newer to the track.
I get the argument that cadence, speed, and time are the most important factors, but sometimes it's hard to get accurate time data when out training, and part of me is craving to see my power numbers. At the same time, I have been told by a couple people, Carleton among them, that having power on the track is a nice luxury, but if you're doing your intervals at home on the road bike with a PM, then I should be good.
Thoughts?
Like you I had an SRM on my road bike close to 10 years now too (wired Pro unit bought used still going strong).
Now I have a mix of wired and wireless SRM's on my TT bike, CX bike and wired track SRM's on both track bikes! If familiar with power training and metrics and will effectively review and use the data why not? Especially if you can get it for a good price!
Now I have a mix of wired and wireless SRM's on my TT bike, CX bike and wired track SRM's on both track bikes! If familiar with power training and metrics and will effectively review and use the data why not? Especially if you can get it for a good price!
Also, for me it wasn't just about, "Well, I have a power meter, may as well use it...". I found that if I sold that power meter, I could use that money for other training/race related things (aero wheels, travel, coaching, etc...).
@topflightpro, you are an experienced cyclists but a new racer on the track. There are several things that you can do that are almost guaranteed to make you faster, stronger, fitter, and a better track racer that are covered in this tread. Maybe consider the power meter a finishing touch as opposed to being the thing that makes you fast?
If you have:
- Annual track pass
- A complete kit of chainrings, cogs, tools
- Home training gear (trainer, rollers)
- Skinsuits
- Aero front wheel
- Aero helmet
- Coaching (This speeds up the learning curve.)
- Shoe booties
- Different crank lengths, bars, etc... to experiment with to see what's best for your style and body type.
- Professional bike fit (by someone who knows how to fit for track) to get you aero and powerful.
- Travel expenses to race at other tracks (experience will win you more races than power).
Then a power meter would be a finishing touch
Last edited by carleton; 07-12-17 at 09:26 AM.
#4149
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Judging from what I've seen at my local track, plenty of others agree. So if you see value in it and the cost isn't prohibitive go for it.
#4150
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5kph out of 77kph is 6.5% faster on the track than the road. Power relates to velocity by the cube, so a 6% increase in speed is represented by a 21% increase in power. The difference between 1400W and 1700W is about 21%, so that seems about right. A good road sprinter, at the end of a sprint, might put out 1300-1400W. A good track sprinter, fresh, on a flying 200 run might put out 1700W. Again, seems about right. Call it a wash between the aero gear/track surface of a track sprinter and the leadout of a road racer.
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Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter