Hubs are good, but what about bottom bracket and pulleys?
Yank the seals and run light weight grease?
Buy something nice, leave the seals?
Ceramic?
Back in my day of down tube shifters and loose ball and cone bearings, and in my current day of Shimano DA hubs in my race wheels, things ran great (with a little TLC) and we didn’t need to stinkin’ ceramic anything.
Also, are we talking measurable improvements here, or am I pissing up a rope?
nothing to be gained there
you still don’t need ceramic anything
.
Hubs are good, but what about bottom bracket and pulleys?
Yank the seals and run light weight grease?
Buy something nice, leave the seals?
Ceramic?
Back in my day of down tube shifters and loose ball and cone bearings, and in my current day of Shimano DA hubs in my race wheels, things ran great (with a little TLC) and we didn’t need to stinkin’ ceramic anything.
Also, are we talking measurable improvements here, or am I pissing up a rope?
Keep your drivetrain clean and well lubed with a quality lube. Replace parts when they are worn out with good quality parts. That’s all you need. Drivetrain friction is not a place for gaining speed…
Rebecca,
Why would you think that you would all of a sudden find ‘free speed’ ?
Just keep things clean and in tune.
Maybe you should invest in these http://www.runningskirts.com/
i’ve heard of pro teams taking out the seal using running light weight grease for TT’s. The time differences between riders is usually very small in pro TT’s whereas the gaps in triathlon are HUGE so it isn’t worth the time and hassle
they do that because mechanics have always done that. it doesn’t actually help.
doesn’t hurt either though
i’ve heard of pro teams taking out the seal using running light weight grease for TT’s. The time differences between riders is usually very small in pro TT’s whereas the gaps in triathlon are HUGE so it isn’t worth the time and hassle
I think there was a VeloNews article on this test they did about the number of watts it took to turn a Record square taper BB and more modern varieties.
Not saying it’s legit, but that article helped the lore.
haven’t seen the test, but if it wasn’t under load … 
I think there was a VeloNews article on this test they did about the number of watts it took to turn a Record square taper BB and more modern varieties.
Not saying it’s legit, but that article helped the lore.
ok ok, I’ll find it…
http://www.cyclebanter.com/showthread.php?t=198020
http://autobus.cyclingnews.com/tech/?id=2006/reviews/FSA_MegaExo
.
haha…4%
hahah
those bastages
the first link seems to be a good discussion though.
the internet is great sometimes…sometimes!
On the recent subject of bearing friction, I think it’s worth taking claims of increased performance with a grain of salt. The amount of power dissipated in even a standard steel ball bearing hub is quite small. I’ve always believed this but decided to calculate it for kicks.In case you’re interested, the calculation is below.Typical coefficient of friction for a ball bearing is about mu=1.5e-3 (for example, http://www.ntnamerica.com/Engineering/PDFs/2200/frictemp.pdf)
Power dissipated in one bearing is
P1 = mu * (m/2) * g * V_bearing where mis mass of rider+bike V_bearing is linear speed the bearing rotates at.
P_bearingloss = 2*P1 total power lost in two wheels
V_bearing = V_bike * d/D d = bearing race diameter= wheel diameter
P_bearingloss = mu * mg * d/D * V_bike
P_bearingloss = C_bearingloss * mg * V_bike where C_bearingloss= mu * d/D, can be compared to C_rolling resistance of tires
For a bearing race diameter of 20 mm and wheel diameter of 668mm (700×23) C_bearingloss = 4.5e-5
for comparison, C_rolling resistance is supposed to be 4e-3for smooth pavement (e.g. from www.analyticcycling.com),or 100x higher.
For a rider+bike of 75 kg traveling at 10 m/s, I get that the power dissipated in wheel bearings is 0.33 watts. I suspect this verges on negligible. A major technological breakthrough that cut bearing friction in half would only gain 0.16 watts. It might be significant in hour records or even the pursuit world record. At my low level of competition, I think the sleep gained in not worrying about it has a greater performance benefit.
Read more: http://velonews.competitor.com/2003/12/bikes-tech/technical-qa-with-lennard-zinn-shifters-and-more-ceramic-balls_5350#ixzz0oHqWPK9l
On the recent subject of bearing friction, I think it’s worth taking claims of increased performance with a grain of salt. The amount of power dissipated in even a standard steel ball bearing hub is quite small. I’ve always believed this but decided to calculate it for kicks.In case you’re interested, the calculation is below.Typical coefficient of friction for a ball bearing is about mu=1.5e-3 (for example, http://www.ntnamerica.com/...Fs/2200/frictemp.pdf)
Power dissipated in one bearing is
P1 = mu * (m/2) * g * V_bearing where mis mass of rider+bike V_bearing is linear speed the bearing rotates at.
P_bearingloss = 2*P1 total power lost in two wheels
V_bearing = V_bike * d/D d = bearing race diameter= wheel diameter
P_bearingloss = mu * mg * d/D * V_bike
P_bearingloss = C_bearingloss * mg * V_bike where C_bearingloss= mu * d/D, can be compared to C_rolling resistance of tires
For a bearing race diameter of 20 mm and wheel diameter of 668mm (700×23) C_bearingloss = 4.5e-5
for comparison, C_rolling resistance is supposed to be 4e-3for smooth pavement (e.g. from www.analyticcycling.com),or 100x higher.
For a rider+bike of 75 kg traveling at 10 m/s, I get that the power dissipated in wheel bearings is 0.33 watts. I suspect this verges on negligible. A major technological breakthrough that cut bearing friction in half would only gain 0.16 watts. It might be significant in hour records or even the pursuit world record. At my low level of competition, I think the sleep gained in not worrying about it has a greater performance benefit.
Read more: http://velonews.competitor.com/...s_5350#ixzz0oHqWPK9l
There’s a test of wheel bearings that’s in the old “Cycling Science” archive CD (http://roadbikerider.com/cscd_page.htm) that looked at cup and cone wheel bearings (under load) in various stages of seal removal and grease vs. oil as a lubricant.
With all seals removed and using oil as a lubricant, there WAS a significant decrease in the drag…BUT, even with all seals in place and using grease (the “baseline” condition) the power requirement was still in the range of milliwatts (i.e. much < 1 W).
In other words, yeah…doing that stuff does reduce drag…it’s just that it does it on a component that has exceedingly small drag to begin with.
2X “almost nothing” is still “almost nothing” 
Oh yeah…this testing was done WAY before anyone had the silly idea putting ceramic balls in a bicycle bearing…but, it probably puts things into pretty clear context on that subject, no? 
Hubs are good, but what about bottom bracket and pulleys?
Yank the seals and run light weight grease?
Buy something nice, leave the seals?
Ceramic?
Back in my day of down tube shifters and loose ball and cone bearings, and in my current day of Shimano DA hubs in my race wheels, things ran great (with a little TLC) and we didn’t need to stinkin’ ceramic anything.
Also, are we talking measurable improvements here, or am I pissing up a rope?
Keep your drivetrain clean and well lubed with a quality lube. Replace parts when they are worn out with good quality parts. That’s all you need. Drivetrain friction is not a place for gaining speed…
What would you define as a quality lube?
Hubs are good, but what about bottom bracket and pulleys?
Yank the seals and run light weight grease?
Buy something nice, leave the seals?
Ceramic?
Back in my day of down tube shifters and loose ball and cone bearings, and in my current day of Shimano DA hubs in my race wheels, things ran great (with a little TLC) and we didn’t need to stinkin’ ceramic anything.
Also, are we talking measurable improvements here, or am I pissing up a rope?
Keep your drivetrain clean and well lubed with a quality lube. Replace parts when they are worn out with good quality parts. That’s all you need. Drivetrain friction is not a place for gaining speed…
What would you define as a quality lube?
DuPont krytox is what Zipp uses, but I think the Phil Wood grease is pretty good (but I don’t know). I always used to used Mobil1 synthetic, but I just use Park grease for most stuff now, which I think it is pretty good. Only my pedals - which is what I relube the most often, I just use the standard grease Speedplay sells.
In most cases, if you use the grease that reputable companies recommend, you will be fine. Do not use crappy white lithium grease that is like $0.50 a tube from Home Depot.
What would you define as a quality lube?
DuPont krytox is what Zipp uses, but I think the Phil Wood grease is pretty good (but I don’t know). I always used to used Mobil1 synthetic, but I just use Park grease for most stuff now, which I think it is pretty good. Only my pedals - which is what I relube the most often, I just use the standard grease Speedplay sells.
In most cases, if you use the grease that reputable companies recommend, you will be fine. Do not use crappy white lithium grease that is like $0.50 a tube from Home Depot.
Sorry - bit thick here. You’d use Krytox on the bearings on the drivetrain?
What would you define as a quality lube?
DuPont krytox is what Zipp uses, but I think the Phil Wood grease is pretty good (but I don’t know). I always used to used Mobil1 synthetic, but I just use Park grease for most stuff now, which I think it is pretty good. Only my pedals - which is what I relube the most often, I just use the standard grease Speedplay sells.
In most cases, if you use the grease that reputable companies recommend, you will be fine. Do not use crappy white lithium grease that is like $0.50 a tube from Home Depot.
Sorry - bit thick here. You’d use Krytox on the bearings on the drivetrain?
Krytox is for bearings. Grease is for bearings. Oil (IMO) is for chains. I use Ernesto lube on my chain - http://ernestolube.com/ Biodegradable and totally non-toxic.
The standard figure for drive train losses is 2%, although I’ve seen it at 3% fairly often in testing.
If, by obsessing over chains, pulleys, BBs, and hubs, we can knock that down 50%, then we’re talking about the same amount of difference as between a rear 808 and a rear disk… at a fraction of the cost. (assuming 250W FTP)
Can I knock 50% off a stock set up? I don’t know. I thought Tom A., Spackler, Senor Lento (that’s Slowman for those of you not living close to the southern border) Rapp* might have an answer.
My hunch is that I can, although there is a cost, both in $ and maintenance.
I’m sure not going to take an answer like ‘it doesn’t matter’ from some prolific poster from Austin running an AOD setup!
don’t make this harder than it needs to be…
The overwhelming component of resistance is the chain itself–and it’s also the cheapest (compared to ceramic bearings…). Use a new(ish) chain for racing. That can be a difference of 5-10 watts depending on the condition of your chain. That’s pretty significant.
Everything else is just scraps. Though if it makes you feel better, go get a DA 7703 rear derailleur (the triple derailleur with the giant pulleys). It’ll probably save you a fraction of a watt as well.
The standard figure for drive train losses is 2%, although I’ve seen it at 3% fairly often in testing.
If, by obsessing over chains, pulleys, BBs, and hubs, we can knock that down 50%, then we’re talking about the same amount of difference as between a rear 808 and a rear disk… at a fraction of the cost. (assuming 250W FTP)
Can I knock 50% off a stock set up? I don’t know. I thought Tom A., Spackler, Senor Lento (that’s Slowman for those of you not living close to the southern border) Rapp* might have an answer.
My hunch is that I can, although there is a cost, both in $ and maintenance.
I’m sure not going to take an answer like ‘it doesn’t matter’ from some prolific poster from Austin running an AOD setup!
Rapp and others have already said that nothing of dire importance in regards to speed gains is gonna take place with the chain/drivetrain outside of keeping it clean and lubed or they would have found it already and said so. some people will never learn.
quit with the excuses already, TRAIN HARDER AND YOU WILL GET FASTER.