Please don’t make this a rim vs disc bloodfest. Stage 17 won with rim brake

Discuss light weight issues concerning road bikes & parts.

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Knightyboy27
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by Knightyboy27

Have tried using this tool before to see the differences it might make

http://bikecalculator.com/

All things equal, bar bike weight, you could feasibly say that because the disc brake builds can't be made to 6.8kg, and the rim can, just on the last km or so, you're talking about a few seconds.

Pogacar won the stage by 2 seconds (I know he sat up a bit at the end)

Those extra 100s of grams could really be the difference in finishes like this!

joejack951
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by joejack951

rollinslow wrote:
Fri Jul 16, 2021 1:13 am
Even if you were to swap a disc wheel from a teammate there is no guarantee if will not just rub the whole way due to alignment issues and tolerance variation. On a critical stage, you need rim brakes. No surprise here. They want to win. No just make statements for marketing materials on instagram.
Any decent mechanic could ensure that all team bikes are set up such that at least front wheels swap without rubbing issues (and minor rubs with discs are inconsequential unlike with rim brakes). And if wheel swaps are such a concern, why not use a lever-style axle that doesn’t need an allen key? This just seems so obvious.

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corky
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by corky

joejack951 wrote:
Fri Jul 16, 2021 4:15 pm
rollinslow wrote:
Fri Jul 16, 2021 1:13 am
Even if you were to swap a disc wheel from a teammate there is no guarantee if will not just rub the whole way due to alignment issues and tolerance variation. On a critical stage, you need rim brakes. No surprise here. They want to win. No just make statements for marketing materials on instagram.
Any decent mechanic could ensure that all team bikes are set up such that at least front wheels swap without rubbing issues (and minor rubs with discs are inconsequential unlike with rim brakes). And if wheel swaps are such a concern, why not use a lever-style axle that doesn’t need an allen key? This just seems so obvious.
It's got v.little to do with initial setup......those thin Shimano rotors warp through usage, heating up cooling down...... any rubbing maybe inconsequential to you but not to everyone....just ask Chris Froome.

rollinslow
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by rollinslow

tomato wrote:
Fri Jul 16, 2021 5:11 am
rollinslow wrote:
Fri Jul 16, 2021 1:13 am
On a critical stage, you need rim brakes.
So, all those stages where they used disc brakes weren't critical?
Exactly. The tour in won on the big climbs. A disc or wheel issue could have been the end for Pog. It's not like he did the switch just for fun.
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tomato
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by tomato

rollinslow wrote:
Fri Jul 16, 2021 5:18 pm
tomato wrote:
Fri Jul 16, 2021 5:11 am
rollinslow wrote:
Fri Jul 16, 2021 1:13 am
On a critical stage, you need rim brakes.
So, all those stages where they used disc brakes weren't critical?
Exactly. The tour in won on the big climbs. A disc or wheel issue could have been the end for Pog. It's not like he did the switch just for fun.
I guess they shouldn't bother with the other stages then.

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Lewn777
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by Lewn777

Why would a cycle team spend thousands of Euros transporting a bunch 'outdated' bicycles around France for no reason unless there was something about them that they preferred for certain conditions? It could be faster wheel changes or a lighter bike or a mixture of reasons, you'd have to ask them. :noidea:

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naylor343
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by naylor343

I was interested to see that during last Sunday's stage to Andorra, Chris Froome changed his bike before the climb of the Puymorens from a disk bike to rim brake, not that it made much difference to his overall finishing position. I can only think it was due to him being fed up with rotors rubbing. He did not appear to have had a puncture at this time. I then read this afternoon that he was spotted using magura calipers during this week, in place of shimano for the same reason, rotor rub.

tomato
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by tomato

Lewn777 wrote:
Fri Jul 16, 2021 7:43 pm
Why would a cycle team spend thousands of Euros transporting a bunch 'outdated' bicycles around France for no reason unless there was something about them that they preferred for certain conditions? It could be faster wheel changes or a lighter bike or a mixture of reasons, you'd have to ask them.
Pro athletes are a funny bunch. They sometimes do things for almost trivial reasons.

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Lewn777
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by Lewn777

tomato wrote:
Fri Jul 16, 2021 8:20 pm
Lewn777 wrote:
Fri Jul 16, 2021 7:43 pm
Why would a cycle team spend thousands of Euros transporting a bunch 'outdated' bicycles around France for no reason unless there was something about them that they preferred for certain conditions? It could be faster wheel changes or a lighter bike or a mixture of reasons, you'd have to ask them.
Pro athletes are a funny bunch. They sometimes do things for almost trivial reasons.
They may be a funny bunch, but the management would still need to sign off' on the expense. Surely if there was no gain, then manager would just say 'your bike is perfectly good enough please use the one you have been provided with'. The only way the management could be convinced of extra expenditure would be if they could understand any advantage - essentially you'd likely need a well rounded argument, more than a whim or preference.
Dragging an extra rim brake bike around France for mountain stages would be similar to providing a TT bike for specific days.

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C36
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by C36

Multiple reasons (not knowing the one that applies to UAE) may exist…
- riders may prefer the responsiveness of the rim frames (was the case of Movistar 3 leaders or Uran before Cannondale twist their arms).
- they measured the rim bikes as more performant (a bit on aero, another bit on weight or rider feel-yes it impacts performance-), was the case of Ineos.
- I rarely heard the teams I know mentioning about wheel changes but that is clearly a plus that doesn’t hurt.

rollinslow
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by rollinslow

Say you are on a big climb, narrow road, no team car. Have a puncture and need a wheel. If you're on rim, it's just pop the quick release and take from your teammate. Gone in under 1 min. If you're on disc, it's not that simple (alignment issues in particular, but just getting your thru axle out unless you have your riders carrying a 5mm hex). Rotor alignment can't be the same because you also have to account for pad wear between bikes plus the hub quality and tolerances must be extremely tight for them to be equal.

Since the stages where disc performance would be most useful are the ones you would need rim to practically have your best shot at winning it makes the disc argument for professionals less relevant.

To get wheels on 10 plus bikes to be interchangeable with no disc rub would be a huge or impossible endeavor. That's a pretty good reason when you actually want to win the TdF. On a flat or less climbing stage you have the car and just take a new bike. You can't count on that high in the mountains.
Last edited by rollinslow on Fri Jul 16, 2021 10:26 pm, edited 2 times in total.
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tomato
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by tomato

Lewn777 wrote:
Fri Jul 16, 2021 9:27 pm
tomato wrote:
Fri Jul 16, 2021 8:20 pm
Lewn777 wrote:
Fri Jul 16, 2021 7:43 pm
Why would a cycle team spend thousands of Euros transporting a bunch 'outdated' bicycles around France for no reason unless there was something about them that they preferred for certain conditions? It could be faster wheel changes or a lighter bike or a mixture of reasons, you'd have to ask them.
Pro athletes are a funny bunch. They sometimes do things for almost trivial reasons.
They may be a funny bunch, but the management would still need to sign off' on the expense.
The expense of adding a rim-brake bike for 3 or 4 riders wouldn't be very much in the big picture.

tomato
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by tomato

rollinslow wrote:
Fri Jul 16, 2021 10:18 pm
Say you are on a big climb, narrow road, no team car. Have a puncture and need a wheel. If you're in rim, it's just pop the quick release and take from your teammate. Gone in under 1 min. If you're on disc, it's not that simple. That's a pretty good reason when you actually want to win the TdF. These things matter.
Again, if it was just about teammates sharing wheels, they could do it by using wrench-free thru axles.

rollinslow
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by rollinslow

tomato wrote:
Fri Jul 16, 2021 10:25 pm
rollinslow wrote:
Fri Jul 16, 2021 10:18 pm
Say you are on a big climb, narrow road, no team car. Have a puncture and need a wheel. If you're in rim, it's just pop the quick release and take from your teammate. Gone in under 1 min. If you're on disc, it's not that simple. That's a pretty good reason when you actually want to win the TdF. These things matter.
Again, if it was just about teammates sharing wheels, they could do it by using wrench-free thru axles.
It's not the simple. Do you own a disc bike? I do and have multiple wheelsets. You don't just grab and go with no rub or issues. Pad wear, alignment tolerances, etc.
Moots Vamoots RSL (2019)-Super Record 12
Cervelo S1 (2010)-Super Record 12 (viewtopic.php?f=10&t=161577)
Kestrel RT700 (2008)-Dura Ace 9000
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tomato
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by tomato

rollinslow wrote:
Fri Jul 16, 2021 10:27 pm
tomato wrote:
Fri Jul 16, 2021 10:25 pm
rollinslow wrote:
Fri Jul 16, 2021 10:18 pm
Say you are on a big climb, narrow road, no team car. Have a puncture and need a wheel. If you're in rim, it's just pop the quick release and take from your teammate. Gone in under 1 min. If you're on disc, it's not that simple. That's a pretty good reason when you actually want to win the TdF. These things matter.
Again, if it was just about teammates sharing wheels, they could do it by using wrench-free thru axles.
It's not the simple. Do you own a disc bike? I do and have multiple wheelsets. You don't just grab and go with no rub or issues. Pad wear, alignment tolerances, etc.
Yes, I've got 2 bikes with disc brakes and my wife has one. I can swap wheels without any problems.

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