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Derailleur pulley upgrades and tire replacements
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Due to a knee injury that kept me off the TT bike for a good two years, I'm looking at doing my first ITT in three years. There are certain consumables I need to replace, and I would like to get suggestions for both pulley wheels and tires.

For the pulley, I'm currently running 6870 Ultegra Di2 derailleur. The derailleur has maybe 50 hours of use, but there's a part of me that is concerned about the pulley wheels that come on the derailleur, as a previous 6770 derailleur (bought used) had pulleys that deteriorated to the point of being very draggy over a period of two years (although it could have happened sooner, don't know b/c I didn't bother to check until quite a bit later). I don't need a fancy a set of fancy Cceramic Speed pulleys, but was wondering if there are any other suggestions. Otherwise i'll be buying the Dura Ace 9000 pulleys.

Also, I have tires from three years ago, the original Vittoria Corsa Speed tires. All in all, I probably have three short TT races (10 milers each) and maybe another 500 miles of training on them. Any ideas as to when I should swap them? Don't want to be pissing away crr watts (due to aging and usage of the tire). Also, I presume that I could just keep on using the 1st Gens, as these are quite fast (and cheap to boot)? I guess I could also spring for GP 5000s, but those don't come in a 23 mm width. I'd estimate that I may be racking up ~350 TT racing miles this year, and maybe a few more just noodling around town.

Thanks in advance
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Re: Derailleur pulley upgrades and tire replacements [echappist] [ In reply to ]
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Was the bike kept inside or outside? Are the tires cracked at all?

I've got 23mm GP 5000s on my track bike so they are available.
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Re: Derailleur pulley upgrades and tire replacements [jaretj] [ In reply to ]
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Inside at all times, but a good chunk of it was inside a garage. So subjected to changes in temperature and humidity

As for the GP 5000, you are correct about regular clinchers. But apparently they didn't bother making a 23 mm for the 5000 tubeless
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Re: Derailleur pulley upgrades and tire replacements [echappist] [ In reply to ]
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Ceramic Speed went and tested the bearing drag in a number of 11t pulleys. I'm not sure what year the test was done, but they did show that going from Ultegra to DA pulleys was worth something like half a watt (for both pulleys). The DA pulleys have steel ball bearings in both pulleys. The Ultegra pulleys had steel balls in one and a bushing in the other.

Now, recall that both DA and Ultegra had generational changes pretty recently. So the pulley construction might differ from when that test was done. I'm looking at Competitive Cyclists's site and I see that current generation DA pulleys are $35 versus $18.44 for current generation Ultegra. I'm going to guess that the difference described in that article probably holds. I'm not willing to pull apart my two sets of new R8k pulleys to find out, I'm afraid.
Last edited by: weiwentg: Feb 4, 20 14:10
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Re: Derailleur pulley upgrades and tire replacements [weiwentg] [ In reply to ]
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weiwentg wrote:
Ceramic Speed went and tested the bearing drag in a number of 11t pulleys. I'm not sure what year the test was done, but they did show that going from Ultegra to DA pulleys was worth something like half a watt (for both pulleys). The DA pulleys have steel ball bearings in both pulleys. The Ultegra pulleys had steel balls in one and a bushing in the other.

Now, recall that both DA and Ultegra had generational changes pretty recently. So the pulley construction might differ.
thanks for the chart; first time i've seen it
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Re: Derailleur pulley upgrades and tire replacements [echappist] [ In reply to ]
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Quick plug for my local guy...

https://www.slfmotion.com/.../hyper-pulley-wheels
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Re: Derailleur pulley upgrades and tire replacements [echappist] [ In reply to ]
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echappist wrote:
...I guess I could also spring for GP 5000s, but those don't come in a 23 mm width. I'd estimate that I may be racking up ~350 TT racing miles this year, and maybe a few more just noodling around town...

I just noticed this bit. Happily, you're wrong! 23mm GP 5ks exist as documented on Bicycle Rolling Resistance. I'm not saying you have to upgrade your tires, mind you. Save that for next time!
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