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11 comments
I think you probably know the answer to this one already.
If it made a difference, significant or otherwise, wouldn't one of the groupset manufactures be spending an extra 2p on materials by making the wheels larger and claiming the advantage over their competitors?
If I add up the various contributions from their summary report I get a typical drivetrain loss of about 10w (making sure I don’t double count lube and chain loss figures).
Elsewhere they reckon on 98% efficiency in the drivetrain, which is 5W at a rider power of 250W.
So if we believe the claims for each individual element, we could buy all their kit and build a drivetrain that propels itself !
This suggets to me a lot of the claimed benefits are within the error bars of the measurement. I can’t confirm this because I haven’t found any data presented with error bars. Maybe it is there on the website, so if anyone else can find it please let me know.
I think any claims for percentage or absolute watts saving from any equipment depend significantly upon the base item being compared to. Here's a youtube video I saw not so long ago on the subject of oversize jockey wheels, the answer seems to be 'not really'.
3watts saving but you can get 1.34 by changing to Ceramicspeed jockey wheels (in 11t). It's on Ceramic Speed but actually data from FrictionFacts https://www.ceramicspeed.com/en/sport/inside/test-data-reports/increase-...
Hmmm...thanks for the link, but I'd rather see data from an independent source.
As above, Friction Facts isn't owned by Ceramic Speed it used to be run by Jason Smith. He's completely independent and actually runs a different company called Zero Friciton cycling; https://zerofrictioncycling.com.au/
If you can get them with a combination of efficient bearings (as efficient as your 11-tooth pulley wheel) and can ensure low-tension, amazingly they're worth around an extra 1% power.
But, shifting may be more sluggish and, for sure, you'll void your derailleur warranty.
Still, would be good to see these become standard on the big brand's chainsets. Or at least an option to the standard.
Do you have any reliable information to show they're worth 1% extra power? Everything I've seen shows there's no measurable power difference (to be fair about 0.25W is the average reading, but that's lower than the accuracy of the measurement)
I think they do look bling. So far as I know no-one makes claims of them improving shifting.
Nothing reliable, no.
But there was something on Velonews about them during this year's TdF. The report quoted the 1% figure. Have a dig around, you'll probably find it.
No-one claims improved shifting. On the contrary I wrote that shifting may be more sluggish than with standard pulleys.
I like the look of them, especially those pimped in vivid colour, but I read somewhere that, despite makers' claims, they make no significant difference to the efficiency of the drivetrain. But hey, it's a bit of fun .....