A no go, or a yes go for this pulley (re)invention?

[Kayrehn]

Doesn't make a difference, will fit them all.

Sent from my SM-G900F using Tapatalk

[BhSimon]

Project to try is take a long cage RD6770 and throw in a 15t lower pulley and will have a play around with sizes up top.

Will have to alter the cage a little, but could work. Has anyone tried this, or know of any potential limitations?

Sounds like an interesting project. Give it a try.

Is there a lip on the inside place of the long cage derailleur? You may need to cut that off or file it down to install a larger-diameter pulley wheel. Shouldn't be too difficult to do, though. I'm guessing this will work out a lot cheaper, too.

[reknop]

http://www.fouriers-bike.com/en/pro.php?m=d&pid=302&cid=52&f=2

The Ultimate Ceramic Bearings SPEEDCAGE FOR SHIMANO ultegra mechs 6800/6870 and DuraAce 9000/9070 looks very similar in design and pricepoint. http://www.ultimateceramicbearings.co.uk/category.php?id_category=117

[wheelsONfire]

Seems there is alot of copies since Berner came out with his 13+15.

It still opens up for a question,... why is this not seen at the later versions of Campa, Shimano and wireless Red Rd's if it's so great!?

[Kayrehn]

Guy who fixed it up for me says it places more stress on the rear derailleur body, not sure if that's true...

Sent from my SM-G900F using Tapatalk

[wheelsONfire]

Guy who fixed it up for me says it places more stress on the rear derailleur body, not sure if that's true...

Sent from my SM-G900F using Tapatalk

Interesting!

Have you noticed any real gains or downsides?

[Kayrehn]

Nope, I don't think the effect is noticeable but I believe in the science showing small watts savings with it.

Sent from my SM-G900F using Tapatalk

[cannondale85]

Is it effective or placebo? Thanks!

[refthimos]

I have one barely used for sale for $400 if anyone is looking for one of these.

[cannondale85]

But does it works?

[nathanong87]

But does it works?

does it shift? and function? yes probably
does it save watts? yes probably
does it cost alot? depending on brand yes probably
does it look sweet? yes it does

even if it didn't do anything. it looks fast. and looking fast = feeling fast = going fast

that fourier joint is cheap enough that i dig it.

[KidKarbon]

I have moved from the Berner to the OSPW its most certainly interesting, it's sprung lighter than a normal Shimano DA pulley as such the chain runs slightly looser and I question if this reduces the friction and is part of the bold claims.
The biggest impact that it has for me is that it has made shifting super slick
Certainly not worth the money though imho

[ebsilon]

Hello All

I have heard from a VERY reliable source that the CS OPWS is very soft in the cage making it hard to fine tune the RD.

But about OPWS in general:

Does it work (saves power) - probably not

Is it a WW dream - nope, OPWS adds weight

Is it cheap - no

Are there some advantages???

Yes, one - it looks so GOOOOOOD

[DMF]

Wouldn't a Fourier cage, running an 11t upper pulley see a lot less gains than something running a 13t or bigger upper pulley. Both with let's say a 15t lower pulley...

Haven't got the actual numbers handy, but from memory tests showing the difference in drive train losses between riding the 11t cog versus the 12t cog on a cassette are just huge...

For those uninitiated in this thread, or disbelievers of the large pulleys, it's mostly in bending the chain thru that tight loop where the losses seem to happen.

Try riding a singlespeed with and then without a dual pulley chain tensioner (á la Rohloff), the difference is extremely noticeable...

[TheKaiser]

Wouldn't a Fourier cage, running an 11t upper pulley see a lot less gains than something running a 13t or bigger upper pulley. Both with let's say a 15t lower pulley...

Haven't got the actual numbers handy, but from memory tests showing the difference in drive train losses between riding the 11t cog versus the 12t cog on a cassette are just huge...

For those uninitiated in this thread, or disbelievers of the large pulleys, it's mostly in bending the chain thru that tight loop where the losses seem to happen.

Try riding a singlespeed with and then without a dual pulley chain tensioner (á la Rohloff), the difference is extremely noticeable...

I agree with everything you have said, however I would like to add that the comparison to 11t/12t cassette cog has to be taken cautiously, as the amount of tension on the chain while interacting with drive cog is far higher than with the derailleur pulleys. In other words, the relative difference in friction may be comparable, but the absolute difference will be substantially different.

Also, as someone else mentioned above, part of the improvement with these cages is not from the change in pulley size and reduced link articulation, but instead comes from the softer spring which results in less tension on the lower run of chain, which touches on my first point.

Good point about the single speed comparison. I would love to see some numbers on this if anyone has run any tests comparing with/without tensioner.