http://www.digirit.com/Products/PulleyWheelKit

I have one installed on my bike, on a DA-9070 di2 rear derailleur. Works great. No testing data on it, but assuming that the friction reduction is largely from pulley wheel size anyways - should be similar. Worst case scenario, it's not making me slower.

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MS: Exercise Science
Your speed matters a lot, sometimes you need to be very fast, where sometimes you need to breakdown your speed.

Except for that thing called aerodynamic drag from the larger pulleys and cage

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I have some. They work fine. Double-check and loctite the screws that hold the pulley wheels in. Mine worked a little loose. Could be catastrophic to have one come out.

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My latest book: "Out of the Melting Pot, Into the Fire" is on sale on Amazon and at other online and local booksellers

how much longer did your chain have to be?

2 links for me.

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MS: Exercise Science
Your speed matters a lot, sometimes you need to be very fast, where sometimes you need to breakdown your speed.

which might be an improvement at certain yaw angles..

Science over marketing. Show me data.

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Can you show me some data that it is worse, aerodynamically? While you're at it, can you also provide the testing context?

Sorry, not my responsibility.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

Can you provide data to back up this claim?



Ah, I understand. The burden of proof is never on you to back up your claims.

That's correct. If you have an issue, please call and get in line to complain.

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Can someone explain the benefits of an oversize pulley?

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--Chris

reduced friction and a lot of money lost from your bank account.

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Thanks to all for the contribution to my question. I need to consider the cost advantage of going with Ceramic Speed over a less expensive copy. It's always R&D we pay for. I cant help but to laugh how often questions and comments turn into online scrums.

Give me a break aerodynamics of a derailleur over drag reduction??? I have one and runs fine.

You can call the complaint number and get behind James. All operators are busy and will get to you shortly.

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Looks cool. Not sure what the data says, but here are some friendly, if slightly critical, thoughts:

If you're gonna completely replace the cage and pulley, why in the world would you design a system where only ONE pulley is oversized? For max benefit, you really do want TWO oversized pulleys, otherwise the chain friction reduction is going to be very, very small. (Most, if not all, of the other high dollar pulley cage upgrades include a system in which BOTH pulleys are oversized.) Then, if you're gonna go with the budget AL models, why in the world would you make the pulley wheels with cutouts? If the pulleys are AL, you're looking at a weight savings of just .0001 grams (don't quote me on that, I just made that number up) from the cutouts. For me, far more important is the way the cutouts attract dirt, grease, and grit (which, of course, adds drivetrain friction). Plus the fact that the pulleys are probably a lot more slippery (aero-wise) when they are solid. So those two things would be deal breakers for me ... But if they were to address these things and the cost is not too crazy, it might be a nice upgrade. Hope the designers are reading this ... ;^)

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
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I have no stake in this outfit and didn't know anything about them until I saw this thread, but from looking at their offerings on ebay they also have offerings where both pulleys are oversized as well.

When you look at how much drag a drink straw adds in the tunnel, yes that big hanger could certainly hurt things.

Shifting performance?

Drag reduction resulting in a Watt or 2 savings at 250W or whatever. . Doesn't take a lot of aerodynamic drag to overshadow that.

CeramicSpeed has proven really good bearings. They're also smart on coatings. And they have a good reputation on quality and support

I'm not a CeramicSpeed fanboy by any stretch. But that's what you're getting for the extra cost if it's worth it to you.'

I'm not a CS or SLF fanboi either, but has anybody actually tested whether there are any drag penalties (or positives) from an over sized pulley system? I personally will never, ever buy one simply because the cost does not justify any "gains" but I'd still like to see data on this claim.

I haven't seen much data as far as aerodynamics on the OSWP but if it is good enough for Starky to have their BB, chain, OSWP and ceramic wheel bearing then the OSWP is good enough for me!

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Speed kills unless you have speed skills!!!

I installed one for a friend a few weeks ago, the quality seemed good to me.

He hasn't magically gained any power, we're still about the same speed. It looks cool though.

CeramicSpeed claims that the theirs was tested and the result was "net zero drag over a range of yaws" (or something like that, I'm paraphrasing). But say they can't release the data. And no one knows if that means there's increased drag at zero yaw or not.

My educated guess is that it makes no real difference with a rider on board. I heard of tests where they couldn't pick it up, but I've not done one personally. What I have seen is that going with a single ring is faster bike only and no difference with rider on. The feet and legs cause a lot of churn so anything near or behind them is in dirty air. I know I'm preaching to the choir a bit here.

To the other poster who compared a drink straw to a long cage, there is no comparison. The drink straw is basically on the leading edge which sees mostly clean air.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Sponsorship paychecks are a great thing for marketing

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I'll revert back to what I have said before on here.

The burden of proof should be on Ceramic Speed, not me. I didn't create oversized pulley wheels and claim they didn't cause drag.

They won't release the data because they don't own it. That's understandable.

Why should I have to spend money to try and debunk them?

If you don't like that answer, I don't care.

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Dude, did you have a really bad race or something? You are way to young to be this bitter. Leave that shit for the old guys like me.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I had a great race. I just don't care for people's sarcastic replies. Go find someone else to mess with.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

Oh, so what you are saying is that you are off your meds?

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

For public knowledge, I don't take any meds. Good try though. You have my number if you also want to complain.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

So the only problem i see is that they haven't released any data... is that why you're trying to strip the brand from everything they're worth???

Obviously if you dont like ceramicspeed then dont buy it, read threads of it and most importantly just leave! This will save you alot of watts i promise! Ha ha ha

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Speed kills unless you have speed skills!!!

I don't have to go anywhere. I just asked for data. Pretty simple concept.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

Then don't go anywhere, call ceramicspeed and ask them for it! I sure as hell dont have it and dont care!!! Have you even tried to contact their customer service? Emailed them?

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Speed kills unless you have speed skills!!!

Dude...go read the other threads on these pulleys.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

Wow you're taking whats on said thread as true & factual?! Something said by a hillbilly has more weight than what ceramicspeed has to say about their own products??? Yup, that makes sense to me!

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Speed kills unless you have speed skills!!!

You have no idea what you are talking about.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

First you discredited their lack of data then discredited their equipment, discredit others of knowledge... 🤔🤔🤔 are you a trump follower??? If not, surely using his tactics to make your point!

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Speed kills unless you have speed skills!!!

Sigh...you are exhausting. I said go search the forums and read the other threads discussing this.

If you did...you would know Ceramic Speed commented and said they cannot release data. Many others have discussed the pros and cons to all of this.

So....please....go read the forum

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I have seen these pop up in the past few months from many manufacturers including RockBros 17t-17t and KCNC 14T-16t. Personally I am still rocking the Berner Cage (13T-15T). I would like to run a cage that at least some aero was put into the design. Airfoils aren't rocket science at this point in the game and at least CS attempts to make a cage that looks like it uses airfoils.

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Well, this has escalated quickly...

Um

I love the sarcastic comments though. Definitely keep them coming

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Whatever you do, don't buy the KCNC. I have one and it is a monumental bodge.

- you have to shim the cage at the lower pulley to make the two cage plates parallel
- stock grease in the bearings has an unnecessarily high viscosity. With CS TT grease the bearings actually start to work
- cylindrical interface with goes into the RD is too long (21.20 vs the shimano 19.45mm) so if you tighten the bolt, the mechanism will bind
- bores for the different spring settings have edges so sharp they will eat the bushing in the RD
- NW tooth design not optimal, the wide tooth will contact the chain plate not the roller. There is no step in the wide tooth to clear the plate
- inner plate is unnecessarily thick at the top pulley (clearance for disc wheels...)
- pulleys have quite a bit of lateral float, debatable if this is a good idea or not

So I would wait for the updated version...

You don't obviously want to flip it upside down if you can avoid it. It is an option though should you need it. Fwiw, I tested this is the wind tunnel, I don't have the data of the top of my head but will post sometime about it. It was slower, as expected. Please don't message about specifics though, I am traveling for a bit and won't have that data for a while as it is home.

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Hi there,
Can I ask what size of the cassette do you have and if the b screw wad long enough? I can’t seem to figure out to gain enough clearance. I have 11-28 cassette atm. Thanks

I’ve run it with an 11-28 and an Ultegra 6700 di2 rear derailleur. Chain long enough?

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___________________________________
MS: Exercise Science
Your speed matters a lot, sometimes you need to be very fast, where sometimes you need to breakdown your speed.

Thanks for fast reply. That was my thought too. I’ve just tried it with brand new chain. 118 links. I have di2 9070. Both pulleys large. Spring setting high. B screw on max.