WickWerks Shifting Examination
Worlds Fastest Shifting Chainrings!
That’s a bold claim! With some cool technology and a lot of racing experience to back it up. Have a look at the business side (shifting side) of the chainrings in the pictures on this page, and note the special ramps. Those are not little bumps . . . Not single-point-of-contact pins . . . Instead, WickWerks ramps are dramatic, full-size, chain grabbers.
The WickWerks concept has two parts: First, many ramps allow a shift to initiate almost instantly. Second, lifting of the chain is at multiple contact points – load points – so shifting is quick and stable – even in extreme conditions.
The Traditional Approach:
Most chainrings have 2 places for the shift to occur with each crank rotation. (Some newer rings incorporate 3 places.) That typically means there are 4 or 6 shift pins, located in pairs (2 for each shift location) around the ring.
The shift pins are in pairs because the pin is designed to grab only the outer link plates of a chain link — (the pins are designed to pass under an inner link, between the outer links). This is important because even though there are 4 pins, there are only 2 chances for a shift with each rotation because only half the pins are able to grab the chain for any given orientation. See the diagrams below.
Shifting with a pin – which is the typical approach – puts all the stress of shifting on one outer plate of the chain. That one outer plate is then held by a single point of contact at the shift pin. The single point means there is just one spot to “fall off” while shifting if things are not just perfect. It also means stresses are higher on that one plate and the 2 adjacent connecting joints of the chain.
At WickWerks we do things a little different. Our approach is to optimize the rider experience by improving shift speed as well as stability. Here’s how we do it:
– First, and most obvious is the number of ramps. Lots of them. In this image here, there are 10 ramps – 8 more opportunities to shift with each full pedal stroke! That means things begin to happen nearly instantly when you command a shift.
Is that faster? Yes, noticeably faster. It’s one of the reasons we claim “World’s Fastest Shifting Chainrings.”
– Second, rather than lifting on a single chain link, the WickWerks ramps lift under the load points of the chain – multiple load points at once.
A “load point” is the joint of the chain where the inner and outer links are connected. By lifting under these points, shifting becomes independent of an inner or outer link – because it’s actually both. When you lift at the load point you are actually lifting both the inner and the outer links at the same time. No need to worry about how the chain is clocked on the ring. (“Clocked” meaning how it sets on the teeth or more accurately, which teeth have the inner links and which teeth have the outer links.)
– Third, by interacting with the chain load points there is less stress on the chain. Less stress means easier on the equipment. It also means less likely to slip off during a shift.
– Fourth, in engineering terms, a load point is the articulation joint of the chain. All chain forces go through these articulating joints where the inner links are connected to the outer links. The chain pin is designed to carry these loads, and since they articulate about the chain pin, lifting at that location gives a much more stable location to apply the lifting forces. This translates to more stable and “less likely to slip off during a shift.”
– Finally, the WickWerks ramps are long – longer than one link of the chain. That means more than one load point can rest on the ramp, increasing stability and, of course, a greater likelihood for a successful shift the first time.
So, How technical should we go with this article? The discussion below has been sarcastically titled . . .
“Perhaps more than you wanted to know . . . ?”
Getting more technical . . . Let’s take a comparative look at how the chain interacts with the lifting elements. At shift initiation, the chain is straight from the top of the driving chainring back to the cassette. Same for both the Traditional (pin type) approach and for WickWerks.
As the shift begins, the chain “bends” around the top of the lift point. In the case of a traditional shift pin, the chain will teeter-totter on the pin just a little as it finds a force balance between the driving forces of the chainring and the loading forces to the cassette. Note the differences between the WickWerks approach and that of the traditional chainrings in the animated images below.
For the WickWerks rings, the long ramps begin to lift multiple points of the chain together. Contact is at the chain load points (articulating joints), so as the chain bends, it bends at the joint it is intended to bend at, not partially pivoting around a chainring lift pin. Additionally, with the chain lifted at the load points, it is the natural link connection, so stresses on any one link plate are significantly reduced. Even as the chain may move on the ramp due to varying forces on the chain, the contact points of shifting with the chain do not change, so the lift is far more stable.
For pin shift systems, when all the force is focused at one link plate, the stresses are higher. Also, as illustrated below, the position of the link with respect to the pin varies as the crank turns – which creates a quasi-stable condition. This is caused by the change in load direction as the crank rotates.
From just about anywhere in the crank rotation, WickWerks rings will shift and engage within a quarter (1/4) turn. Competitors rings can do that only from certain locations on the ring. Most competitors rings have spans that take 3/4 rotation or more from the time of shift until tooth engagement. That is one reason there is a noticeable difference in the speed of shifts with WickWerks rings.
We’ve heard people say that with so many ramps, all of those shift positions can’t be perfect. Yes, that’s a good observation. On all our rings there are sweet spots that shift more perfectly. We locate those in the traditional locations like other rings, but the amazing thing we’ve found is the “not so theoretically perfect” positions also shift very well.
We don’t place the ramps at random, they’re positioned at strategic sites for good shifting. The result is amazingly fast shifting and most of the time you can’t tell if the shift happened at a “perfect” place or if it happened at a “not so theoretically perfect” position. The truth is, even though a “perfect” site for the shift may exist, all the conditions needed to make that shift perfect are not always present. Derailleur movement, pedaling speed, deflections, vibrations or bumps on the road or trail, chain flexing, cross chaining … these things all add up. In our opinion, making the shift fast and making it stable compensates a great deal for any theoretical imperfections. The end fact is the chainrings shift, they shift fast, and the shifts are more stable.
Who’s blowing smoke?
Yes, we are well aware that much of the above sounds like a sales pitch. Even facts can sound that way. Listen to our competition and they’ll show how their pins make good shifts too. It’s true. Shift pins have been a round a long time, and a lot of smart people have made them better and better over the years. Today many companies make quality products with them. We are not saying shift pins are bad, we’re saying WickWerks is providing the next step in better shifting, and the real test is how they feel under your feet.
We had a booth at Interbike Outdoor Demo. We had several demo bikes for visitors to try. The one consistent message we got back was “I’m surprised at what a difference a chainring can make.”
You have to try them to really understand.
But, there’s more to a great chainring that just speed of the shift. The shift needs to be precise, and dependable. You’ve got to know when you grab a gear, the shift will happen every time and in all sorts of conditions.
WickWerks has made a name in Cyclocross where the conditions are often nasty. Cross’ers love our rings because they’ll shift when other can’t. ‘Cross riders love our rings because they shift when you’re ready to shift, and as fast as possible. The dirt, the transitions, the rough courses, the contamination — it’s all part of Cyclocross racing, and WickWerks rings have demonstrated an ability to deal with it all better than the competition.
Of the millions of chainrings out there being raced, compared to the relatively few WickWerks chainrings in use, I was quite surprised at the disproportionately large number of podium positions held by WickWerks riders at CX Worlds in Louisville, KY in 2013 — especially for the Masters. There were many. Was it because the really good riders choose to race on WickWerks? Or was it because the course was so incredibly muddy and the WickWerks rings survived better in those adverse conditions? Maybe some of both? Either way, it speaks to the quality and dependability of WickWerks chainrings.
The same quality and dependability are also found in our Mountain and Road rings. Though conditions are not usually as nasty, the same technology that Cross’ers love is there to make your mountain and road shifts better, faster and more dependable. Being in the right gear at the right moment, and being able to shift precisely and quickly when you’re ready to shift, makes the ride (or the race) so much better.
If you like to race, you know the small differences can make the big difference – if not the actuality of the lighter weight or the time saved shifting, the mental pleasure of knowing you have something better than your competition can assist in propelling you through the transitions and over the finish line before your buddy.