Williams Racing Products Release New CentreHub Decoupling Spider
The CentreHub, installed on Shimano XT crankset.
The best thing about the bike industry is the people with a passion. For me, it’s about the riders creating solutions to the problems they come across while riding their own bike, experiencing it for themselves.
Mic Williams, of Williams Racing Products, is one of these industry figures. A BMX rider who came to mountain biking a little later than some, that clearly didn’t hold him back and he quickly progressed to racing World Cup DH for several seasons as a privateer. What it did mean, however, is that Mic saw some of the foibles of the modern mountain bike with a slightly detached objectivity. Soon after getting on a mountain bike, he was already designing parts for them. One of the first things he created was the CentreHub. In fact, when he finished his degree in 2017, he actually included the component as part of his engineering thesis.
Since starting WRP, Mic has started making anything from dropouts and linkages to skid plates, should you want to incorporate BMX style tricks into your downhill riding. WRP also, rather interestingly, makes custom stems. If you tell them your desired dimensions they’ll make it for you.
The device is meant for any type of bike, but will probably be best suited to the needs of downhill and enduro riders.
So, What Does it Do?
The device is essentially a slipper clutch but for your mountain bike. It swaps out with the spider on your cranks and helps decouple the drivetrain forces from your pedals. This will matter on some suspension designs more than others.
As the bike goes through its travel the rear center elongates and adds tension to the chain. Then, as we brake, where the suspension may squat a little, it can also pull on the chainring, and therefore our feet. A device on the cranks such as this is designed to remove the interference of the suspension forces on the drivetrain. Yes, your rear center will still grow but thanks to the one-way bearing in the crank, it will just rotate the chainring and without rotating the crank arms themselves.
This, of course, isn’t the only way to achieve this. You might have seen racers file down or remove one of their cassette sprockets. This “neutral gear” delivers a very similar result, however, it also runs the risk of you accidentally engaging that gear as you begin to pedal which could end rather badly.
But maybe the idea of a neutral gear is somewhat applicable here too as this device will let you change gear at any time without the need to be pedaling. This means that even when hard on the brakes or going into a turn and realising you're in the wrong gear you can easily change gear without having to move your feet. For people that ride janky, technical or undulating trails, a device like this could prove very useful.
A complete setup ready to bolt on and go. A SRAM direct mount spacer installed with a 104 BCD spider. DT Swiss lockout rings are also available for an ultra-clean look.
How Does it Work?
The WRP CenterHub is a completely modular design that is adaptable to most direct mount cranksets. If they have a removable spider then the chances are that the device will fit.
The device is made up of a spider, a one-way bearing and a crank adaptor. The interchangeable and adjustable spider is held in location via a patented pinch-bolt securing mechanism and is made from 6061-T6 aluminum. The replaceable direct mount adaptors vary to fit almost any crankset on the market. They are held in place by a patented blind-wedge system that uses a 3D printed titanium piece. The device weighs 309 grams. It also enables you to adjust your chainline as needed, so it will carry between bikes well.
The crank adaptor is 3D printed titanium and is the only piece you would need to replace if you swapped to a different crank setup.
Thanks to the one-way bearing, the CentreHub offers instant engagement and near zero rolling resistance. It also runs totally silent. In terms of durability, Mic explained that he's had a device on one of his bikes for nearly two years without any issue.
The simple device is easily serviceable and swapping out any needed parts should be very easy.
Pricing and Availability
Mic, by his own admission, doesn’t have his sights set on world domination. Instead, he is looking to do small runs, selling to similarly passionate riders, and keep all production in Australia. The consequence of this is that the device isn’t particularly cheap, admittedly, but that is so often the way with locally made specialty equipment.
Pre-orders are now open and the device will cost $1,199 AUD. WRP are aiming for an end of 2021 shipment of the first orders.
To keep tabs on WRP follow their instagram or sign up for any updates via their website.
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Yes you can use a oval chain ring on an E-bike, but takes a bit of get used to!
This thing will feel normal to pedal, but should provide the same benefits as Ochain if you're moving forward at a decent clip.
Andrew Major of NSMB wrote about another freewheel spider that Rocky Mountain developed for an ebike. It's an interesting read as his articles always are. nsmb.com/articles/reinventing-and-moving-freewheel
Anyway, I would love to try one but cannot afford spending so much cash on something which very likely will turn out as having no sense. Somehow the idea of chain spinning all the time bothers me
For AUD$1199.
Um. Ok then.
m.pinkbike.com/news/day-3-randoms-eurobike-2021.html
Why didn't they put standard rear hub (with freewheeling on)?
Your feet are locking the chain to move out of the way she the suspension cycles trough it's travel whilst with this design (or HXR, Intend) allows to spin the chain or slow it down trogh that movement. Even if the wheel slows down it won't affect your leveld crank position...might be very wrong but makes sense to me
• While pedaling: Kickback is essentially unavoidable. Any device that can eliminate it would cause more "weirdness" than it would prevent. The crank does not actually counter-rotate, the rate of rotation just briefly decreases then increases, before returning to normal, which feels like it went backwards.
• While coasting, wheel rotating (not skidding): It is almost impossible for any kickback to occur, let alone problematic kickback. The required ratio of impact to riding speed would apply to a trials rider, not a trails rider.
• While coasting, wheel locked (skidding): Kickback may occur. The amount of kickback will not be the full value often shown on kinematics charts, as that would require the suspension to move through 100% of the stroke and for the hub to engage precisely at the beginning of the event. Realistically, it might be a few degrees per event, depending on the hub.
If that is true, then the pedal kickback you will get with this system is likely more than the pedal kickback you will get without this system. It cannot be less. With a conventional freehub, you don't get kickback unless the elongation rate of the upper run of the chain is fast enough to cause the freehub to engage (which is a function of rear wheel rotation speed, of course). So if this system engages faster (taking into account relevant ratios) than the freehub, kickback happens more. The only way it can reduce kickback is if it takes longer to engage.
OChain is completely different in that it adds significant compliance (maybe slop is a better word) to the system. It reduces engagement, but at the same time ensures that when you hit a bump, you always have some amount of rotation before that first engagement point. This product, on the other hand, ensures you have instant engagement, which makes pedal kickback as consistent as possible, but also as bad as possible.
Edit: It actually looks like they have something holding the crank in place on the left bike. That would explain why the wheel is driven while the crank doesn't move at all.
@SickEdit: It depends on the bike, as there's quite a range of chainstay growth rates. For a realistic maximum shock shaft speed (i.e. most violent impact that's likely to occur during normal riding), many bikes can completely eliminate kickback in any sprocket - even with zero hub lag - at walking speed or running speed. Some bikes and some sprocket combinations require speeds over 20 km/h, but these are for sprocket combinations typically used at about double that speed, so kickback is unlikely to occur - and I want to reiterate that even if it did occur, we're talking about the threshold of kickback with zero hub lag, not the maximum possible kickback. As you noted, OChain would be most useful for the skidding scenario; it could smooth out some pedaling kickback, but only if the spring force is high enough that your pedaling is within the sprung region (i.e. not bottomed out), which could cause more weirdness than it would prevent.
@lubb1: The smaller wheel won't necessarily help, as the rider would be using a slightly different sprocket combination to compensate for the slightly smaller wheel, and these factors offset each other. Bikes with smaller rear wheels can have slightly different suspension geometry to achieve similar kinematics due to the different amounts of BB drop, so a bike with a smaller rear wheel can be less susceptible to kickback for this reason. It's a small difference, though, and doesn't change the overall message about the kickback situation.
@DaneL: Yes, we're discussing different aspects of the same issue. You were looking at the function of the kickback reduction devices and I was addressing whether kickback even exists and, if so, whether it's a problem and, if so, whether it's solvable. As you noted, depending on the stiffness of the OChain, it can either just add more delay to the driver engagement or create an elastic feel to the drivetrain - neither of which sounds appealing, to me, which is why I say such devices add more weirdness than the prevent. Even if the Williams product manages to distinguish between pedaling inputs and suspension inputs, the best it could do would be to allow minimal engagement lag while eliminating coasting kickback (not pedaling kickback) with the rear wheel locked, since that's the only realistic situation that would produce non-trivial kickback. This situation can already be minimized by reducing skidding, choosing a bike without extremely high anti-squat, choosing a bike with a decoupled (idler) drivetrain, and/or accepting a hub with more engagement lag, making the Williams product an expensive solution to a problem that barely exists - and that assumes the product can distinguish between pedaling inputs and suspension inputs; if not, it would just shift the engagement lag from the hub to the crank or increase the lag, like the OChain. The ability to shift while coasting could be the more significant benefit for some riders, though several such devices have come to market and haven't been adopted, even in World Cup downhill racing, suggesting limited benefit to shifting while coasting.
in traditionals systems the wheel doesnt turn, but the cranks are forced to cause of the rear hub (on compression)
in freewheel-cranks you just invert all of that. now the cranks dont turn, but the wheel is forced to by the hub in the front. also its turning not on compression like in a traditional system, but on rebound.
This would only happen if the suspension squatted, on the brakes, while not moving, right?
My understanding of this problem, that is being solved by devices like this, and people that say that high engagement hubs can adversely affect suspension performance, are not considering that you are actually moving when all this stuff happens, therefore it really only happens when you are basically doing drops at super low speed. I feel like I have seen an analysis of this where the person figured out that a large part of the affect on the suspension was due to all the inertia of the lower part of the chain wildly slapping around during a suspension event. That same analysis actually was able to look at when the suspension would be affected by the chain forces and if I recall it, the speeds required to have chain tension ever come into effect were around 5 mph, for the set up they were using.
However, this doesn't make sense to me, because a wheel on a suspension bike, having to follow uneven ground must travel further to keep up with the main triangle of that bike. I understand that the wheel will be going slower and then faster than the rest of the bike as it goes through its travel, but not by much of a difference.
Gee Atherton doesn’t do things slowly and he bothered with this:
m.pinkbike.com/photo/17449411
Buy cheap hubs!
I have not done all the research and testing, but Gee Atherton's neutral gear solution seems like it would help eliminate the chainslap, at the top and bottom sections of chain, from affecting the suspension as much/in the same way.
A low engagement hub also doesn't mean that it has to have 6,10 or more degrees of rotation to engage, it just means that it will need to rotate that much maximum to engage. Low engagement hubs feel awful in the only situation that I have ever felt pedal kickback, pedaling through really rough terrain where the freehub is disengaging sometimes when the rear suspension is rebounding. In that situation I have always felt that something like an Onyx hub would feel best, with a slightly soft engagement.
Didn't see the rear wheels slowing down during impact. Also kind of funnily, only on one, maybe 2 of the bikes did I ever see the chain above the chainstay go taught for even a moment while the suspension was compressing. This isn't the worst case scenario for pedal kickback, but kinda bad and I only saw indication that it would have happened, even a little bit, on the GG and maybe the Intense. The chain was taught only for a small fraction of the suspension compression event and then went totally slack and smashing around like it did on all the other bikes the whole time.
Your feet are locking the chain to move out of the way while the suspension cycles trough it's travel whilst with this design (or HXR, Intend) allows to spin the chain or slow it down trogh that movement. Even if the wheel slows down it won't affect your leveld crank position...might be very wrong but makes sense to me
Do another run with a chain that is 2x as heavy and see if you feel a difference that way as well.
IIRC, Troy Brosnan is also running one.
And yeah, I think ever since Gwinns famous chainless run, people have been thinking a LOT more about how the chain impacts the suspension than they did before.
Similar idea. Much cheaper.
And that is why they are both silent, and instant engagement.
So there’s the answer to pedal feed back. Don’t spend money on tech. Just get fat or big, or big and fat.
Wouldn't feel the best when you started pedalling as there would be alot or crank movement but... ?!
It doesn't mean that at all. If anything, it means that he was able to look at mountain bike design with a particular subjectivity formed from his external experiences. That subjectivity may have given him something of an outsider perspective, that made him more critical of some of the technological norms of mountain biking, but it didn't make him objective.
I recently went SSDH an I left the chain a bit longer than usual for the initial fitting thinking I would fine tune it later..
I can't say if it's the SS or the longer chain but on the first ride the difference was night an day, a LOT better on the rear. It felt like I'd 'freed up' the rear travel, the rear end felt a lot more active when both freewheeling and pedaling.
As for DH Riders running O-Chain - weren't there a bunch of DH riders like five years ago running some magic vibration absorption stickers? I'm not entirely certain the riders themselves are immune to placebo.
Just my thoughts....
[Reply]
www.wideopenmountainbike.com/2018/05/how-does-mountain-bike-suspension-work-part-3-pedalling-forces
If this has instant engagement, then it is not going to do anything different than and instant engagement hubs at stopping pedal kickback, which to be clear is nothing at all. I personally don't think that pedal kickback is anything to worry about at all unless you are talking about when you are already pedalling.
Ochain has a soft engagement, at the chainring, plus whatever delay caused by the freehubs POE, which theoretically helps reduce pedal kickback while coasting, but only at really low speeds. This device claims to have instant engagement which would cause you to feel all the kickback, at really low speeds.
After thinking about it a bit more I think that since sprag clutches are a sort of soft engagement that this would be a bit softer, when in gears that a person would be typically descending in. This is due to gear ratio, not due to the location of the engagement mechanism.
In the end I just don't think that pedal kickback is what ends up effecting suspension while coasting at any speed above a slow jog. Instead I think it is more about chains smashing around, slamming into the top of the chainstay, and whipping around below the chainstay that has a bigger effect on the rear suspension.
Ochain works by allowing the chainring to rotate backwards by 6-12 degrees, negating pedal kickback with the downside of slightly worse engagement.
Long story short, this doesn't negate pedal kickback as pedal kickback affects it for the same reason it affects a freehub as that's essentially what this is. A relocated freehub.
Overall, cool idea, but not practical for most applications.
This system, with a constantly rotating drivetrain, 100% has more drag than a O-chain or any conventional drivetrain with a freehub.