Weird But Wonderful
OChain Active Spider Review
The effect your chain has on our suspension, as well as how much feedback is transferred to our feet, have been hot topics recently. Steve at Vorsprung made a video about 'pedal kickback' a while ago that is well worth watching as it gives the best explanation of what’s happening. Others have written about pedal kickback but many fail to discuss the points Steve tackles, which are vital to understanding what’s happening and how the OChain can help improve things.
Fabrizio Dragoni felt the effects of the chain on his suspension were significant enough to create a product designed to reduce them. The OChain Active Spider has been subject to much skepticism, but there’s no denying that riding a bike chainless can improve suspension performance and feel; the bike remains calmer, is smoother, and grip improves. Aaron Gwin and Neko Mullaly have each posted incredible race runs after their chains were lost and many believe the improved suspension performance without a chain flapping around helped their performances.
A downside of riding chainless, that has taken some time for me to adjust for, is how freely my feet move. Feeling the light movement of the cranks without a chain when encountering holes or off jumps is unnerving at first. Once I get comfortable and stop trying to pedal out of corners, it's far more enjoyable.
What Does OChain Do?
OChain claims their Active Spider provides at least some of the benefits of removing the chain altogether. While riding bike park laps without a chain is possible (despite still requiring some 'skating') it's out of the question for trail riding. And you wouldn't dare race a World Cup without a chain; unless it breaks out of the start hut, as it did for Aaron Gwin. Many World Cup Downhill racers have used the OChain device now, including the current World Champion, Reece Wilson, who had it on when he won last year in Leogang. Looking at the coverage from the weekend in Leogang, OChain’s use at the World Cup level appears to be growing. Troy Brosnan is a notable racer using the spider, racing it to another victory at the first World Cup DH of 2021.
The OChain spider allows the chain to rotate backwards a small amount, effectively isolating the chain’s movement from the feet as the rear wheel is compressed and extended repeatedly. Many dual-suspension mountain bikes have a rearward portion to the wheel's axle path, usually in the early part of wheel travel, which lengthens the chain in response to an impact. Our derailleurs allow for chain growth, which explains why single speed setups won't work without a tensioner or derailleur on dual-suspension bikes, but there are also forces pulling at the top of the chainring that the derailleur doesn’t counteract. This only partly explains why the bike feels different when the chain is removed because there's something else going on.
The chain bouncing up and down as the wheel encounters impacts also changes how the bike feels. How greatly this affects the bike will depend on the suspension kinematics to a degree but also the length of the chain, the gap between chain and stay, and also the terrain. To counteract the chain's effects on the chainring/cranks and suspension, OChain's Active Spider rotates backwards a set amount. Provided elastomers of three sizes allow either 4, 6, or 9 degrees of backward rotation, with an option to purchase a 12-degree setup as well.* With many different suspension designs and riding styles on the trails, OChain provides the four sizes to allow users to customize the feel.
*OChain originally released the Active Spider with 6, 9, and 12-degree setups but has since updated it to the settings above.
Setup & Riding
My OChain arrived with the 6-degree elastomers installed. Mounting relies on a direct mount chainring setup – SRAM, Shimano, e*thirteen, Hope, Cane Creek and Race Face – and a chainring with a 104 BCD. Removing the old chainring from my Shimano SLX cranks was straightforward and the OChain slotted into place easily. Sitting on the bike immediately felt strange, with the extra movement creating a slight delay before the chain engaged the pawls in the rear hub.
For the duration of testing, the OChain was paired with a Hunt rear hub that features 3 degrees of engagement. I've not typically found myself lusting for the highest engaging rear hubs, but the benefits are noticeable for at least the first ride or two. The same can be said for the effects of the OChain. After the first ride, I was hunting technical climbing scenarios to see if it hindered me and cannot say it had a noticeable effect.
It's also worth mentioning that the duration of testing – just shy of 1,000km of trail time since mid-December – was spent on flat pedals. OChain informs me that clipped-in riders also benefit from the active spider – refer to the World Cup DH bikes for reference – but flat pedal riders can benefit more from the device. This is thanks to flat pedal riders needing to load the bike differently than clip riders, who can ride lighter on the pedals, particularly in rough sections of trail. I also used an STFU for most testing, which also limits the amount of chain movement, further improving ride quality.
With the OChain installed, which was relatively easy to do, I headed for the trails. The inaugural ride began with a few loops of some newer jump trails in Squamish – Miki's Magic and Slippery Salmon. There wasn't much notable on these trails and I chalked anything I felt up to a placebo effect. But moving from there into the tech chunk in the Alice Lake network opened my eyes.
In terrain with more feedback, the benefits of the OChain are clear. I'm still cautious about claiming climbing produces anything more than excessive focus on what's happening, but descending is another story. It feels amazing across chatter and through medium-size hits, isolating much of the feedback I usually feel at my pedals. Sudden square-edged obstacles still produced a very noticeable thud at my feet in some situations with the 6-degree setting. The quieter feeling in most situations amplified this, catching me off-guard, but it also highlighted that a higher degree of rotation in the OChain could be warranted.
Through transitions where we use our feet to force chain tension, pumping momentum from the terrain, the minimized feedback left the bike feeling a bit vague. I stopped and hit some sections like this repeatedly early in testing, adjusting how I rode them. The OChain allowed me to float across these chattery sections. Where I'd normally be braced for impacts and preparing to pump the terrain, I found myself out of the section quickly and riding lighter as the bike seemed to hover across the ground.
As rides progressed, I adjusted my technique to work with the changes the OChain had on the bike and found myself able to ride with greater comfort. The bike tracks better with the OChain, and going back-to-back is a stark reminder of the chain's impact on suspension performance and comfort. I did find that on the trails I frequent with the G1, the 6-degree setting continued to tug at my feet when encountering quick square edges of a few inches in size. I eventually swapped for the 9-degree elastomers to see if things would improve.
With work, life and winter stalling the swap, it was a while before I got around to making the change. In that time, the OChain saw roughly 650km of trail use. The extra time spent on the 6-degree elastomers wore on them, smashing away the leading edge. I reached out to OChain about this and was informed that it's mostly from the pedalling forces, which engage the inners against the elastomers and the appropriate metal spacer under a more constant load. I didn't hear any of the metal clangs from the spider that Fabrizio informed me happens once the elastomers are toast – said to be after roughly 50,000m of climbing – so I still have life in them despite their appearance. I cleaned everything up, installed the thinner 9-degree pieces and all was good.
For my bike and riding, the 9-degree option is great and I'm happy to stick with it. The unexpected spike of feedback in my feet when encountering square edges with the 6-degree setting was drastically reduced with this setup. Fabrizio has removed the 12-degree elastomers from the stock kit and is now recommending it specifically for downhill bikes. Pedalling on the 12-degree setup feels squishy, with no metal spacer to help provide a solid endpoint and the small spacers do little. I was informed that trail riding with these would result in them needing replacing often and it’s not recommended. If I still owned a downhill bike I’d likely install the 12-degree OChain setup. Once I get up to the bike park I’ll do a bit more testing on the 12-degree elastomers but I won’t go back to it since most of my riding is self-powered.
The amount the OChain improved my rides has been surprising and although I thought the delayed pedal response would be a problem, it hasn't been. But what caught me by surprise most was the improvement in chainring wear. Riding left foot forward, the front-most edge and around the bottom of the chainring exhibits wear, but it’s much less than I had with my previous chainring. It also took much longer for any sign of wear to show up. Across the top of the ring where I usually see an equal amount of wear, it's minimal.
There is potential for chainline and clearance to be a problem on some bikes. With the OChain fitted, it was tight between my chainguide and the spider’s backing, thanks to the thicker body of the spider housing the parts that make it work. Thinking I had just enough space, I hit the trails but found in sloppy winter conditions the grit got caught between the parts, causing the spider to rub the chainguide, particularly a clip on the OneUp Bash Guide. The clip isn’t needed for the guide to function and once it was removed the bike ran smoothly and quietly, regardless of the conditions.
The delay in power to the rear wheel will be a deal-breaker for some riders but the improved performance and comfort when descending may be enough to sway others. Switching to a lower engaging rear hub – a DT 240s with 36t star ratchet providing an engagement of 10 degrees – I can’t say the difference was noticeable. There’s a bit more delay before pickup but nothing clearly noticed otherwise. I'll be performing a back-to-back test in the Whistler Bike Park with the high vs low engaging wheels soon to better report on the effects they have on the trail. At that time I'll also perform back-to-back tests from no OChain with a low engaging hub to a high engaging hub with the OChain, to better discuss the differences between each.
Finally, the OChain is a performance part that results in increased maintenance and cost. Despite having no idea how to perform a service, a complete clean and re-grease took 30 minutes max, following OChain’s guide. After 1,000km on the spider, it was pretty grimy inside but there was no noticeable effect on performance.
The OChain is a great addition for riders after improved suspension performance and comfort. In the last 18 months, it stands out as the product with the most resounding impact on my riding enjoyment and now I dread riding without one. As long as a device like OChain is around, there will be one on my bike. Going out on a limb, it's one of the most beneficial suspension upgrades available, and it’s not a suspension part.
It won't, however, be for everyone. Riders who absolutely must have the tightest transmission won't be happy with the delay it can introduce. I haven't found it to cause an issue on any of the technical climbs in Squamish and I struggle with the same climbs while making the ones I was able to before. Riders that prioritize comfort, grip and suspension performance over everything else will enjoy the benefits OChain provides.
More on the OChain Active Spider.
Ape Index: 1.037
Trail on Repeat: Changes as often as my mood.
Current Regular: Every test product spends time on Entrail