Ride a high-pivot swingarm DH or AM bike like the Orange and you'll discover that the rearward axle path and strike angle that the configuration produces dominates over the rocks and roots. Unfortunately, chain-torque issues caused by the conventional chain-line of a derailleur bike defeat any advantages of the high-pivot suspension design. Chain growth is a huge negative factor with conventional high-pivot design - to the point that most bike makers have long abandoned the concept. Zerode, however, has taken a different, more successful tack on the matter. By placing a gearbox high in the frame, aligned with the swingarm's pivot, the Zerode G-1 circumvents the chain-growth problem entirely. In fact, the Zerode gearbox design only requires a minimal chain take-up device on the rear and a single guide mounted near the upper side of the gearbox drive sprocket to manage a whopping, 9.25 inches of travel.
Zerode G-1 Frame Details:
-Travel: 9.25 inches
-Gearbox:8-speed modified Shimano Alfine hub
-Frame: Aluminum, 1.5-inch head tube, high-pivot swingarm with a primary and secondary chain drive
-Near-Concentric chain line eliminates suspension bob and produces active suspension
-Frame supplied with Fox DHX RC4 shock, shifter, gearbox, chain tensioner, rear sprocket and spacer kit, rear axle
-Price: $3495 USD
While the Zerode G-1 is known by many riders. I was intrigued by the well-executed design and thought I'd give the New Zealand DH design a closer look. The frame is beefed up where it needs to be, with a pair of CNC-machined spars holding up the gearbox and drive bits. The shock is tucked low in the frame and driven by a large aluminum rocker that doubles as a stabilizer for the chainstay suspension link. In effect, the G-1 is a single pivot suspension turned up-side down. The gearbox is then conveniently located in-line with the high-pivot swingarm so that a lot of suspension movement creates only a tiny bit of chain slack - which is easily taken up by a derailleur-style jockey pulley arrangement near the rear sprocket.
Zerode takes an eight-speed Shimano Alfine planetary gear hub and converts it to a gearbox with the addition of two torque plates that incorporate chain adjusters and a sweet looking drive-sprocket that bolts onto the hub's spoke flange. It looks pretty sexy.
Zerode says that the weight of the modified Shimano Alfine hub and its trigger shifter is nearly the same as the parts that it replaces - roller chain guide, rear derailleur, and cassette, but that probably refers to a heavy low-end drivetrain setup. I'd bet that the Zerode gearbox arrangement gains some weight where it supports the Alfine hub and extra drive gears that isn't calculated into the equation. Still, a look around the Zerode G-1 indicates that its designers have been around the block. It's well executed. The Zerode G-1 comes in small and large sizes and its geometry and purchase options
can be found on the Zerode website.A look under the Zerode G-1 shows that chainstay link of the swingarm pulls on a beefy rocker link as the suspension compresses, which then drives the shock. Two machined-aluminum plates surround the moving bits of the G-1 - a sturdy configuration that keeps much of the frame's weight centrally located.
The Zerode website claims that the rearward axle path that the G-1 swingarm scribes is the natural angle that the rear wheel is deflected when hitting a square-edged or substantial-sized bump. This plays out in the real world, as similar suspension designs have simply owned the rocks on many of the world's toughest courses. Science also says that the in-line chain path of the Zerode will negate the negative chain torque issues that plague the high-pivot genre. In addition, by transferring the weight of the cassette and rear derailleur to the center of the bike and off of the wheel, the Zerode reduces unsprung weight in the suspension, making it quicker to respond to terrain. So far, so good.
A 34-tooth crankset drives the hub-gearbox and then a separate chain runs from the gearbox to a single rear drive sprocket. The transmission has the spread of a conventional 11 x 34 cassette. Photo on right courtesy of Zerode
Two items, however, remain questionable. No high-pivot suspension that I have ridden has been neutral in braking. In fact braking has a tendency to lock up the suspension with minimal pressure on the rear brake lever. Also, 9.25 inches of rear wheel travel is almost unheard of on the Pro DH racing circuit these days, mainly because riders want low bottom bracket heights for cornering and thus must be willing to sacrifice suspension travel to achieve this goal. It would be interesting to ride a Zerode to see if the rough-ground benefits of the suspension outweigh the slightly higher bottom bracket necessary for its extra wheel travel. When that happens, expect a full report
- RC
Mine is well under 43lbs. Weight is irrelevant IMO anyway with these, as it's all centered and the rear is so light and flickable. I actually like the centered ballast weight of the gearbox and shock, keeps the bike stable.
www.fallbrooktech.com/cycling
tasty.
They're not as low as they look. Zerodes run a 32tooth chainring, so it's higher the every other bike running 36-38 and/or Bashie/Tacho. So you hit it less than you would any other DH bike. Carbon guard is replaceable, but can handle heaps of hits anyway. None of the 11 Zerode customers in Australia(all aprox 1 year old)have needed a new carbon guard yet.
With the new Can Creek Double Barrel option, it's even less of an issue as the piggy back angles up following the frame.
You'd have more chance of your Fox RC4 blowing it's piggy back up itself than a Zerode destroying it on a rock.
But yes, I've hit mine, no drama. The real downside to the carbon guard is it's noisy on sandy type tracks with front tyre debris hitting it, and wrecks the otherwise silent ride of the Zerode. Still quieter than other bikes but.
www.cyclingnews.com/features/photos/nahbs-2012-part-6-alliance-to-wound-up/211665
Long answer: Belt drives all need a split in the rear stays to accommodate the belt coming from inside the rear triangle to outside (because you can't split a belt as carlmontnative correctly states). You could to get the belt through the stays with this bike but it would entail undoing the pivot nearest the rear axle for one belt and taking the swingarm off and removing the gearbox for the other.
But that's all academic because you can't put a belt on this bike because the chain length changes - hence the need for a rear derailler. Belts need very high tension on them so that they don't slip. Belts and their 'sprockets' are also much wider and I doubt you'd fit two past each other where they cross at the front.
If Zerode were to move the upper pivot to the axle of the "gearbox" then you would be able to run a belt on the secondary jackshaft drive. (tween the "gearbox" and rear cog)
A belt drive has a lower efficiency than a chain!
Also an Alfine hub has a lower efficiency than a normal cassette and mech.
You would loose between 5% and 10% power with a belt drive.
The way it is just now is the most efficient drive train, up to 98% efficient.
Oh... and belts will stretch unless they are too heavy and more inefficient .
Think of the packaging concerns too - in this case the width of the belt/belt sprockets themselves.
I love the bike, Its clean, well engineered and just something different. If the DEMO ever goes a Zerode will replace it.
typical problems are stripped rear cog (where it interfaces with freehub body), damage to rear hub bearings, damage to bottom bracket bearings, and even snapped belts
all related to over tight belt tension, which is supposed to be "set" using a manual Gates 'Pitch tool' or their I-Phone APP where your I-Phone records the sound and compares this to the specification for belt torque
without getting the belt tension within a 10% +/- range you suffer from these wear problems, or if set too lose, then from "ratcheting" where the looser belt slips over the cog teeth under high pedalling loads and damages the belt
not sure what the customer is supposed to do, if they puncture, and don't have the right Pitch tool to reset the belt tension....
belt drive seems to be a "solution to a problem that does not exist" and the efficiency of a belt is nowhere near that of even a dirty and worn chain!
The Banshee Legend MKII we had built with exact same kit was 40LBS even the Zerode was 41.5 So you gained about 1.5. The 2012 frame has 1.5 LBS removed. The new frame will build to 38 easily. We did not use any Carbon or XC stuff on our test sled. In fact we didnt even use a Ti spring.
The BB is 14" it corners very well. The weight is centered and not very high. In fact it was one of the best cornering DH bikes I have tested in last 2 years.
Very easy to ride. You can ride from the middle without heavy front or rear weighting. The Gearbox allows for no chain growth and keeps suspension fully active. If you rode one and the hub engagement was an issue it was not set up correctly.
The trail bike is in works............
Am I missing something? How is the BB high compared to other bikes?
Yep the weight is higher... but I came from a 36lb Socom build to this and it felt fun and stable. The Socom feels more skittery so the weight isn't even a negative point just a different riding style.
A fixed rear wheel would be good but I can't say I noticed a massive lag on the drivetrain.
Main benefits - super smooth handling of square edge bumps, very quiet and bombproof setup (no more lost mechs and mashed wheels) and also helping fund a small company produce a frame that others have struggled with.
They aint for everyone but I think I'd be hard pressed to hand on heart say the feel of the suspension is some of the best I've felt on a dh bike.
I don't recall the rear suspension locking up under braking; I had a single pivot Gary fisher kingfisher at the time so I know what that feels like.
The BB height seemed fine also.
There are improvements I can think of for the G2.
The main pivot and gearbox output sprocket on the same axis, with a small eccentric cam at the dropout would do away with the need for a derailleur and look a lot better.
160-180 travel, mini DH version.
Full carbon, internal routing. I'm told that on a run of only 500 bikes, carbon becomes cheaper than aluminium to manufacture(true?). Zerode, you should go for it.
I don't know anyone using 11-34 for DH. I would have thought 11-23 or 11-21 would be ideal for an 8s box. Will Shimano ever make that? I almost bought a Giant Cityspeed flat bar road bike for the ride to work this year. What attracted me was the clean line of the internal hub. What killed my enthusiasm was the far too widely spaced gears of the Alfine hub.
I'll wait to see what the MK2 looks like in a few years, but definitely I am interested in the concept. It's the first bike I've seen which really breaks the mould since the Cannondale DHF, in my opinion. Totally out of left field and fantastic looking.
Approaching the bike it looked just as good in real life as it does in pictures. Unlike some of its competitors it is not particularly light- although this one was built up with some truly high end parts. Compressing the suspension in a stand still felt slightly odd because the bike actually stretches a little due to the unusually high main pivot.
On the trail I felt right at home and confident. The bike's most prominent characteristic is probably its balance. The bulk of the bike is located right in the center and as low as possible, giving it a light and maneuverable feel while maintaining a stoic quality on straights and in high speed turns. The suspension felt taut and playful, yet very smooth in the face of those french pistes littered with brake shafts.
I've been avoiding single pivot bikes for a couple of years because I dislike the brake jack usually encountered- this one however showed only a whiff more than my GIANT Glory '09. Pedalling however did feel quite different: it seemed a lot more efficient, compressing the suspension noticeably less. As for the gearbox's performance- forget everything you've gotten used to with your derailleur mech- Alfine means instant gear selection- period. Last but not least the silence experienced while riding the Zerode is a real treat for your ears.
All in all the G1 has a laid back character that likes to paint the town red - very nicely balanced...
Bike is quiet as can be even in the rough stuff. Gearbox is interesting. Great thing about it is once you get the hang of it, making downshifts or upshifts without the need to pedal really shaves the seconds compared to traditional shifting in the same situations
. Only negative thoughts so far: some tolerances are very tight. have not had it in the mud yet so not sure if it will be an issue. For me the carbon shock guard is a mistake. mine is already busted. I hear the new bikes will be coming with poly pro plastic guards. not as trick as carbon, but probably more durable. The guard mounting is quite interesting, but makes it hard to pull the guard off to adjust the shock. I ended up using velcro. easy on, easy off and stays put.
The Alfine acts as an Idler wheel ALA Canfield/Brooklyn. The High Pivot's issue of chain growth is thus eliminated and makes it 100% active the entire time. ALso you save weight off rear wheel making small bump compliance super good.
also can they either ano the links and that stuff orange or put the stickers in gold.... seeing the two clashing would piss me off on a 3500 frame!!!!
www.downhillnews.com/storage/WX8P0162.jpg?__SQUARESPACE_CACHEVERSION=1335559923568
I take it the rear axle is a 150x12mm? And I'd guess the BB to be 83mm wide? Any issues reliability wise (bearings, gearbox, etc.)?
Hope I'll be able to get the cash sometime... .
As for the braking issues- too bad they're not running a system similar to TREK, DEVINCI and BERGAMONT- That would just be the cherry on top! *I dislike patent pending... !*
2. Is the Alfine hub off the shelf? Replaceable? Upgradeable when a next gen. Alfine comes out?
14" BB or 13" with slack cups........
Any doubters just need to get a ride on one, a good enough ride to let your brain adapt to it's new found advantages with the shifting anywhere without having to pedal.
If the primary chain on the bike you rode was loose it would have more lag. This is easily/quickly adjustable, and needs doing very rarely as the chains run straight.
With the output right near the pivot, and a touch of anti squat you'll find the Zerode is one of the best pedaling DH bikes out there.
Maybe it wasn't set-up correctly on the one you tried?
Cool video intro of bike....
video.mpora.com/watch/3OowvrrOn
farm6.static.flickr.com/5282/5335536558_9c6654641c.jpg
forums.freeriden.co.nz/files/glory4_675.jpg
think old giant glorys and they never seemed to have a really bad reputation for smashing shocks even of they are exposed.
Another thing is that this low shock position actually lowers the bikes center of gravity which going off that alfine hub which is quite high isn't a bad thing!
The bb is355mm which is the same as the Wilson, TR450, and Aurum so I dont see that being a problem and any lower and it would cause issues with pedal ground clearance.
The chain is less likely to get caught in trousers since the sprockets are covered by the frame
cdn1.static.mporatrons.com/site/dirt//wp-content/uploads/2011/05/zerode_52G9470.jpg
and the chain which is going rearward is not going to be flapping about since there is so little chain growth that it can be kept tensioned pretty tightly
In all I do understand your gripe about the shock placement (even though they have it covered) but they other things aren't too much of an issue.
I would really love to take one of these bikes down a hill.
You are $1K off on your pricing BTW.
$3499 USD so its 100% inline with other frames...... you save about $500 in parts as well!
High CoG of frame has marginal effect on the system effective CoG. Alfline hub weight is 80times lower than your weight.