Zerode Taniwha FAQ
Is Grip shift the only option?
It turns out that the grip shift is a very nice match to a drive train when you do not have to pedal to change gear and the gears change instantly. If you get caught out in the wrong gear on a pinch climb you can back off for a split second and rip through a bunch of gears with a twist while the derailleur guys are trying to pedal over the top of the wrong gear or click and crunch through gears one at a time. There is no comparison in this situation. You can grab gears when coasting, back pedalling so you adapt and change when and where you shift, the grip shift lets you do this in a seamless way. I have no doubt a trigger will be available at some point. I have designed one on paper, friends have made their own but I'm not sure experienced pinion users will want to swap the grip for a trigger.
Why no horst link?
In a nut shell. I don't link them. The pedalling performance of a Taniwha is second to none. The "real" pivot design combined with a fixed chain line means it is possible to achieve very stable pedalling through the entire range of suspension travel while independently control the suspension rate via a link. With a Horst link or VVP design the virtual pivot races all over the show making it hard to control suspension rate and pedalling independently. You get a compromised design but one that marketing departments love…
There is a huge amount of misinformation online about brake effect. The story goes, "single pivot designs suffer from brake Jack or brake lock out". In reality all bikes, even bikes equipped with horst links have brake effect to some degree. What happens is the traction force at the rear tire tends to rotate the suspension about the pivot whether real or virtual causing a suspension compression. It's worth noting the traction force at the rear wheel is usually small and so is the compressive effect and that the suspension is still free to respond to other inputs. Some bikes have more compression than others, in some situations this compression helps performance, in other situations it hinders performance.
I could go into an in depth analysis of brake effect. However, there is no need, motorcycles have used simple swingarm designs for over a century now, motorcycle designers fully understand brake effect and understand that a simple swingarm design is the best solution. Almost every DH world champ since records began had a bike with a brake effect essentially the same as that of a single pivot bike.
I magine a 10-60 cassette. Enough said.
Obviously there is an extra element in the drive train so there has to be losses. The loss is small and depends on load and gear. A comparison with a clean mech with a chain in the middle of the cassette would obviously have a standard mech come out on top. If you take into account a significant reduction in unsprung weight changing gears instantaneously and the fact the a mech drive trains efficiency falls off quickly when the chain is at the top or bottom on the cassette or when sprockets are small, then add a little bit of dirt or mud the Pinion becomes very attractive. I wouldn't use one on a road bike but a 160mm trail/enduro bike for riding proper mountain bike trails it is a no brainer .
Why a gearbox/what about the weight?
If you add a Pinion gearbox, take away a cassette (unsprung weight), derailleur( unspring weight), chain guide and build a lighter stronger rear wheel and the disadvantage is ~800g. Given that you have to power yourself and the bike up hills and overcome rolling and air resistance the extra effort required when climbing is almost not measureable. Even if it was I would happily breathe a little harder while cruising up the hills with my mates if my reward was a significant improvement in suspension performance, 600% gear range, stronger rear wheel, almost no maintenance, chains that last years, shifting without pedalling, instantaneous shifting, no chain slap, optimised pedalling etc etc I'd be very surprised if Taniwha owners go back to a derailleur.