Recently on my daily internet hunt I was turned onto a frame in the
Santa Cruz Riders thread. JBDirtJumper linked to a couple photos of a new Nukeproof Downhill bike! That's right, a component based company is stepping into the realm of DH bikes.
Here's some info on the new rig...
Here is what the crew in the UK had to say when I asked them about the new frame:
"It's super early in it's development at the moment, with no production date scheduled yet.
Basics are a linkage actuated singlepivot, with contemporary long, low, slack geometry, though we're specifically working on rear triangle and pivot/linkage details, so the system could be applied to any geometry we fancy. 8in travel from a 3in stroke shock.
Our first build came in at
37lb 11oz with pedals."
Also, on
NukeProof's
Facebook this info has been spread:
- 1.5in head tube for geometry tuning
- based around a 63deg head angle right now.
- Ride height adjustable via magic things.
- Singlepivot with triple rate change swing link
Source: Hotlines
Stay tuned for more information!
But I like it anyways ;-)
Anyone remember the junk hubs they made years ago with the carbon fiber shells??? Hahahahaha
Also I won't touch a Titus either Chris Cocalis is a lying cheating bastard and I witnessed him in person bashing a box in only to make a claim with UPS, worthless company it's so great he tainted the water with a new company Pivot... Right? That new management mentality sucks. The problem is that some of the companies need to start completely from scratch, and change their names.
And look at the terrible welds too>>>...
(Im a welder)
Where the swingarm is above the BB sorta looks like a Foes.
Are they 4mm heads on the pivot top caps? I know they are only covers, but on something that gets serviced a lot I'd want to see 6mm, or at least 5mm. I hope that changes in production.
and @jbizzle whats wrong with those welds?? its a prototype, its not meant to be perfect...
Gringo.
Final word, yes, they work 'fine' but just not that great.
"uh, neither of those are linkage driven single pivots. what magical 4 bar did you ride?"
Pick one....
CHeers
ive got some nukeproof wheels and bars and they have been amazing, im really looking forward to this hitting production, its definately replacing my current ride
I think it looks sick, but pretty much like everything else at the moment, hopefully the price'll be nice and low though ;D
Anti squat works best when at 100% - 100% anti squat will mean minimum pedal bob. Anti squat is at 100 when the main pivot, or in the case of a 4 bar suspension design, the instant centre, is inline with the chainline.
This means that it is very easy to get good anti squat properties from a single pivot suspension design - if the main pivot is placed on the chainline, just infront of the BB, you get a very stable anti squat around 100%... wait, where have nukeproof put their main pivot???
Oh, and about the derailleurs... It's because motocross bikes have this magical thing called a gearbox
I was referring to chain length variations which require a derailleur to let out or take up slack, not to the ability to shift gears.
On a single pivot bike, you can put an idler on the pivot for 0 chain growth. This means, if you could have a gearbox on a single pivot bike, you wouldn't need a derailleur. However, current gearbox designs are too heavy/expensive/power inefficient to be viable for use on a mountain bike.
On a 4 bar design, the instant centre moves, meaning you can't use an idler to stop chain growth. So they'd still need a derailleur.
My basic argument is not that single pivot is wholly bad, but that it is not that great, unless you add said items above. and as you say its not feasible. That said, this nuke proof bike is very nice, fancy looking, and well made, but I cant get excited about a bike that will likely cost a lot of money and yet be out performed by a bike that is 1/2 the price but a better design. People get way to caught up in nice new stuff but fail to see the limitations of that item just because it has a fancy name or is shiny and new.
Bottom line, there are better bikes out there for less $$ with a better performing suspension system than this - therefore, I cannot get excited or praise it aside from what it is - nice looking.
An idler is certainly not to heavy for a DH bike - it's just a cog, and used in the K9 industries bike, aswell as the katipo.
A 4 bar suspension design will have all the same problems with chain growth as a single pivot, if it has the same axle path end point.
The main advantage to 4 bar designs is extra tuneability in design, and no brake jack. However, an extra pivot between the main frame and the wheel will mean extra flex in the rear end. So, it will have to be overbuilt to reduce flex, meaning the weight won't be much/any less than a single pivot with a floating brake.
Nice...