28/11/2011 | 8 comments
This weeks homebrew bike is a stainless steel eight inch travel downhill beast called the “Gorilla”
Yann Watkins built the Gorilla back in 2008 and is working on the mark two version now (the Orangutan?)
Anyway enough of the monkey business here’s Yann top tell us about the bike:
My name is Yann Watkins and I am a Product/Industrial Designer with a passion for bikes. I did some design work related to the bike industry in the late 90s early 00s. Then I moved to Chile, were I am currently located right now.
I designed and built the “Gorilla” because I wanted a downhill bike that would pedal like a hardtail. This is achieved thanks to its jackshack configuration and internally geared hub. The lack of a rear derailleur, a non extending chain, a jackshaft double chain system and high pivot location proved to be a winning combo. It carries speed and pedals like no other bike, it certainly doesn’t feel like an 8″+ rear travel bike when you pedal.
I used to own a metalwork shop and I built the bike overnight when the machines weren’t being used (and kept working during the day) thus the dull mobile phone pictures.
All of the machining has been done on old fashion mills and lathes (hard but very rewarding) including the linkage and head tube.
The head angle, bottom bracket height, chainstay length, rear travel (6.7 to 9.5), shock compression rate, shock size (it can take 3 different shock lengths: 220 – 230 – 240) are adjustable.
Wheelbase : 110 / 113 cm
Chainstay: 40 / 43 cm
Bottom bracket height: 35 / 39 cm
HA: 65 / 67
Shocks: 220 / 230 /240 mm
Frame weight w/o shock: 4.6 kg
The Gorilla is completely build in stainless steel, except the linkage mechanism that is made of 7000 series aluminum. The bike is extremely stiff.
Downside: complete it weights around 19 kg. it feels heavy compared with newer dh bikes
It is currently fitted with and Shimano alfine 8 hub. (A wonderful piece of engineering)
– old school suspension pack: a fox vanilla rc at the rear and a 1998 DDG floozy forks – sometimes I used a de-gutted heavily modified RST R1, great chassis crappy interiors)
The bike was finished in 2008, so it is getting old now but it’s till going strong and thanks to its huge adjustability the geometry it’s not that out of date. Weight though, that’s another story!
I will soon start work on another the “evo” so stay tuned for that!
Have you built your own bike frame? Yes? Then get in touch with Billy