Archive: Hemlock

Cotic Hemlock full suspension frame

Discontinued. This page is kept as an archive record for owners and for anyone researching an older Cotic Hemlock.

Years of production: 2006-2009

The Hemlock was Cotic's first full suspension bike: a super versatile trail riding animal. Proof that one bike really can do it all, it had the full-on, grab-it-by-the-scruff-of-the-neck handling Cotic is known for, with two distinct travel flavours.

The 120mm 'short' travel rocker gave punchy performance and a sharper platform, a great all round UK ride from trail centre to tech. The 150mm 'long' rocker gave plush, bottomless performance for big mountain holidays and epic rock fields. With a quick swap of rocker link and tyres, the bike went from speedy trail demon to mighty mountain flattener and back again. Keep two suspension bikes in the garage? Not any more.

Sizes: Small, Medium and Large.

Features

The frame had a super low slung top tube to keep the ride tight and chuckable, with even more standover clearance than our famously compact hardtails. The massive 1.5" standard head tube was intended for an internal headset (such as Hope's Reducer Low Stack or the Cane Creek Double Flush XC) to keep the bars low and weight forward. The 1.5" standard also allowed external headsets for a 0.5 degree slacker angle, or tapered E2 steerer forks, so the frame was completely futureproof.

The massively stiff 2" down tube hooked up to a radically stiff rear end via a 15mm pivot axle and massive 35mm bearings. New-for-2010 supersized chainstays locked in handling confidence in high pressure, high speed situations. Tyre clearance was enormous, for up to 2.4" tyres, and the torsion box chainstay brace sloped away to stop mud shelving on top of it. The full length seat tube allowed full saddle height adjustment, and cable routing used the same mud-repelling semi-outer design as our hardtails.

The heart of the frame was a 4-bar linkage suspension with a chainstay pivot and a manipulated axle path, giving incredible climbing traction without excessive pedal feedback deeper into the travel. Net Zero Reaction (NZR) brake mounting placed the caliper as far forward as possible to minimise braking inputs, so the suspension stayed stable when you needed it most. We teamed up with Fox to supply the RP23 Boost Valve shock as standard, with spectacularly good damping and feedback and tunable ProPedal. The long 57mm shock stroke gave precise control on the 150mm setting and super low leverage for great response with the 120mm rocker.

All pivots used double sealed, off-the-shelf cartridge bearings, with double sided chainstay pivot bearings to keep stiffness high and bearing load low. Easily sourced bearings meant cheap, hassle-free replacement. The bearings in Cy's own bike survived over a year of Peak District gritstone and post night-ride hose downs, with only the main pivot bearings needing replacement.

Setup options

Rear: two rocker link options, 120mm (short) or 150mm (long) travel. Both keep the same frame geometry at ride height with 20% (12mm) shock sag. The short travel rocker has a rising rate to prevent excessive bottoming out; the long travel rocker is more linear, with a fantastic open mid-stroke for control and stability. The rockers were also sold separately, so you could keep the other one on the shelf for trips.

Front: the geometry works best with 130-160mm travel forks.

Example set-ups:

Short/Mid (120mm rear, 130-140mm fork): general XC, enduros, singletrack and hard hitting trail centres. Sharp singletrack carving, with the pert short travel rear kicking under power and gripping in corners. Ian's preferred guiding set-up in the Pyrenees, on Magura Thor forks.
Short/Long (120mm rear, 140-160mm fork): a step up from a long travel hardtail without losing precision and chuckability. A rock solid stance in fast rocky sections, with the short travel rear taking the sting out. Cy's preferred set-up, on Magura Wotan forks.
Long/Long (150mm rear, 140-160mm fork): big rides in the hills and mountains where the rocks are large and the terrain is steep. Insane climbing traction from the supple rear end. Go light on forks and wheels for a mega-mile muncher, or fit stout single crowns and tacky tyres for drops and downhill.
More options: run short travel with more sag and a stout fork for berms and dual tracks, or fit an external headset and 160mm forks for a super slack technical trail weapon.

In developing this frame, we refused to define capability and type of use by travel alone: the Hemlock could be set up for the kind of riding you do.

Frame details

Custom 7005-T6 and 7046-T6 aluminium tubing
Fox RP23 Boost Valve long stroke shock
Super-compact frame layout and low stack front end for maximum room to move, with a full length seat tube for hassle-free saddle height adjustment
Fully sealed standard cartridge bearings in all pivots. Frame fitted main pivot bearings with a massive 15mm axle, and double sided chainstay bearings for stiffness and bearing life
Machined swingarm heads and torsion box cross brace with a sloped, mud shedding design, for stiffness and clearance for up to 2.4" tyres
One piece dropout and disc mount, with overhead disc mount location to ease wheel insertion and minimise braking effects
Long or short travel rocker options
Geometry for 130-160mm travel forks
Sizes: Small, Medium and Large
Weight: 6.7lbs for the Medium

Geometry

Ultra Compact Geometry means the frames are small and long, even more so on the Hemlock. The Small and Medium have more standover clearance than a Small Cotic Soul.

Frame size	Small	Medium	Large
Seat tube (centre-top)	16.2"	17.5"	19"
Top tube length	22.75"	23.25"	24"
Head tube length	110mm	120mm	130mm
Chainstay length	16.75"	16.75"	16.75"
Usual rider height	Up to 5ft 9in	5ft 8in - 6ft 1in	5ft 11in - 6ft 3in
Stem length (min/max)	50mm / 90mm, all sizes
Maximum tyre diameter	670mm (26.4"), all sizes
Short travel frame, mid travel fork (120mm rear static, 130mm fork at 500mm axle to crown, internal headset)
Head angle	68.5°	68.5°	68.5°
Seat angle	72.5°	72.5°	72.5°
BB height	13.5"	13.5"	13.5"
Long travel frame, long travel fork (150mm rear static, 160mm fork at 540mm axle to crown, internal headset)
Head angle	67°	67°	67°
Seat angle	71°	71°	71°
BB height	14.3"	14.3"	14.3"

With 20% sag, both travel settings sag to the same position, so geometry with the rider on board only changes with fork length, not rocker choice.

Not sure about sizing for a used frame? Email size@cotic.co.uk.

Component sizes

Seatpost diameter: 31.6mm (you will probably need a 400mm post)
Front mech: 34.9mm, conventional high clamp, bottom pull
Bottom bracket: 73mm, threaded
Headset: 1.5" standard. Stock geometry is based on an internal headset with a 1 1/8" steerer
Shock: 200mm eye-to-eye x 57mm stroke, 8mm fittings
Maximum tyre: 2.4"