Archive: RocketMAX Gen2

The Cotic RocketMAX Gen2 in Gloss Teal and Tangerine

Discontinued, superseded by Gen3. This page is kept as an archive record for owners and for anyone researching an older Cotic RocketMAX.

Years of production: 2018-2020

The RocketMAX Gen2 was the first RocketMAX with Longshot geometry, and the first with a UK made front triangle. See the RocketMAX archive for the other generations.

The RocketMAX Gen2 was Cotic's big wheel, 29er steel full suspension enduro bike: 150mm rear travel, built around a 160mm fork.

It was the fastest bike in the range at the time, aimed squarely at the rockiest descents and steepest technical trails. Its Reynolds 853 frame carried speed through lines that would have been a fight on other bikes, with the stability and precision to stay composed on any gradient, and it still pedalled back up happily.

Reviews

BikeRadar, 4.5/5 (Gold Eagle build): the reviewer rated it Cotic's best bike to date and one of the best bikes from any brand. Read the review.

BikePerfect, 4.5/5 (Gold Eagle build): the testers found it stayed calm and confident well past their usual limits, ranked it among the fastest gravity bikes they had ridden in any material, and praised the way steel damped the trail while keeping a lively, accurate feel. Read the review.

Finishes and sizes

Finishes: Gloss Teal and Tangerine, Gloss Metal on Metal
Sizes: Small (390mm), Medium (425mm), Large (460mm), XL (495mm)

The Cotic RocketMAX Gen2 in Gloss Metal on Metal

Origin: UK and Taiwan

The RocketMAX Gen2 was designed, developed, engineered and tested by Cotic in the Peak District, with Cy Turner as lead designer, and lab tested beyond the ISO 4210 safety standard. Most of the production happened in the UK: Five Land Bikes in Scotland built the Reynolds 853 front triangles in small batches, mated to droplink rear ends from Cotic's suppliers in Taiwan. Unite Components and Bear Frame Supplies made much of the remaining machined parts.

The major frame parts were dip coated in manganese phosphate against corrosion, then painted in durable automotive spec paint by Five Land. After their hand finishing and QC, Cotic checked the parts again before assembly in the Peak District. UK made frames were Datatag registered from the factory. Singletrack published a feature on how these frames were made.

Features

Longshot geometry. Designed around a very short 35mm stem and a slack head angle, Longshot kept the bike stable in rough ground, planted in corners and accurate in steep tech, while the short stem kept the steering quick and the bike eager to pop off every feature.

Reynolds 853. A light, lively and robust front end, including Cotic's ride tuned Ovalform top tube. The steel frame's compliance helped it find grip and feedback in poor conditions.

MAX: 29" wheels. Big wheels roll easily and give stability, confidence and speed in rough terrain, at the cost of a little weight and playfulness compared with 27.5". The MAX frame packaging (longer rear end and wheelbase, taller front end) also suits taller riders well.

droplink suspension. Supportive and progressive, keeping the 150mm travel lively and interactive with grip on the descents and traction on the climbs.

Frame details

Cotic Longshot geometry, designed for very short 35mm stems for responsive steering with high speed confidence
Reynolds 853 Ovalform and DZB tubed front end for precision, ride feel, durability and strength
44mm standard head tube with an external bottom cup for taper steerer compatibility and a zero stack top cup for minimal stack height
Custom Cotic designed 35mm Reynolds 853 seat tube for super stiff support for the main suspension pivots
31.6mm dropper compatible seatpost size, with internal Stealth dropper remote routing
ISCG05 mounts on a regular threaded bottom bracket
Rear mech cable routed internally through the steel seatstay for clean lines and low noise
Dedicated 1x drivetrain design: maximum width swingarm pivot, low drop, forged swingarm heads and an integrated OneUp Components Top Guide
6066-T6 aluminium swingarm with a Syntace X-12 Boost148 x 12 rear axle
15mm pivots for the BB and droplink, with a thru axle style linkage clamp
1 bottle mount
Clearance for big tyres: 29 x 2.5" or 27.5 Plus (see component sizes)
Optimised around 160mm forks
150mm of Cotic droplink suspension with a strong progression rate
Sizes: Small (390mm), Medium (425mm), Large (460mm), XL (495mm). Small was added during this generation

Geometry

The chart is a guide to frame size. Longshot geometry means the frames are low and long, with plenty of standover. We recommended the size for your height on the chart, with a short 30-35mm stem. Consider your leg length too: if you upsize, a long dropper may not fit, either because the collar hits the seat tube top or the post bottoms out on the droplink pivot.

160mm fork

Frame Size	Small	Medium	Large	XL
Seat Tube (centre-top)	390mm	425mm	460mm	495mm
Top Tube Length (effective)	604mm	631mm	657mm	686mm
Head Angle	63.5°	63.5°	63.5°	63.5°
Seat Angle	75.3°	75.3°	75.3°	75.3°
Chainstay Length	448.2mm	448.2mm	448.2mm	448.2mm
BB Drop	-27mm	-27mm	-27mm	-27mm
Head Tube Length	100mm	110mm	120mm	130mm
Reach	443.0mm	467.0mm	490.0mm	515.0mm
Stack	620.4mm	629.3mm	638.3mm	647.2mm
Wheelbase	1234.3mm	1262.3mm	1290.3mm	1319.3mm
Usual Height Range	165-172cm	169-180cm	178-188cm	186-195cm
Stem Length	25-45mm	25-45mm	25-45mm	25-45mm
Frame Wheel Travel	150mm	150mm	150mm	150mm
Maximum Seatpost Insertion (incl. actuator)	164mm	199mm	235mm	270mm

All measurements are static, based on a 160mm travel fork with 571mm static length. Maximum seatpost insertion leaves 25mm clear below the actuator for a hose or cable to route through the frame. Your post may need more or less, and an externally routed dropper won't need this margin.

Not sure about sizing for a used frame? Email size@cotic.co.uk with details of what you ride now and the seatpost you plan to use.

Component sizes

Seatpost diameter: 31.6mm (380mm long minimum)
Front mech: not applicable, 1x drivetrains only
Fork: minimum 150mm, maximum 160mm travel, 573mm axle-crown (unsagged)
Bottom bracket width: 73mm
Bottom bracket thread: conventional English/BSA
Chainring: single only, Boost chainline
Chain guide mounting: ISCG05 bottom two tabs, plus the integrated Cotic x OneUp Components Top Guide (supplied with the frame or bike)
Headset: 44mm for taper steerer forks: Hope 2H, Cane Creek ZS44 top/EC44 bottom, Chris King Inset I7
Rear hub: Boost148 x 12 bolt through
Rear axle: Syntace X-12
Rear mech hanger: Syntace X-12 Type 1 (conventional or Shimano Direct Mount)
Shock: 200 x 57
Shock fittings: 15.75 x M8 down tube end, 24.0 x M8 seatstay end
Dropper post routing: Stealth via the down tube
Rear brake mounting: I.S., compatible with rotors up to 203mm
Maximum tyre size: 29 x 2.5" or 27.5 x 2.8"

Owner's manual: download the Cotic droplink Longshot user manual (PDF).

Setup guide

Sag. droplink suspension works best with 25-30% of the travel as sag, and 30% is our preferred starting point. The RocketMAX Gen2 uses a 57mm stroke shock and a 160mm fork, so aim for 15-17mm sag at the shock (start at 16mm) and 32-40mm at the fork (start at 36mm).

Setting shock sag. Start with 170psi in the shock and any lockout or climb switch off. Ride in full kit, with your pack and water if you carry them, saddle at full pedalling height. Bounce on the saddle to work the shock, stop, slide the o-ring against the seal, then sit on the bike with your feet off the pedals and get off gently without compressing the shock. Measure from o-ring to shock body and adjust pressure until you hit your target.

Setting fork sag. Then check the fork, aiming for 20-25% sag. Ride slowly with the saddle dropped, slide the o-ring to the seal while rolling, stand into an attack position, then sit back and roll to a stop without braking hard. Measure, adjust, and recheck the rear. Repeat until both ends are right. Because weight distribution varies with saddle position, stem length and bar width, always set up by sag measurement, not a generic pressure.

Cane Creek base tunes (all relative to fully open):

DB Air IL: no volume spacers, HSC fully open, LSC 4 clicks, HSR 1.5 turns, LSR 2 clicks
DB Coil IL: HSC 1.0 turn, LSC 5 clicks, HSR 1.5 turns, LSR 2 clicks. If you have a used frame with a coil shock, contact us for spring rate advice. Do not add more than 2 turns of preload: the spring can coil bind at bottom out and damage the frame
DB Air CS: no volume spacers, HSC fully open, LSC 4 clicks, HSR 1.0 turn, LSR 2 clicks

Other shocks. Start with rebound 3 clicks from fully open, and add damping only if the bike kicks you out of the saddle or springs back too hard off drops. Run compression or pedal platform off or at minimum: droplink is designed to pedal well without it.

Fork damping. Start rebound mid-range, then go faster until it feels sketchy and back off one click. Run high speed compression fully open or close to it, and add volume reducers rather than damping if you use the travel too easily. Start low speed compression mid-range: reduce 3 clicks if it feels chattery, add 3 clicks if it dives under braking or on steeps.

A bit of advice. Don't set rebound with the bounce-in-the-street test, it leads to rebound that's too slow for grip on the trail. If you catch pedals or want quicker steering, add air and reduce sag by 1-2mm. Lap a trail you know, change one thing at a time, and keep a written base setup to go back to. Our base settings run on the lively, fast rebound side, so give them a couple of rides before changing them.

Videos

Cy told the story of how Longshot geometry was developed on the Downtime Podcast.

Development history

Gen2 was a ground-up change from the Gen1 RocketMAX. It moved to Longshot geometry (63.5° head angle, much longer reach, short stems), a 160mm fork and 150mm rear travel (up from 140mm), a dedicated 1x drivetrain with an integrated OneUp top guide, a 6066-T6 swingarm, and Stealth-only dropper routing. Production of the front triangle moved to Five Land Bikes in Scotland.

During its run the range grew to four sizes with the addition of a Small.