The RocketMAX Gen4 is Cotic’s newest 160mm-travel, 29in-wheeled enduro bike that features a host of changes over the Gen3 model it replaces, including more sizes, compatibility with longer-travel forks and a host of travel and wheel-size options.
The RocketMAX Gen4 is a true enduro shred sled. It wouldn’t be a Cotic if it wasn’t made from steel, and the new RocketMAX uses custom-specced Reynolds 853 tubing for its front triangle that’s made in the UK. The 6066-T6 swingarm is manufactured in Taiwan. Like the rest of Cotic’s bikes, the new RocketMAX Gen4 is available in several build options. The bike I tested is an up-specced Gold XT build with Fox 38 Factory forks and Float X2 Factory shock, along with Hope’s all-new Tech 4 V4 brakes, boosting the base £4,999 price to £5,873.
Cotic RocketMAX Gen4 Gold XT frame and suspension
The brace tube between the down and seat tubes is a new addition. The Gen4 RocketMAX represents an evolutionary rather than revolutionary change to its design, retaining, for the most part, an identical shape. The UK-made front triangle’s Reynolds 853 tubing has been custom-specced for its strength and stiffness, but Cotic claims the overall steel construction of its tubes means there’s plenty of vibration absorption and compliance. There’s now a brace between the down and seat tubes, replacing a gusset.
Externally routed cables are good news for the home mechanic. Out back, the 6066-T6 aluminium swingarm has a Boost 12x148mm rear axle and can fit a 29×2.5in tyre. Cables are externally routed – except where the gear cable passes through the seatstay – and water bottle mounts feature on the under side of the top tube, with a secondary set on the underside of the down tube.
The linkage and its axle are keyed for a stiffer interface. Although the Gen4 still uses Cotic’s Droplink suspension system – with a main single pivot and a linkage to control suspension kinematics – it has been modified for this iteration of the bike. The new linkage is keyed into the axle to help reduce twisting and flexing. But that’s not all. The progressive rear end now uses a lower leverage ratio to create a supple but highly supportive feel, and it’s compatible with both coil- and air-sprung shocks.
The linkage makes the rear end around 30 per cent progressive. Travel is adjustable by installing a shorter or longer stroke shock. A 65mm stroke gives 160mm of travel, while 155mm or 150mm is possible by decreasing its length.
Cotic RocketMAX Gen4 Gold XT geometry
The C3 sits in the middle of Cotic’s C-Sizing range. Targeting the heavy-hitting enduro rider, it comes as no surprise to see Cotic’s Longshot geometry with long, slack and low figures on the Gen4 RocketMax. This latest iteration of RocketMAX has dumped the standard small to extra-large sizing names in favour of numbers, or C-Sizing as Cotic calls it. This is intended to deter people from arbitrarily defaulting to their usual size and instead pick the right one based on its geometry. Cotic has also expanded its range from four to five sizes, with smaller jumps in reach figures as the size increases.
|Seat tube (mm)||390||417||444||471||496|
|Top tube (mm)||599||621||639||660||679|
|Head angle (degrees)||63.5||63.5||63.5||63.5||63.5|
|Seat tube angle (815mm seat height) (degrees)||75.5||75.5||76.2||76.2||76.2|
|Chainstay length (mm)||448||448||448||448||448|
|BB drop (mm)||23||23||23||23||23|
|Head tube length (mm)||100||110||120||130||130|
|Recommended rider height (cm)||162-172||170-178||176-184||182-190||184-192|
My C3 test bike – in its 160mm-travel, 29in-wheel configuration – has a slack 63.5-degree head tube angle, a generous 482mm reach, long 448mm chainstays and an impressive 1,290mm wheelbase. These numbers are coupled with a 76.2-degree seat tube angle. The RocketMAX’s geometry screams speed and stability.
Cotic RocketMAX Gen4 Gold XT specifications
The Shimano XT drivetrain was as impressive as ever. For the £4,999 asking price, Cotic’s RocketMax Gold XT build represents decent value for money. It’s fitted with Shimano’s XT M8100 drivetrain and a BikeYoke Divine dropper. Elsewhere, there are Hunt Trail Wide wheels wrapped in WTB rubber and a Cotic-branded bar and stem.
Cotic has fitted its own-brand 35mm-long stem. Although the stock build sports RockShox’s ZEB Ultimate fork and Cane Creek’s Kitsuma air shock, along with Shimano M8120 four-piston brakes, this test bike has been upgraded with Fox’s 38 Factory fork and Float X2 rear shock, plus Hope’s Tech 4 V4 brakes. The asking price is upped to £5,873. Each model of the RocketMAX can be customised depending on its purchaser’s needs.
Cotic RocketMAX Gen4 Gold XT ride impressions
Its long geometry made it super-stable. I met up with Cotic big boss and founder Cy Tuner on my home trails in Scotland’s Tweed Valley, host of the UK’s round of the Enduro World Series, to get some initial ride impressions of the all-new Gen4 RocketMAX. Despite only riding the bike for a single day, I was able to take it down all of my well-trodden test routes in familiar conditions and get a good handle on how it performs.
This version is a clear improvement over the previous bike. I set the Fox 38 fork’s external damping adjustment to fully open, installed three volume-reducer spacers in the air spring and set it to 98psi. On Cy’s instruction, I set the rear shock to 30 per cent shaft sag, and initially set the damping to Cotic’s recommendations: 1 click of high-speed compression; 5 clicks of low-speed compression; 0.5 turns high-speed rebound; 2 clicks low-speed rebound. After my first lap, I ended up backing off all of the compression and rebound damping adjustment so the shock was fully open.
Cotic RocketMAX Gen4 Gold XT climbing performance
It would be good to see a slightly steeper seat tube angle. The RockMAX’s seated climbing position is fairly relaxed and upright, where not too much of my weight was concentrated through my hands. This helped reduce fatigue and improve comfort on longer fireroad winches to the trail head; arguably the sort of climbing the enduro-focused RocketMAX is going to be doing most of the time.
Comfort levels created by the fluttery rear-suspension action were also good. The rear end’s sensitivity – helped considerably by the large negative air volume in the Fox Float X2 shock – provided plenty of traction too. I didn’t notice the rear end stiffening up excessively while pedalling, and although that meant there was some pedal bob when cranking in higher gears, it also gave the bike a very neutral feel.
It pedalled neutrally on the climbs, where the suspension was still able to absorb plenty of bumps. Coming off a bike with a 78-degree seat tube angle, I felt the Cotic positioned my hips further behind my feet than I would like. However, this criticism is relatively small, and had I not been riding a bike with a much steeper seat angle just prior to testing the RocketMAX, I’m not sure I would have noticed the difference as much.
Cotic RocketMAX Gen4 Gold XT descending performance
The steeper the trails the better. Unsurprisingly, the Gen4 RocketMAX excelled on the gnarly, steep and fast enduro descents – the exact terrain it’s designed for. The super-long wheelbase and chainstay figures made it feel incredibly stable, where the exaggerated yawing effect in rough terrain felt on shorter bikes was muted impressively. This reduction in unwanted chassis movement made the bike easy to control and keep on line, and slowed down the intensity of the trails regardless of how gnarly they were, enabling me to focus on riding quicker rather than compensating for instability.
Speed and rocks are the RocketMAX’s ideal conditions. It took extremely bad line choice or body positioning to get out of shape on the RocketMAX, with big, deliberate movements needed to upset its balance. Coupled with a high front end – Cotic says it has increased stack height while upping fork travel for the Gen4 bike – weighting the front wheel in turns on steeper terrain was confidence-inspiring, and the temptation to lean back when it got gnarly to compensate for conservative geometry wasn’t there.
There’s plenty of traction through turns. Cornering felt inspiring, where the highly progressive rear suspension could be relied on to provide support driving speed through the turns, while the long back end meant there was plenty of traction and it didn’t begin to break away into a slide too easily. That same progressiveness meant that hammering rough terrain didn’t result in successive harsh bottom-outs. Instead, the RocketMAX exuded a calm and composed character with a bottomless rear end.
Cotic RocketMAX Gen4 Gold XT details
- Cable routing: The RocketMAX’s cables are routed externally, which is good news for those who can’t stand brake bleeding or trying to feed cables through tubes. However, the gear cable enters the swingarm for a short portion of internal routing, and where it enters it rubs on the swingarm during compression. Maybe alternative routing would be more effective.
The gear cable passes close to the shock and rubs on the frame during suspension compression.
- Tyre choice: During the one-day test ride, I managed to slash the rear WTB Trail Boss Light tyre. Although a tubeless repair plug fixed the puncture, and Cotic said upgrading to a Tough carcass version would be a no-cost option, it would be good to see tough tyres fitted from the off.
We’d like to see tougher-casing tyres as standard factory equipment.
- Chain slap: There was a fair amount of chain slap during the test ride. While this could have been an under-tensioned derailleur clutch, it could also be caused by a lack of chain and seatstay protection.
More chain slap protection would be good.
- Frame storage: With two bottle bosses and space for Cotic’s bespoke frame bags, there are plenty of options to store your essentials without needing a back pack or hip packs.
The Cotic’s tubes are sleek and there’s plenty of space for bottles and frame bags.
Cotic RocketMAX Gen4 Gold XT early verdict
Most at home on enduro trails, the RocketMAX is a true racer’s bike. Despite only having a limited amount of time on the RocketMAX Gen4, it was crystal clear that it’s a true enduro racer’s dream, where speed is the primary focus. Rivalling the Pole Stamina 160 Remastered in terms of stability and pace, the RocketMAX is a massively capable bike most at home on the gnarliest, steepest, roughest and fastest terrain.