YT Decoy SN MX Core 4 long-term review – initial report

The YT Decoy SN MX Core 4 is an ultra-bling, mid-support electric enduro ebike, sporting a carbon fibre frame, 430Wh battery, Fazua motor and some of the best components money can buy.

That’s helpful, given its £8,499 RRP – although it’s currently on sale for £5,499.

At 20.6kg, it’s not breaking any records when it comes to lightweight eMTBs, but that heft helps give it a planted ride feel when chewing up the chunder.

This bike is a real monster on the descents. Although it’s gravity-focused, the Fazua Ride 60 motor is designed to offer a ‘supernatural’ ride feel (hence the SN). It should enable you to get back to the top quicker than on a non-electric bike, while feeling a little more as though you earned the climb than on a full-power electric mountain bike.

YT Decoy SN MX Core 4 frame, suspension and specifications

The Decoy SN frame is made from carbon fibre. A flip chip on the rear shock yoke enables you to adjust the geometry between ‘Low’ and ‘Regular’ settings, ‘Low’ being descent-focused and ‘Regular’ intended for more relaxed trail riding.

A tool caddy is located under the front of the top tube and there’s room for a water bottle or range-extender battery within the front triangle.

Extensive chainstay and seatstay protection is built in. Internal cable routing can be found throughout the frame.

Pedalling assistance is provided by a Fazua Ride 60 motor with 60Nm of maximum torque and 450W of peak power.

A 430Wh battery is hidden within the down tube; the level of charge can be monitored using the LED hub integrated into the top tube.

YT’s four-bar linkage suspension system delivers 160mm of rear-wheel travel, controlled by a Fox DHX2 Factory coil shock, fitted with a 425lb spring.

Up-front is a 170mm-travel Fox 38 Factory air-sprung fork. The bike rolls on mixed-size Crankbrothers Synthesis Alloy rims (29in front, 650b rear) laced to Industry Nine hubs and wrapped in Continental Kryptotal tyres.

A 12-speed SRAM GX Eagle AXS Transmission takes care of drivetrain duties, paired with 160mm e*thirteen Helix Race E*spec cranks.

YT Decoy SN MX Core 4 specification

• Sizes: S, M, L, XL, XXL
• Weight: 20.6kg
• Frame: Carbon fibre
• Fork: Fox 38 Factory air-sprung
• Shock: Fox DHX2 Factory coil
• Motor: Fazua Ride 60 motor / 430Wh battery
• Chainset: e*thirteen Helix Race E*spec
• Cassette: SRAM GX Eagle
• Derailleurs: SRAM GX Eagle
• Shifters: SRAM POD
• Stem: Renthal APEX 35
• Bar: Renthal Fatbar 35
• Grips: ODI Elite
• Headset: Cane Creek
• Saddle: SDG
• Seatpost: YT Postman
• Brakes: SRAM Maven
• Wheelset: Crankbrothers Synthesis Alloy rims (29in front, 650b rear)
• Tyres: Continental Kryptotal

YT Decoy SN MX Core 4 geometry

I normally ride a medium, but opted for the large size of the Decoy SN. The numbers in the geometry chart suggest it shouldn’t feel too out of the ordinary.

While the 475mm reach is longer than I’m used to and the 50mm stem that comes as stock may make it challenging to pick up the front wheel for manuals and wheelies, the 442mm chainstays are relatively short for an ebike and, along with the smaller rear wheel, should make for a snappy and responsive ride in the corners.

The bottom bracket sits only 344mm from the ground, which should keep the centre of gravity low and help with that planted feel.

At 64.2 degrees, the head angle is designed to provide great control while descending, while the 78.3-degree seat tube angle should give a fairly good seated position for most climbs.

Why did I choose this bike?

As the videographer and video editor for MBUK TV, a bike with at least some assistance helps me get around with all our camera gear when I'm out on shoots.

Last year, I rode a Specialized Turbo Levo SL. This was my first experience of a lightweight eMTB and I was left impressed.

Weight isn’t something that usually bothers me, but for ease of use and better bike control, the lighter-weight options sounded better for my needs.

Not only that, but I wanted a bike I could also ride for fun and chuck about in the air on weekends – after leaving my camera bag at home, of course – so the descent-focused Decoy SN MX sounded ideal.

The mixed-wheel setup is also something I’ve come to prefer over the past few years, so that was another reason for picking this bike.

Lastly, while I enjoy riding MTBs of all types, I prefer to have a long-travel bike for most rides, because I like to push my limits, hitting bigger jumps and drops, and trying to improve my overall speed through rough sections of track.

So, the 160/170mm of travel on this bike was also a box ticked.

YT Decoy SN MX Core 4 initial setup

I haven’t made many changes to the bike, as of yet. This is because – for the most part, at least – it felt fairly good out of the box.

I’ve tweaked the saddle angle slightly, running it close to parallel to the ground, but with the nose nudged down a touch, so I can winch up my local climbs comfortably. If I lived somewhere with steeper inclines, I’d push the front down a little further.

On my first ride at BikePark Wales, I noticed the handlebar was rolled further forward than I’m used to, putting me in an overly aggressive position, so I rotated it back a little to give a better balance of ‘elbows out’ control and playful handling.

Up-front, I’ve put 90psi in the fork’s air spring. The 425lb coil spring at the rear feels pretty good, albeit on the softer side.

I’m not super-familiar with coil shocks, so it’ll take some time and playing around before I work out what feels right for me.

I’ve pumped the front tyre up to 26psi and the rear to 29psi, to stand up to some heavy landings.

YT Decoy SN MX Core 4 ride impressions

First impressions were pretty good. The Decoy SN felt a little alien on the first descent, but that's to be expected when jumping on any new bike.

By the second run, I felt as if I’d known this bike my whole life. I was able to charge ahead with very little desire to touch the brakes.

The bike felt like a tank – solid, planted but easy to control. I was able to throw it around a bit in the air too, and had no issues with getting the back end out, without feeling like a squid.

High-speed impacts through rooty sections felt nicely damped. I look forward to seeing what else this bike can do downhill.

Ascending the ebike climb at BikePark Wales was interesting. The Decoy SN didn’t feel as though it had as much power as the Levo SL, despite that bike’s Mahle-built motor delivering a lesser 50Nm of torque and 320W of peak power.

I probably need to experiment with my cadence, because some ebike motors work better the faster you spin the cranks.

However, the Fazua drive unit provided a natural pedalling feel.

That’s not to say the Decoy SN felt like an non-assisted bike by any means, but I was getting to the top of climbs mildly out of breath and with warm legs, rather than boosting my way up sweat-free and feeling guilty when sitting down for ice cream later that day.

Unfortunately, my first impressions were then soured somewhat.

By the second climb, the indicated battery charge had already dropped by two bars (out of five), and by the third, there was only one bar left.

The Fazua battery then died on me completely, midway up my fourth climb.

When I got home and tried to recharge it, I was met with a flashing red light on the charger and no response from the unit itself. This issue was reported to YT and the bike sent off for repairs.

After a couple of weeks, I got the bike back and took it out on a shoot. This was when a second issue reared its head.

The motor was randomly disengaging, allowing the cranks to spin with no resistance.

This was manageable when climbing, because the motor would eventually cut back in.

However, it was rather scary when exiting a corner, going to put in a couple of hard pedal strokes to pick up speed and finding there was no chain tension to push against.

I dropped the bike off at the YT Mill in the Surrey Hills for another inspection, and it was handed back to me a week later with this problem resolved.

Since then, I’ve had no further issues. However, this experience has left me feeling a little cautious when riding the bike, even though I’m enjoying my time on it.

YT Decoy SN MX Core 4 upgrades

I’d like to fit a 35mm stem to bring the handlebar closer, and to cut the bar down a little, in line with my standard setup.

I’m also keen to try a higher-rise bar and see what the fuss is about – there’s a 50mm-rise Renthal Fatbar35 in the office that I’ve got my eye on.

While the SDG saddle is okay, it’s not the most comfortable for me. I get on well with Ergon saddles, so a swap to a different MTB saddle is something to consider.

I’m not familiar with the Conti Kryptotal tyres, but I’m enjoying the feel so far, so I’ll leave some time before I decide whether to change them.

My biggest bugbear is the SRAM AXS Pod Ultimate Controller, which is too sensitive for my liking when trying to shift up or down through the gears on chattery trails.

I’d like to upgrade this to an AXS Rocker Paddle shifter.

Other than that, the parts spec is solid. Whether or not I’ll need or want to upgrade anything else, only time will tell.

BikeRadar‘s long-term test bikes

BikeRadar's long-term test bikes give our team the opportunity to truly get to grips with these machines, so we can tell you how they perform through different seasons and on ever-changing terrain, through a year of riding.

Some choose a bike from their favoured discipline and ride it hard for a year, others opt for a bike that takes them outside of their comfort zone.

We also use our long-term bikes as test beds for the latest kit, chopping and changing parts to see what really makes the difference – and help you decide which upgrades are worth spending your money on.

These bikes also provide an insight into the team's riding through the year – how they like to ride and where life on two wheels takes them, from group rides on local lanes and trails, to adventures further afield.

To see all of the BikeRadar team’s long-term test bikes – and to stay up-to-date with the latest updates – visit our long-term review hub.