When searching for the best kids’ and youth mountain bikes, cheap and heavy bike-shaped objects sadly still dominate the ranges of even big-name manufacturers, credit therefore due to Marin for this genuinely capable ‘my first full-susser’ based on its popular Rift Zone. Like its 27.5 and 29-inch wheeled big brothers, the Jr is a trail-optimised all-rounder that can serve as a springboard for whatever riding style your young’n fancies pursuing.

Need to know

• Sensibly priced first suspension bike
• Compatible with 24in and 26in wheels
• 120mm of travel front and rear
• One size, one price, one colour scheme
• Ready to unleash the potential in your little rippers
• 1×11 gearing with wide spread of ratios

The Rift Zone JR is a proper scaled-down trail bike

Kids’ bikes are a tough market to crack, given the balance to be struck between affordability for parents and a spec to inspire little riders. As such the Marin Rift Zone Jr provides solid foundations and a carefully considered build that can be upgraded and adapted to suit different applications as your kid’s riding progresses. The fact you can switch the wheels out from 24in to 26in means the Rift Zone Jr could last two ‘buying cycles’ as well, which is a bonus given kids can grow out of bikes faster than they do school shoes, and are often ready to go up a wheel size before you might think.

X-Fusion suspension needs a lighter damping tune to suit the low pressures used by sub-50kg riders

Marin’s MultiTrac full suspension design is carried over from the full-size Rift Zone and is basically a branded twist on the tried and tested single pivot and linkage-driven shock configuration. 120mm of travel front and back seems a sensible mid-range for younger riders and the Jr looks every inch the downsized ‘proper’ mountain bike that it is, with a stylish two-tone paint job, neat graphics and a curved top tube to maximise standover for little legs. Short version? Parents and kids alike dig the looks and it clearly has all the cred of the full-sized Rift Zone in a downsized package.

Proper brakes are more than up to the job, even for little hands.

Given the price point the spec is well thought-out with X-Fusion supplying both fork and shock, brakes and drivetrain from Shimano’s unflashy but dependable Deore range, a SunRace 11-speed cassette and Marin-branded finishing kit. Short 155mm cranks show a commendable attention to detail and are better suited to little legs while the 11-46t cassette has a decent range for the climbs. At 720mm the bar is crazy wide for our seven-year-old tester but offers scope to trim to fit – we cut them down to 660mm which seemed about right.

Short 155mm cranks show Marin has delved into the details.

If there’s one big disappointment it’s the lack of seatpost adjustment resulting from the curved seat-tube. From full extension and the limit mark on the post you can only drop it 65mm before it fouls the inside of the frame, meaning we had to swap to a cut-down post to get the saddle low enough and accept the limited range to raise it for the climbs. A dropper is the obvious answer, and the frame has internal cable guides ready to accept one, but the maximum insertion depth of 160mm is half that of most posts and will leave the saddle too high, even in its lowest setting. Perhaps less of a problem for taller riders but for our tester we had to make do with a traditional quick-release and the limited adjustment range.

Wheel and tyre combo is overkill and lighter options could transform the ride

The heft of the wheel and tyre combination is the other big limitation. The front axle is a 15mm bolt-through but only 100mm between the dropouts while the rear uses a conventional 135mm axle with a screw-in style quick-release, though with the dropout adaptors removed you can switch to a 142x12mm bolt-through if you prefer. Credit to Marin for giving you options if you take up the invitation to upgrade to 26-inch wheels at a later date.

Proper tapered head tube and a fork that’s ready to accept a 26in wheel means the Rift Zone can grow with your child

That will be your opportunity to save a chunk of rotating weight, the wheels alone knocking on 3kg before you’ve even fitted the draggy looking Vee Tire Flow Snaps at nearly a kilo apiece. There’s not a huge range of compatible 26-inch options around but a couple of mail-order packages we found would take nearly a kilo off the wheels alone for a couple of hundred quid.

The seat tube length was a limiting factor on the RIft Zone, even if standover clearance was good.

How it rides

Obviously we’ll have to caveat riding impressions for the Rift Zone Jr on the basis we had to draft in junior MBR test team member Florence, who at seven years old and 130cm in height was just about big enough to fit.

Given her 27kg weight, both fork and shock needed little more than a couple of strokes from the pump to achieve the recommended 15mm/30 per cent sag. Both have adjustable rebound, but even with that backed all the way off both ends felt a little sluggish, suggesting a lighter damping tune might be in order. Of course it might already be the lightest tune offered by X-Fusion. A YT Jeffsy Primo 24 we had in on test at the same time was an interesting comparison here, the fancier Manitou Machete and McLeod fork and shock combo on that bike clearly better optimised for a rider of Florence’s weight.

Our mini-testers were happy to tackle technical features that would have been a stretch on their hardtails.

For all that, ridden back to back on the same Alpine trails, the O-rings on the Marin’s fork and shock were a good way into their travel, suggesting she was getting enough of the 120mm from both ends to make a difference. A slightly older ripper we bumped into was clearly enjoying his identical Rift Zone Jr in the bike park, confidently sending some huge gaps and ably demonstrating the Marin can support small riders with big ambitions.

Long back end gives room for a 26in wheel at a later date.

Geometry for kids’ bikes obviously isn’t a like for like comparison but a look at the stats suggests the Rift Zone Jr is relatively long for a 24-inch bike, which makes sense given it needs clearance for bigger wheels as well. You get the impression Marin has built this as a bike to grow into, so a rider of Florence’s size may feel a bit stretched initially. But the relatively steep 67.5º head-angle and short front centre would seem to position the rider further over the front than the slacker YT.

The Rift Zone got the thumbs up for looking cool and inspiring confidence. That could be adjusted with offset bushings, an angle headset or even a mullet wheel set-up if you want to get creative, but both Florence and fellow tester Nancy were happy enough on the Marin to hit steeper and more challenging terrain than on the hardtails they usually ride. Anyone who’s ridden with kids will know confidence is key to helping them progress, and if they feel the bike is on their side they’ll be happier pushing their limits.

In the Marin’s case the heavy wheel and tyre combination were a significant drag on the climbs. But the speed both testers were willing to carry on the downs suggests the Rift Zone Jr’s handling opens up terrain beyond the trail centre blues you may currently be sticking to for family rides.

Review by Dan Trent/Florence Trent