MERACH S29 Pro Exercise Bike Review: 10kg Flywheel, 159kg Limit

The S29 Pro is MERACH's heavy duty take on the studio-style magnetic bike, and the headline number is the weight limit rather than anything on the console. MERACH rates it for riders up to 159kg, puts a 10kg flywheel on a reinforced steel frame, and sells it for around £309.99 at the time of writing (1 October 2026). The machine itself weighs about 35kg. If you're a bigger rider who's been put off by the 100kg to 120kg limits on most budget bikes, this is the reason to read on.

We rate it 4.1 out of 5. It's a sensible, solid bike with a short warranty and an app story that's thinner than MERACH's marketing suggests.

Who it is for

Buy it if you weigh more than 110kg or so, or if you share the bike with someone who does. Most spin bikes at this price stop well short of 159kg, and a bike rated close to your weight works at the edge of its design every session. Taller riders benefit too: MERACH quotes a fit range of 145cm to 195cm.

It also suits anyone who mainly wants steady rides and intervals without a subscription. The MERACH app is free, and the bike works perfectly well as a plain machine with a phone timer.

Skip it if you want Zwift on day one or a long warranty. For broader options, our best exercise bike UK guide and best spin bike UK guide cover the alternatives.

Check the MERACH S29 Pro price on Amazon£309.99

Frame and weight limit

Here's where the S29 Pro earns its money. A spin bike's weight limit tells you how much margin the frame, seat post and crank have, and 159kg gives a lot of it. For a 90kg rider, that's a frame working at well under two thirds of its rating, which should mean less flex when you stand for climbs and less creaking as the bike ages. MERACH uses reinforced steel tubing, and the bike's own 35kg or so of mass means it shouldn't skate across a mat during sprints.

The trade-off is portability. At around 35kg, it's a two-handed job to tip onto its wheels, and it isn't something to carry upstairs alone. Decide where it'll live before it arrives.

Flywheel and resistance

A 10kg flywheel is a good size at this price. Heavier flywheels keep spinning between pedal strokes, which smooths out the dead spots and makes slower, heavier efforts feel more like riding on a road. On magnetic bikes the magnets do the real work of setting resistance, so flywheel weight matters less than it did on old friction-pad bikes, but there's no downside to having the extra mass.

MERACH doesn't say how many resistance levels the S29 Pro has, which is an odd omission. If you want to repeat sessions precisely, note down your settings and cadence, or use the app's resistance readout, which MERACH says displays live.

Noise is quoted at under 25dB. That's for the magnetic system itself, and it's believable; contact-free magnets and a belt drive make very little sound. In a real flat you'll hear the rider more than the bike, and a mat under it helps with vibration through the floor.

App and tracking

MERACH's own app shows resistance level, distance, time and calories in real time, and FantomFite turns the ride into a game, which some riders love and others ignore after a week. Both are free. Your sessions sync to Apple Health or Google Fit, so they'll sit alongside your watch data.

What's missing is any mention of Zwift or Kinomap for this model. MERACH's newer self-powered exercise bike does list both, so check that review if virtual racing matters to you. Treat calories on the S29 Pro as a number for comparing your own rides, because a bike without a power meter can only estimate them.

Fit and comfort

Four-way adjustment on both the seat and the handlebar is what you'd hope for at this price: up, down, forward and back on each. The quoted 145cm to 195cm range covers almost every adult. Spend five minutes getting the saddle height right on your first ride, because a saddle that's too low loads the front of the knee and a saddle that's too high makes your hips rock. Our exercise bike seat height guide walks through it.

The dumbbell holder is a small extra that's genuinely useful if you like to pair rides with light arm work at the end of a session.

What it's good for

Steady rides and intervals, mostly. Interval training on a bike works well for busy people: a meta-analysis of 37 studies found interval and endurance training raised VO2max by about 0.5 litres per minute over 6 to 13 weeks (Bacon et al., PLoS One 2013). The NHS recommends 150 minutes of moderate or 75 minutes of vigorous activity a week, and three 30 minute rides gets you most of the way to the moderate target on its own.

If you're new to it, start with our exercise bike HIIT workout, which includes beginner sessions.

How it compares

Against MERACH's own lineup, the S29 Pro sits between the cheaper MERACH smart exercise bike at around £190 and the self-powered model at roughly £320 to £370. The cheaper bike has a lighter build; the self-powered one swaps the heavier frame focus for adaptive resistance, no mains lead and wider app support. If your priority is a high weight limit and a solid frame, the S29 Pro is the one to buy. If you want smart features, the self-powered bike is better value.

See today's MERACH S29 Pro price

Recommended reads

• The best exercise bikes in the UK
• The best spin bikes in the UK
• MERACH self-powered exercise bike review
• Exercise bike seat height: how to set it
• Exercise bike HIIT workout