Exercise Bikes · Buying Guide
Best Folding Exercise Bikes
A folding exercise bike solves one problem brilliantly, having nowhere to put a full-size one. It packs down to a fraction of its size and lives behind a sofa or under a bed between sessions. Here are the best folding exercise bikes in the UK, ranked on FitRank, with an honest account of what you gain and what you give up.
Let us be straight from the top, because this is a category where honesty matters more than usual. Folding bikes are a compromise. They have light flywheels, basic consoles and modest resistance, so none of them rides like a proper spin bike or a comfortable recumbent. If you have the floor space for a full-size bike, buy one, and our best exercise bikes guide will point you to it.
But if space is the real, binding constraint, a flat with no spare room, a bedroom that has to double up, a home shared with people who do not want a bike on permanent display, then a folding bike is not a compromise, it is the only thing that fits. Judged as space-savers rather than as training tools, these three do the job. They are ranked on FitRank, our editorial score, which is why the numbers here are lower than on our other guides. That is the format, not a fault in these particular bikes.
The quick list
- Best overall · Viavito Onyx · FitRank 3.0 · £99
- Best for a sturdier ride · Xterra FB350 · FitRank 3.0 · £169
- Best budget backrest bike · Xterra FB150 · FitRank 2.9 · £149
Viavito Onyx

The Viavito Onyx is the pick of a small field, and the most genuinely liveable folding bike here. It collapses to just 33 by 41cm, small enough to slide behind a sofa or under a bed, and at £99 it is the cheapest bike on the whole site. You sit upright and pedal gently through eight levels of magnetic resistance, with a simple console tracking the basics.
It is built for light, casual sessions rather than training, which for the person buying a folding bike is usually exactly right. Nobody choosing this is trying to win a race, they are trying to move a bit without a machine taking over the room.
Best for Small flats and shared rooms where the bike simply has to disappear between uses.
Watch-out A light 1.2kg flywheel, fixed handlebars and a 100kg user limit, so it is strictly for gentle riding.
Xterra FB350

The Xterra FB350 is the more substantial folding option. It has a heavier, steadier feel than the ultra-compact Onyx, a more supportive seat with a backrest, and a pulse grip on the handlebars, which makes it the better pick if the Onyx feels too flimsy or too upright for you.
It still folds for storage, though it is bulkier folded than the Onyx, so it is the choice when you want a bike that feels more planted and can spare a little more room for it.
Best for Riders who want a more stable, supported folding bike and can give it a bit more space.
Watch-out Bigger and heavier than the Onyx when folded, and still a light-duty bike rather than a training one.
Xterra FB150

The Xterra FB150 is the entry point, a compact folding bike with a backrest seat that suits gentle, upright riding and rehab-style movement. It covers the same brief as the FB350 in a slightly smaller, simpler and cheaper package.
If you want the supported, backrest-style seating of the FB350 but at the lowest possible price, this is the one, as long as you accept it is the most basic bike here.
Best for The cheapest route to a folding bike with a supportive backrest seat.
Watch-out The lowest-specified bike on this list, with a light flywheel and a basic console, for gentle use only.
The three compared
| # | Bike | Type | Price | FitRank |
|---|---|---|---|---|
| 1 | Viavito Onyx | Folding | £99 | 3.0 |
| 2 | Xterra FB350 | Folding | £169 | 3.0 |
| 3 | Xterra FB150 | Folding | £149 | 2.9 |
Who a folding bike is really for
The honest answer is people for whom the alternative is no bike at all. If you live in a small flat, if your only space is a bedroom or a living room you cannot fill with equipment, if you share a home with people who would rather not look at a spin bike every day, or if you simply want to tuck the thing away when guests come round, a folding bike is the answer. It exists to fit a life, not to build fitness records.
It also suits light, gentle use by design, casual pedalling while watching television, keeping moving during recovery from illness, or very light rehab movement. The low resistance and upright position that make it a poor training tool make it an approachable, unintimidating one. For that reason folding bikes are also worth a look for some older riders in small homes, which we cover in our best exercise bikes for seniors guide.
What you give up
Being clear about the trade is the whole point of an honest guide. A folding bike gives up ride quality in three specific ways. The flywheels are light, typically one to two kilograms against thirteen or more on a proper spin bike, so the pedal stroke feels less smooth and cannot deliver a genuinely hard workout. The resistance range is modest, so strong riders will spin out at the top level. And the frames, being made to fold, are lighter and less planted than a fixed bike, so they can feel less stable when you push.
What you do not give up is the basic benefit of cycling. Gentle, regular movement on a folding bike still supports your health, still gets your legs moving, and still beats not exercising because there was nowhere to put a bike. The mistake is expecting it to do more than that. Buy it for what it is.
How to choose a folding bike
Folded size and weight
This is the reason you are buying one, so check it first. Look at the folded dimensions against the actual space you have, whether that is behind a sofa or in a cupboard, and check the weight if you will be moving it regularly. The Viavito Onyx leads here, folding to around 33 by 41cm.
Seat and riding position
Folding bikes split between simple upright saddles, like the Onyx, and backrest seats, like the two Xterras. A backrest is more comfortable and more supportive for gentle, longer sessions, while an upright saddle keeps the bike smaller. Choose on comfort, since a folding bike you find uncomfortable will stay folded.
User weight limit
Folding bikes often have lower limits than full-size ones, so check the figure against your own weight rather than assuming. The Onyx is rated to 100kg. Heavier riders are usually better served by a full-size upright, which is sturdier as well as more capable.
Be realistic about resistance
If you want to train hard, a folding bike is the wrong category and no amount of choosing well within it will fix that. If you want gentle, regular movement in a small space, any of these will do it. Match the bike to the job.
The alternative worth considering
Before you commit to a folding bike, it is worth asking whether a compact full-size bike would fit after all. Some upright bikes are smaller than people expect and ride far better, and a genuinely compact connected bike like the Reebok i-Bike has a footprint of around 131 by 51cm while offering a proper flywheel, app connectivity and a much better ride than anything that folds.
It does not fold away, so it is only an option if you can leave it out, but if you can find the corner for it, the jump in ride quality over a folding bike is large. Our best exercise bikes under £500 guide covers the compact full-size options worth weighing against these.
How we chose these bikes
Every bike here has been scored with FitRank, our editorial rating out of 5 that weighs performance, build quality, value and features against each bike’s rivals and its price. Folding bikes score lower than full-size ones because the format involves real compromises, and we would rather show you honest scores than inflate them to make a thin category look stronger than it is. We do not rank by commission. Within the folding category, these are the three worth considering, ordered by FitRank.
Frequently asked questions
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If you can spare a corner, a compact full-size bike rides far better, see our best exercise bikes under £500. For small-space options aimed at older riders, read our best exercise bikes for seniors guide, and for the full field start with our best exercise bikes guide.
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