Under MR-S04 Exercise Bike Review
Our verdict
The best-selling exercise bike in this batch by monthly volume, the Under MR-S04 moves 1,000 units a month at $109.99, weighs just 18 pounds, and supports users up to 280 pounds.
Check price on AmazonBest for
Buyers who want a lightweight, easy-to-move exercise bike under $120 with a 280-pound capacity and strong mass-market validation at 1,000 monthly purchases.
Skip if
You need confirmed resistance type or floor dimensions before buying; neither spec is published in the product data.
- Weight 18 Pounds
- Max User Weight 280 Pounds
- Color Black & Blue
- Priced 44% below the category median ($194.99 across 52 tracked models)
Our scorecard
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Owner rating4.4/5
4.4 average across 1,359 owner ratings
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Popularity3.1/5
1,359 owner reviews, more than most models here
The overall score is owner satisfaction weighted by how many reviews back it, so a high rating from few reviews counts for less. The bars below show where this model stands against the other home gym and fitness equipment we track in this category on price, popularity and size. Context, not marks against it, and our read of the data, not a lab test.
Overview
The Under MR-S04 is an exercise bike priced at $109.99. At 18 pounds it is the lightest standalone exercise bike in this batch, making it simple to reposition between rooms or store upright when not in use. The 280-pound max user weight is above average for a bike under $120, and the Black and Blue color scheme is the published option.
The standout data point is demand: 1,000 monthly purchases with 1,359 reviews at 4.4 stars. No other bike in this batch comes close on monthly sales volume. That level of ongoing buyer traction at this price signals genuine, word-of-mouth-driven purchasing across a large buyer population rather than a promotional spike.
Resistance type and floor footprint dimensions are not published in the product data. Before purchasing, verify those details on the Amazon listing, particularly if you have a resistance preference or a specific floor-space constraint to work around.
Pros
- 1,000 monthly buyers, the highest demand signal in this batch by a wide margin
- Weighs only 18 pounds for easy repositioning and storage
- 280-pound max user weight, above average for a bike under $120
- 4.4 stars across 1,359 reviews
- Priced at $109.99, strong value relative to demand and capacity
Cons
- Resistance type not published; verify before buying if that spec matters to your workout style
- Footprint dimensions not published; check the listing before ordering
- Lighter 18-pound frame may offer less stability than heavier bikes during high-intensity efforts
Specifications
| Weight | 18 Pounds |
|---|---|
| Max User Weight | 280 Pounds |
| Color | Black & Blue |
Performance notes
The Under MR-S04's 18-pound weight is notably light for a standalone exercise bike. This makes it easy to move and store but may limit the planted stability that heavier frames provide during vigorous, high-cadence efforts. The 280-pound capacity is a reassuring margin for most buyers in this category. Resistance type is not in the product data; check the Amazon listing for that detail before purchasing.
What buyers say
1,000 monthly purchases at 4.4 stars across 1,359 reviews is a consistent, high-demand signature. At this sales velocity and rating, buyer satisfaction is clearly sustained over time. The combination of a low price, light and portable frame, and a solid 280-pound capacity checks the core boxes for a large share of the home-gym market, which the monthly sales data confirms.
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Frequently asked questions
How heavy is the Under MR-S04?
It weighs 18 pounds per the published product specs, making it easy to lift and reposition.
What is the weight capacity of the Under MR-S04?
The max user weight is 280 pounds per the published product specs.
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