Product · BH
BH SB Mag: magnetic, 20 kg flywheel, poly-V belt
Note: This page contains affiliate links. If you buy through them we may earn a commission at no extra cost to you. Learn more
BH's SB Mag is built for riders who spend real time on an indoor bike each week. BH rates it for intensive home use of between 7 and 20 hours weekly, which is far beyond the occasional half-hour most budget bikes are designed for. A 20 kg flywheel, magnetic brake and poly-V belt aim to give a smooth, road-like feel, and a triathlon handlebar invites a lower, aero position.
- Flywheel
- 20 kg
- Resistance
- Magnetic
- Pedals
- Not stated
- Max user
- Not stated
- Apps
- Not stated
In its favour
- BH rates it for intensive home use of 7 to 20 hours a week.
- Magnetic braking and a poly-V belt for quiet pedalling.
- A triathlon handlebar with vertical micro-adjustment and a reinforced bottom bracket.
Good to know
- Max user weight and pedal type are not stated in the listing.
- A heart rate chest strap is optional, not included.
Our take
Drivetrain and resistance
A 20 kg flywheel carries momentum through the pedal stroke, which helps the bike feel smooth at both low and high cadence. Power reaches it through a poly-V belt, a ribbed belt known for quiet running. Resistance is magnetic and increases progressively, so there are no felt pads to wear down.
BH also mentions a reinforced bottom bracket, the bearing assembly at the cranks, intended to stand up to long, demanding sessions.
Position and fit
Saddle height and fore-aft position adjust, as do the handlebars, and BH says you can set the bike up much like a road bike. The ergonomic triathlon bar offers vertical micro-adjustment so you can find a comfortable reach and elbow position.
Specific adjustment ranges are not listed, nor is pedal type or maximum user weight.
Console and heart rate
The LCD shows speed, RPM, calories, distance, workout time and heart rate. Heart rate comes via 5 kHz wireless from a chest band, which is optional rather than included. No app connection is mentioned.
One quirk: much of Amazon's spec table for this item contains unrelated apparel data, so rely on the bullet points. The bike's weight is listed as 55 kg, which suggests a heavy, stable frame but also one that is hard to move.
How it compares
The VirtuFit Stage 2.0i offers a slightly heavier 22 kg flywheel plus Zwift, Kinomap and Fitshow support, 24 levels and stored profiles. The Capital Sports Evo Race also has a 22 kg flywheel and Kinomap via an included pulse strap. The SB Mag's case is durability for heavy weekly use and a cleaner, quieter drive rather than connected features.
Verdict
Pick the SB Mag if you ride many hours a week and want a solid, quiet bike with a heavy flywheel and triathlon bars. If you want Zwift and onboard programmes, the VirtuFit Stage 2.0i is better equipped, and heavier riders who need a stated weight rating should look at the Wenoker JC318.
Compared with alternatives in: Best spin bikes for home
Amazon listing title: BH Fitness – Indoor Bike SB mag BH Fitness