Condensed Answer: Cruiser bars can be installed on a mountain bike as long as the stem and the bars are of compatible sizes. The conversion increases comfort but alters the bike’s geometry and hurts maneuverability.
Stem and Handlebar Diameters
If you have a retro MTB with a quill stem, you will need cruiser bars with a 25.4mm or 26mm diameter in the middle.
If you have a modern MTB stem, it is designed either for 25.4mm or 31.8mm bars (more common).
If you’re already in possession of cruiser bars that are too thin for your stem, you can use a shim to make up for it. Shims are a piece of metal that wraps around the bars to artificially increase their diameter.
The solution isn’t the most aesthetic, but it can work just fine for bikes that won’t be used for aggressive off-roading which is likely the case for MTBs equipped with cruiser bars.
Conclusion 1: Make sure that the stem and the handlebars are of compatible sizes.
Brakes Levers and Shifters
The brake levers and shifters of MTBs are normally designed for flat bars and can therefore be directly installed on the new bars. However, it may be necessary to shorten or lengthen the cables and housing to make the new set-up clean.
The original grips can also be transferred directly to the new cruiser bars.
Cruiser bars have a large rise and put the rider in a very upright position. Consequently, there’s more weight on the sit bones.
Regular MTB saddles are designed for more forward lean and don’t always provide the necessary comfort for fully upright riding. Thus, you may also have to replace the saddle with one engineered for upright commuting.
The Benefits of Converting to Cruiser Bars
- Lower Back Stress
Cruiser handlebars encourage an upright posture which lowers the stress on the back.
- Lower Wrist Stress
The stress on the wrists diminishes because they support less weight and are placed in a more neutral position.
- Relaxed Riding
Cruiser handlebars encourage the rider to be more relaxed and less aggressive.
- Greater Visibility in Traffic
The more upright you are, the taller you sit on the bike. As a result, it’s easier to see and be seen by other vehicles.
The Downside of Converting an MTB to Cruiser Bars
- No Longer an MTB
The second you put cruiser bars on a mountain bike, it’s no longer a mountain bike. Cruiser bars will always underperform in off-road conditions in comparison to flat bars or risers due to the lack of precision and leverage.
For that reason, the conversion is only recommended to people who don’t plan on using their MTB as an MTB.
If you want to convert because the existing bars are too low for you while continuing to ride on off-road terrain, you can switch to risers and/or a stem with a greater degree of rising.
- Poor Climber
Cruisers are poor climbers due to the extra drag and lower leverage that the bars offer during out of the saddle riding. If you live at a location with lots of hills, you may have to add lower gears to the bike to minimize the need to get out of the saddle.
- Increased Drag
The more upright the rider is, the greater the body drag. Hence why road and TT bikes put cyclists in such aggressive forward leans.
Truth be told, there’s nothing less aero than a city bike making the rider’s back perpendicular to the ground. And with cruiser bars on an MTB, you will be getting pretty close to that position.
Thus, if you intend to turn your MTB into a fast hybrid, cruiser bars do not match the objective.
- Extra Stress on the Sit Bones
As already mentioned, the cruiser bars put the rider in a more upright position and shift a lot of weight towards the rear wheel. The result is more stress on the sit bone area.
Sometimes the benefits offered by cruiser bars can also be acquired through other means.
Below are a few options that you may find interesting in the quest for comfort:
- Raise Your Stem
If you have a quill stem, you can easily raise it by untightening the stem bolt and pulling the stem up. Respect the maximum height setting indicated on the stem to avoid component failure.
- Switch to a High Rise Stem
If you like flat bars but need them to be taller, you can switch to a stem with a greater rise.
- Switch to Riser or BMX Bars
Another option is to go for riser bars with a massive degree of rising or BMX bars designed for MTBs.
- Switch to Alternative Bars with Multiple Hand Positions
Cruiser bars are nice, but they aren’t suitable for technical riding and work best in urban environments. You can put other types of handlebars on your bike that better preserve the precision of flat bars while also offering extra comfort.
A common example would be the butterfly handlebars often found on European touring bikes.
The Conversion Works Best On Vintage MTBs
Truth be told, putting cruiser bars on a modern, aggressive MTB is rather silly.
Modern MTBs are expensive and should be used for their intended purposes. Chances are that you want to install cruiser bars on an MTB to turn it into a commuter.
Commuters are used primarily for asphalt riding and are often locked outside. Thus, a full-suspension MTB is a liability because it’s slow on paved roads and too expensive to leave unattended.
For that reason, the conversion makes the most sense when the bike in question is either a CX hardtail made for comfortable pedaling or a rigid MTB.
Summary: What You Need to Know
- You can install cruiser bars on an MTB as long as the stem and the bars are of compatible sizes.
- You can “transplant” the brake levers and shifters directly onto the cruiser bars.
The downsides of cruiser bars on an MTB are:
- Less precise
- Poor climbing out of the saddle
- Extra Drag
- More stress on the sit bones
- Poor off-road performance.
The pros of putting cruiser bars on an MTB are:
- Upright position and thus reduced back stress
- Relaxed riding
- Lower wrist stress