Alt Bar Picker

This article is about flat, riser and alt bars width. We cover riser bar widths here and bar sweep here.  

Unless you live under a rock, stone,  boulder or meteorite, you probably have seen a contemporary mountain bike with exceptionally wide handlebars.  Some of these bars are in excess of 81cm wide.  The bikes fitted with these extraordinary levers tend to have long travel forks (140mm +) slack head angles and very short stems.  In other words, they are very similar in design to Motocross bikes, albeit lighter weight and with no motor.  Motocross bikes have wide bars because of these same reasons: slack head tube, lots of travel, designed for speed.  The wide bars, which effectively are a long pair of levers, one lever to each side of the stem, help control the bike at speed over technical terrain.  

If you are riding that kind of bike, this article isn’t for you, ignore it.  Go iron the brim of your hat.  

The basic rule of thumb is: the slacker the head tube angle and the longer the travel on the fork, the wider the bars need to be to maintain control.  The catch is, many currently available bars only come in one or two widths: Wide and really wide.  If you are riding say, a Bridgestone MB-1 with a 71 degree head angle, or a Tanglefoot Moonshiner with a 69 degree head angle, and you mount 81cm bars, your bike will handle very quickly because of the extra long lever AND you will be quite uncomfortable.  The wider the bars, the closer your shoulder blades get to each other.  Close shoulder blades leads to neck pain and shoulder pain.  

Do an experiment:  Hold your arms out right in front of yourself, like a Zombie.  Tense up.  Grab that imaginary handlebar.  Now move your arms out 4 or so inches per side, like your bar got wider.  Get a sense for your shoulder blades and neck.  You can do this seated, standing, whatever.  Stay tense.  Now go 4 more inches out again.  Feel that tension building?  Now imagine that feeling over a 1-5 hour ride.  I know I’d rather feel the Zombie tension than the 8 inch per side wider stance’s tension.  The latter is exponentially worse.  

Narrower bars are not going to kill you or make you crash.  There is 120 years of evidence to the contrary.  I am not arguing for shoulder width bars on every bike, but rather that you don’t have to swallow the universal perscription for wide bars.  You should get bars based on your anatomy, your bike, and the kind of riding you do.  

Just like a person with a size 6 foot shouldn’t go for a hike with size 13 shoes, a smaller rider shouldn’t ride with bars made for someone who goes by Sasquach.  

To find your ideal bar width, you’ll need to measure a few things:  

Shoulder width.  Measure Acromion Process to Acromion Process.  Here’s a diagram.  The Acromion Process is a little bony protrusion on the back your shoulder, where your humerous meets your shoulder socket (more or less).  It’s the only pointy thing back there, dig around and you fill find it.  You have to have a friend measure.  Do it with shoulders relaxed.  You want that number in centimeters, so multiple by 2.54 if you just have an imperial measuring device.

Arm Span.  Measure finger tip to finger tip, arms outstretched like Leonardo DiCaprio in that movie about the metallurical failings of early 20th century ship building.  

Head tube angle of your bike.  Refer to the geometry chart for this.  

Fork Offset of your bike.  

All of this presupposes your bars are at the right height and reach.  We can help with height and reach, but it’s a bit more involved.  Read more about our Enlightened Fitting here.  

Here’s the Analog Cucles riser / flat bar / alt bar formula, in centimeters

20cm + Shoulder width + (Arm Span - Overall Height) + (2cm for every degree below 73 degree head angle {IE +4cm for 71 degree HTA, +8cm for 69 degree HTA) - (2cm for every 10mm of fork rake over 60mm) 

So a rider with 36cm shoulders with an Arm span of 164 and an overall height of 162cm, riding a Surly Bridge Club with a 70 degree HTA and 50mm of fork offset would ride a 620mm wide handlebar.  

A rider with a 44cm shoulder measurement, 2cm longer arms than overall height, and riding a Tanglefoot Hardtack would be on 730cm wide bars.  

Formulas are of course made to be broken.  There are exceptions to every rule, and you should consider that bit of math to be a starting point.  Bar Sweep has a lot to do with bar comfort, the most sweep the more ergonomic the bar.  Grips play a big roll as well, and the aforementioned bar reach and height.  If you use the formula, you will get on a bar that’s neither monsterously wide or way too narrow.  

For shorter riders and folks with narrower shoulders, it will be harder to find bars that fit, because of current industry trends.  We like the Nitto Forest Ambler and the Jones 660cm bars (which can be cut down) for these riders.  Taller riders have many more options.

As usual, if you have more involved fit questions, or just want to do a full in person or remote fitting, contact us and we’ll get you started on the Enlightened Fitting process.