How To Measure For Ape Hangers: The Complete Guide To Custom Handlebar Sizing

Measuring for ape hangers requires calculating five critical control line extensions—brake lines, clutch lines, throttle cables or throttle-by-wire harnesses, and electrical switch wiring—relative to your motorcycle's stock setup and your desired rise. By accounting for correct pull-back angles, riser clamping heights, and safe routing paths, you can install custom handlebars without risking binding, stretched wiring, or accidental throttle engagement during full-lock turns.

Pre-Operation & Equipment Checklist

Upgrading to ape hangers transforms your motorcycle's ergonomics and aesthetic, but improper sizing leads to dangerous line tension, restricted steering, and costly returns. Before beginning your measurements, you must gather the correct equipment and understand the mechanical scope of a handlebar swap.

• Essential gear, tools, and materials: A flexible fabric tape measure or carpenter's tape, a rigid metal ruler or yardstick, a sturdy helper to hold the motorcycle upright and keep the handlebars centered, painters tape for temporary marking, a notepad for logging imperial and metric dimensions, and wire fish tape or string for routing calculations.
• Mandatory prerequisite knowledge and standards: Familiarity with Department of Transportation (DOT) handlebar height regulations in your jurisdiction, an understanding of the difference between overall rise and grip height, and knowledge of whether your motorcycle utilizes a mechanical cable clutch or hydraulic line, as well as single or dual-disc front brakes.
• Estimated budget and duration benchmarks: Expect to spend between two to four hours on the measuring and planning phase, with a total project budget that must account for replacement control lines, extended wiring harnesses, and new polyurethane or solid handlebar bushings.

Step-by-Step Ape Hanger Measurement Workflow

Step 1: Establish Baseline Ergonomics and Riding Position

Sit on your motorcycle with the bike upright on a level surface, preferably supported by a central stand or held steady by an assistant. Have your feet on the pegs and your hands resting comfortably where you naturalize your reach. Measure the vertical distance from the top of your triple tree (where the lower handlebar clamp mounts) straight up to your knuckles to find your target grip height.

Pro-Tip: Do not measure from the ground up, as seat modifications and suspension changes alter your seating position. Always reference fixed points on the front end like the upper triple clamp or the base of the current risers.

Step 2: Calculate the Total Handlebar Rise

Subtract the height of your current stock handlebars and risers from your target grip height to determine the exact rise you need for your new ape hangers. Keep in mind that handlebar manufacturers measure "rise" from the bottom of the knurled clamping area to the center of the highest point of the grip or top bend.

Warning: A 16-inch ape hanger advertised by one manufacturer may measure significantly higher or lower depending on how they calculate the base sweep and bottom bend radius. Always request a detailed dimensional drawing from the manufacturer before purchasing.

Step 3: Measure Brake and Clutch Line Extensions

With your handlebars turned fully to the left and right lock positions, use a flexible tape measure to trace the path of your existing upper brake line from the master cylinder down to the ABS module or junction block. For cable clutches, measure from the clutch lever perch down to the transmission side cover housing.

1. Note the stock length of the brake line and clutch cable.
2. Add the exact difference between your new handlebar rise and your old handlebar rise to this stock length.
3. Add an additional two to four inches of slack to ensure the lines do not pull taut when turning the front forks from lock to lock.
4. For hydraulic systems, decide whether you need an entirely new custom-length braided stainless steel line or if an upper extension kit will suffice.

Step 4: Account for Throttle Cables and Electronic Wiring Harnesses

Locate the exit points where your throttle cables or throttle-by-wire (TBW) harness and handlebar switch wires enter the frame or head tube. Pull slack from inside the headlight nacelle or frame spine to see how much hidden length you have to spare.

1. Measure from the switch housing grip entry point down along the handlebars to the triple tree clamp.
2. Trace the wire path down to the neck of the frame where the main harness connectors live.
3. Calculate the total required length by taking your stock wire measurement, adding your height increase, and adding three inches for internal handlebar routing if you plan to run the wires through the bars for a clean custom look.

Handlebar Sizing, Clamping Diameters, and Component Matrix

Common Measurement Errors and Field Fixes

• Root Cause: Failing to account for internal handlebar wiring pull length, resulting in wires that are too short to reach the frame connectors once threaded through the tubing.
  
  
  • Actionable Fix: Always add a minimum of three to four extra inches of wire length when ordering extensions to accommodate internal routing corners and solder shrink connections without placing tension on the pins.
• Root Cause: Measuring straight up vertically without accounting for the pullback angle of the ape hangers, which pushes the grips closer to or further from the rider's chest.
  
  
  • Actionable Fix: Dry-fit the bars into the lower risers before tightening completely, and sit on the bike to verify that wrist angles remain neutral and do not cause hyperextension or shoulder fatigue.
• Root Cause: Ordering control lines based purely on handlebar height ratings rather than measuring the actual physical routing path with the front end turned to full lock.
  
  
  • Actionable Fix: Secure a length of flexible garden hose or rope along the exact routing path of your control cables while turning the forks from side to side, then measure that rope to find your true required length.

Frequently Asked Questions

How do I know if I need new cables for 12-inch ape hangers?

Most motorcycle models cannot accommodate a jump to 12-inch ape hangers using stock cables and wiring. While some models with exceptionally loose stock routing might stretch to fit a 10-inch mini-ape, 12 inches almost universally requires extended brake lines, clutch cables or hydraulic lines, and electrical wire extensions.

Can I extend my wiring without soldering or buying extension kits?

Soldering and heat-shrinking is the most reliable DIY method for extending handlebar wiring, provided you stagger your solder joints to prevent a bulky harness bottleneck. However, plug-and-play wire extension kits are strongly recommended for modern CAN-bus electrical systems to prevent resistance spikes and data bus communication errors.

What is the difference between grip height and overall rise?

Overall rise refers strictly to the vertical distance from the bottom of the handlebar clamp to the highest point of the bar. Grip height includes the combined height of your lower risers, the riser bushings, and the handlebar rise itself, representing the total vertical distance from the triple tree to your hands.

How do I measure handlebar clamping diameter?

Use a digital caliper or a flexible tailoring tape to measure the circumference of your handlebars at the exact point where they clamp into the risers. Standard Harley-Davidson and cruiser measurements are typically either one inch straight, 1.25 inches tapering to one inch at the controls, or 1.5 inches for fat-bar custom setups.

Will taller ape hangers require me to change my mirror setup?

Depending on the height of your new ape hangers and your physical shoulder width, your stock mirrors may end up projecting too low or being blocked by your hands and arms. Many riders switching to 14-inch or taller ape hangers transition to under-mounted mirrors or bar-end mirrors to maintain a clear rear field of view.

Get your custom ape hangers fitted right the first time by exploring our complete inventory of premium extended cables, wiring harnesses, and handlebars designed for your exact make and model.