New Trailblazer Geometry & Fit Tool: Find Your E-Bike Size in Seconds
Buying a Trailblazer online used to mean reading a geometry chart, guessing which of three frame sizes fits, and calling us to double-check. Not anymore. Our new interactive Trailblazer geometry and fit tool lets you enter your height and inseam, then shows a rider your size sitting on the actual Trailblazer frame, with every measurement updating as you go. It is the fastest way to answer the question we hear most: what size e-bike do I need?
What the Trailblazer geometry tool does
Most e-bike size charts give you a height range and leave the rest to you. The Trailblazer geometry tool starts with the same full-carbon frame outline we build every bike on, then puts you on it:
- Four bikes, one chart. Switch between the Trailblazer, Trailblazer Pro, Trailblazer AT and Trailblazer AT Pro, in Medium, Large or XL.
- Your body, to scale. Slide in your height, inseam and arm length, and the rider figure resizes to match. The tool recommends a frame size as soon as you set your height.
- A full pedal stroke. Rotate the cranks through the stroke to see your knee bend at the top and bottom, not just a static pose.
- Dropper up or down. Flip the dropper post down to see your descending position, or switch on standover to check clearance when you step off.
- Real build options. Compare the stock dropper with 125mm, 150mm and long-travel posts, toggle mullet wheels, or try the 170mm fork upgrade, and watch the angles, bottom bracket height and wheelbase change.
- Metric or imperial. Every number is available in millimeters or inches.
Your fit, measured
Under the chart, the tool turns your numbers into a fit readout for the frame you picked. Here is what a 5'10" rider with a 33" inseam sees on a Large Trailblazer:
| Fit check | Result |
|---|---|
|
Saddle height Crank center to saddle top |
29.2 in |
|
Knee bend, bottom of stroke Checked against the ideal 25 to 40° range |
30 ° |
|
Knee bend, top of stroke With the Trailblazer's 160mm cranks |
106 ° |
|
Back angle From horizontal, hands on the grips |
68 ° |
|
Reaching the ground when stopped Seated, dropper all the way down |
Balls of both feet |
Example readout from the live tool. The rider figure uses typical body proportions for the height and inseam you enter, so your own results will vary with your build.
It also tells you whether the stock dropper post sits flush at your saddle height, which is the detail that decides between sizes for a lot of riders. Run your own numbers here.
Which Trailblazer size do I need?
Every Trailblazer comes in three frame sizes. Start with your height, then use the fit tool to confirm with your inseam:
| Size | Rider height | Reach | Stack | Wheelbase* |
|---|---|---|---|---|
| Medium | 5'4" to 5'8" | 442 mm | 623 mm | 1,232 mm |
| Large | 5'9" to 6'1" | 470 mm | 632 mm | 1,258 mm |
| XL | 6'2" and up | 488 mm | 641 mm | 1,285 mm |
*Trailblazer and Trailblazer Pro with the stock 160mm fork. Head angle is 64.9° and seat angle 74.5° on every size.
Between sizes? The larger frame gives a longer, more stable ride at speed. The smaller frame is easier to throw around on tight trails. Set both in the geometry tool and compare how you sit on each.
How the four Trailblazer models compare
All four bikes share the same full-carbon Trailblazer front triangle, so reach, stack and angles are nearly identical. What changes is the wheels, the rear end and the fork, and with them the bottom bracket height and standover:
- Trailblazer: 27.5+ wheels, 160mm front and 155mm rear travel, 349mm bottom bracket height.
- Trailblazer Pro: 29" wheels and pro-grade suspension, with a slightly taller 359mm bottom bracket.
- Trailblazer AT and AT Pro: 26 x 4.8 fat tires, 160mm travel front and rear, and a 31mm longer chainstay, which settles the head angle at 64.6°.
Pick any of them in the chart for exact numbers in your size.
Mullet wheels and the 170mm fork, visualized
Two of the most popular Trailblazer upgrades change the geometry, and now you can see how much before you order.
Mullet setup. A 29" front wheel with a 27.5" rear tips the bike back to about a 64.5° head angle on the Trailblazer, and 64.4° on the Pro, where the smaller rear wheel also drops the bottom bracket for a more planted feel in corners.
170mm fork. Running the stock DVO fork at 170mm instead of 160mm slackens the head and seat angles by about 0.4°, raises the bottom bracket about 3mm and adds about 4mm of wheelbase for more confidence on steep, rough descents.
Flip the mullet and 170MM FORK switches in the geometry tool to see every number for any combination. These options apply to the Trailblazer and Trailblazer Pro, so the chart hides them on the fat-tire AT models.
How to measure your inseam
Your inseam is the single most useful number for e-bike fit. It sets your standover clearance and your saddle height range.
- Stand barefoot with your back against a wall.
- Pull a hardcover book up snug between your legs, spine up, like a saddle.
- Measure from the floor to the top of the book.
- Enter it in the Trailblazer fit tool, and leave arm length on average unless you know yours run long or short.
Trailblazer geometry FAQ
What size Trailblazer should I get?
Medium fits most riders 5'4" to 5'8", Large fits 5'9" to 6'1", and XL fits 6'2" and up. Enter your height and inseam in the interactive geometry tool to confirm standover clearance and saddle height on your size.
Is the Trailblazer Pro geometry different from the Trailblazer?
The frame is the same, so reach, stack and angles match. The Trailblazer Pro rolls on 29" wheels, which raises the bottom bracket and standover by about 10mm compared with the 27.5+ Trailblazer.
Can I see how I sit with the dropper down?
Yes. Switch on Dropper down in the tool and the rider drops into a descending position. You can also pick a different dropper length and see if it sits flush in your frame size.
Does the tool work on my phone?
Yes. The Trailblazer geometry page works on desktop and mobile.
What if I am still between sizes?
Call us at (818) 734-1600 or email sales@hpcbikes.com. We will look at your numbers and how you ride and help you choose.
Ride responsibly
High-power Trailblazer builds go well beyond the legal definition of an electric bicycle and are for off-road use only: private land, closed courses and approved off-road areas. Always wear full protective gear and check the rules where you ride.
Find your size, then build yours
Find your fit in the Trailblazer geometry tool, then configure your Trailblazer, Trailblazer Pro, Trailblazer AT or Trailblazer AT Pro. Want the numbers behind the power? See our 2000W V2 torque and power curves.