BMX Gear calculator
| created by bmxultra.com | |
| Units (Inches): | |
| Tire brand: | |
| Tire size: | |
| Front chain wheel: | |
| Rear free wheel: | |
| Show decimal: | |
| Saved data: | |
Tires Listed
Tioga
- PowerBlock 20×1.75
- PowerBlock 20×1.60
- PowerBlock 20×1.40
- PowerBlock 20×1.95
- PowerBlock 20×1 3/8
- PowerBlock 20×1 1/8
- PowerBlock 24×1.40
- PowerBlock 24×1.60
- PowerBlock 24×1.75
- PowerBlock 24×2.1
- Comp 3 20×1.75
- Comp 3 20×1.50
- Comp 3 20×1 3/8
- Comp 3 20×1 1/8
- Comp 3 24×1.75
- Comp 3 25th 20×1.75
- PowerBlock OS20 20×1.85
- PowerBlock OS20 20×1.6
- FASTR 20×1 1/8″
- FASTR 20×1 3/8″
- FASTR 20×1.75
- FASTR 20×1.85
- FASTR React 20×1.6
- FASTR React 20×1.75
- FASTR X 20×1.6
- FASTR X 20×1.75
- FASTR X 20×1.85
- FASTR X 20×1 1/8
- FASTR X 20×1 3/8
- FASTR X 24×1.75
ITS
- Micro Knobby MK2 20×1.75
- Micro Knobby MK2 20×1.50
- Micro Knobby MK2 20×1 3/8
- Micro Knobby MK2 20×1 1/8
- Micro Knobby MK2 20×1
- Micro Knobby MK2 24×1.75
- Micro Knobby MK2 24×1.50
- Micro Knobby MK2 24×1 3/8
- Micro Knobby MK2 24×1 1/8
- Micro Knobby MK2 24×1
Maxxis
- DTH 20×1 1/8
- DTH 20×1 3/8
- DTH 20×1.75
- DTH 20×1.5
- DTH 24×1.75
- Torch 20×1.75
- Torch 20×1.50
- Torch 20×1.95
- Torch 20×1 1/8
- Torch 20×1 3/8
- Torch 24×1.75
- Holy Roller 20×1.75
- Holy Roller 20×1.95
- Holy Roller 20×1 3/8
- Holy Roller 20×1 1/8
- Holy Roller 24×1.85
- Grifter 20×1.85
- Grifter 20×2.10
Odyssey
- Super Circuit 20×1.75
- Super Circuit 20×2.10
Alienation
- TCS R1 20×1.60
- TCS R2 20×1.75
- TCS F1 20×1.95
- Differential 20×1.75
- Graffiti TCS 20×1.85
S&M Bikes
- Trackmark 20×1.75
- Trackmark 20×1.95
- Trackmark 24×1.75
Kenda
- Konversion 20×1.75
- Konversion 20×1.65
- Konversion 20×1.50
- Konversion 24×1.75
- Konversion 24×1.50
- Kompact Folding 20×1.75
- Kontact Folding 20×1.75
VeeRubber
- Speed Booster Elite 20×1.60
- Speed Booster Elite 20×1.75
- Speed Booster 20×1 1/8
- Speed Booster 20×1 3/8
- Speed Booster 20×1.60
- Speed Booster 20×1.75
- Speed Booster 20×1.85
- Speed Booster OS20x1.75
- Speed Booster 24×1.60
- Speed Booster 24×1.75
- Speedster 20×1 3/8
- Speedster 20×1 1/8
- Speedster 20×1.50
- Speedster 20×1.6
- Speedster 20×1.75
- MK3 Foldable 20×1
- MK3 Foldable 20×1 1/8
- MK3 Foldable 20×1 3/8
- MK3 Foldable 20×1.50
- MK3 Foldable 20×1.75
- MK3 Foldable 24×1
- MK3 Foldable 24×1 1/8
- MK3 Foldable 24×1 3/8
- MK3 Foldable 24×1.50
- MK3 Foldable 24×1.75
- MK3 Foldable 24×1.85
Answer BMX
- Carve 1.60
- Carve 1.85
- Carve 20×1 1/8
- Carve 20×1 3/8
Box
- One Folding 20×1 1/8
- One Folding 20×1 3/8
- One Folding 20×1.5
- One Folding 20×1.75
- One Folding 20×1.9
- One Folding 24×1.75
- Two Wire 20×1 1/8
- Two Wire 20×1 3/8
- Two Wire 20×1.5
- Two Wire 20×1.75
- Two Wire 20×1.9
- Two Wire 24×1.75
- Hex Lab Folding 20×1 1/8
- Hex Lab Folding 20×1 3/8
- Hex Lab Folding 20×1.75
- Hex Lab Folding 20×1.95
Driven
- System 2 Folding 20×1.75
- System Y Folding 26″
IRC
- Siren Pro 20×1.75
- Siren Pro 20×1.90
- Siren Comp 20×1 1/8
- Siren Comp 20×1 3/8
- Siren Comp 20×1.50
- Siren Comp 20×1.75
- Siren Comp 20×1.90
- Siren Comp 24×1.75
- Siren 20×1 1/8
- Siren 20×1 3/8
- Siren 20×1.50
- Siren 20×1.75
- Siren 24×1.75
Arisun
- XLR8 Foldable 20×1.50
- XLR8 Foldable 20×1.75
- XLR8 Foldable 20×1.95
- XLR8 20×1 1/8
- XLR8 20×1 3/8
- XLR8 20×1.50
- XLR8 20×1.75
- XLR8 20×1.95
- XLR8 24×1.75
Radio
- Oxygen 20×1.60
- Oxygen 20×1.75
- Oxygen 20×1.95
Michelin
- Pilot SX 20×1.70
- Pilot SX Slick 20×1.70
And if your specific tire is not listed you have two options
Generic sizes
- 16×1.75
- 18×1.75
- 20×1 1/8
- 20×1 3/8
- 20×1.50
- 20×1.75
- 24×1 1/8
- 24×1 3/8
- 24×1.75
Custom
- Measure up the outer diameter of your rear wheel and work out your rollout
We started to create the bmxultra.com BMX Gear Calculator over a decade ago. It’s been modified along the way to a point we are extremely happy with the result and even converted it into an App for iPhone and iPad.
What does it all mean?
Gear Inches are used to give a numerical value to how a particular chainwheel/cog combination will feel. Classic BMX gearing evolved over the years to be 44/16, which has approximately 55 gear inches. The most popular gear ratios are pretty close to a 55 inch, which just seems to feel best for most people. The number is derived from a simple formula: (chainring size / cog size) X wheel size.
Another popular unit for measuring gearing is Roll Out in inches. This is the distance your bike rolls with one rotation of the cranks.
The number is derived from a simple formula: (chainring size / cog size) X (wheel size X PI).
iPhone/iPad App
Our BMX Gear Calculator was released on iTunes July 1, 2013. We hope you will find it as useful as we do.
Want to know more about the App? Take a look at the support page.
Accuracy
We take care to ensure our measurements are as accurate as possible. Of course there is room for variation, and our measurements may not match yours. There can be many contributing factors for measurements to not match up, they can be as simple as tire wear, rim width, tire pressure. We consider our BMX Gear Calculator to be a very accurate guide.
Gear Chart
If you don’t need a calculator, and just want to see a standard BMX gear chart then click here.
Updates
Gear Calculator
06-10-2023 – V1.40 – Added optional Decimal Gears
19-05-2020 – V1.30 – Added option to select Roll Out
05-07-2013 – V1.20 – Added more tire models and sizes
19-03-2007 – V1.10 – Corrected some wheel sizes
27-01-2006 – V1.03 – Increased the range of gears
19-11-2002 – V1.02 – Fixed pulldowns so they don’t disappear off the screen.
Gear Chart
23-02-2010 – Improved usability, better formatting and highlighting. Mouse over highlights the cell to give you a summary.
Tioga Specific gear chart and calculator
Finally you can work out the ratios specifically for your PowerBlock and Comp III tyres. Click here!
