Dragy Moto Lab
Login / Register 0 0

Features

Features

What Chainline does

Every tool below is part of the app at /app/. Screenshots are from the live app (demo and sample data where noted).

Open the App
Pricing
Chainline app hub on a phone listing Chainline gearing, GPS timer, Times lab, Spark, Weather and the Pro trial, with LITE and PRO badges

The hub

One place for every tool

The hub lists Chainline gearing, GPS timer, Times lab, Spark and Weather, then the garage and quick calculators, and the Pro trial. Each card shows a LITE or PRO badge from the server. Tapping a PRO card without Pro opens the Pro page instead of the tool.

Gearing bench · LITE

Chainline gearing bench

Sprockets, chain, rear tire and roll-on pulls. Sport bikes from 2005 on are listed by generation wherever a gearbox and sprocket pair were published: 137 bikes across Aprilia, BMW, Buell, CFMoto, Ducati, Honda, KTM, Kawasaki, MV Agusta, Suzuki, Triumph and Yamaha. If yours isn’t listed, choose Bike not listed and enter it by hand.

Chainline gearing bench on a phone: Find the bike by search, year, make and model, with the selected bike's published specs
Chainline gearing bench sprocket section on a phone: front and rear teeth steppers, final ratio and per-gear speed table
Chainline roll-on pulls on a phone: estimated 60-130, 100-150 and 60-180 mph times plus custom pull controls
Chainline chain section on a phone: chain pitch, inner width, OEM and needed link count and retailer search links
  • Find the bike: search or pick year, make and model to load engine, power, torque, wet weight, primary ratio, sprockets, chain and rear tire.
  • Sprockets: step the front and rear teeth and see the final ratio, a per-gear table (OEM vs now mph at redline, rpm at a cruise speed, shift drop), gearing, aero and realistic top speed, and nearby rear sprockets from −3 to +4 teeth.
  • Pulls: roll-on times for 60–130, 100–150 and 60–180 mph, presets like 30–70 and 80–120, distance pulls (1/8 mi to 1 mi, 1000 ft) and up to 8 custom pulls.
  • Power to weight: rider, gear and bike weight, horsepower, torque and aero class give lb/hp, W/kg, hp/ton and an estimate of hp at the wheel.
  • Rear tire: try sizes and see the height and road-speed change.
  • Chain: pitch, width, OEM and needed link count and sprocket center distance.
  • Profiles: save up to 24 bikes with their sprockets and tire. They stay in this browser.
  • Shop links: search RevZilla, Chaparral, Partzilla, Rocky Mountain, Sprocket Center and Parts Unlimited for the parts on the bench.
Chainline gearing bench in a desktop browser: profiles, pulls and the sprocket table with speed chart

Figures come from owner’s manuals, factory spec sheets and sprocket catalogs. Pull times are modeled, not a dyno sheet or radar trap. Confirm sprockets, pitch and link count on the bike before you order parts.

Gearing bench guide →

Phone GPS timer after a demo pass, showing speed, ET, peak speed and the Arm button
Phone GPS timer timeslip tab with a scored demo pass and graphs

GPS timer · LITE

Phone GPS timer

Uses your phone’s GPS (not a Dragy box). Arm it, launch, and every pass is scored automatically.

  • 0–60, 60–130, 1/8 and 1/4 mile ET and trap, 1/2 mile and 1 mile.
  • Distance marks: 60 ft, 330 ft, 1/8 mile, 1000 ft, 1/4, 1/2 and 1 mile, plus your own speed windows and distances.
  • Graphs of speed, elevation, acceleration and GPS accuracy.
  • Timeslip with weather and density altitude. Save it to history, copy it, download JSON or send it to the Times lab.
  • Settings: mph or km/h, rider and bike weight, launch threshold, auto-end, keep screen awake.

Phone GPS is usually ~1 Hz and a few meters off. Results are for your own bike-to-bike testing, not a certified timeslip. Screenshots show the built-in demo run.

GPS timer guide →

Times lab · LITE

Times lab

Pull Dragy / Dragy Pro times, or time a pass with the phone GPS timer, then correct them for weather, weight and setup.

  • Log runs: 0–60, 60–130, 1/8 and 1/4 mile, 100–200 km/h, best lap, peak speed and more, with weather, rider weight and a setup note.
  • Import decrypted Dragy JSON/CSV, a Dragy times file or RaceChrono CSV, or paste data.
  • Corrected snapshot: density altitude plus corrected 0–60, 1/4 mile and trap speed.
  • What-if calculator and Compare two runs.

Corrections are workshop estimates, not NHRA class indexes. Runs stay in this browser.

Times lab guide →

Times lab on a phone with sample motorcycle times: best times and corrected values
Times lab on a phone: log a run form and corrected snapshot with density altitude
Spark ignition estimator on a phone: recommended timing in degrees BTDC, MBT and knock-limited estimates
Spark estimated ignition map on a phone: RPM by throttle position table with color-coded advance

Spark · PRO

Spark ignition estimate

An estimated ignition-timing calculator for liter-class sportbikes. Start from a preset (Honda, Suzuki, Yamaha, Kawasaki, BMW, Aprilia and Ducati liter bikes) or a blank engine.

  • Inputs: chamber type, bore, stroke, compression, cylinders, redline, fuel and octane, and the operating point (rpm, throttle, AFR, intake and coolant temperature, baro, boost, safety retard).
  • Outputs: recommended timing in °BTDC, MBT and knock-limited estimates, CA50 target, burn duration, flame speed, piston speed and more.
  • Timing vs RPM chart and an RPM × throttle map. Download the map as CSV.

Educational estimate only. Real maps are dyno- and knock-sensor calibrated. Too much advance holes pistons. Do not flash this number into an ECU without a wideband, knock detection and a load dyno.

Spark guide →

Weather · LITE

Weather & density altitude

Live conditions for your location or any place you search: temperature, feels-like, humidity, wind, pressure, rain, clouds, elevation and density altitude. Includes US weather alerts, a 24-hour and 7-day forecast and a radar loop.

Conditions also feed the GPS timer’s timeslip weather fields. Forecast by Open-Meteo, radar by RainViewer, place names by BigDataCloud, US alerts by the NWS.

Weather guide →

Live weather in the app on a phone: temperature, humidity, wind, pressure and density altitude
Live radar map in the app's weather tool on a phone, with play and step controls

Garage & quick calculators · LITE

Garage and quick calculators

A second group on the hub works from one shared garage. Pick or add your bikes once, and the quick calculators use the active bike. Bikes, pulls and dyno entries are saved in this browser on this device. For the full model with torque curves, aero and shop links, use the Chainline gearing bench.

Chainline Garage on a phone: two saved bikes, a CBR1000RR and the active YZF-R1, with Edit and Remove buttons and Add from bike database

Garage LITE

Keep your bikes in one list, pick the active one for the quick calculators, and edit or remove them.

How to use it →

Chainline Edit bike screen on a phone: profile name, year, make, model, horsepower, torque, weight, redline and sprocket fields

Edit bike LITE

Change a bike’s power, weight, redline, primary ratio, sprockets, chain, tire and gear ratios, or enter a new bike by hand.

How to use it →

Chainline Bike database on a phone filtered to Kawasaki models, each with engine, horsepower, wet weight, stock sprockets and chain

Bike database LITE

Search the 137 bikes from the gearing bench library and add one to your garage in a tap.

How to use it →

Chainline Quick gearing on a phone: front and rear sprocket steppers, final drive and top-gear speed at redline for a YZF-R1 on 16/43

Quick gearing LITE

Step the sprockets and see the final drive and speed at redline in every gear, stock vs now.

How to use it →

Chainline Chain length on a phone: 122 links needed for 16/43, change versus stock, pitch and sprocket center distance

Chain length LITE

How many links you need for new sprockets, worked out from your stock chain and sprockets.

How to use it →

Chainline Tire size on a phone: current and new rear tire diameter, road speed change and true speed at 100 indicated

Tire size LITE

Compare rear tire sizes: diameter, road speed change and true speed at 100 indicated.

How to use it →

Chainline Roll-on pulls on a phone: estimated times and distances for 60-130, 100-150 and 80-120 mph

Roll-on pulls LITE

Quick roll-on time and distance estimates for the speed windows you care about.

How to use it →

Chainline Power to weight on a phone: hp per ton, pounds per horsepower and watts per kilogram with rider, horsepower and bike weight inputs

Power to weight LITE

hp per ton, pounds per horsepower and watts per kilogram for your bike and rider.

How to use it →

Chainline Dyno log on a phone: a form for setup note, peak hp, peak lb-ft and date, and two logged runs with the best marked

Dyno log LITE

Keep peak hp and torque from your dyno sheets, with the sprockets each run was on.

How to use it →

The /app/ page on a phone in full-screen app view, showing the Sign in form
The in-app Pro page: 7-day free trial, $0 today then $4.99 per month after 7 days

Account & app view

Made for your phone

  • On a phone, /app/ opens full screen with app-style sign-in and create-account screens.
  • Signed in, it goes straight to the hub. The ··· menu has Subscription, Back to site and Log out.
  • Add it to your home screen to open it standalone.
  • The Pro page shows your plan and a Manage subscription button.

Will be used in accordance with our Privacy Policy.