Build a cockpit around proven contact coordinates.

1. System overview & core philosophy

DialedRide N+1™ is a client-side, local-first workshop for adjusting an existing bicycle cockpit and evaluating a prospective frame. The bottom bracket is the coordinate datum. The engine resolves steerer angle, headset cap and spacer projection, stem length and angle, bar reach and rise into modelled contact reach and stack, with fit adjustments for cockpit width, crank length, seatpost setback and seat tube angle. Lateral stance is also reported separately. These effective coordinates are model outputs, not a substitute for measuring the fitted bike. The physical hood / grip position from the BB, and an estimated saddle position, are shown separately (section 3).

Sandbox: the default workspace for adjusting your current bike within the supported input ranges. N+1 Fit Translator: a candidate-frame workspace that compares a proposed build with your reference coordinates. A numerical match does not establish that the hardware can be assembled safely.

Currently available: Drop Bar and Flat Bar cockpits with Road and Gravel presets. TT / Triathlon controls and loading are temporarily paused; previously saved TT setups are retained locally.

2. Global Rider Profile

On first use, complete Body & Bike Data, then select Save Body & Bike Data — Open Sandbox. It becomes a compact summary below the navigation; use Edit Rider to reopen it. Rider measurements, bike settings and the comparison baseline are saved locally. Separate PCs or browser profiles do not synchronise this data. Clearing site data or using Clear All Data & Cache removes the saved rider and bike data.

Auto saddle height (mm) = round[inseam (cm) × 10 × (0.883, or 0.865 when inseam > 88 cm)]

For drop or flat bars, a manual saddle height more than 15 mm from the formula baseline shows an informational amber notice. It does not block the calculation. The formula is a starting point, not a clinical prescription.

3. Workspace 1: Single-Bike Sandbox

1. Define the reference bike. Enter frame reach, frame stack, head tube angle (HTA), and headset bearing top-cap height from the frame's published geometry or measurements. Add the Effective seat tube angle (°) from the geometry chart (often listed as effective or virtual STA). It is optional; until you enter it the tool uses 73.5° and labels it assumed. Older saved bikes open with the angle not entered and calculate exactly as before.
2. Choose cockpit type. Select Drop Bar or Flat Bar. Changing bars preserves the selected frame category. The effective-reach model adds 0.4 × the width difference in millimetres from a neutral 420 mm drop bar or 600 mm flat bar. This is a fit adjustment, not a physical forward movement of the bar.
3. Configure hardware. Set stem length (60–140 mm in the Sandbox), stem angle (−17° to +17°), spacers (0–50 mm), bar width and reach, and drop-bar rise (0, +10, +15, or +20 mm). Set crank length (160–175 mm) and seatpost setback (−20 to +25 mm).
4. Save a baseline. Valid frame reach, stack and cockpit hardware are needed to calculate, solve, save or export a setup. Select Save as Baseline Bike to store the current contact coordinates as the comparison anchor and save the bike in the garage. Without a baseline, the target starts from the live setup. Loading a saved reference bike or auto-solving can also capture an anchor; on reopening the page, a valid restored reference setup can become the baseline automatically.
5. Experiment. The large Effective Reach / Stack readings follow the current frame and hardware. The smaller Target readings show the requested position (see Position goal below). Check Base: [reach, stack] to see the anchor; when the Sandbox differs from it, the card lists what changed since the baseline was saved (for example the seat tube angle, spacers or saddle height). Editing or saving Body & Bike Data leaves an existing baseline intact. Save as Baseline Bike replaces it deliberately; Revert to Baseline restores its frame and hardware; Clear removes the anchor without deleting garage bikes. Older baselines with unknown contact points or incomplete geometry must be loaded from a saved bike or saved again.
6. Read the estimated saddle position. Under the saddle height, Estimated saddle position shows the seat tube angle, the saddle's position behind and above the BB, the hood / grip position from the BB, and the saddle-to-bar reach and drop. The saddle point runs up the seat tube line at the seat tube angle for your saddle height, then back by the seatpost setback; it is the saddle top where the post clamps, not the nose. A steeper angle puts the saddle further forward (about 12–13 mm per degree at a 750 mm saddle height) and slightly higher; a slacker angle puts it back and lower. The hood / grip position comes from the frame and cockpit only, so changing the seat angle, seatpost or cranks never moves it; the saddle-to-bar distances change instead. These are estimates, not measurements.
7. Choose a position goal. Keep my saved position aims at the saved baseline exactly, with nothing added. Relaxed, Neutral and Performance ask instead for a starting riding position from the body model (your height, inseam, shoulder width, arm length and saddle height) for this frame's category. They need the rider profile, and the note under the buttons compares the position with your saved baseline. Neutral is a body-model position of its own, not "no change". The goal is one setting shared with the N+1 Translator. When you save the baseline (or transfer the bike) with Relaxed, Neutral or Performance selected, the bike remembers that it was set up that way.
8. Use the try-builds slider. Setup vs requested position shows where the current setup sits on a shorter-and-higher to longer-and-lower scale, and the line under it states the difference in millimetres. Dragging it asks the solver for hardware that sits further that way, using the same rules as Auto-Solve. It describes coordinates only; it is not an assessment of your posture.

Estimated saddle: behind BB = saddle height × cos(STA) + seatpost setback; above BB = saddle height × sin(STA)

Effective reach and stack measure the hood / grip position from a standard saddle (73.5° seat tube angle, 20 mm seatpost setback, 172.5 mm cranks). A saddle further forward, from a steeper angle or a forward seatpost, therefore reads as shorter effective reach, though the bars have not moved. Seat angle and seatpost setback are handled the same way and counted once. If you enter or change the seat tube angle after saving a baseline, the baseline comparison shows the saddle shift; save the baseline again if it is the same frame.

4. Mechanical & handling advisories

The Sandbox raises real-time flags at these thresholds. They are prompts for component-specific checks; the app does not verify your fork, stem, frame, or rider's physical safety.

5. Workspace 2: N+1 Fit Translator

1. Transfer your setup. In the Sandbox, select Transfer This Position to a New Frame (N+1) → to replace the baseline with the current Sandbox coordinates, carry over cockpit type and relevant hardware, and set the goal to Transfer my position. Revert first if you want to transfer a saved baseline. Simply opening the N+1 tab keeps an existing baseline and goal; if no baseline exists and tape measurements are incomplete, it captures the valid Sandbox setup. A blank workspace with garage bikes loads the newest saved baseline, or the latest saved bike if none is marked as a baseline.
2. Choose what the new bike should give you. Transfer my position reproduces the reference position as closely as sensible parts allow, and nothing is added to it. If the reference bike was set up as Relaxed, Neutral or Performance, its position already carries that goal: the transfer copies the position and labels it, for example "set up as Relaxed", without shifting it again. Transfers work best between similar bikes; on a different kind of frame the audit shows what cannot be matched and why. Relaxed, Neutral and Performance ask for a riding position from the body model instead, using the Road or Gravel preset (it starts on the candidate's category). They do not copy the reference bike; the note under the buttons compares them with it. In the body model, Relaxed shortens reach by 0.8% of modelled torso-plus-arm length (usually about 11 mm) and raises the bars 20 mm against Neutral; Performance does the opposite. These are starting estimates, not a fit.
3. Transfer source. A transfer offers Sandbox reference bike, which uses the saved baseline, or Tape measurements. Tape measurements require positive saddle height and reach to hoods / grips, plus explicitly entered saddle setback and saddle-to-bar drop; zero is valid for the latter two. Reach is the horizontal saddle-to-contact distance minus setback. Stack is saddle height projected at the standard 73.5° minus drop. The tape block's Effective seat tube angle (°) is the same value as the Sandbox bike's, so it cannot conflict. When the Sandbox has moved away from its saved baseline, the reference summary says which settings changed and Use current Sandbox setup captures a new baseline; until then the target is the saved one.
4. Cross-discipline transfers. The frame category never moves the target. A road position transferred to a gravel frame stays the road position; the category decides which builds pass the handling checks (section 4). If those checks rule out a close match, the closest sensible build is shown with the reason. Many riders set a gravel bike a little higher and shorter than a road bike; choose a riding position instead of a transfer if that is what you want.
5. Enter candidate geometry. Supply the new frame's reach, stack, HTA, headset cap and, ideally, effective seat tube angle. Check contact position and control access if changing between drop and flat bars. The candidate's Estimated saddle position compares its seat tube angle with the target bike's (the body model uses 73.5°) and says how far the saddle moves, for example about 25 mm forward and 7 mm higher from 73° to 75° at a 750 mm saddle height. Effective reach and stack include that difference, so a match places the hoods / grips about as far forward and up as the saddle moved, keeping the saddle-to-bar reach and drop. An angle that is not entered is assumed to be 73.5° and marked as assumed.
6. Run the solver. Select Calculate Optimal Hardware (or Auto-Solve to Target in the Sandbox). The target is a fit window: a range of positions you can ride comfortably in, rather than one exact point. The window is ±10 mm in effective reach and ±10 mm in effective stack around the requested position. Any build inside it counts as a fit, so the solver stops chasing millimetres there; it only fine-tunes spacers or flips a stem toward the centre, and never buys a part to do so. Outside the window, each millimetre costs more. It favours reusing the saved baseline hardware for the same cockpit type, otherwise the current build. It searches common stem lengths in 10 mm steps, −17°, −6°, +6° and +17° angles, and owned/current values; drop bars also have a +15 mm rise option. Bar reach and width, crank length and seatpost setback stay at the entered settings. Unconventional choices cost extra, so they are recommended only when the conventional builds stay well outside the window: a ±17° stem the rider does not own (a high-rise stem is ordinary on flat bars), a 70 or 130 mm drop-bar stem or a 60 or 110 mm flat-bar stem the rider does not own, and a stem of −10° or steeper raised on more than 15 mm of spacers. Such options are tagged.
7. Review the app's mechanical checks. Proposed spacers never exceed 30 mm; the headset cap is part of the headset and is not counted. No proposed option trips the handling advisories in section 4 (for example, no stem at −10° or steeper and none of 120 mm or longer on gravel, none under 5 mm of spacers on gravel, and no +10° or steeper on road). If no build passes these checks, the solver says so. Passing these checks does not establish physical compatibility or safety.
8. Review the options. The top option is labelled Recommended when it is inside the fit window, otherwise Closest sensible build. If it needs no changes, it appears alone. Otherwise up to three distinct options are listed, each showing what changes from the current build. An alternative never lies further outside the window than the top option, and never needs a kind of part (stem or bar), or a kind of unconventional choice, that the top option avoids. When the top option misses, a note explains why: either the closest build on the full grid needs parts the checks or preferences rule out (named, so you can set them by hand), or no common combination gets closer and the frame's reach or stack is the limit.
9. Check mismatch and apply. If the top option is more than 5 mm outside the fit window, an amber mismatch banner appears and nothing is applied automatically. Select Apply on a listed option only if you accept the gap. Applying an option updates the relevant bike's hardware and closes the result drawer.
10. Read the result. The audit card reports Requested (the transfer or riding position and its coordinates) and Result (the difference in millimetres, longer or shorter and higher or lower) separately. The fit is graded the same way everywhere, including the dossier: In window inside the ±10 mm box, Just outside within 5 mm of its edge, otherwise Outside window. Each reach and stack card also says whether that axis is inside the window. These are coordinate differences, not an assessment of the rider's posture.

Distance outside the fit window = √[max(0, |Δreach| − 10)² + max(0, |Δstack| − 10)²] mm, where Δ is build minus requested position

Lateral stance is reported separately and is not included in the fit window. When translating between drop and flat bars, the candidate reach calculation omits the width-based reach adjustment; check lateral stance and actual hand position separately. Cross-discipline matches need a real-world control and clearance check even when reach and stack are close.

6. Exporting the Build Setup Dossier

Select Export / Print Build Dossier for the active Sandbox or translator setup. Review the preview, then select Print / Save PDF to print or save a PDF through your browser.

• Configured frame geometry: bike name, frame reach, stack, HTA and seat tube angle (or “Not entered (73.5° assumed)”).
• Contact audit: requested position, configured build, offset, and In window / Just outside / Outside window status for effective (saddle-adjusted) reach and stack, and lateral stance width, with the distance from the requested position and from the fit window. Below it: what was requested, the result, a category note for cross-discipline transfers, and, when the build misses, what Auto-Solve could change or why it cannot get closer.
• Saddle and pedalling foundation: shared saddle height, saddle setback, seatpost setback and crank length. Saddle setback prints as Not entered unless a measurement was supplied; it is not inferred from seatpost setback. For drop and flat bars it also lists the seat tube angle, the estimated saddle position, the estimated saddle-to-bar reach and drop, the hood / grip position from the BB and, in the N+1 Translator, the saddle shift from the seat angle against the target bike. Estimated values are labelled as such.
• Assembly hardware: stem length and angle, spacers plus headset cap, bar reach and width, and bar rise.
• Verification: mechanic / fitter sign-off and a reminder to verify manufacturer torque specifications before dynamic testing.

Status labels are coordinate comparisons. Passed or Acceptable does not certify component compatibility or roadworthiness.

7. Scope & Legal Disclaimers

These notices do not remove statutory consumer rights or liability that cannot lawfully be excluded. Consumer terms and notices remain subject to the Consumer Rights Act 2015 and its fairness requirements. The wording below should be read subject to those protections.

• No Purchasing or Sizing Liability:
  DialedRide N+1™ is an exploratory geometric modeling and mathematical estimation tool provided solely for informational and comparative purposes. DialedRide, its creators, developers, and contributors accept no liability or responsibility for any financial loss, purchase decisions, component acquisitions, frame choices, or mechanical outcomes arising from the use of this software.
• Physical Verification Mandate:
  Riders, builders, and mechanics are solely responsible for physically verifying all frame geometry charts, component compatibilities, cable/hydraulic hose routing clearances, manufacturer sizing recommendations, and real-world ride comfort prior to purchasing or assembling any bicycle, frameset, fork, or cockpit component. A mathematical match in Cartesian space ([X,Y] coordinates) does not guarantee physical suitability, handling satisfaction, or ergonomic comfort for any individual athlete.
• Not a Medical or Clinical Assessment:
  DialedRide N+1™ executes deterministic trigonometric coordinate translations based strictly on user-supplied numbers. It does not assess joint angles under dynamic load, spinal mobility, soft-tissue compression, pelvic tilt, or musculoskeletal pathology. It is not a substitute for a comprehensive in-person dynamic bicycle fitting or clinical musculoskeletal assessment by a qualified professional.
• Hardware & Structural Safety:
  Athletes and mechanics bear sole responsibility for verifying component torque ratings, fork manufacturer carbon steerer spacer limits, and physical frame/component clearances prior to dynamic operation.
• Governing Jurisdiction:
  This software, its calculation algorithms, and all associated documentation are governed exclusively by the laws of England and Wales. Any disputes arising hereunder shall be subject to the exclusive jurisdiction of the courts of England and Wales.