bellcrank

Bellcrank — Terms of Use

Last updated: 23 August 2026

These Terms of Use ("Terms") govern access to and use of the Bellcrank web application and API (the "Service"), a suspension-kinematics simulation tool operated by Bellcrank UG (haftungsbeschränkt), Schneefinkenweg 12A, 81827 München, Germany ("Bellcrank", "we", "us"). By creating an account or using the Service you accept these Terms. If you do not accept them, do not use the Service.

1. The Service

Bellcrank lets you define suspension assemblies and motions, run kinematic simulations, and inspect, store and export the computed results. Feature availability depends on your subscription tier.

2. Accounts

You must provide accurate information at signup (name and e-mail address) and keep your credentials confidential. You are responsible for all activity under your account. You must be at least 16 years old, or the age of digital consent in your jurisdiction, to create an account.

If you create an API key, it is personal to your account and must be kept confidential; you are responsible for all activity performed through it, the same as activity in the web application. Using the Service through the API is use of the Service and counts against the same tier limits.

3. Engineering disclaimer — no warranty on simulation results

Read this section carefully.

  1. The Service produces numerical simulations. Results depend entirely on the inputs you provide (geometry, motions, parameters) and on mathematical models that idealize physical reality (rigid bodies, ideal joints, no compliance, no friction, no manufacturing tolerances).
  2. Simulation results are provided "as is" and "as available", without warranty of any kind, express or implied — including, without limitation, warranties of accuracy, correctness, completeness, fitness for a particular purpose, or merchantability.
  3. Simulation results are not engineering advice. They must not be the sole basis for the design, validation, homologation or operation of any vehicle, component or system, in particular any safety-relevant application. You are solely responsible for independently verifying any result — by calculation, physical testing or review by a qualified engineer — before relying on it.
  4. To the maximum extent permitted by applicable law, we accept no liability whatsoever for wrong, inaccurate, incomplete or misinterpreted simulation results, nor for any decision made or action taken in reliance on them. This includes, without limitation, personal injury, death, property damage, product recalls, loss of profit, loss of data or any other direct, indirect, incidental, consequential, special or punitive damages.
  5. Nothing in these Terms excludes liability that cannot be excluded under applicable law (e.g. liability for intent or gross negligence).

4. Acceptable use

You must not: (a) breach applicable law; (b) attempt to gain unauthorized access to the Service or its infrastructure; (c) probe, overload or disrupt the Service; (d) resell or provide the Service to third parties without our written consent; (e) reverse engineer the Service except where permitted by law; (f) use the Service to develop a competing product; (g) share or publish your account credentials or API keys, or use automated or programmatic means to circumvent or exceed the rate or usage limits that apply to your account.

5. Your content

You retain all rights to the models, motions and results you create ("User Content"). You grant us the technical license needed to store, process and display User Content for the purpose of operating the Service. We do not use your User Content for anything else and do not share it with other users, except that content stored in a team's shared space is accessible to the members of that team.

6. Subscriptions and fees

Paid tiers are billed as described at the point of purchase. Payments are processed by Stripe, which acts as merchant of record for paid subscriptions: your purchase of a paid plan is concluded with Stripe as reseller of the Service, and Stripe handles payment collection, invoicing, applicable VAT and refunds. Displayed prices include VAT where applicable. You can manage your subscription, payment methods and invoices through the Stripe billing portal linked from the Service. Tier limits (for example, simulation credits, consumed at a rate that reflects the size and length of each simulation run, within a rolling billing period) are enforced by the Service. We may change prices with reasonable advance notice effective at your next renewal.

7. Teams

A team is a shared workspace for several accounts. The account that creates a team is its owner; the owner manages the team's billing, invites and removes members, and can transfer ownership to another member. Models, motions, results and exports created in a team's shared space belong to the team, not to the individual member who created them, and remain part of the team after that member leaves.

Team plans are billed per seat, with a minimum of three seats, set when the team is created. An owner adds members by e-mail invitation; an invitation reserves a seat until it is accepted, declined or revoked.

Student teams are offered at discounted, seat-capped pricing subject to verification of student eligibility: a full name, university and proof of enrollment, submitted for manual review as described in the Data Privacy Policy. Providing false information in a student-team application, or inviting members who do not share the owner's university e-mail domain, is a breach of these Terms.

Dissolving a team is permanent: it cancels the team's subscription and deletes everything the team owns, including its models, motions, results and exports. Remaining days in the current billing period are not refunded.

8. Availability and changes

The Service is provided without an availability commitment. We may modify, suspend or discontinue features at any time; where a change materially reduces a paid feature, we will inform you in advance.

9. Termination

You may delete your account at any time, except: while you own a team — transfer ownership or dissolve the team first (see "Teams" above); or while a team's subscription is still billed to your account after you transferred ownership — cancel that billing through the Stripe billing portal first. We may suspend or terminate accounts that breach these Terms, with notice where practicable. Sections 3, 10 and 11 survive termination.

10. Limitation of liability (general)

To the maximum extent permitted by law, our aggregate liability arising out of or in connection with the Service is limited to the amount you paid us in the twelve (12) months preceding the event giving rise to the claim, or EUR 100 if you use a free tier. Section 3 applies to simulation results specifically and prevails over this section where results are concerned.

11. General

These Terms are governed by the laws of the Federal Republic of Germany, without regard to conflict-of-law rules; mandatory consumer protections of your country of residence remain unaffected. If a provision of these Terms is held invalid, the remainder stays in force. We may update these Terms; material changes will be announced in the Service, and continued use after the effective date constitutes acceptance.

Contact

Bellcrank UG (haftungsbeschränkt), Schneefinkenweg 12A, 81827 München, Germany.

Questions about these Terms: info@bellcrank.io