# Track width

> What does track width do and what are the RC limits?

- Category: Car design › Suspension geometry
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/track-width/ · JSON: https://xemstudio.com/api/geometry?object=track-width · Plain text: https://xemstudio.com/objects/track-width/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- Track width governs side-to-side stability while wheelbase governs front-to-rear stability (CompetitionX). It also appears directly in the Ackermann condition (raw.org).
- RC classes set it by maximum car width: 190 mm without body for EFRA touring cars, 250 mm for 1/10 off-road, 172 mm for 1/12.

## Sizes

| parameter | value or range | source |
|---|---|---|
| EFRA touring width | 190 mm without body, 200 mm with | EFRA |
| ISTC width | 170-190 mm without body | AARCMCC |
| 1/10 off-road max width | 250 mm | EFRA |
| 1/12 max width | 172 mm | EFRA |
| FSAE example | 1262 mm front, 1392 mm rear | Univ. of Utah FSAE |

## Where the files are

- CompetitionX: [RC Wheelbase Explained](https://www.competitionx.com/?p=1253) — web — Publisher's page; dimensions are facts
- raw.org (kinematics notes): [Ackerman steering](https://raw.org/book/kinematics/ackerman-steering/) — web — Publisher's page; dimensions are facts
- EFRA: [EFRA Handbook 2010, Appendix 3: Electric Cars](https://www.efra.ws/wp-content/uploads/2010/03/Handb10App3.pdf) — web — Publisher's page; dimensions are facts
- AARCMCC: [Section 3: Electric On Road, Technical Rules (Oct 2006)](https://www.rctech.net/forum/attachments/australian-racing/180184d1162811203-aarcmcc-online-tech-road-oct-06.pdf) — web — Publisher's page; dimensions are facts
- University of Utah, Mechanical Engineering: [Formula SAE Suspension System (senior design)](https://mech.utah.edu/wp-content/uploads/2024/12/5-Formula-SAE-Suspension.pdf) — web — Publisher's page; dimensions are facts

## Questions

**How do I widen track on RC?**

With wheel hex offset or arm length, within the class width limit.

## Fits with

- [Camber angle](https://xemstudio.com/objects/camber/)
- [Caster angle](https://xemstudio.com/objects/caster/)
- [Front kick-up (RC)](https://xemstudio.com/objects/kick-up/)
- [Front toe (toe-in / toe-out)](https://xemstudio.com/objects/toe-front/)
- [Rear toe-in](https://xemstudio.com/objects/toe-rear/)
- [Ackermann steering geometry](https://xemstudio.com/objects/ackermann/)