RS125 Bible is an independent workshop record of the Aprilia RS125. It is not affiliated with Aprilia, Piaggio, or any owner, club, or seller. It covers every generation, from the 1992 two-stroke Extrema to the current four-stroke, and it leaves a figure blank when the sources do not give one.

Liveries are recorded as model history. The 1998 Valentino Rossi replica is a documented scheme. Chesterfield is listed for 1994, as Biaggi Chesterfield for 1995–96, and again for 1999–2005. It is not listed as a 1998 scheme, and the site says so instead of smoothing it over.

The gap this site is for: there is no single English record that covers every generation with restoration steps, UK law and import, and a parts directory that admits when it does not know a price. Hartrusion is the closest workshop source and it is German-first. rs125.it is the history, in Italian. The forums have the scars, buried in threads.

What “To verify” means

A figure is printed only when the research brief sourced it. Torque, clearances, jet charts, paint codes, OEM numbers and sterling prices were not in that brief, so they are not in the tables. A forum number does not fill the gap. When you have copied a figure from the workshop manual for your VIN, or written down a price with the date you saw it, that is the moment to replace a marker — and to say where it came from.

Still open

• Whether a 1998 Chesterfield scheme exists. Sources list Chesterfield for other years only.
• A Loris Capirossi RS125 replica. It is named in passing and not confirmed.
• The exact year the four-stroke took the RS 125 name back. Sources say 2016, 2017 or 2019.
• Common faults on the RS4 and the current four-stroke. No owner-forum list was researched.
• UK-market model codes and the hardware behind the restricted 15 bhp bikes. The codes in the brief are mostly German homologation data.
• The current eBay Partner Network UK rate, the Demon Tweeks rate, the Vercel Pro price, and the DVLA first-registration fee. £55 in the brief is a summary, not a checked tariff.
• Torque settings and jet sizes. They belong in the official workshop manual, not in a forum post and not on this site until they are copied from that manual.
• Year letters the brief did not list (2003–2009 and 2013 onward), including the ISO clash of S and T with 2025 and 2026.
• Paint codes, fork oil, brake-fluid grade, coolant, oil-pump stroke, and every OEM part number.
• Whether ‘RS125’ in a domain needs a trade mark check. The brief marks a UK IPO search as still to do. Aprilia itself is kept out of the site name.

Trade marks

The site is not affiliated with, endorsed by, or connected to Aprilia, Piaggio, Rotax, or any seller named in the directory. Aprilia is a trademark of its owner. It is used here only to identify the motorcycle. It is not used in the logo or the site name.

Corrections

A correction with a source is how the markers come off. Use the form on thecommunity page. Contributors who fix a guide get credited on it. The site ships with no analytics and no advertisements. Affiliate slots render nothing until an ID is set.

Every source in the brief

• Aprilia RS125 (opens in a new tab) — Wikipedia
• RS 125 (1995–2012) review and buying guide (opens in a new tab) — MCN
• Modellübersicht RS 125 2T (opens in a new tab) — Hartrusion
• Differences between Rotax 122 and 123 (opens in a new tab) — Hartrusion
• Aprilia RS125 parts and engine ID (opens in a new tab) — PJME
• Storia e modelli (opens in a new tab) — rs125.it
• RS 125 replica decal sets by year (opens in a new tab) — Decalmoto
• Aprilia model list (opens in a new tab) — Motorcyclespecs
• Derestriction guide (opens in a new tab) — The RS 125 blog
• Bike categories, ages and licence requirements (opens in a new tab) — GOV.UK
• Importing vehicles: telling HMRC (NOVA) (opens in a new tab) — GOV.UK
• Over-10-year imports exempt from approval (opens in a new tab) — VCA
• RS50 D50B engine (opens in a new tab) — Pedparts
• RS 125 2006–2010 parts catalogue (PDF) (opens in a new tab) — Aprilia Superstore
• Affiliate programme (opens in a new tab) — Sportsbikeshop
• Associates commission rates (opens in a new tab) — Amazon UK
• EPN UK rate card (2019) (opens in a new tab) — eBay
• Fair use: Hobby is non-commercial (opens in a new tab) — Vercel
• RS125 Euro-archive (opens in a new tab) — ApriliaForum
• Aprilia RS125 forum (opens in a new tab) — 125cc Sportsbikes