NEW DELHI: Jawa's official All Stars 42 OG specification table lists a 100/90-18 tubeless front tyre and a 150/70-17 tubeless rear tyre on alloy wheels. The sizes belong to this named model. An owner ordering replacements should check the actual motorcycle's handbook and complete tyre markings before treating a listing for another Jawa 42 as a match.
| All Stars 42 OG item | Official specification |
|---|---|
| Front tyre | 100/90-18, tubeless, alloy wheel |
| Rear tyre | 150/70-17, tubeless, alloy wheel |
| Front disc | 280 mm |
| Rear disc | 240 mm |
| Braking system | Dual-channel ABS |
| Rear suspension | Twin gas-filled shock absorbers with adjustable preload |
Start with the full model name
The official site separates the All Stars 42 OG from the All Stars 42 FJ and All Stars 42 Bobber. That distinction should survive the move from a product page to a workshop job card. Simply writing “Jawa 42 rear tyre” leaves an avoidable gap in a parts enquiry.
For an Indian owner arranging a replacement between workdays, the practical preparation is straightforward: record the model shown in the motorcycle's documents, photograph the existing tyre markings and carry the handbook. Ask for the proposed replacement specification in writing before the old tyre is removed. This creates a clear record of what is being fitted.
The same care applies when a motorcycle has already been modified. The tyre currently fitted is evidence of what is on the wheel, but it does not by itself prove factory approval. Keep the manufacturer's specification, the motorcycle's documents and its present condition as separate checks until any discrepancy is resolved.
What the front and rear codes describe
Michelin's official tyre-size guide explains that the leading metric number describes nominal tyre width, the following number is the aspect ratio and the wheel-diameter number is expressed in inches. Applied to Jawa's table, the front and rear use different wheel diameters as well as different tyre dimensions.
For the 100/90-18 front, that means a nominal width of 100 mm, a 90 aspect ratio and an 18-inch wheel fitment. The rear's 150/70-17 code gives a nominal width of 150 mm, a 70 aspect ratio and a 17-inch fitment. These are identifiers to match carefully, rather than a set of interchangeable measurements.
The size code is only part of a tyre's description. Michelin also identifies construction, load and speed information as relevant markings. Jawa's short wheel-and-tyre table does not supply a complete replacement service description, so this article does not invent a load index, speed symbol or approved alternative size.
Tubeless is part of the specification
Jawa explicitly labels both tyres as tubeless and pairs them with alloy wheels in the specification table. Michelin explains that TL and TT identify tubeless and tube-type tyres respectively, and that the wheel type also matters. A matching headline size alone is therefore an incomplete fitment check.
Keep a replacement enquiry specific: front or rear position, full size, construction and service markings, together with the motorcycle identity. If a seller proposes a substitute, ask for the manufacturer-approved basis for that substitution. An available tyre is not automatically the correct tyre for this wheel and motorcycle.
Michelin recommends retaining the original dimensions unless the vehicle manufacturer validates an alternative. For the All Stars 42 OG, a wider-looking replacement should therefore prompt a compatibility check rather than an assumption that it improves the motorcycle. This guide does not prescribe a different size or a change in construction.
Keep braking hardware in the service discussion
The All Stars 42 OG also has disc brakes and dual-channel ABS in its official specification. A tyre appointment is a useful point to make the workshop aware of the complete wheel assembly and any concerns the owner has already noticed. Ask for those concerns to be recorded on the job card rather than folded into an unexplained replacement recommendation.
Record pressure instructions separately
The dimension table should not become a tyre-pressure chart. Obtain the applicable pressure instructions from the motorcycle's own handbook or manufacturer guidance, including the conditions attached to them. Keep those instructions with the service record so a later tyre change does not rely on a remembered number from another model.
During the appointment, ask the workshop to explain any difference between the requested specification and the tyre presented for fitting. Photograph the new sidewall and retain the invoice with the exact product description. That makes a future enquiry easier if the tyre's name or abbreviated invoice wording is unclear.
For other ownership tasks in the family, see our guides to 42 Bobber first-service checkpoints, 42 FJ booking refunds and Perak warranty records. Each concerns a different motorcycle or process; none replaces the All Stars 42 OG handbook for tyre fitment.
Official sources: Jawa All Stars 42 OG specifications, Michelin tyre-size guide and Michelin motorcycle tyre FAQ.
