Ariel Square Four
77/100 Overall
58 On the road95 As a classic
Classic motorcycle head-to-head
Ariel Square Four vs BMW R90S
Ariel Square Four scores 77/100 overall against BMW R90S on 88/100. On the road: 58–83. As classics: 95–93. Overall result: BMW R90S.
BMW R90S
88/100 Overall
83 On the road93 As a classic
The numbers
Category-by-category result
| Category | Ariel Square Four | BMW R90S | Advantage |
|---|---|---|---|
| road | |||
| PerformanceDirect comparison of power, acceleration and usable performance across the pre-1990 classic field. | 7 | 8 | BMW R90S |
| HandlingSteering, stability, weight and real-road manners. | 6 | 8 | BMW R90S |
| BrakingDirect comparison of real stopping ability without an age allowance. | 4 | 7 | BMW R90S |
| ReliabilityEngine, electrics and general dependability when properly maintained. | 5 | 9 | BMW R90S |
| Ease of ownershipMaintenance, parts supply and access to specialist knowledge. | 5 | 9 | BMW R90S |
| ComfortRiding position, vibration and suitability for longer journeys. | 8 | 9 | BMW R90S |
| classic | |||
| StylingDesign quality, visual presence and period appeal. | 9 | 10 | BMW R90S |
| Historical importanceInfluence on motorcycling and importance within its era. | 10 | 9 | Ariel Square Four |
| Collector appealLong-term desirability among classic motorcycle enthusiasts. | 9 | 10 | BMW R90S |
| CharacterSound, feel, personality and memorable riding experience. | 10 | 8 | Ariel Square Four |
Choose the Ariel Square Four if…
you want unique engineering, refined four-cylinder character and one of Britain's most distinctive luxury motorcycles.
Choose the BMW R90S if…
you want high-speed touring ability, engineering quality and one of BMW's most significant sporting classics.
Background
History
Ariel Square Four
The Ariel Square Four was produced from 1931–1959 and used a air-cooled square-four engine. Within this comparison library it stands out particularly for historic importance, character, styling. It suits riders who value the qualities described in its original profile rather than choosing by specification alone.
BMW R90S
The BMW R90S was produced from 1973–1976 and used a 898cc air-cooled opposed twin. Within this comparison library it stands out particularly for styling, collector appeal, reliability. It suits riders who value the qualities described in its original profile rather than choosing by specification alone.
Interesting details
Did you know?
Ariel Square Four
- Its production span in this library runs from 1931 to 1959.
- The recorded engine description is: air-cooled square-four engine.
- Its strongest comparison scores are historic importance, character, styling.
BMW R90S
- Its production span in this library runs from 1973 to 1976.
- The recorded engine description is: 898cc air-cooled opposed twin.
- Its strongest comparison scores are styling, collector appeal, reliability.
Present-day appeal
Collector notes
Ariel Square Four
Collector interest is strongest where condition, originality and correct period details support the identity of the Ariel Square Four. Its library score for historic importance is 10/10. Values and desirability can vary substantially between years, specifications and restoration quality, so individual examples should be assessed on their own evidence.
BMW R90S
Collector interest is strongest where condition, originality and correct period details support the identity of the BMW R90S. Its library score for styling is 10/10. Values and desirability can vary substantially between years, specifications and restoration quality, so individual examples should be assessed on their own evidence.
Before you buy
Buying checks
Ariel Square Four
- Confirm the frame and engine identity match the advertised model and year.
- Check cold starting, smoke, oil leaks and unusual mechanical noise.
- Inspect the frame, wheels, brakes and suspension for wear, damage or poor repairs.
- Verify that important model-specific parts have not been replaced with incorrect later components.
- Review the paperwork, ownership history and any restoration invoices before purchase.
BMW R90S
- Confirm the frame and engine identity match the advertised model and year.
- Check cold starting, smoke, oil leaks and unusual mechanical noise.
- Inspect the frame, wheels, brakes and suspension for wear, damage or poor repairs.
- Verify that important model-specific parts have not been replaced with incorrect later components.
- Review the paperwork, ownership history and any restoration invoices before purchase.
Period opposition
Historic rivals
Rivals to the Ariel Square Four
Rivals to the BMW R90S
Final result
The verdict
BMW R90S wins the direct on-the-road comparison. Ariel Square Four wins the classic-motorcycle comparison. BMW R90S takes the overall result after the road and classic scores are weighted equally.