tirewheelguide
Head-to-head Updated

Avon Spirit ST vs Pirelli Diablo Rosso IV — Compared

Relative Score (0–100): the weighted average of the categories below, each 60% road tests and 40% owner reviews (comfort 40/60). Based on 0 + 1 road tests and 14 + 182 owner reviews. How we score

Spirit ST leads, 81–77 Narrow edge

Check price on Amazon · Spirit ST or Diablo Rosso IV on Amazon
Add your size for an exact match
/R

Both Amazon links then search this exact size.

TireWheelGuide may earn a commission from purchases made through these links.

Avon Spirit ST
Tire AAvon

Spirit ST

Summer

± 8Provisional

Tests – · none yet Owners 86 · 14 reviews

Pirelli Diablo Rosso IV
Tire BPirelli

Diablo Rosso IV

Summer

± 7

Tests 75 · 1 test Owners 81 · 182 reviews

Best test result: #5 of 12 in 2025 Sport and Hypersport Motorcycle Tyre Test (wet handling)

Category by category

Relative Score per category, 0–100. Open “Why this score” for the tests and owner ratings behind it.

  1. 81

    Dry

    Spirit ST +6
    75
    Why this score
    SourceSpirit STDiablo Rosso IV
    Professional tests (TWG score) · – / 1 tests≈ 76 (est.)68
    Reviews found online8887

    Spirit ST: 60% × 76.3 (est.) + 40% × 87.6 = 81

    Diablo Rosso IV: 60% × 67.8 + 40% × 86.8 = 75

    No road tests of dry for Spirit ST. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.42).

  2. 86

    Wet

    Spirit ST +4
    82
    Why this score
    SourceSpirit STDiablo Rosso IV
    Professional tests (TWG score) · – / 1 tests≈ 83 (est.)82
    Reviews found online9283

    Spirit ST: 60% × 82.6 (est.) + 40% × 92.1 = 86

    Diablo Rosso IV: 60% × 81.7 + 40% × 82.7 = 82

    No road tests of wet for Spirit ST. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.55).

  3. 77

    Comfort

    Level
    77
    Why this score
    SourceSpirit STDiablo Rosso IV
    Professional tests (TWG score)≈ 71 (est.)≈ 71 (est.)
    Reviews found online8181

    Spirit ST: 40% × 71.3 (est.) + 60% × 80.9 = 77

    Diablo Rosso IV: 40% × 71.2 (est.) + 60% × 80.7 = 77

    No road tests of comfort for Spirit ST or Diablo Rosso IV. The test half is the tested tires’ average (69): owners’ comfort ratings barely follow the road tests.

  4. 74

    Treadwear

    Spirit ST +5
    69
    Why this score
    SourceSpirit STDiablo Rosso IV
    Professional tests (TWG score)≈ 71 (est.)≈ 68 (est.)
    Reviews found online7971

    Spirit ST: 60% × 70.5 (est.) + 40% × 78.6 = 74

    Diablo Rosso IV: 60% × 67.9 (est.) + 40% × 71.1 = 69

    No road tests of treadwear for Spirit ST. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.35).

    No road tests of treadwear for Diablo Rosso IV. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.35).

  5. 85

    Handling (owners)

    Diablo Rosso IV +1
    86
    Why this score
    SourceSpirit STDiablo Rosso IV
    Reviews found online8586
Scores at a glance
CategoryAvon Spirit STPirelli Diablo Rosso IV
Relative Score 81 77
Dry 81 75
Wet 86 82
Comfort 77 77
Treadwear 74 69
Handling (owners) 85 86

Higher is better. The Relative Score follows your weights below; category scores do not change.

Weight the categories that matter to you

Wet grip starts at “Important”. Treadwear starts at “Neutral” here: road tests measured it for at most one of the two tires, so it rests on owner reviews. Move the sliders and the scores update instantly.

Important
NotLessNeutralImportantMost
Important
NotLessNeutralImportantMost
Less important
NotLessNeutralImportantMost
Neutral
NotLessNeutralImportantMost
Less important
NotLessNeutralImportantMost
Recomputed
Headline score
± 8

Spirit ST

± 7

Diablo Rosso IV

Pros, cons & observations

Themes extracted from owner reviews found online — not the opinion of TireWheelGuide.

Tire A Spirit ST

Pros

  • Excellent wet and dry weather grip
  • High durability and resistance to squaring off
  • Strong value proposition compared to premium competitors

Cons

  • Reports of vague steering feedback and reluctance to turn on certain bikes
  • Inconsistent quality control leading to high-speed vibrations for some users
  • Poor customer support resolution for warranty claims
All owner themes in the Spirit ST review

Tire B Diablo Rosso IV

Pros

  • Exceptional dry and wet grip with a high level of rider confidence
  • Fast warm-up time and predictable handling at deep lean angles
  • Improved steering precision and turn-in compared to previous generations like the Diablo Rosso III

Cons

  • Higher price point compared to some competitors and previous models
  • Noticeable reduction in grip and increased rear wheel spin as the tires wear down
  • Requires full operating temperature for optimal performance late in its life cycle
All owner themes in the Diablo Rosso IV review

Specs side by side

Attribute A · Avon Spirit ST B · Pirelli Diablo Rosso IV
CategorySummerSummer
Vehicle typeMotorcycleMotorcycle

Which one should you actually buy?

Avon Spirit ST

Pirelli Diablo Rosso IV

Narrow edge: Avon Spirit ST — better dry, treadwear and wet. Where the Pirelli Diablo Rosso IV is ahead, it is by less than 3 points. Avon Spirit ST rests on little evidence so far (0 tests, 14 reviews), so read this result as provisional.

Pick tire A You want the most grip on dry roads

Avon Spirit ST scores 81 vs 75 on dry.

Pick tire A You want the longest tread life

Avon Spirit ST scores 74 vs 69 on treadwear.

Pick tire A Your priority is wet-weather safety

Avon Spirit ST scores 86 vs 82 on wet.

Tire A · Avon Spirit ST
Check price on Amazon
Tire B · Pirelli Diablo Rosso IV
Check price on Amazon

TireWheelGuide may earn a commission from purchases made through these links.

Spirit ST or Diablo Rosso IV?

Which is better in the wet, Spirit ST or Diablo Rosso IV?

Avon Spirit ST, 86 vs 82 on our wet score.

Which grips better on dry roads, Spirit ST or Diablo Rosso IV?

Avon Spirit ST, 81 vs 75 on our dry score.

Which is more comfortable, Spirit ST or Diablo Rosso IV?

Neither, by our numbers: 77 vs 77 on the comfort score, within 3 points.

Which lasts longer, Spirit ST or Diablo Rosso IV?

Avon Spirit ST, 74 vs 69 on our treadwear score.

How do we compare tires?

Every category score blends two independent signals. 60% comes from professional tire tests (braking distances, lap times, noise measurements), each result compared with every other tire in the same test and newer tests counting more. 40% comes from owner reviews found online, adjusted for how generously each site rates. Both use one scale: the average tested tire gets 70, the best 100. When a tire has only one of the two, the missing half is estimated from the other and the score stays closer to average; with no road test and fewer than five owner reviews it gets no score yet.

Handling is the exception: road tests measure it inside the dry and wet scores, so its own row comes from owner ratings only and starts as less important.

Community buzz from Reddit and forums is shown for context only — it never changes the score. Full methodology