77
/ 100
Objective (60%)
–/100
No test data yet
User signal (40%)
75/100
10 owner reviews
Prices change daily — check the retailer for your size.
Head-to-head
Updated September 2026
Bridgestone Battlax BT 021 vs Pirelli Diablo Rosso IV — Compared (September 2026)
Our Relative Score blends 60% objective test data with 40% owner-review signal — so any two tires can be compared even if they were never tested on the same day.
VS
81
/ 100
Objective (60%)
70/100
1 professional test
User signal (40%)
87/100
7 owner reviews
Prices change daily — check the retailer for your size.
VerdictWinner: Pirelli Diablo Rosso IV — better handling, comfort and dry. Pick the Bridgestone Battlax BT 021 if treadwear matters most to you.
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Category breakdown
5 categories, side by side
Each bar is the Relative Score for that category. Expand a tile to see the test results and owner ratings behind it.
Dry
Score (0–100)
Diablo Rosso IV leads by 3
Why this score
| Source | Battlax BT 021 | Diablo Rosso IV |
|---|---|---|
| Professional tests (TWG score) | – | 87 |
| Tyre Reviews owners | 86 | 93 |
Wet
Score (0–100)
Diablo Rosso IV leads by 1
Why this score
| Source | Battlax BT 021 | Diablo Rosso IV |
|---|---|---|
| Professional tests (TWG score) | – | 67 |
| Tyre Reviews owners | 71 | 79 |
Comfort
Score (0–100)
Diablo Rosso IV leads by 7
Why this score
| Source | Battlax BT 021 | Diablo Rosso IV |
|---|---|---|
| Tyre Reviews owners | 79 | 86 |
Treadwear
Score (0–100)
Battlax BT 021 leads by 3
Why this score
| Source | Battlax BT 021 | Diablo Rosso IV |
|---|---|---|
| Tyre Reviews owners | 79 | 76 |
Handling
Score (0–100)
Diablo Rosso IV leads by 17
Why this score
| Source | Battlax BT 021 | Diablo Rosso IV |
|---|---|---|
| Tyre Reviews owners | 74 | 91 |
| DriverReviews owners | – | 92 |
Scores at a glance
| Category | Bridgestone Battlax BT 021 | Pirelli Diablo Rosso IV |
|---|---|---|
| Relative Score | 77 | 81 |
| Dry | 86 | 89 |
| Wet | 71 | 72 |
| Comfort | 79 | 86 |
| Treadwear | 79 | 76 |
| Handling | 74 | 91 |
Higher is better. The Relative Score follows your weights below; category scores do not change.
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Recomputed
Headline score
77
/ 100
Tire A
81
/ 100
Tire B
From owners
Pros, cons & observations
Themes extracted from owner reviews across retailers and review sites — not the opinion of TireWheelGuide.
The Bridgestone Battlax BT-021 receives a polarized reception, with user experience heavily dependent on riding style and tire pressure management. While some riders praise its longevity and consistent performance for commuting and touring, others report significant issues with handling, feedback, and wet-weather confidence.
Pros
- Exceptional tread longevity and durability for high-mileage commuters
- Reliable performance for motorway and long-distance riding
- Strong grip characteristics when tire pressures are correctly calibrated
- Confidence-inspiring stability for many sport-touring applications
Cons
- Handling characteristics can feel unpredictable or heavy if pressures are not perfectly matched to the bike
- Reports of poor wet-weather grip and lack of rider feedback
- Tendency for the center of the tire to flatten out significantly during high-mileage motorway use
- Inconsistent turn-in feel, described by some as fighting the rider
Observations
- Users noted that the tire is highly sensitive to manufacturer-recommended pressures, with incorrect settings leading to poor handling on bikes like the Kawasaki.
- Commuters on middleweight naked bikes reported high mileage but experienced uneven wear patterns, specifically flattening of the center tread.
The Pirelli Diablo Rosso IV is widely regarded as a top-tier hypersport tire that offers significant improvements in feedback, warm-up time, and lean-angle confidence over its predecessors. While users consistently praise its performance in both wet and dry conditions, the consensus notes that these gains come at a premium price point and with potential longevity trade-offs depending on riding style.
Pros
- Exceptional dry and wet grip with rapid warm-up times.
- High level of precision and confidence at deep lean angles.
- Improved feedback and stability compared to previous generations (DR2/DR3).
- Surprisingly good low-speed stability and handling characteristics.
Cons
- Higher price point compared to competitors and previous models.
- Performance consistency may degrade as the tire reaches the end of its service life.
- Potential for increased wear rates under aggressive riding conditions.
Observations
- Users reported significant improvements in resistance to cupping on smaller displacement bikes (e.g., PCX 125) compared to the Diablo Rosso II.
- Aggressive riders utilizing standard sportbike sizes (120/70 and 190/55) report that the tire maintains performance characteristics comparable to more track-focused compounds like the Rosso Corsa II.
Specifications
Specs side by side
| Attribute | A · Bridgestone Battlax BT 021 | B · Pirelli Diablo Rosso IV |
|---|---|---|
| Category | Summer High Performance tires | Summer Max Performance tires |
| Vehicle type | Motorcycle | Motorcycle |
Final verdict
Which one should you actually buy?
77
/ 100
Bridgestone
81
/ 100
Pirelli
Winner: Pirelli Diablo Rosso IV — better handling, comfort and dry. Pick the Bridgestone Battlax BT 021 if treadwear matters most to you.
Pick tire B
You enjoy sharp, responsive handling
Pirelli Diablo Rosso IV scores 91 vs 74 on handling.
Pick tire B
You want the most comfortable ride
Pirelli Diablo Rosso IV scores 86 vs 79 on comfort.
Pick tire A
You want the longest tread life
Bridgestone Battlax BT 021 scores 79 vs 76 on treadwear.
Pick tire B
You want the most grip on dry roads
Pirelli Diablo Rosso IV scores 89 vs 86 on dry.
Tire A · Bridgestone Battlax BT 021
Tire B · Pirelli Diablo Rosso IV
More comparisons
Also compared with
Bridgestone Battlax BT 021 also compared with
Pirelli Diablo Rosso IV also compared with
How do we compare tires?
Every category score blends two independent signals. 60% comes from professional tire tests (braking distances, lap times, noise measurements) normalized against the best tire in each test and weighted toward recent tests. 40% comes from thousands of owner reviews collected from retailers and review sites. When a tire has only one of the two, we use what exists and say so.
Community buzz from Reddit and forums is shown for context only — it never changes the score.