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40Race Shoe FinderEst. 2023 · London

Head to head

HOKA Rocket X 3vs
Nike Streakfly 2

Rocket X 3

£140

Typical street price · £220 RRP

39mm — road legal
Streakfly 2

£105

Typical street price · £155 RRP

32mm — road legal

Choose the Rocket X 3 if…

  • You want the bigger return: 2.9–4% economy gain against 1.8–2.9%, and that gap widens the longer you are out there.
  • You want more shoe underneath you late on: 39mm against 32mm, which is protection over a long race rather than speed over a short one.
  • You want a conventional fit rather than a narrow or wide last.
  • You are racing Half marathon or Marathon — built for it, where the Streakfly 2 is not.

Choose the Streakfly 2 if…

  • You want the lighter shoe: 170g against 200g, a 30g difference you will feel late in a race.
  • You have a narrow foot and want to be locked in.
  • Money matters: it is selling around £105 against £140, and the time difference between them is smaller than the price difference suggests.
  • You are racing 5K — built for it, where the Rocket X 3 is not.

What does this
mean for you?

Every figure below is recalculated from your race and your current time. The gap between two shoes is not fixed — it grows with how long you are on your feet.

Over 10k from 45:00

Time back
Rocket X 3: 33s–51sStreakfly 2: 16s–33s
Cost per second saved
Rocket X 3: £0.18Streakfly 2: £0.21

Ranges, not promises. Both figures are against a standard trainer, and the honest answer for most runners is that the difference between two shoes of this class is smaller than the difference a month of decent training makes.

Every number.

010203040503934
Rocket X 3
010203040503226
Streakfly 2

What you pay

Street price
Rocket X 3£140
Streakfly 2£105■

What the shoe is actually selling for across the shops we read, not its RRP.

RRP
Rocket X 3£220
Streakfly 2£155

List price. Almost nobody pays it for a race shoe.

Cost per race
Rocket X 3£7.50
Streakfly 2£5.25■

Street price divided by the races the foam stays fast for.

Cost per second saved
Rocket X 3£0.18■
Streakfly 2£0.21

The whole-life question: what each second of race time costs you.

What it does

Estimated saving
Rocket X 333s–51s■
Streakfly 216s–33s

Against a standard trainer, over the distance and time set above.

Economy gain
Rocket X 32.9–4%■
Streakfly 21.8–2.9%
Built for
Rocket X 310K · Half · Marathon
Streakfly 25K · 10K
Best use case
Rocket X 3HOKA’s legal racer, and much the better shoe for anyone who actually needs to comply with the rules. Balanced and predictable.
Streakfly 2A proper short-distance racer for people who find full super shoes unwieldy at 5K pace. Lower, firmer, more connected to the ground.

How it is built

Weight
Rocket X 3200 g
Streakfly 2170 g■

Manufacturer figure at men's US 9.

Stack (heel)
Rocket X 339 mm
Streakfly 232 mm
Stack (forefoot)
Rocket X 334 mm
Streakfly 226 mm
Drop
Rocket X 35 mm
Streakfly 26 mm
Foam
Rocket X 3PEBA
Streakfly 2ZoomX
Plate
Rocket X 3carbon fibre
Streakfly 2nylon

Rules and fit

Road legal
Rocket X 3Yes (39 mm)
Streakfly 2Yes (32 mm)

World Athletics caps road racing shoes at 40 mm of stack.

Fit
Rocket X 3standard
Streakfly 2narrow
Stability
Rocket X 3balanced
Streakfly 2balanced

Neither is better in the abstract — it depends on your stride.

Race life
Rocket X 3~280 km
Streakfly 2~300 km■

How long the foam stays fast, not how long the shoe survives.

Data confidence
Rocket X 3estimated
Streakfly 2estimated

■ marks the better figure where one is genuinely better. Fit, foam, drop and stability carry no mark — they depend on your foot and your stride, not on which shoe is superior.

In your size.

Where to buy

Your UK size

Best price today — some sizes£140at Interval Running — £80 under RRP

9 retailer checks failed on the last run, so their prices are missing rather than wrong.

Prices are captured when the site is built and stamped with the time of that check. We never rank a retailer by what it pays us; where a link earns a commission it is marked sponsored and the price you pay is unchanged.

Where to buy

Your UK size

Best price today — some sizes£104.99at Run North West — £50 under RRP

9 retailer checks failed on the last run, so their prices are missing rather than wrong.

Prices are captured when the site is built and stamped with the time of that check. We never rank a retailer by what it pays us; where a link earns a commission it is marked sponsored and the price you pay is unchanged.