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40Race Shoe FinderEst. 2023 · London

Head to head

Nike Streakfly 2vs
Saucony Endorphin Pro 4

Streakfly 2

£105

Typical street price · £155 RRP

32mm — road legal
Endorphin Pro 4

£120

Typical street price · £210 RRP

36mm — road legal

Choose the Streakfly 2 if…

  • You want the lighter shoe: 170g against 217g, a 47g difference you will feel late in a race.
  • You race off a strong, repeatable stride and want the more aggressive ride rather than the safer one.
  • You have a narrow foot and want to be locked in.
  • You are racing 5K — built for it, where the Endorphin Pro 4 is not.

Choose the Endorphin Pro 4 if…

  • You want the bigger return: 2.7–3.8% 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: 36mm against 32mm, which is protection over a long race rather than speed over a short one.
  • You want something more forgiving. This is the steadier platform — useful if your form goes late, or if you are on your feet longer.
  • You want a conventional fit rather than a narrow or wide last.
  • You want more races out of one pair: about 350km of competitive life against 300km.
  • You are racing Half marathon or Marathon — built for it, where the Streakfly 2 is not.
  • You would rather buy on measured numbers: this shoe's specs are manufacturer-confirmed, the Streakfly 2's are estimated.

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
Streakfly 2: 16s–33sEndorphin Pro 4: 30s–47s
Cost per second saved
Streakfly 2: £0.21Endorphin Pro 4: £0.13

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.

010203040503226
Streakfly 2
010203040503628
Endorphin Pro 4

What you pay

Street price
Streakfly 2£105■
Endorphin Pro 4£120

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

RRP
Streakfly 2£155
Endorphin Pro 4£210

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

Cost per race
Streakfly 2£5.25
Endorphin Pro 4£5.14■

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

Cost per second saved
Streakfly 2£0.21
Endorphin Pro 4£0.13■

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

What it does

Estimated saving
Streakfly 216s–33s
Endorphin Pro 430s–47s■

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

Economy gain
Streakfly 21.8–2.9%
Endorphin Pro 42.7–3.8%■
Built for
Streakfly 25K · 10K
Endorphin Pro 410K · Half · Marathon
Best use case
Streakfly 2A proper short-distance racer for people who find full super shoes unwieldy at 5K pace. Lower, firmer, more connected to the ground.
Endorphin Pro 4The stable, sane super shoe. Lower stack, wider base, far less demanding than the flagships and much longer lasting.

How it is built

Weight
Streakfly 2170 g■
Endorphin Pro 4217 g

Manufacturer figure at men's US 9.

Stack (heel)
Streakfly 232 mm
Endorphin Pro 436 mm
Stack (forefoot)
Streakfly 226 mm
Endorphin Pro 428 mm
Drop
Streakfly 26 mm
Endorphin Pro 48 mm
Foam
Streakfly 2ZoomX
Endorphin Pro 4PWRRUN HG
Plate
Streakfly 2nylon
Endorphin Pro 4carbon fibre

Rules and fit

Road legal
Streakfly 2Yes (32 mm)
Endorphin Pro 4Yes (36 mm)

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

Fit
Streakfly 2narrow
Endorphin Pro 4standard
Stability
Streakfly 2balanced
Endorphin Pro 4stable

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

Race life
Streakfly 2~300 km
Endorphin Pro 4~350 km■

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

Data confidence
Streakfly 2estimated
Endorphin Pro 4verified■

■ 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£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.

Where to buy

Your UK size

Best price today — some sizes£119.99at Run North West — £90.01 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.