Position
£420
2 hours · up to 10 runs
- Your bike on the balance
- Bar, pad and head changes
- CdA and watts per run
- Smoke video of your best position
strake Wind tunnel, Manchester
- Rider position sessions
- Helmet and kit testing
- Building and canopy models
- Wings, drones and prototypes
Book an hour of 40 km/h air. Bring your bike or your model, and leave with the drag measured in watts and the smoke on video.
What we measure
Above about 30 km/h, most of your effort goes into pushing air. We measure how much, in watts, and show you where it goes.
01
612
riders tested since the tunnel opened in 2021
02
18 W
median saving at 40 km/h after one position session
03
±0.002 m²
repeatability of a CdA run, same rider, same position
04
07:00
first run, Monday to Saturday. Last run 19:00.
What you can book
Sessions.
4 kinds, from £420
Two hours on your own bike on the balance. We measure your drag in your current position, then change one thing at a time: bar height, pad width, head, hands. Up to 10 measured runs.
What happens in a sessionThree hours to compare helmets, skinsuits, overshoes or bottles, on you or on our mannequin. Each item is run twice, in random order, so the difference you see is bigger than the noise.
Kit testing in detailFor architects and landlords with a courtyard that funnels wind, a canopy that lifts, or a door nobody can open on a windy day. We build or take your 1:50 model, film the smoke and measure pressure on the parts that matter.
See the Loom Street canopyDay hire for small teams: university projects, drone arms, sails, wheelchairs, anything that fits in a 2.4 by 1.8 metre jet. You get the balance, the smoke wand and an engineer who has seen a lot of stalls.
Tunnel specificationsA position session, in one minute
One rider, three positions.
- 01 Hoods
Hands on the hoods, back at 45°. The air lets go at the helmet and shoulders; the wake reaches head height.
- 02 Drops
Hands in the drops, back at about 30°. The wake drops with the shoulders: 25 W less at 40 km/h.
- 03 Aero bars
Forearms on pads, back flat, aero helmet. The air follows the back to the hips, so the wake stays low: 72 W less.
CdA0.320m²
Watts to push the air at 40 km/h269W
Wake height0.00m
Saved vs hoods0W
Power = ½ · air density 1.225 kg/m³ · CdA · speed³. Typical values for one rider; yours will differ, which is why we measure. The green line is measured from the simulation as you watch: inside it the air moves at less than 70% of the stream speed on average.
Recent sessions
Three sessions from this year, with the numbers. A triathlete's position, a courtyard canopy that kept lifting, and four sleeve fabrics for a Yorkshire kit maker.
What it costs
Prices.
Including VAT, engineer and report
Race kit most booked
£640
3 hours · up to 16 runs
- Everything in Position
- Up to four helmets or suits
- Each item run twice, random order
- Yaw sweep at ±10°
Full day
£2,100
8 hours · teams, brands, projects
- The tunnel and an engineer
- Six-component balance
- Smoke wand and rake
- Raw data at the end of the day
Building and canopy studies are quoted, because model-making time varies. Most start at £1,800. Moving a session is free up to 48 hours before it.
Before you book
What people ask us most. Anything else: call 0161 496 0718 and you'll speak to the engineer who runs your session.
Everything to know before you come.
Yes, the bike you race on, set up the way you race it, with the shoes, helmet and kit you race in. We mount it on the balance by the axles; nothing is changed without you.
It's water-based stage fog from a hand wand, the same fluid used in theatres. It's released in short puffs downstream of your face, and the tunnel is open-return, so it leaves the room with the air.
Repeat runs of the same rider in the same position agree within ±0.002 m² of CdA, about 2 W at 40 km/h. We repeat any change smaller than twice that before we call it real.
The ranking of positions holds; the exact watts depend on wind, road and how long you can hold the position. That's why the report gives you the position you can hold for your event, not only the fastest one.
We keep eleven common road and time-trial helmets in sizes M and L. Tell us which ones when you book and we'll have them ready.
Moving a session is free up to 48 hours before it. Inside 48 hours we keep half the price, unless we can fill the slot.
Two bays in the yard for people carrying bikes or models; tell us your registration when you book. Otherwise, the tunnel is a ten-minute walk from Manchester Piccadilly.
Tell us what you're testing. We'll reply within one working day with two slots that suit it.
Ruth Adeyemi
Runs the position sessions
Runs the position sessions