On-One Inbred Swap-out SS review

Iconic steel hardtail

Our rating 
3.5 out of 5 star rating 3.5
GBP £849.00 RRP | USD $1,097.30

Our review

Some frame details need fixing but they don’t detract from the sorted steel ride of this singletrack Magimix
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The Inbred steel singlespeed is the bike that online company On-One started with. It’s available in various incarnations today. We stuck with one gear to meet the test’s budget but specified a suspension fork instead of a rigid carbon one. Fifty quid extra is a small price to pay to avoid a pummelling.


You pay a premium for steel frames over aluminium, and this one also has a plush fork that outclasses its coil equivalent. Something has to give and obviously it’s the gears – 26 of them. If you can live with one gear, this version of the Inbred still offers a rewarding, if sometimes exhausting, XC ride. If you can’t, you’ll have to push the budget towards £1000 to buy a rear derailleur, shifter, new chain and cassette.

Ride & handling: Whips along pedally singletrack

It’s not quite as long as the racing-snake-only On-One Whippet, but it’s equally low and it feels quite old-school XC, particularly with this handlebar. It’s at its best whipping along pedally singletrack, where the combination of a smooth fork and resilient frame provide an engaging ride. It’s hard work at times, of course. Singlespeeds climb better than you think they will, mostly because you have to commit 100% on the approach, and a charge is enough for short slopes. Long climbs hurt, however, and some will reduce you to walking.

Technical descents are not the Inbred’s forte, due to the head down position and the narrow bar. You could sit up more with a riser bar. If you want a hardtail for technical fun and games, get the Inbred’s 456 stablemate. One happy side effect of the singlespeed gearing is that drivetrain chatter is pretty much eliminated. You descend more like a stealth bomber than a bag of spanners.

Frame: Long and low chromoly steel

The Inbred has a fairly long and low chromoly steel frame with a wishbone seatstay arrangement and bridgeless chainstays. Some things haven’t changed over the years, such as the rear rack mounts and the strengthening plates welded to the top and down tubes where they meet the head tube. Other things have changed. The top tube is now 35mm diameter like the 456’s, instead of 28.6mm. That adds weight and strength, presumably to meet the CEN standard. It would support a taller fork better too but the geometry is designed around 120mm maximum.

At the back, the stays are still more sturdy than svelte but now terminate in swap-out drop-outs, which we’re not entirely convinced by. On-One’s previous ‘slot drop-out’ design offers the same benefits without the bolts, while sliding drop-outs would be better yet as you wouldn’t have to faff with chain tugs when replacing the wheel. There are some curious frame details now – mounts for V brakes on the seatstays for retro heads, vestigial cable guides on the left-hand seatstay (the cable now runs along the chainstay) and the gear cable stop on the seat tube is gone.

Equipment: Plush air fork and decent finishing kit

The fork is a 100mm Recon Gold RL solo air. It’s a decent fork, with rebound adjustment and remote compression lockout. The latter is really useful on a singlespeed because you have to attack climbs out of the saddle, and unlocked-out suspension slurps up your pedalling effort. The drivetrain is the ubiquitous 32×16. Unless you like to mash the pedals you might be better off with 32×17 or 32×18 to take the edge off climbs. The chainring is 3/32in rather than the 1/8in of the chain. It still works fine, and it won’t need replacing if you switch to a 1×9 or 1×10 set-up.

The wheels feature decent Mach 1 Sub Zero rims on Deore hubs. The rear wheel uses a standard Deore freehub, converted for singlespeed use with a set of spacers and a splined sprocket. It’s a much better option for less fanatical singlespeeders than a threaded hub with a screw-on sprocket, because you don’t need a whole new wheel if you decide to run gears. Schwalbe Albert tyres ride okay in most conditions. They’re only 2.1in, but you could fit much fatter tyres.

The Middleburn cranks are 175mm. Some people say 180mm is better for singlespeeds, but we’re not convinced. Longer cranks increase your leverage but all they’re really doing is reducing your gearing, which you can do by fitting a bigger sprocket. They’re also harder to spin quickly.


The Avid Elixir 3 brakes are fine, as is the On-One finishing kit. Nothing says XC like a narrow flat handlebar and this one is 600mm. While you miss the extra control of a wide bar on descents, it works fine for a light bike with an effective fork. The thing that’s missing is bar ends, because you have to climb out of the saddle on a singlespeed so you wrestle the bar.

Product Specifications


Name Inbred Swap-out SS (12)
Brand On-One

Description Sizes: 14, 16, 18 (tested), 20in. Chainset: Middleburn RS8 X-type, 32T. Wheels: Mach 1 Sub Zero rim, Shimano Deore M525 hub.
Seatpost On-One Twelfty, 400mmx27.2mm
Wheelbase (in) 43.1
Top Tube (in) 23.4
Standover Height (in) 30.3
Seat Tube (in) 18
Chainstays (in) 16.7
Bottom Bracket Height (in) 13
Weight (lb) 25
Weight (kg) 11.38
Stem On-One, six degree rise, 80mm
Seat Angle 73
Bottom Bracket Shimano XT Hollowtech II
Saddle On-One Bignose
Headset Type FSA The Pig
Head Angle 69.5
Handlebar On-One flat, 600x31.8mm
Grips/Tape On-One Bob On lock-on
Frame Material Chromoly steel
Fork RockShox Recon Gold RL, air, 100mm
Chain KMC K710, singlespeed
Cassette On-One singlespeed converter kit and 16T sprocket
Brakes Avid Elixir 3 hydraulic disc, 180/160mm rotors
Tyres Schwalbe Albert, 2.1in