One of the big talking points aside from tubeless tyres and sock length in the last few years has been 1X drivetrains. 3T’s stunning Strada road bike showed what could be done by manufacturers using the single front chainring / 1X platform. Many gravel bikes and even more mountain bikes come in 1X format.
So, is your front mech destined for the redundant parts bin, amongst the toe clips and frame mount gear levers?
How Does that Work?
The key component is the chainring. 1X chainrings feature alternating narrow / wide teeth, these teeth fit pefectly into the narrow / wide links on a standard chain – This perfect fit between chainring and teeth offer un- parralleled chain retention. Narrow-wide chainrings can only be manufactured in even numbers, eg 40,42 and 44 as the teeth need to alternate narrow and wide.
Conversion Shopping list
Cheap(er) Option Tips
Go for the same number of gears (same gear shifter & cassette).
1 – Clutch rear derailleur (eg Dee 1X10, SLX1x11,Ultegra RX800 1×11, GRX1x11,Force1x11).
2 – Narrow Wide 1X single chainring & bolts, (eg Wolf, Hope Retainer, Shimano Dee) make sure the number of crank arms (4 or 5) and the BCD (bolt circle diametre) of your chainset and chainring both match.
If you replace chainrings for a narrow wide 1X chainring & swap to a ‘clutch’ rear derailleur you shouldn’t ever have a dropped chain. However! If you are riding mainly road or smooth trails you might well get away without the clutch mech. (Worth remembering though, the 3T Strada 1x road bikes use a sram clutch mech)
Question of Teeth
Before embarking on a mission to join the 1X cool kids gang with a 1X conversion, check that you will be able to ride your usual routes with the gears you are selecting. If you are using your original cassette, this might cause an issue. Also ensure your new 1X clutch derailleur will cope with the biggest sprocket you will need. For example, if you are going from 34/50 chainrings and an 11-28 cassette, a new 1X40 tooth chainring would require a 11-34 cassette to have a similar lowest gear. A 40 tooth chainring with a 28 sprocket whould be a similar gear size to your current 34 chainring on the 25 sprocket. If you are using your existing derailleur, a Wolf Link will extend its capacity for bigger rear sprockets.
Check out a great online gear table calculator here.
So depending on how hilly your local terrain is, you might need a new wider ratio cassette.
‘Gappy Gears’ though?
For me, without wanting to sound like a fence sitter, it depends. It depends a lot on whether you can cope with the bigger gaps between cassette sprockets on a 1X drive train. I don’t mind the gear gaps but really like the cleaner look and silent, smooth running transmission. If you live somewhere relatively flat, you could run a close ratio cassette and not have big gaps between gears.
Top 1X Kit
Raceface Narrow Wide Chainring £42.95
Sram Force CX1 Chainring £59.95
Hope Retainer Chainring £36.00
Wolf Tooth Single Chainring Bolts £22.00
Wolf Tooth Goat Link £22.00
Shimano GRX 810 Rear Derailleur £74.95
Shimano Ultegra RX800 Rear Derailleur £85.00
Shimano GRX 600 Chainset £89.99
Shimano SLX M7100 Chainset £99.95
Shimano R7000 11-34 Cassette £54.95
Merlin Malt G2X GRX – £1149
3T Exploro Gravel Bike from £3300
3T Strada Pro Aero Road Bike £2425