Convert triple crankset to 1x

Hi,

I have an SLX triple crankset (find me in jurassic park 🙂)  I’d like to convert to 1x having picked up an 11-46 10sp Cassette and derailleur in the CRC firesale.

Before splashing on a dedicated 1x crankset I’d like to try the gearing with current crankset so looking for a suitable 30t chainring that I could mount in the middle ring position.

The bike is a genesis vagabond, used for most of my riding around the Lothians/Borders and a bit of bikepacking during the summer months.  Just want to make sure 1x works for me before spending any more cash.

Can anyone point me in the direction of a chainring that would fit?

Tredz do a 96mm BCD 30T narrow wide chainring that I think will fit

you’ll most likely need shorter chain ring bolts. You don’t need a ‘dedicated’ 1x crankset BTW, this conversion will be all you’ll need to do. The chainline might be 1mm out of whack either way, but not so much that it’ll effect the shifting alignment so that you’d notice.

Have you checked the bcd of your current middle chainring? Get the number for that then just do a search with that number and 30t and that should give you your options.

As above. This should be dead easy.

I think something like this – below – would work in the middle ring position and be narrow/wide, which is what you want, though maybe not in purple… I run 10-speed 1x with a 30-tooth ring and 11-46 on two mountain bikes, mostly in the Peak and found it fine btw, though with the Shimano Deore cassette, there’s a big gap between the two lowest cogs, which can be irksome:

https://www.uberbikecomponents.com/view-product/Uberbike-Made-In-Sheffield-104mm-BCD-4-Arm-Narrow-Wide-Single-Chainring-30-32-34-36T-options-Purple

My bike is 1x with a narrow wide chainring on the middle cog position using deore 11-46 cassette and shifter. It works fine.

If wanting cheap and semi disposable chainring just to try then look at eBay or AliExpress for one in a suitably garish colour.

Mine now has a race face one on it from CRC sale.

Yes should work. There is also a handy gearing calculator online that lets you input both config to compare before and after.

https://www.gear-calculator.com/?GR=DERS&KB=22,36&RZ=11,13,15,17,19,21,24,28,32,36&UF=2215&TF=90&SL=2.6&UN=KMH&DV=teeth

You will be surprised how little you lose and how much you gain from a cycling enjoyment pov

Depends on which SLX crankset you have, but it will likely be a 104mm BCD for the middle ring position. (96mm BCD is the double I think??)  Measure and check anyway. Then superstar, uberbike etc will have one to fit. The 104mm 30t BCD one will have a built in spacer to give chain clearance so that reduces the chainline a bit, but it will work fine. With the built in spacer, then the existing chainring bolts will work as the chainrings are often threaded. Or if not you will use the existing bolts and nuts. If you are not using a chainring with a built in spacer then you will need shorter bolts.

As Yak said, an old SLX triple will likely be 104bcd for the outer and middle rings. 30t will be threaded and spaced most likely. I’ve been using just this combo (M660/5 chainset) as 1×10 for ages (and 1×11 on the gravel bike!). Only issue lately has been a new frame where the ‘old’ chainline meant the ring was too close to the chainstay, just because of the tubing shape on that frame. Should be fine on a Vagabond used with the same triple already!

FWIW it think the old SLX stuff is really nice, and is still good quality and decent weight. Newer lower end 1x chainsets aren’t Hollowtech II and fairly chunky.

Current SLX chainset is H2 and pretty good/light/stiff. Really happy with mine.

I have been using an old XT triple for the last 18 years. After three rings I reduced it to two and now one mounted in the central position. It has given no trouble whatsoever although it is now on a boost frame with the chain ring very close to chain stay.

Depends on which SLX crankset you have, but it will likely be a 104mm BCD for the middle ring position. (96mm BCD is the double I think??)  Measure and check anyway. Then superstar, uberbike etc will have one to fit. The 104mm 30t BCD one will have a built in spacer to give chain clearance so that reduces the chainline a bit, but it will work fine. With the built in spacer, then the existing chainring bolts will work as the chainrings are often threaded. Or if not you will use the existing bolts and nuts. If you are not using a chainring with a built in spacer then you will need shorter bolts.

Came here to say that, I did it with an On-One chainring which is similar offset.

I have been using an old XT triple for the last 18 years. After three rings I reduced it to two and now one mounted in the central position. It has given no trouble whatsoever although it is now on a boost frame with the chain ring very close to chain stay.

Boost is near as dammit the outer position on an old triple. It’s between that and the outer of some of the later dedicated double chainsets, but there’s only 2-3mm between all of them so you’re only =+/- 1mm from the perfect chainline (i.e. more accurate than a lot of frames will be made).

Magic.  Many thanks good people.

Ordered one from superstar.

Cheers.

I have had such a setup on a XT triple for about a decade… Some extra tips from my experience –

I put an aluminum bashguard in place of the big ring, narrow-wide in the middle place (and actually the granny ring mounts have been angle grinded away completely from this crank), and I installed a N-Gear JumpStop on the frame – it is a simple adjustable metal plate that will drop the chain back on the chainring if it jumps off towards the inside.

I have never dropped the chain during all these years, and I am running a clutchless rear derailleur (I still have a large stash of unused 9-speed XT derailleurs 🙂 )

https://www.n-gear.com/whatis.html

Or without a bashguard, something like these are great for 1x setups:

https://www.bike-discount.de/en/xlc-cr-a18-chain-guide

@mrauer

Do you need all the extra bits with a narrow wide chainring?

I thought you needed NW plus clutch. I’ve certainly dropped the chain when I’ve left the clutch off by mistake.

Narrow wide plus clutched mech, but if you’ve got one of those chain dropper thingummies you’ll be grand. As others, I had a narrow/wide chainring on the middle of my old triple for years. Bashguard on the outer and left the Grammy where it was for emergencies.

Bashguard on the outer and left the Grammy where it was for emergencies.

Not such a daft idea leaving the tiny tiny granny ring on there…. You might end up with oily fingers, but useful on long alpine climbs.

Bash+jumpstop are not strictly necessary with modern derailleurs that have a chain-tightening clutch.

I am running XT 9-speed that has no clutch, so the chain slaps more than with newer derailleurs, so the bash and jumpstop are there to make sure chain will not jump off when bike is bouncing around more. For peace of mind …

Still have 3 more unused 9sp XT shadow derailleurs to use before I can step up to the next gen of 10/11 speed ones with clutches 🙂 Front chainring is 30T and cassette is 11-36, that is just enough range for my local flat terrain.