Single Speed Conversion

Hi, this is my first post so apologies if it’s in the wrong place. I’ve recently become very into MTBing and am looking to convert my 2×8 To a single speed in the simplest and cheapest way possible. I’ve tried looking around online for guidance of what to buy, but I haven’t been able to find anything that I know for sure will work.

Could anybody suggest a conversion kit that will work for my bike and what tools I will need please? My bike is a Carrera Hellcat (Large) with specs in the link:

https://www.halfords.com/bikes/mountain-bikes/carrera-hellcat-mens-mountain-bike-2020—-black—s-m-l-xl-frames-346662.html

I’d be very grateful if someone could help, thanks.

I don’t think you’ll be able to remove the chain rings on those cranks to replace them with a traditional 4 bolt ring. Are the double chainrings seperate? If not, new cranks needed. Then new ring, ideally a chain and a SS kit for the rear.

Put it all on, realise singlespeed is crap, take it all off again.

If you haven’t already, experiment with which chainring/sprcket combo of the current setup works for you for your typical rides.

Going on https://www.sheldonbrown.com/gear-calc.html , I’d start with something like 36/24 (your 3rd biggest sprocket?) and go from there.

+1 for what Noddy says – try a “faux SS” setup first to figure out what gearing is best for your riding and your area. Remember the gearing as a ratio – 32:24 which is 1.33 then you can work out what size cog and chainring to get. Don’t go below 18T cog as there won’t be enough wrap of the chain.

It’s unlikely you’ll find a chainring to fit but since it’s a square taper BB you can take that out, fit a cheap Deore HT2 BB and then a standard 24mm spindled crankset which will take a single chainring, a narrow-wide one will be ideal.

Put it all on, realise singlespeed is crap, take it all off again.

20 years without gears and counting, when am I supposed to realise it is crap?

Ditto.

And a 16t is fine in terms of chain wrap, 32*16 was standard for 26ers. But you’ll probably want a bigger cog for a 29er anyway.

Remove the gear shifters and cables.

Lock the mechs into the big ring at the front and one of the cogs at the rear by screwing the limit adjusters all the way in.

When you’re sure what gear ratio works for you then buy/beg/borrow some singlespeed cranks/chainring, and rear sprocket.

You can continue to use the rear mech as a tensioner, but a specific singlespeed tensioner will be lighter.

You don’t need a narrow wide chain ring for SS but they are probably the cheapest non ramped chainring on eBay!

Sorry for being stupid. I’ve got my terminology wrong. I meant I want to convert my drivetrain from 2×8 to 1×8. I think a 32T chainring would make the most out of this conversion at the front. However, what is the easiest and cheapest way to carry out this conversion? Do I need to buy a specific chainring for my bike or will any fit on? I really know very little about bike mechanics…

Any narrow wide should fit but the bigger issue is your crankset. If it’s this one then you will need a new set plus a bottom bracket if you want to keep the chain line correct (unless you find one with the same offset).

This is where it gets expensive I’m afraid. Your best bet is finding a second hand crankset but you could still be looking at the best part of 50 quid all in (say 20 quid for cranks, another 20 for a bottom bracket and a tenner for a snail chainring)

20 years without gears and counting, when am I supposed to realise it is crap?

You should have realised after your first ride/after the first hill so if you’ve not realised by now I assume theres something wrong.

HTH (serial SS bike builder/seller)

I did actually find freewheel single speed a bit crap as soon as I moved to fixed gear in 2003 but all single speed nonetheless.

Anyway, seems we are now actually talking about a 1 x 8 which is 7 gears too many for me so I am out.