I’ve entered SSUK – Whooo
It’s in the Lake District – Whooo!

I’m abysmally unfit and it’s only two months away – bollocks

So to make Swinely a bit more like the Lake District on a normal bike, what gear inches for the fatty?

Was running 30/20 because a) I got a 30t chainset cheap and b) I felt anything bigger than 20 on the back was an admission of hopeless weedery but couldn’t face anythign smaller.

It worked surprisingly well last winter with 4″ tyres. I’m in the soft south so hills tend to be short and sharp rather than long and gruelling and there’s not much actual ‘flat’ but it’s generally been fine

I ran the whole of this winter between 32/19 & 32/20. I’m circa 85ish KG….some lighter folks around here go down to 32×18 or lower…I ran 32/18 for 2 weeks and ended up with rather inflamed knees so when back to wimpish ratios!

These ratios worked well on full fat (3.8 & 4.0rear x 4.8front) and plus fat (650bx3rear & 29x3front). Rolling diameters between fat 4.0 & 650bx3 are negligible IMO.

Our hills here in sunny Glasgow (mugdock) were all relatively short but punchy so all ‘just’ about doable depending on your willingness to burst a lung or two! I have to get out of the saddle for all such climbs.

For me SS was fine for anything up to a 2.5hr ride…anything longer than that and I was burst. Summer rides means I’m back on the Rolloff and going out for longer trips but missing the lightish rear end flickability.

With decent knobby tyres so I can take advantage of where fat bikes can go, I’m on 32/22.

But that’s a PITA when it comes to riding to the trails, so I’m biting the bullet and putting gears on my fatbikes. (But not Satan’s invention, it will be hub gears).

Sounds like 32-20 might be the way to go.

I’ve not tried it yet, but I bought an On One 16T SS conversion kit back at Xmas to go with 34T up front, did deliberate whether to go with 18T instead. Sounds like I chose unwisely!

32-16 would be normal on a 26″ wheel (giving a 52″ gear)
32-18 would be normal on a 29″ wheel (giving a 51.5″ gear)

On a fat bike that sounds a bit optimistic though! If you’ve a scrap cassette anywhere you probably have a part-worn 20t in the middle of it that will swap straight for the one in the kit and last long enough to experiment.

I’ve went for an oval 32/19. Got up some steep nadgery stuff I’d not managed to clean on a geared 29er.

The grip gives you the ability to exploit the top end of your power output on short sharp stuff. And the roll-ability probably allows you to push a higher gear/higher speed on longer, draggier climbs too – the bumpier ones, anyway.

34/16 does sound punchy!

I’ve got wonky 35/17 on my 21lb 26er, which is great round me (shortish, medium steep hills)

I rode 38/17 on the fattie at BOTB. Mostly too spinny or too hard!

My puffin had 30×17 with 4″ tyres. Felt it was a bit high so put an 18 on and feels much better. About 48 inches I think. Surrey hills riding so can be quite steep, but it gets up most stuff as long as the legs/lungs/heart hold out.

34/16 is about a 62″ gear; pretty tasty. Personally I aim for 52″ish, although I’ve not tried it on a fat bike.

The problem with gearing too high is if you ride the squelchy stuff.

You’re more likely to come to a grinding halt. Now where do you put your feet as the bike starts to tip over… 🙂 It really pays to be able to keep going.

For ordinary trails that you can ride on a 29er, use the same gearing as your 29er.

I figured that as I normally use 34/15 for flattish tarmac and my old Tricross Singlecross was 42/17 iirc, the 16 would be fine.

The stupid thing was I bought a stainless 34t chainring at the same time, when I could have picked a 33 or 32!

I will have to give a try sometime this summer, with the two tone kmc ss chain, the complete bundle was ~£14.