…the gearing had 22-34-42 up front and an 11-36 cassette out rear.
Why?
My usual 26″ ‘race’ HT has a std 22-32-44 triple with an 11-32 cassette. What’s so different about a 29er that the set-up above is deemed necessary and specced differently to a ‘normal’ 26″ bike?

Edit: forgot to say that I’m usually a big ring masher and do loads of road miles, so I’m used to the bigger wheel size and road gearing. If I go ahead with a purchase then my instinct is to swap drivetrains with my current 26er, but can’t understand the reason(s) for the 29er being different.

Few of points to cover.

First, a standard triple now would be 24-32-42, this improves the situation where when you change a gear at the front. you don’t need to make a correction change at the back.

Secondly 29er wheels are bigger and therefore change the gearing, this can be corrected by running a bigger cassette (usually giving a granny gear 2 bigger than what you would have on a 26er) or running a chainset with 2 teeth less on the chain rings 22-30-40, which is what I do because I don’t like big jumps between gears.

Thirdly wide ratio cassettes are in fashion.

ps, the kitten is now dead, I hope you are happy.

The circumference of a 29er wheel is about 10% larger than that of a 26″ one so to do the same amount of work per revolution of the pedals you need a gear ratio which is about 10% lower. A 22 rather than 24 tooth granny ring would give you that.

What’s so different about a 29er that the set-up above is deemed necessary and specced differently to a ‘normal’ 26″ bike?

Bigger wheels make the gears effectively higher, so they spec lower gears to compensate.

Cheers MSP. It’ll have to be a suck-it-and-see job then if I go down that route. It’ll be doubling as a CX bike too, but mainly round school playing field type courses where I’ll be expecting to be on the big ring quite a bit.

Edit: missed the next two replies as I was typing. Thanks.

But, if say the events that you do are around 50/50 on road/off road and you want to maximise speed/time on the flat/easy bridleways/tarmac, then once you’re rolling the lower gearing would/could be considered a negative? Remember, I’m by nature a big ring masher and prefer a lower cadence. I know it sounds a bit specific, but the 44t already feels very low sometimes when I switch from road riding to the mtb.
Climbing is climbing, so I just find a suitable gear for the occasion and grit my teeth. It’s kind of irrelevant as long as I can keep going hard.

Just built an xc ht 29er using old 9’spd drive chain 22/44 with 34 rear cassette tbh didn’t have any issues with it at the FOD Enduro last weekend, I’m not fast or anything either so not willy waving 😉

I’m not claiming to be particularly fast (I’m sure there’s a few on here that will confirm that), but when I do ‘race’ I give it everything I’ve got and compared to most I spend a considerable amount of time in the big ring. I’m not trying to wave my willy about that fact, it’s just how I ride. The more spinning I do then the more susceptible to cramp I am, so I’ve developed a style that seems to suit me.

The bike you test rode actually had a bigger big gear than the bike you currently ride so what’s the problem ?

I just wanted to understand why the difference, that’s all.
But how is a 42-11 bigger than a 44-11? Because of the wheel size?

Cos the wheels are bigger!

A 29er wheel has a circumference of 91 inches. 42:11 means that you travel 347.5 inches for each rotation of the chainring.

A 26″ wheel has a circumference of 81.7 inches. 44:11 means you travel 326.8 inches for each rotation of the chainring.

So the 29er is about 6% higher geared

Big ring multiplied by wheelsize divided by rear sprocket gives you gear inches , what you currently ride is 44 x 26/11 = 104 the 29er gears are 42 x 29/11 which is more . I don’t have a calculator handy and can’t be bothered to work that one out on a piece of paper .

Thanks. Perhaps I’m getting a bit too hung up about cadence and worrying about my potential to cramp.

I think the point is, you can worry about the cadence and cramp. Thats not a problem.

Mainly because if you want higher gearing, then the 29er with 2 less teeth is better for.your perceived needs.

Cramping when you spin out over mashing doesnt make sense to me though. As youre not hitting your lactate threshold. Any sports physics people about to confirm?