[Closed] How much attention do you give the numbers - TT, Reach, Stack etc?

reach matters most imho

Obviously there's no substitute for riding the things......

I had a medium Specialized Pitch (the old FS, not the new cheap HT) which apparently had a 450mm reach, (and a 66 HA) the same as a lot of modern, large bikes. It was too short even with a lot of layback and a 70mm stem.

Similarly I've tried bikes with apparently the same reach, and they've handled just fine.

The numbers definitely only tell you half a story.

bugger all. couldn't tell you what any of those numbers are on my bike.

6'2" here and spent a lot of time on bikes that looked right but were too small.

Being tall you can adapt to ride almost anything but at 6' plus I think you have to ride a big bike, however ungainly it might look. Once on board it suddenly clicks

Reach is one thing but depending on your shape, leg room can be more important. Leaning forward and having your knees up around your chest is no good at all

As a giant with a very long back I have a passing interest in reach being relatively long and would want to make sure head angle isn't too slack. It doesn't matter too much though, just ride the damn bike. Someone will be along about analysing shock leverage curves or whatever they are and brake jack shortly.

Reach and effective top tube are the two I look at the most.

However it is a bit of a mission, especially with the current bendy seat-tube trend; two bikes may have the same reach, but one may have a slacker seat angle which then affects the effective top tube, which [i]then[/i] can affect chainstay length and the wheelbase. Also, hardtails will change when the rider sits on it, so it's always worth checking whether the numbers are static of sagged.

Head tube angles will slightly affect reach and considerably affect wheelbase. I'd also bear in mind the head tube length - as said above, no-one likes being bent double over the handlebar and some forks only warranty steerers up to a certain number of spacers (not to mention adding in spacers reduces reach).

Too much!

I've not got much time for test riding, or many riding buddies so all of my bike purchases are made with the help of size guides and previous experience, the latter is less useful these days as bike lengths have grown.

I was on the cusp of sizes according to CRC on my current bike, who agreed with Cotic and some others on what size I should get so went for the medium option. Orange and Bird would have put me on something the length of a large or XL. Current reach is just under 420mm would be keen to try something a bit longer.

I'm beginning to wonder if 'stack' get's over-looked...

ie. can a bike with a big stack-number feel 'bigger'? dare i say it, 'longer' than the the reach number would suggest...

which leads onto: does a 29er (with a high front end) need a shorter reach, to feel the same as a 27er with a longer reach...

or have i spent to much time in the sun?

have a look when I'm thinking of buying a new bike. which I am at the moment.

question: with stack, if the bb drop is 1cm more and the stack is 1 cm less (than current bike) then my saddle to bar drop when saddle is at right height (assuming same no of spacers) should be the same?

edit: Ahwhiles - sureley other way round, higher stack, higher bars, shorter feeling reach as closer to you shoulders?? its a minefield 😆

I'm not currently buying, but I definitely got a feel for roughly what I liked for some of the numbers.

When looking now, I just compare with the bike I own, as I love it.

jam bo - Member

bugger all. couldn't tell you what any of those numbers are on my bike.

Same as that...

I bought the Parkwood because it's a nice, cheap, good handling bike in reviews
The Whyte i bought because everyone said they were great.

I love both bikes despite one being too big, one too small and both completely different.

bugger all. couldn't tell you what any of those numbers are on my bike.

Me too, I am quite happy to ride road bikes with flat bars and went through a long succession of frames before I settled on my hardtail. Maybe if I had bothered with the numbers I could have cut that testing period down but there is more to frames than numbers alone.

Almost none, but then I'm a regulation 5' 10", as I think this thread shows, it's the tall and short who seem to care the most. I can see why, you got the impression in the past that bike companies design the medium frame, and then photocopy the design by 80% for the small and 120% for the large - I didn't see an XL frame until a few years ago. Personally it takes about an hour of riding to know if it’s right or not, but I can tell in a few mins if it’s going to be ballpark enough that I can fix anything with a different stem etc.

I know some people have, in recently years anyway really took notice of this sort of thing, reach, head angle, BB height and that is mostly a good thing, understanding design makes for better consumers, but personally I don't think it tell the whole story. You read on here about people shopping for bike on paper - "ah if only it was half a degree slacker it would be what I'm after or" "It needs to be 20mm longer for me" etc and then doing odd things like going for an XL even though they're under 6 foot because it's measurements mostly tick the boxes for them. I think that’s a mistake. We’re not all pros who have reached such a panicle of performance that we need the most extreme geometry possible to get the best out of it, IMHO some riders are being held back by bikes that whilst look good on paper, need a level of commitment beyond the riders ability or indeed desire to use – you wouldn’t expect to jump into an F1 car and expect to be able to drive it, so why do with think we can master Richie Rude’s race bike? Most of us mere mortals ride as fast as we’re confident, a shorter, less-slack bike with a slightly longer than directly over the star-nut stem might just let go a bit faster, even if it’s theoretical performance isn’t as great.

Very few of us here actually race, yeah I know STRAAAAAVA and all that, and I’m sure most of us what to keep up with our mates but does it matter? IMHO, whilst it’s hard to really test bikes these days, I learn a lot more about a bike from sitting on it and going for a pedal around the shop than I ever would looking at a diagram of angles and lengths. I’d rather ask “is this fun” rather than “if I spend the next year agonising over times, could I go half a second quicker on this” and fun cannot be calculated with a ruler.

Obviously there's no substitute for riding the things......

It's a good guide as to which you'd actually try IMHO.

That said I think you can overplay this... because
a) Bike geometry has changed so much... so if you chose your last bike based on the figures of the previous you might be carrying forwards old geometry

b) A lot of people are probably riding "the wrong bike".... I've ridden a few bikes I thought were a good fit... (and were by the numbers) but about Oct-Dec last year I ended up hiring quite a few bikes.

Since I was hiring I decided on a bit of variety so I did hardtails to downhill and (to use one of those annoying ads) "what I found shocked me"

Obviously a downhill tuned bike has completely different geometry to a hardtail... but I found some manufacturers where bikes suddenly clicked irrespective of if it was a £1000 hardtail or £3000 mid-travel trail or downhill.

I think this of course goes back to

Obviously there's no substitute for riding the things......

or have i spent to much time in the sun?

No, it's an important number, especially at the shorter and taller ends of the spectrum.

Obviously there's no substitute for riding the things......

And there's this, which is one reason I ride a Bird and a good friend rides a Cotic.

I bought the Parkwood because it's a nice, cheap, good handling bike in reviews

I love my parkwood, the "numbers" would make most stw members faint and it's probably way too short for me but it's great fun. I need to sell it though 🙁

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Stack is very important, 2016 enduro vs 2017 is a very good example. This year the stack is lower and so the reach is longer, but when you bring them up to the same stack height, this years is actually slightly shorter!

I like a good high stack so I guess, in theory, usually, I should always go for a bike with longer reach as my high stack will bring that down....