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Bike Reach (Modern geometry)
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xcracer1Free Member
Having sat on a large bike recently, has got me thinking I may be on the wrong sized bike. At 5’ 10” I have always gone for a medium as I have shorter legs, so the seat tube length and ability to run a 150mm dropper post mostly determined my bike size.
But as newer bikes have a smaller seat tube length – this opens up being able to size up to a longer reach bike.
My current bike has a reach of 455mm but I think something around the 470/480mm would suit me better.
What is your height / bike reach and anyone sized up with the more modern geometry bikes?
tomhowardFull Member6ft, averagely proportioned. 475mm and 480mm on modern full suss, trying a 450mm hardtail shortly. (all ‘Large’ size)
Also ride a 2014 full suss with 435mm reach, still like how it rides…
majorspanielFull Member6’6″ here, 510mm reach hardtail and contemplating a 521mm reach FS.
sillyoldmanFull Member5’9”
475mm on FS bike
465mm on HT
470mm on rigid hardtail.Reach shortens with sag on FS, lengthens with sag on HT, so for rigid SS custom frame, I opted for in between the two others.
CheesybeanZFull Member5’10” with longish arms,
My Starling Murmur is 465
My new Kenevo sl is 485 and feels way better.marsbarmanFree Member6’6” here as well. FS has a 530mm reach with a 50mm stem and the HT is about 513mm reach, again a 50mm stem.
It’s been the last couple of years that I’ve felt like bikes are finally starting to fit me.
sillyoldmanFull MemberSorry if obvious, but reach alone is pretty worthless regarding fit. Need stack and STA info also.
If stack is adjusted with spacers, this affects reach significantly – especially with slack HAs. Assuming 65 HA, a 10mm spacer beneath the stem will shorten the reach by about 5-6mm. Someone who actually remembers trigonometry will be able to correct me!mattvandersFree Member5.9” and ride a nicolai geomatron in longer (medium) with a 500mm reach. Have to run a 32mm stem and have the seat pushed forward but feels very comfortable once on it for the ups and downs
spooky_b329Full MemberHow are you all measuring… Plumb bob through centre of BB to stem bolt?
endomickFree MemberLong torso 5’10” definitely puts you in a large frame category, unless you’ve got T rex arms 470/80 sounds about right, shoulder width, arm span and length also plays its part.
tomhowardFull MemberHow are you all measuring… Plumb bob through centre of BB to stem bolt?
Centre of BB to centre of top of headtube
funkrodentFull MemberHow are you all measuring… Plumb bob through centre of BB to stem bolt?
Reach is measured by running a vertical line up through the bb and a second vertical line that intersects with the centre of the top of the head-tube. And measuring the horizontal distance between the two. Stem length doesn’t come into it.
Importance of reach is really about how much of the effective top tube length is in front of the bb. Particularly important when you’re out of the saddle.
However, with the advent of very steep seat tube angles, people sometimes forget that a bike with a long reach can have a surprisingly short effective top-tube. Which can be a bad thing, particularly when seated. The Stif Squatch doesn’t even quote effective top tube figures on the geometry charts on their website..
thols2Full MemberThe same topic comes up at least once a month.
1. Different people have different body proportions so two people of the same height might need quite differently sized bikes depending on the lengths of their legs, torso, arms, etc.
2. Manufacturers labels of “S”, “M”, “L”, etc. are pretty much worthless.
3. Reach is the horizontal distance from the BB axle to the center of the top of the headtube. This is the critical measurement when you are out of the saddle. If you run your bars a lot higher than this (with very high-rise bars or a riser stem, for example) the effective reach will be reduced. If you run the bars very low (flat bars and negative rise stem, for example) the effective reach will increase. You have to look at the overall geometry of the entire bike to be able to compare two bikes, a single number isn’t enough.
4. Ultimately, the only way to find a bike that fits you is to try different bikes and play around with stems and bars. There is a fair bit of personal preference involved too. I prefer slightly shorter bikes for agility in tighter trails. Other people seem to like really long bikes.
AGrayFree MemberWhatever frames you are considering I would try and get as many test rides on them as you can.
Reach is just one tiny part of what makes for a bike that I enjoy.I’m 6ft4 riding a 2016 Canyon Strive with 486mm reach.
I’ve spent a decent amount of time on a friends XL Yeti SB150 with 506mm reach and it is an amazing bike but a completely different ride – basically feels like a huge plough.Also spent some time on a Scott Ransom 920 XL with 505mm reach which felt far too stretched out once you sat into the bike and is the worst bike I’ve ever ridden. Absolutely hated it.
Another bike i’ve spent a lot of time on in an XL Turner RFX with 455mm reach. It does feel just slightly short but was my favourite bike out of the three until I coiled my Strive and improved the back end.
Hope you find out what you like/suits you best – everyone’s different!
jediFull MemberI’m 5ft 9 and ride a small pivot firebird with slack set 1 degree and saddle pushed forward
didnthurtFull MemberI’m 5’11” and am in the same boat. I used to ride an 18″ or medium in mountain bikes but now ride a large.
A medium now feels twitchy in comparison.Being 5’10” generally does put you in between sizes which is a bit of a blessing and a curse.
JordanFull Memberthols2
If you run your bars a lot higher than this (with very high-rise bars or a riser stem, for example) the effective reach will be reduced.High rise bars or a riser stem are ways to increase bar height while maitaining the same reach. Spacers under the stem will reduce reach.
andyrmFree Member5’9″ with 29″ inside leg, long torso/wingspan/wide shoulders.
Currently on an S3 Stumpy Evo thats been mulleted, so c480mm reach but SA is too slack so had to slam saddle forward.
New custom steel FS incoming has 490 reach, 80 degree HA but most other dimensions similar to Stumpy Evo as I get on really well with it.
At your height/shape that you suggest, I reckon 490-520 reach or thereabouts is about right, obviously with caveats on ST angle etc. Any particular bikes you like the look of?
thols2Full MemberHigh rise bars or a riser stem are ways to increase bar height while maitaining the same reach. Spacers under the stem will reduce reach.
Nope. Effective reach is to the level of the grips, that’s the point of the steerer that your hands pivot around. It doesn’t matter how you get the grips to that level, you can use spacers, a riser stem, or riser bars, they all have exactly the same effect – your hands are still pivoting around that point in the steerer. If you raise your grips, the effective reach is reduced. The reach figures published by manufacturers are to the top of the head tube. These are misleading if you raise or lower your bars by any significant amount, it doesn’t matter how you do it.
xcracer1Free MemberWhat long travel bike with a shortish seat tube is available – Stumpy Evo S4, SC Hightower Size L, …..? I’m 5’ 10” with a 30” inside leg, so the seat tube must be 430mm ish so I can run a 150mm dropper.
endomickFree MemberPeople who argue about spacers under the stem vs higher rise bars being the same really need to get the tape measure out and do a practical test.
andyrmFree Member@xcracer1 stealth ad but I’ll be selling my 2019 Stumpy Evo S3 frame (with a bunch of upgrades inc shock and Cascade link) very soon. 2019 S3 has 490mm reach and 450mm ST if that’s any use to you?
thols2Full MemberPeople who argue about spacers under the stem vs higher rise bars being the same really need to get the tape measure out and do a practical test.
Putting riser bars on (assuming the sweep is the same as flat bars) will increase the effective stem length. The grips will remain the same horizontal distance ahead of the BB but they will be further in front of the steering axis. This is the same effect as fitting spacers and a longer stem. You’ve reduced effective reach, increased effective stem length, and kept the bars the same distance in front of the BB.
Changing the effective stem length DOES NOT increase reach. Increasing the stem length does not affect reach because reach is measured to the center of the steerer, not to the bars. Moving the grips forwards or backwards by changing the stem or changing bar sweep doesn’t change effective reach if the grips are the height above the BB.
The effective reach takes account of the height of the grips because the grips provide your contact point with the bike, so this is the point at which your weight is transferred. If you move the grips upwards, the effective reach is reduced. Think of the effective reach as being what the physical measurement to the top headset bearing would be if the head tube were extended so that you ran a zero rise stem and flat bars. That’s basically the point at which your hands are rotating around the steering axis.
tomhowardFull MemberWhat long travel bike with a shortish seat tube is available – Stumpy Evo S4, SC Hightower Size L, …..?
Deviate Highlander, 430mm in large.
chiefgrooveguruFull Member“People who argue about spacers under the stem vs higher rise bars being the same really need to get the tape measure out and do a practical test.”
If you can’t feel how the steering feel changes with vertically rolled riser bars then arguing about tape measures is irrelevant. Ditto with changing distance to the grips with stems or bar sweep, they both change the steering feel.
eddFull MemberI am very similar body proportions to the OP and I’ve been riding a “long” Geometron, which I’ve found very comfortable, for the last few years. It has a 485mm reach and is for sale on eBay here:
https://www.ebay.co.uk/itm/185238845889oikeithFull Member6’1 on a bike with 511 reach, love it, came from a large with a 465, wouldn’t go back.
ta11pau1Full Member150/160mm FS is 510mm reach 660mm ETT.
150mm hardtail is 485mm reach 665mm ETT.Both 29ers.
6ft 3in and wouldn’t accept anything under 500mm reach on a FS now, hardtail can be shorter as I like them to be more playful/agile.
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