When going for a new bike do you size up, or down?

For years ive found myself between sizes on a lot of bikes. Generally ive sized up and adjusted fit slightly with stems and inline seatposts. Ive found this works well for me with mountain bikes.

Im about to buy a gravel/granduro thing and planned to do the same thing.

Anyone have an opinion?

Oh, and im not imagining it am I, bikes are getting longer right?

Ta

FWIW .. I've built up a road bike that I suspected might be a size too big (it comes in 1cm increments so hardly a huge jump, but still, 8mm on the TT so almost normal road sizing gap). Built it with the right stem length etc. 250 or so miles on it since building and I'm happier with the fit than my old Equilibrium that's done 1000s of miles with same stem, bar shape and saddle position. Just able to relax into the fit rather than feel slightly bunched up at the times I'm trying to work hardest. Subtle but effective difference. So, tempted to say beware of going for a drop bar bike that's on the small side.

Bikes are getting longer, stems getting shorter to match. Drop bars have less reach and drop now compared to the 80s-90s.
I'd be less inclined to put an inline post on a drop bar bike as it might put me out of balance overall, but if you don't feel too 'pitched/falling forward' from the forward saddle position then no reason not to.

I was badly bitten by my first "modern" MTB. A poorly informed salesman persuaded me onto a Small and I struggled getting that bike to work for me. Since then I've tended to size up when in doubt. That's worked pretty well for me. Having worked in bike rental(and so been forced to ride bikes of all sizes) I reckon a little stretch is better than feeling cramped.

As well as frames getting longer, bars have got wider (on MTBs at least). That has an impact too.

I've always sized down, prefer the nimbleness of riding a smaller bike!

5''7 and my Salsa El Mariachi and Salsa Mukluk are both 13.5 inch frames with lots of seat post out The El Mariachi feels spot on whilst I should have gone to the 15 inch frame for the the Mukluk. The El M feels like a massive BMX and is great fun on the single track yet feels fine for touring/longer rides.

My road bike is also smaller, so the seat to bar drop is lots (think more than 10cm), so takes a few rides after the winter to get used to the aggressive position.

Obviously the best bet is to find a dealer that has both sizes in stock, which is easier said than done

I'm between sizes also - I have medium frames on most of my bikes, but the one small frame I have is probably the most fun as it's nimble and fast feeling. I still tend to go up slightly size wise though.

Up, personally. I always think it's easier (i.e. makes less detrimental changes to handling) to make a big bike smaller than making a small bike bigger (long stems, massive bars, lay-back posts etc).

My last new bike / frame was a Fireline. I've still got a 26". I wouldn't know if new bikes are getting longer

Between sizes of small and medium so a 17" MTB is ideal for me

I generally do M for a FS and Small for a Hardtail [ though i currently have a small and a medium]

Road I ride anything from 52-56 depending on the actual bike

TBH when i put all my bikes together to measure reach and points of contact and all that - they all essentially end up with the bits in the same place so not really sure it matters beyond personal preference.

bike sizing tends to be a joke nowadays.

my ecr is a xl, seat tube is 22''. my cube mtb is a xl with a 23'' seat tube. both are proper xl sized bikes. spesh bike are good to at xl sizing.

I had the largest jones plus bike. seat tube measure just under 19'' as did a xl ramin I owned. how are these sized xl ?

I had the largest jones plus bike. seat tube measure just under 19'' as did a xl ramin I owned. how are these sized xl ?

In the Ramin's case,
Sized for 6' up to 6'4" max, the XL bike has a 505mm / 19.9" seat tube. (so that's XL within the height percentiles the bike range is for, it won't all fit riders at the <5% or >95% ends)

A 6'4" rider of average proportions is likely to have an inside leg of 35-36", let's say 37", = 940mm
940 x 0.883 (Lemond method for saddle height) = 830mm
830mm less the 505mm of the frame = 325mm

so that's about 300mm of post with a slim saddle on top, or 275mm post and an average saddle. A bit of adjustment room in that with a 400mm post and the insertion limits of most posts. It would leave the bars a bit low compared to the saddle but it's the extreme end of the saddle height the bike's intended for, maybe 30-40mm over the likely max.

Ideally there would be an XXL and an XS but the volumes of the brand won't support it - we'd be ordering 10 or 20 of some XXLs esp in the MTBs, vs 100-300 in M.


FWIW related to my first post since FLV mentions gravel bikes, my comfiest MTB is about the smallest I've owned since I stopped riding 4X style bikes for XC, it's a Jones old shape, 23" TT and slack seat angle / short reach geo. I'm a bit over 6".

First Bike = Swift size Medium
Current Bike = Pegasus size Large

Prefer the dimensions of the bigger frame so similar comment to those above

Size down f you plan to use a large seatpack with a rear light on the post. I say this cos find with my larger frame, with the seatpost not being stuck out as much, its a bit tight with the Ortlieb 17L seatpostbag when try8ng to mount a rear light at bottom of the post...

Alternately, being a large frame it gives me more room for a rather large framebag...

If not thinking in terms of bikebags and capacity then (for me) its small as I can get for mtb but larger the better for road (which i prefer the planted LWB type of feel).

Obviously you're thinking gravel so I'd probably go smaller, chuckable-er and (at a guess) the longer stem you might end up using might be easier and better with the barpacks...

Not sure if that helps but

Thanks every one.

looks like my choices are too low a stack and run lots of spacers, of a bit long and mitigate with short stem and in line post (with short reach bars)

Probable no wrong answer

Or buy a different frame/bike....

There is that Scotroutes,

But its the exact same with most I am looking at.

I want Bolt through axles (already own 1.5 sets of wheels) and geo within a boundary mn 45c tyres on 700 diameter

Pinnacle Arkose = same story, med is a bit low, large a bit long
Nordest Albarda = same story, med is a bit low, Mlarge a bit long
Brother mehteh = same story, med is a bit low, large a bit long
Cannondate topstone = same story, med is a bit low, large a bit long
Norco Search = same story, med is a bit low, large a bit long

etc etc

inbetween sizes... I'm used to it with mtb's and can make the call. road / gravduromonsterXsuperRoad... I'm not used to so dont know which side to lean

I'm currently looking at a Ribble CRG Ti. The suggested max height of the small is 5' 9", with the min-height of the medium being 5' 9". You can guess how tall I am right?

I'm hopefully going to pop into their shop next week to throw my leg over them and see how they feel.

Can you not go sit on one and get a feel for what you think you would prefer?

Pinnacle Arkose = same story, med is a bit low, large a bit long

How tall are you? I'd go L, a longer bike with a bar at a reasonable height is pref to a short and low one. And Evans will swap it within 30 days if you're not happy with it. https://www.evanscycles.com/help/right-bike-guarantee

The L may look long on the TT compared to a road bike trad sizing but ime it's not a big bike. The TT length added is less than the stem length removed, compared to an average ~58cm / L road bike.

Hi, I'm 5ft 11in (180cm)

MY 56cm road bike has an 80mm stem on it currently. You're right about being too low though, thats not nice

5'11" - L Arkose should be good. Really. Height range for the L is 5'10" to 6'1". ~400mm reach seemed long when the Arkose went that way a while back but is fairly common on gravel bikes now as stems settle in the 80-100mm range vs the 110-120mm I'd expect on a road bike. So, same may count for the other bikes in L that you listed?

https://static.evanscycles.com/producti ... ose_19.pdf

An average 56cm road bike with 80mm stem sounds short for a 5'11" rider, not saying it's wrong, just that if it's what you're used to many L bikes will feel long at first but may feel better overall after a few rides.

FLV wrote: ↑Wed Aug 21, 2019 6:10 am When going for a new bike do you size up, or down?

For years ive found myself between sizes on a lot of bikes. Generally ive sized up and adjusted fit slightly with stems and inline seatposts. Ive found this works well for me with mountain bikes.

Im about to buy a gravel/granduro thing and planned to do the same thing.

Anyone have an opinion?

Oh, and im not imagining it am I, bikes are getting longer right?

Ta

I've been selling bikes for 16 years and always use the size down as you can make a smaller bike bigger, but not a bigger bike smaller.

I'm always between l and xl and I never choose xl. Always large with the seat up.

Hope this helps :)

always use the size down as you can make a smaller bike bigger, but not a bigger bike smaller.

May have worked in the past but less so now? Your saddle position is the starting point of good fit and it wouldn't change between a M or L, then when you consider the range of stems available and how they can effect bike handling for good and bad, the best answer is as likely to be size up as it is size down, surely? You can vary stem / bar position a fair bit once you're sat in the right spot, yet bikes were generally within only 10-15mm reach between sizes until recently. Now MTBs may be 25-30mm between sizes and 30mm is a big change in MTB stem length. Also, now that road (gravel) bikes rarely have level TT / square geometry, stand-over isn't really a factor in fit so sizing up can work well - assuming front wheel weighting is still OK for the riding style etc.

I'm 5'10 and have found similar with most brands. The only road bike I've had was a Giant Defy who tend to do intermediate sizes. I was right in the middle of the range and it fit/felt good from the off. I've since moved onto a GT Grade size 56 and even with a dropper (inline post) and a 80mm 25° rise stem I still feel a little stretched on it.

I'm not really thrilled by Giants gravel offerings but I'm loathed to buy a new bike and have the same issue. I seem to think Trek may do intermediate sizes to?

jameso wrote: ↑Thu Aug 22, 2019 10:18 am

always use the size down as you can make a smaller bike bigger, but not a bigger bike smaller.

May have worked in the past but less so now?

I guess it depends how far you look into it, I still swear by the rule at 6ft 1. Larges in most brands will or can go to 6.1 and XL starts at 6.1. I'm 6ft one and ride large. If you want to keep it super simple, that rule will apply. If not, then it will become very complex...

RobLyon wrote: ↑Thu Aug 22, 2019 11:05 am

I'm not really thrilled by Giants gravel offerings....

As far as Giant go, one of the funnest bike's I've ridden in a long time

20190605_212441 by Escape Goat, on Flickr

There's a lot of choice out there, though you can bamboozle yourself with all the numbers. Best of luck to you :)

If you want to keep it super simple, that rule will apply. If not, then it will become very complex...

Maybe the only rule in all this is gravity : ) a balanced rider is a happy, comfortable rider.

Loads of great info here, thanks. I'll let you all know on this thread which way I go and how it is!

Onto the next problem - How much bloody money do they want to charge for roadie chainrings!!

FLV wrote: ↑Thu Aug 22, 2019 8:24 pm Loads of great info here, thanks. I'll let you all know on this thread which way I go and how it is!

Onto the next problem - How much bloody money do they want to charge for roadie chainrings!!

Please buy oval absolute black. You'll never look back.