What size

Wailin

What's the general advice if you're between sizes lads? Thinking of changing my bike and I'm 175cm with 79cm inside leg which, in most brands, is between M and L. I read somewhere that if you're between sizes, go up. My current bike is M and is perfect, vitus escarpe. Bike I'm looking at is YT Jeffsy, and they appear to be smaller. Website is saying L is my size, but only just.

maddness

Wailin wrote: »

What's the general advice if you're between sizes lads? Thinking of changing my bike and I'm 175cm with 79cm inside leg which, in most brands, is between M and L. I read somewhere that if you're between sizes, go up. My current bike is M and is perfect, vitus escarpe. Bike I'm looking at is YT Jeffsy, and they appear to be smaller. Website is saying L is my size, but only just.

Years ago when mountain bikes came along you would have always gone for a smaller bike but they were simple bikes compared to what we get now.
I would always prefer to be on a bike that’s a bit too small rather than a bit too big. Think about how you like to ride the bike, if you throw it about a lot a smaller bike would be a better option.

rizzodun

My advice is to size up.

I bought a Canyon a few years back on their recommended Medium size based on my height of 175cm and it was a huge mistake. Bike was clearly too small, impossible to get off the front of the bike and crashed more times when the trail pushed the bike to it's limits.

I've bought 3 bikes since and all in a large, no matter what the sizing charts said, and as well as my skills advancing the bike has felt a lot more comfortable and stable. I find the ability to chuck the bike around is more than just sizing, so don't find a bigger bike is necessarily harder to move around than a smaller one.

As you mentioned, 175cm is nearly always on upper end of one size and just off the next one.

I will usually look at Reach, Wheelbase and Chainstay when checking a bike fit, I prefer a long bike with a reach over 450mm. I'm no expert though, there's no substitute for sitting on a bike and riding it, preferably on a trail and not around a carpark.

My Fuel EX has 475mm reach

Some explanations here too:

https://www.mbr.co.uk/news/mountain-bike-geometry-326498

Wailin

Cheers lads. I would have tended to size down rather than up but good points rizzo, you're same height as me and happy with L. I guess going larger is better for stability and going medium for those who like to throw the bike about, which I'm not at that level yet! I like stable!

Tony04

Personally id only size up if it were an xc bike, any bike thats meant to be pointed down is going to require the rider to move around alot which would be easier to do on a bike thats a tad to small than a tad to big. Then again you dont want to be adding a long stem and flat bars to your enduro bike.
But geometry charts your best friend for this, compare reach and stack to your old bike to be sure.

Wailin

They are near enough identical regarding reach and stack. Escarpe 450/629 and jeffsy 450/622. Big difference with these bikes is the chainstay, 450 v 435, and seat tube angle, 74.5 v 77.5.

My problem with the escarpe is the perched feel when pointed downhill due to the BB too high. Also, the dropper post can't be seated into the seat post as low as it can go, otherwise it doesn't rise high enough for the climbs. So I have to have it up about 2 inches, so gets in the way when fully dropped. A well known issue with them pre 2021.


Edit: Yes, I'm only looking for excuses to upgrade

Tenzor07

Wailin wrote: »

What's the general advice if you're between sizes lads? Thinking of changing my bike and I'm 175cm with 79 cm inside leg which, in most brands, is between M and L. I read somewhere that if you're between sizes, go up. My current bike is M and is perfect, vitus escarpe. Bike I'm looking at is YT Jeffsy, and they appear to be smaller. Website is saying L is my size, but only just.

This is where bricks&mortar shops are good for people to throw a leg over a bike before they buy...

But... picking the larger frame might be good if you're hitting the Alpine bike parks, but for Ireland I'd recommend you go for the medium, I know enough people who are around the 180cm mark on mediums and they like them just fine...

Wailin

Tenzor07 wrote: »

This is where bricks&mortar shops are good for people to throw a leg over a bike before they buy...

To be honest, I find that is not always the case. I bought a road bike a few years back and tried it in the shop. Felt perfect. On long rides I was getting low back pain and a bike fit showed the bike was too big for me. Was something that I, or the sales assistant, couldn't tell in the shop.

rizzodun

Tenzor07 wrote: »

This is where bricks&mortar shops are good for people to throw a leg over a bike before they buy...

But... picking the larger frame might be good if you're hitting the Alpine bike parks, but for Ireland I'd recommend you go for the medium, I know enough people who are around the 180cm mark on mediums and they like them just fine...

Seems it's different everywhere, I know loads of lads who at 180cm wouldn't sit on a medium, our mantra has always been if near the upper end, or if in doubt, size up. Rather a slightly sluggish bike in the twisty stuff over a bike that's just too unsettled when riding fast.

Besides that, 435mm chainstays will allow the back end to be thrown around just fine. 450mm on the Escarpe would be considered long, that's 10mm longer than YT's XL.

Trek Fuel has 437mm / Slash has 434mm and last years redesigned Orbea Occam which got good reviews for it's descending ability for a trail bike has 440mm.

I'd also add in all the years riding I have far, far more examples of guys who wished they had sized a bigger bike when buying than those that wished they had sized smaller.

Plastik

OK so a bit of a spurious observation, I'm marginally taller again ~183cm and sitting on a medium frame for me feels like sitting on a child's bike. I went from a 2016 Large Kona with 460mm reach to a 2021 XL Giant Trance X with 510mm and I'm loving it. Fair bit of procrastination before I made the choice, but MTB geometry and philosophy is very diverse. Giant would say I (183cm) shouldn't be on anything bigger than a large frame with 486mm reach, but others (Bird, Pole etc.) would put me on one of their frames 500+. Always found the 460/Kona very cramped and couldn't see a 486/Giant making a substantial difference, so took a chance. Long story short, sized up, don't regret it.

prunudo

I know with road bikes its more common, but is bike fit a thing for mountain bikes. Any of my mates who ride on the roads swear by it before making a purchase.

Another factor to think about is the type of trails you ride. I'm 178cm and went size large for my latest bike and initially it felt fine but now due to covid I've had to ride woods closer to home which have tighter twister trails, long story short, I'm starting to second guess whether I should have gone with the medium and installed a longer stem if it felt wrong.
But ultimately in the long run, when I get back to my regular riding spots, I think the large will be the better choice.

Wailin

Got the following response from the guys st YT:

"Going by your measurements you would overlap with the frame sizes M & L.

Since our frames tend to run a bit compact, we usually recommend going for the slightly longer frame. The smaller size would be a bit more agile and playful, whereas the larger frame size offers more stability especially at higher speeds. For additional clarification you could also measure your inseam (in cm):
Ideally use a water level pinch between your thighs (a large book against a wall will work too at a 90° angle)
Make sure to get the level as close to the seat bones as possible
Measure the distance from the upper side of the level to the floor (barefoot)

The inseam range on the JEFFSY for the Medium (125mm Dropper) would be:
76 cm - 83 cm
For the Large (150mm Dropper):
80,5 cm - 87,5 cm

Generally speaking, it would be beneficial to be on the lower side of the spectrum, as that usually results in a more comfortable upright position and allows for the saddle to be dropped out of the way more easily."


So going with this info, it's more or less size up if between sizes. But, my inseam is 79cm, yes, I've stumpy legs! So that means I should go with medium, thats what I take from the above?

rizzodun

Wailin wrote: »

Got the following response from the guys st YT:

"Going by your measurements you would overlap with the frame sizes M & L.

Since our frames tend to run a bit compact, we usually recommend going for the slightly longer frame. The smaller size would be a bit more agile and playful, whereas the larger frame size offers more stability especially at higher speeds. For additional clarification you could also measure your inseam (in cm):
Ideally use a water level pinch between your thighs (a large book against a wall will work too at a 90° angle)
Make sure to get the level as close to the seat bones as possible
Measure the distance from the upper side of the level to the floor (barefoot)

The inseam range on the JEFFSY for the Medium (125mm Dropper) would be:
76 cm - 83 cm
For the Large (150mm Dropper):
80,5 cm - 87,5 cm

Generally speaking, it would be beneficial to be on the lower side of the spectrum, as that usually results in a more comfortable upright position and allows for the saddle to be dropped out of the way more easily."


So going with this info, it's more or less size up if between sizes. But, my inseam is 79cm, yes, I've stumpy legs! So that means I should go with medium, thats what I take from the above?

I get from that that being on the lower side of the size spectrum (range) means the saddle stays lower and out of the way, i.e. the seatpost is slammed and you get the full benefit of the dropper post.

Basically, better to be on the lower side of a large than the upper side of a medium.

I could be wrong but that is another benefit of sizing up, all my bikes have the full seatpost down into the tube out of the way and still perfect height for climbing.

Wailin

Yes that's the problem I have with the vitus. I can't get the saddle low enough because its only a 125mm dropper. I guess I should go large, at least that won't be a problem.

Plastik

I'd only be surmising, but in terms of mtb vs road 'fit', obviously mtb is much more dynamic. You're stopping, starting, maybe walking, chatting, standing, falling, checking out lines ... whatever. Even something as simple as using flat pedals your feet are never in the same position for more than a few minutes. On the road you're locked into one of two positions, seated or standing, for hours and your feet locked into the same interface with the pedal constantly, so proper fit to avoid issues is probably much more important. I know my road saddle height to the mm but I've no idea what the mtb saddle is set to, I did it by feel. But it's definitely lower than the road bike.

c montgomery

Wailin wrote: »

What's the general advice if you're between sizes lads? Thinking of changing my bike and I'm 175cm with 79cm inside leg which, in most brands, is between M and L. I read somewhere that if you're between sizes, go up. My current bike is M and is perfect, vitus escarpe. Bike I'm looking at is YT Jeffsy, and they appear to be smaller. Website is saying L is my size, but only just.

I have a Jeffssy CF Pro 27.5
I'm 173cm and bought a M
It's an amazing bike and I love it but my friend has a L Capra and it seems to fit me better.

Wailin

You reckon a large would have suited you better? I like the capra too but reckon it's just too much bike for here in this country, plus I'd prefer the jeffsy on the climbs!

fatbhoy

Wailin wrote: »

You reckon a large would have suited you better? I like the capra too but reckon it's just too much bike for here in this country, plus I'd prefer the jeffsy on the climbs!

I'm of the opinion that it's better to have a little extra than to want a little extra. Maybe you'd be grand with 150 f/r travel, but there's plenty of places in Ireland that you'd be glad of 170.

Vegeta

Lads, I am mad keen to get my firsy proper mountain bike (looking at current supply, so is half the world it seems). Riding will be mostly Coillte roads and tamer trails. Issue I am having right now is trying to figure out bike sizes. I am 183cm with inseam of 89cm (both in socks). I know there is a lack of standards when it comes to MTB sizing but is there any conventional wisdom on what reach to aim for etc.

My older brother has an XL frame cannondale hardtail and it has a 465mm reach (843mm standover ha ha). That seemed nice (but very aware it felt like a big bike) when I took a spin up and down the flat road. What has me scratching my head is lads roughly my height/size above discussing reach in the range of 500+

I'll probably get a trail hardtail and was going to aim for a frame size that gave a similar reach (and stack but more bail friendly standover) to my brother's bike. Any crazy flaws in that logic/approach for a newb with limited opportunities to get saddle time in shops or on people's bikes.

Plastik

Go somewhere like Ballyhoura, Ticknock or Ballinastoe and talk to the lads renting the bikes there. Usually rental is for 3h odd. They might accommodate you in taking a L/XL for 1.5h each to see which you prefer. XL 465mm reach is very short, what year/model is the frame?

Vegeta

Plastik wrote: »

XL 465mm reach is very short, what year/model is the frame?

It's a 2021Trail SE 3