Bike sizing, ape index, reach, stand over height, etc.

[sdcoffeeroaster]

OK, I admit I am no long 5'8" at age 72. I am officially 5' 7". Stretch is only 5' 4" or a negative ape index of -3". Inseam is only 30". Stand over on my medium jam2 is "painful", lol. Medium mullet with 2.6" tires and 150mm forks gives me 1205+mm wheelbase, std long 457mm stays and a seat position that I run all the way forward with 50mm stem spaced all the way up. In short I think a small size bike with shorter stays might be a better choice for me. I am not a fast crazy downhiller and prefer tight switchback or twisty single tracks for fun. My first bike was a medium Anthem 2 four years ago and while it felt slightly large for me the short wheelbase and short stays made it very playful. I can't say the same for my 2018 Jam2. It is a tremendous hill climber and now a fair down hiller with the mullet setup and the Lyrik Ultimate and DVO Topaz 3 combo. But manuals, hops, bunny hops are only a dream for someone my size (and ability). I really want to learn trials moves and trying on the Focus has been a bit tough and tiring too. It's why I'm looking at a 2nd bike, a cf Levo SL and now maybe a small too. The Focus will always have it's place and I intend to keep it.

 

[Gary]

Ape index is a nonsensical measurement for cycling as it doesn't take into account chest/shoulder width OR inseam/torso ratio.

You're short and being older may have less mobility /flexibility so modem medium sized bikes (which are now far longer than old skool larges) may well feel too stretched for you.
There's nothing wrong with riding a small.
I'm 5'11" and early 50s with good flexibility and ride a small 27.5 bike as its waaay more nimble.

Small FS bikes these days rarely have noticeably more standover height than mediums.

But other than that sizing down can have major benefits

 

[Gary]

The 2018 Anthem was a far far shorter bike in every way to most modern small sized Emtbs.
But being an XC bike they had longer stems fitted as standard and narrower bars and didn't have a steep seattube angle like modern bikes now have. So when riding seated your bodys tilt towards the bars would have actually been more despite it being a much shorter bike.

The Anthem is also a very light weight bike. You simply can't replicate the nimbility of a lightweight mtb with a heavy Emtb. But choosing an embt with shorter reach, wheelbase and chainstay does go someway to increaseing its nimbility over the larger options.
And that's exactly why I ride an emtb 2 sizes smaller than sizing charts would recommend.

 

[Gary]

Learn hops, and mannies on a normal bike. Preferably a small hardtail.
Once you have the technique it's all transferable to larger heavier bikes. You just need to preload much much harder and alter your timing slightly.

I can hop and manual an XXL Emtb but it's horrible and way more tiring.

 

[sdcoffeeroaster]

Ape index is a nonsensical measurement for cycling as it doesn't take into account chest/shoulder width OR inseam/torso ratio.

You're short and being older may have less mobility /flexibility so modem medium sized bikes (which are now far longer than old skool larges) may well feel too stretched for you.
There's nothing wrong with riding a small.
I'm 5'11" and early 50s with good flexibility and ride a small 27.5 bike as its waaay more nimble.

Small FS bikes these days rarely have noticeably more standover height than mediums.

But other than that sizing down can have major benefits

Thanks. I've recently cut my bars down to about 750 because I have narrow shoulders and 780 was way too wide. I move pretty good but a broken collar bone 3 years ago hurt my mobility a bit. No arthritis or made knee/elbows. The focus standover is sort of variable due to the high stack height and the angle. I am always being impaled by the seat and almost on my toes. I even tried a 200mm dropper but that didn't help much. The feeling on Focus is one of riding on top of the rather than in it or part of it. The sl did not feel that way in spite of being a large and way too long. But I do love the Focus for climbing. I'm a coffee roaster and like coffee, it comes down to one thing...taste for coffee and how you feel on the bike for biking. Got to try or even rent a small for a day soon.

 

[Mikerb]

I do not know the Jam2 but from your description it does sound like a different bike would suit you better. A lot of the newer bike designs have shorter stack/standover but they also tend to include a longer reach especially if you continue to look at medium sized bikes, so that may push you towards a size small.
I would say that you are more likely to find the type of bike you want if you stick to pure trail bikes. If you want a more playful bike it is not just the chainstay length that makes things easier or harder. A shorter wheelbase, steeper ( e.g 66.5) head tube angle, lighter component build, and more active suspension tune will also make a big difference.

 

[sdcoffeeroaster]

I do not know the Jam2 but from your description it does sound like a different bike would suit you better. A lot of the newer bike designs have shorter stack/standover but they also tend to include a longer reach especially if you continue to look at medium sized bikes, so that may push you towards a size small.
I would say that you are more likely to find the type of bike you want if you stick to pure trail bikes. If you want a more playful bike it is not just the chainstay length that makes things easier or harder. A shorter wheelbase, steeper ( e.g 66.5) head tube angle, lighter component build, and more active suspension tune will also make a big difference.

Yes the sl is 66 deg head tube and the Focus is now closer to 64.5-65 but running 51mm offset which is what the sl has as well. The Focus FOLD suspension has a tendency to blow thru mid range and then not use the last 15-20mm of shock travel, especially with a lighter rider like me. The 2021 Lyrik ultimate made my bike more lively than the 34 rhythm along with being less harsh too. I do have a dvo topaz t3 but not yet tuned right. Reach on my medium is 630mm and the medium SL is 635mm (small is 615mm) but the SL is about 25mm shorter wheelbase in medium. I run my seat all the way forward to feel comfortable which says 615mm might be just right.

I do think it's a matter of riding both but really need to take them on a several hr ride hitting a variety of sections to know if the small is what I want or if the medium will do. Might have to find a small sl rental, lol. The medium sl is about 25 mm shorter than my Focus medium too. I do know that the large sl felt better to me even though it was a large and only 3 lbs lighter than my Focus. Hard to describe but I felt like I was riding with or in the bike rather than on top of it. I rode a medium IBIS at lunch today it felt much like the SL did to me and direction I'm trying to go. But it was set up with very light components too.

 

[Gary]

Don't worry about the head angle too much.
A few degrees makes very little difference to a bikes playfulness. Not in comparison to reach and chainstay length.
That's from someone who rides everything from 69deg 100mm hartdails to 63deg DH bikes. And everything in between.
All my bikes are playful. Even the DH bikes.