Jam2 sizing

[DTBB]

Hi all, looking at a Jam2 6.9 9 2021. I am 178cm tall with 78cm inseam. Focus website advises size M but online bike shop reccomend going for L as I am between sizes. No shop near me with stock I can try. Am worried about standover height on L versus being cramped on M. Current ride is Canyon Neuron CF 8 2019 in M, this has longer stem and toptube than Focus in M. Any advice from similar height/proportioned Jam2 riders. Thanks

 

[GrahamPaul]

Hi all, looking at a Jam2 6.9 9 2021. I am 178cm tall with 78cm inseam. Focus website advises size M but online bike shop reccomend going for L as I am between sizes. No shop near me with stock I can try. Am worried about standover height on L versus being cramped on M. Current ride is Canyon Neuron CF 8 2019 in M, this has longer stem and toptube than Focus in M. Any advice from similar height/proportioned Jam2 riders. Thanks

I'm the same dimensions as you. I've got a size L Jam² 6.7 and it is just a tad long for me.

I ride my size L normal MTB once a week and I always notice the stretch going back onto the Jam². I'm considering changing the bars to something a few cm shorter and a little upswept. I haven't tried the M but think I might have been better with it.

Standover height isn't an issue.

 

[DTBB]

I'm the same dimensions as you. I've got a size L Jam² 6.7 and it is just a tad long for me.

I ride my size L normal MTB once a week and I always notice the stretch going back onto the Jam². I'm considering changing the bars to something a few cm shorter and a little upswept. I haven't tried the M but think I might have been better with it.

Standover height isn't an issue.

Thanks Graham, the reach on the L is longer than my current bike so the M may be better for me

 

[steve_sordy]

Geometry

A = distance from centre of BB to the top of the downtube.

		S​	M​	L​
A	Size	410​	440​	470​
B	Effective Top Tube	582​	602​	622​
C	Head Tube Angle (°)	66.5​	66.5​	66.5​
D	Effective Seat Tube Angle (°)	74.5​	74.5​	74.5​
E	Chainstay	470​	470​	470​
F	BB Drop	20​	20​	20​
G	Head Tube Length	120​	120​	140​
H	Fork Length	551​	551​	551​
I	Fork Offset	51​	51​	51​
J	Wheelbase	1195​	1215​	1230​
K	Stack	618​	618​	636​
L	Reach	410​	430​	445​

My 29er is a Large and the standover height (from floor to the lowest point of the top tube) is 730mm

 

[Steve38]

Standover Heights are pretty similar on most eMTB sizes due to Frame Geo limitations with Motors and Shocks

You have to be careful of the Seat Tube Length
440mm to 470mm is a big jump
But it does also depend on the Dropper Length and Crank Length

For me, this would determine what size bike best fits

 

[Sonicfly190]

Hello Steve38, I ride the jam 2 S, with the same measurements like you, bike is ridable but I feel cramped up, I have constant tennis elbow after a ride since my upper body weight is too much forward...I would advise for the medium since my jam 2 S is far to small for my height.


Cheers

Rob

 

[argee1977]

The sizes in the table above are off, think that might be 2020 or earlier, 2021 has the medium sitting with 445 reach, large is 470, stack is about 13mm different, so standover will be about half an inch higher on a large, not a huge number for an additional inch of reach, but it depends what you like, shorter reach for a more 'playful' bike, or 470 for a more stretched out feel, these numbers of course can be tweaked by adding 10 or 20mm to the stem, wider/narrower bars and so on.

 

[steve_sordy]

Those are big differences! The chart above is 2020. I will go back and edit my post to say so.

 

[BBear]

I have the same leg measurement as you but am 1cm shorter in height. I‘ve recently sold my 2019 Jam2 in medium but it was the absolute perfect size for me. I did try a large when I bought it and I reckon it would have been ok but did feel slightly too big both in reach and stand over height. Not sure if the 2021 frame geometry is the same?
without wanting to state the obvious you really need to actually try them for yourself as everyone has slightly different requirements even between people of similar size. Appreciate of course that you may not be able to do this but you want to be sure you can change sizes if not right for you, even if it’s a faff.

 

[Flog]

@DTBB
Where in the UK are you, if south west more than happy for a social distant spin on mine. I have the 6.8 large and inside leg is round about the same. I bought mine without trying so not sure what the medium is like, but the large feels comfortable to me?? Not much help I know.

 

[DTBB]

Hi, cheers for the offer. I took the plunge and ordered a medium, arrived on Monday, perfect fit

 

[Ntinos]

Hello Steve38, I ride the jam 2 S, with the same measurements like you, bike is ridable but I feel cramped up, I have constant tennis elbow after a ride since my upper body weight is too much forward...I would advise for the medium since my jam 2 S is far to small for my height.


Cheers

Rob

Can you please measure the actual standover of the small size ?