GT Avalanche 1.0 frame size confusion
I you look at GT Avalanche 1.0 specs at
you'll get 734 mm standover height for a Medium sized bike. I don't know why GT confuse people by stating this number in their specs. I measured the Avalanche 1.0 frame and found that what GT mean by 'standover' is height from the ground to the top of top tube at the seat tube connection point!
If you measure the 'real' standover of the M size you'll get around 790 mm! By 'real' I mean standover from the ground to the top of top tube at the mid-point of the top tube between the head tube and the seat tube.
We have another bike - Fuji Nevada 1.0 17" and in it's specs the standover is 731 mm. If you place two bikes together frame to frame you'll be suprised - the Avalanche 1.0 Medium which is supposed to be very close in size to Fuji 17" looks more like Large of even Extra Large!
In fact Fuji Nevada 1.0 20.5" standover height is 788 mm and that's the size Avalanche Medium is.
My question is why do GT use this unconventional measurements system that confuses people?
I'd like a little further eleborate on the GT Avalanche 1.0 frame geometry for those who will be interested in this bike in the future although GT of course may change the design. At least for now I determined that 'M' - size will safely fit men from 6'1" up. I'm 5'8" with normal legs lenght (32.7" inseam) and find that only about 2" is left to the top tube when I'm normally standing over the frame in my cycling shoes (what I mean by 2" is the space left before I can sit down on the frame). It mean that when I stand over the frame my b@lls are actually touching the frame. That could be alright for a road bike but is totally unacceptable for the ATB. On the other hand the GT Avalanche has a shorter top tube and if I go one size smaller - to 'S' the frame will be too short for me.
All in all weird design.
I had an Av and I went for a M - I'm about 5' 7". Even then I found the way it was set up made it feel a little short - tall stem and riser bar put the front end too high for climbing and just felt too "cruisy". So I put on a 0 degree stem and flat bar and that was find for XC riding with a preference for climbing.
The small would have been too short I feel.
I didn't have a lot of standover but it was really never an issue - how often does one really stand over the top tube rather than either bailing off the back or using some other option?
The craziest thing GT did was with the first lot of I Drive 5's - even the small frame was a ball buster for me - and that's on a longer travel trail bike where people generally want more room to move over the top tube.
The '09 Zaskar alloy bikes seem to have a few more options out there, they seem to run a bit longer in the seat tube and are longer in the top tube. It seems GT has shied away from speccing a more upmarket Av for 2009 and offered more options in the Zaskar range.
I would guess it has to do with the triple triangle frame design. To maintain the triangulation at the top, they couldn't run the tube any lower.
I have to disagree that the M is only suitable for men 6'1" and taller.
Maybe your balls are just too big? If that were the case though, I suspect you would be out jumping something extreme... not on here whining about your interpretation of standover height.
Nope, everything is pretty average size...
Originally Posted by koldsimer1
Of course everyone has their own interpretation of safety requirements for a frame size but when you accidentally come off the pedals on a moderately rough terrain (isn't an ATB made for this?) it would be nice to have at least some 3 inches of standover clearance.
Yes, I agree that's most likely a result of triple triangle design but anyway be warned when considering the GT's Avalanche frame size, it's not conventional.