Frame Size Question

[iliketomtbike]

Recently I was out in Moab, Utah (an absolute must for any mountain biker.. porcupine rim trail is far superior to biking on mars aka slickrock trail) Anyway, while I was out there I had the opportunity to rent a Turner 5 spot... something like a $4000 bike. Anyway, the frame was an XL ,first time I had ever riden an XL. I am 6.2 and have been sticking to the L frames pretty much my whole life but for some reason I felt much more comfortable on the XL frame . I felt as though I had a better (lower) center of gravity which made me more agile on the trails, but perhaps it was the fact that the bike had 5 inches of rear travel and kept me lower to the ground. Anyway, I was wondering, does anyone know actually facts that perhaps an XL frame would keep one lower to the ground. I understand, either way your butt is at pretty much the same height but the distance from the seat to the handlebars seemed longer which would lead me to think I was stretched out a little more leaving me lower to the ground and not so upright. Hopefully someone can help me out. Happy Memorial Day, enjoy freedom and mountain biking, and save up to go to moab, just dont go now. H O T Oh yeah... and finally, since a turner 5 spot is out of question (cost wise) for me to get does anyone have any sweet suggestions for a good all mountain bike (moving to utah in january) no more than 30 lbs but still maintain good rear travel as well as be sub 1500 dollars. Thanks! rock on!

[soupboy]

Michael,

Glad to see you had fun on Porc, great trail. The Turner 5 Spot is an excellent bike but it's sizing and center of gravity are not unusual. Couple things:

1. XL vs. L vs. 19" vs. 21" means very little other than indicative sizing. A bike's the Effective Top Tube (ETT) length drives fit (absent extreme proportions), this is especially true in the world of full-suspension mountain bikes.

2. Center of gravity is purely a function of bottom bracket height assuming you're comparing the sensation across different bikes keeping other key factors stactic such as saddle to BB distance, crank length and cockpit dimensions. To that end, the 5 Spots BB height of 13.25" is pretty "standard" for a 5" travel bike.

The stretched out position you describe is a bit contrary to the intended design of most modern "trail" bikes - e.g. Turner 5 Spot. These bikes are generally intended to place a rider in a more upright, centered (fore-aft) position than the flat-back racerboys with 4" saddle to bar drops.

At the price point you're considering I'd suggest checking out the Jamis Dakar XLT, Speshy Enduro and whatever the Kona equivalent is in terms of similar purpose.

Since you're moving to UT, you might also want to wait and check out some higher end used bikes when you get there since LBSs out there tend to carry a wider variety of brands and models than you'll see here in the Midwest. Demo several to find the one that works for you. Enjoy UT!

[Danimal]

I have had XL bikes all my life (I'm 6'4") and until this year I moved down to a large. The only difference I've noticed is for long treks it becomes an issue (bent over too much) but since I'm outta shape long treks are seldom done anyway. This is caused by my bottom bracket (as mentioned below). My prophet's pedals sit considerable higher to clear log piles and the likes, as compared to my lower Specialized ride, thus cramping my long body in a tighter space vertically.

My seat post is extended to the max. when on lengthy relatively flat rides. However when hitting the trails I drop the seat down and it is more throwable, I can toss the bike around more and I seem to have more control.

Depending on your usage go with what feels right. If you do long treks go with a larger ride. If you like tossing it around on jumps etc. always go smaller.

[soupboy]

This is caused by my bottom bracket (as mentioned below). My prophet's pedals sit considerable higher to clear log piles and the likes, as compared to my lower Specialized ride, thus cramping my long body in a tighter space vertically.

The only reason your body would be in a "...tighter space vertically..." is that you have a shorter saddle to BB distance on your Prophet than your Specialized and/or you have more saddle to bar drop on your Prophet than on your Specialized.

Tall people and high BB heights can make you feel out of sorts as your COG gets much higher above your axles. That's one of the beauties of 29ers as all else being equal the COG is lower relative to the axles than on a 26" bike.

Again, L vs. XL is largely meaningless. For FS bikes the ETT is going to dictate the vast majority of fit decisions as one company's XL could be another company's L. Standover is probably the next most important fit-driver. BB height is purely a rider preference.