Mountain Biking - Should "All Mountain" MTB's Be Sized one Size Smaller?

I'm considering an All Mountain style of MTB. Should the frame be sized smaller than what a person typically rides?

I ask for it seems these bikes have a lot more suspension travel, as such they seem to sit higher from the ground. I realize some of this will be compensated with suspension squat once on the bike.

I ride a 17.5" Hard Tail, However the bikes I'm interested in come in 16.5" or 18". I have tried a few 18" AM's and they seem a bit bigger than I would like. They Boys seem to be at risk with the 18" AM bikes.

Thoughts?

This should be an interesting thread...smaller than what?

I run a size 19"-20" on my XC hardtail and my AM bike.

I'd prob. run an 18-19 on a hucker or DH, but not AM. Unless that is you're just going to do nothing but technical riding. You still want it to be somewhat efficient which is difficult when you're cramped up in the cockpit.

Buy what fits and feels comfortable, don't worry if it's not the same size as your other bikes. My FS and HT have a 3" difference in the seat tube sizing...the FS is smaller yet when I have it set up for trail riding, it's harder to get onto than the HT because of the height (higher BB and sag in the shock).

Is this at the XC end of 'all mountain' or the DH end of 'all mountain'?

Generally, for more technical riding, a smaller frame is used, but sometimes manufacturers adjust for this in their sizing ahead of time.

I would be safe and get what you would normally be.

Look at the geometry of the frames/bikes you are looking and compare them to a current bike of yours. Maybe you will find in Size X, the effective toptube is an inch longer than on your current bike. Now in your mind you can simulate what it will be like.

Thanks for everyone's response.

I think a 16.5 would be too small.

this is all so very personal prefrence, but in that regard, here is mine.

for myXC bikes, i size it mostly with the same requirements as my road bike. an emphasis on pedaling efficiancy. a larger frame is better.

on my freeride/DJ/Urban bike i went allot smaller, i need to be able to get behind the seat easily, i need lots of clearance for bunnyhops, and need to be able to get off the thing easily when i crash.

an AM bike is a compromise, you'll adjust the seat regularly to get it up for climbing, and down for clearance on the descents. you'll need to split the diffrence and compromise. its an all around bike, which means you may not be able to get into that ideal XC pedaling position, but very close to it, you'll need to get behind the seat for descending, but never as well as a freeride bike.

is that sufficiantly confusing?

this is all so very personal prefrence, but in that regard, here is mine.

for myXC bikes, i size it mostly with the same requirements as my road bike. an emphasis on pedaling efficiancy. a larger frame is better.

on my freeride/DJ/Urban bike i went allot smaller, i need to be able to get behind the seat easily, i need lots of clearance for bunnyhops, and need to be able to get off the thing easily when i crash.

an AM bike is a compromise, you'll adjust the seat regularly to get it up for climbing, and down for clearance on the descents. you'll need to split the diffrence and compromise. its an all around bike, which means you may not be able to get into that ideal XC pedaling position, but very close to it, you'll need to get behind the seat for descending, but never as well as a freeride bike.

is that sufficiantly confusing?


No, thats as good an explanation as I read, and I subscribe to the same thoughts. :beer:

Man, just when I think I need to update my MTB bike I realize I need about 3 new MTB bikes. An XC Racer, a FS-AM, and a maybe a 29'er or other :D

Oooohh, do tell, what ya getting? The ETSX that's in your sig?

Of course everyone needs a bunch of MTB's. Personally I NEED:
1) a sub 20lb ht race bike
2) a ti hardtail with a Rolhoff and disc brakes for winter/mud
3) a XC fully for marathon races
4) a rigid singlespeed

That should do it!

personally id size your AM bike based on horizontal top tube length rather then seat tube length.

typical medium travel full sus AM bikes tend to have longer top tubes compared to their seat tubes, meaning if you use a long seat post you can avhieve a nice stretched tall position for pedaling, while still beig able to drop the seat right down when needed.

Oooohh, do tell, what ya getting? The ETSX that's in your sig?

Of course everyone needs a bunch of MTB's. Personally I NEED:
1) a sub 20lb ht race bike
2) a ti hardtail with a Rolhoff and disc brakes for winter/mud
3) a XC fully for marathon races
4) a rigid singlespeed

That should do it!


Ya forgot your Heckler with a Fox 36 and Session 10 bikes, ya weight weenie!:D

Oooohh, do tell, what ya getting? The ETSX that's in your sig?

Of course everyone needs a bunch of MTB's. Personally I NEED:
1) a sub 20lb ht race bike
2) a ti hardtail with a Rolhoff and disc brakes for winter/mud
3) a XC fully for marathon races
4) a rigid singlespeed

That should do it!

Don't want much Do you? Sub 20lb race bike is possible- providing you stay hardtail and My L/W bike was19Lbs, before it got too Flexible. Ti is nice but the rolhoff puts a very expensive bike over the top for what the rolhoff can deliver. XC for marathon- Presume you mean distance- and this I can agree on- takes a lot of sorting and Is worth it in the end. Only thing- My distance bike cost me a bit more than I wanted but at least I never get left on my own-A full offroad Tandem.

Now onto the MtB sizing- One critical measurement- Standover height should be 4". I get away with "2 but then I never get off the bike Till I fall off. Small guy and I have a Bianchi Grizzly as my main XC Solo. Only a 15 1/2" frame and This one fits. Went to the next size up and it was too big- on standover and reach.
Forget what it says on the packet and the small print- Try a frame out and see if it fits-

Oooohh, do tell, what ya getting? The ETSX that's in your sig?

Of course everyone needs a bunch of MTB's. Personally I NEED:
1) a sub 20lb ht race bike
2) a ti hardtail with a Rolhoff and disc brakes for winter/mud
3) a XC fully for marathon races
4) a rigid singlespeed

That should do it!


:beer: On Number 2 :) It must be living in Saskatchewan that makes us want to have a Ti bike for winter slop and slush. Your spec sounds like something I want too.


The Rocky Mountain is a barely used ETSX 70 2004 frame I picked up, it is a 18". I thought it may make a fun build. I'm not sure I really needed a FS-AM type bike for my intended use, but I may as well try it out. I think I really wanted a Rocky Element, but this will do for now.

I have decided against the 29'er for now as it just doesn't seem right for me. I can't get over that big road bike feel.

The seller told me it's a 2004, howver I think it's a 2003 as it looks just like this 2003 with the burnished Flame Job.

http://www.bikes.com/bikes/2003/zoom/images/etsx-70_detail.jpg

http://img223.imageshack.us/img223/6277/cc901fa4.jpg



personally id size your AM bike based on horizontal top tube length rather then seat tube length.

typical medium travel full sus AM bikes tend to have longer top tubes compared to their seat tubes, meaning if you use a long seat post you can avhieve a nice stretched tall position for pedaling, while still beig able to drop the seat right down when needed.


While I understand what you are saying, I'm not sure I totally agree. Top Tube length while critical can always be adjusted with stems and set back, and some times the top tube measurement doesn't vary as much as a seat tube does between sizes.

Sure seat tube can be adjusted with seat post as well, but sizing by seat tube puts you in a ballpark range for stand over clearance, which I find to be more important. I could be wrong, but that's my take on it.

However when I was playing with a 17" Trek Fuel X and a 18" Specialized FSR. I like the stand over and feel of the Trek, however it's cockpit felt cramped due to it's smaller size and shorter stem. The 18" specialized fit as I like in the cockpit, but the stand over was marginal, and over all the bike felt bigger than I was use to.

Now onto the MtB sizing- One critical measurement- Standover height should be 4". I get away with "2 but then I never get off the bike Till I fall off. Small guy and I have a Bianchi Grizzly as my main XC Solo. Only a 15 1/2" frame and This one fits. Went to the next size up and it was too big- on standover and reach.
Forget what it says on the packet and the small print- Try a frame out and see if it fits-


This is howmuch Standover I'm use to having :D

My saddle is about 1 inch lower than usual for winter.

http://img212.imageshack.us/img212/6776/winride4cw2.jpg

......Rocky Mountain is a barely used ETSX ....I think I really wanted a Rocky Element..... the 29'er for now as it just doesn't seem right for me....

The Jedi Knight mind control thing really works? :eek:

:DT.J.

That's a 2002.5, first year they were made and the only year with the cool flame paint job.

Beware these early ETSX's are very prone to brakeage on the seat tube where the upper pivot is. Rocky has been VERY good at replacing frames under warantee but only to the original owners and the warantee was 5 years. Both of which likely mean you can't get this replaced under warantee if it brakes. Keep this in mind, if the price is right it still will be a fabulous bike, but keep in mind you might need to invest in a new frame sometime down the road.

This is howmuch Standover I'm use to having :D

My saddle is about 1 inch lower than usual for winter.



About the same as I use on the Bianchi- but if I get my feet on the ground- my crotch will be in front of the saddle and I only have about 2" standover. Those compact frames are very deceptive to look at.

Surprised you can use Mudguards in the snow? Snow collects on the guards worse than thick clay in my part of the world, but we don't get much of it over here.

That's a 2002.5, first year they were made and the only year with the cool flame paint job.

Beware these early ETSX's are very prone to brakeage on the seat tube where the upper pivot is. Rocky has been VERY good at replacing frames under warantee but only to the original owners and the warantee was 5 years. Both of which likely mean you can't get this replaced under warantee if it brakes. Keep this in mind, if the price is right it still will be a fabulous bike, but keep in mind you might need to invest in a new frame sometime down the road.

Thanks Kris.... Well you know how it is with anything, you pays your money, you takes your chances :) I thought it would make a good project, and i loved that burnished flame treatment on it. I thought it would be a good place to hang some parts on to for the time being.

About the same as I use on the Bianchi- but if I get my feet on the ground- my crotch will be in front of the saddle and I only have about 2" standover. Those compact frames are very deceptive to look at.

Surprised you can use Mudguards in the snow? Snow collects on the guards worse than thick clay in my part of the world, but we don't get much of it over here.


The tires I'm running are Continental Spike Claws, which seem to clear very well. Even in deep sticky snow I have not encountered any problems. I actaully put the fenders on during the transistion season when it would snow and then melt, but now that it is colder (we get a very dry cold), they work so well, I'll just leave them on. I too was concerned about the packing, but I just haven't encountered it yet.

Even in this soft sticky stuff the fenders didn't pack up Temp was about -12C.

http://img90.imageshack.us/img90/4677/img3088mediumyz9.jpg

http://img90.imageshack.us/img90/5054/img3089mediumox0.jpg


This was from my joy ride yesterday at -27C.

http://img234.imageshack.us/img234/733/winride1yr6.jpg

http://img212.imageshack.us/img212/1349/winride5qn7.jpg

http://img293.imageshack.us/img293/259/winride6fv2.jpg

The Jedi Knight mind control thing really works? :eek:

:DT.J.


:roflmao: My Master, You are all Powerful :D

Don't put too much stake in the breakage thing.

Most everyone promised me my 2000 Rocky RM6 would break at the swingarm if I looked at it the wrong way. Instead, it lasted an ungodly long time, and eventually cracked somewhere completely different from plain old metal fatigue.



Edit: I wish the roads around here could look like that last picture all winter long, instead of the "brown brine soup" look we go for in Toronto.

Don't put too much stake in the breakage thing.

Most everyone promised me my 2000 Rocky RM6 would break at the swingarm if I looked at it the wrong way. Instead, it lasted an ungodly long time, and eventually cracked somewhere completely different from plain old metal fatigue.



Edit: I wish the roads around here could look like that last picture all winter long, instead of the "brown brine soup" look we go for in Toronto.

I hear you... I generally don't worry to much about things like that, if it break it breaks.

I too like it when it's colder and the roads are firmer and more consistent. I took a ride today down to our River and was able to rid on the frozen South Saskatchewan for quite a way. it was nice to break new tracks, and while riding on the firm ice.

http://img380.imageshack.us/img380/5766/defride1lc1.jpg

http://img233.imageshack.us/img233/4392/defride4uk5.jpg

http://img79.imageshack.us/img79/4977/defride3sb7.jpg

http://img79.imageshack.us/img79/3431/defride7rf5.jpg

http://img81.imageshack.us/img81/9759/defride10dz2.jpg

http://img233.imageshack.us/img233/1787/defride9zn7.jpg

Personally I NEED:
1) a sub 20lb ht race bike

what is your RM as a matter of interest?

what is your RM as a matter of interest?


Yes, please fill us in again as all that was lost in my 29'er thread that when MIA :)

oh, btw viper, i love your italian job colnago... do you ride it much? if i ever see one riding around in s'toon i'll have to stop you to have a look.

oh, btw viper, i love your italian job colnago... do you ride it much? if i ever see one riding around in s'toon i'll have to stop you to have a look.


Thanks Free Pizza :beer: I built it late into the season, so I have only taken it on 2 rides. One was a 100 KM Club ride, It was great! Here is my Ride Report (post #580) (http://www.bikeforums.net/showthread.php?t=213765&page=24)


Are you in Saskatoon?

what is your RM as a matter of interest?

I think it's about 21.5, one day I'll take it down to Blocks and weigh it on his hanging scale.

I've got some new parts for it on the way! I'm ditching the LX HTII crankset as I've never cared for the looks of it, it's going on wifeys bike as her bb and middle ring are done. On the way is an all black Middleburn DUO two ring crank. Also I needed a new rear mech as my XT had developed a lot of slop, XTR 952 short cage on the way. With these two additions the bike will be all stealth black. I'll post it up again when I get the parts.

Are you in Saskatoon?
Regina:mad:

I think it's about 21.5, one day I'll take it down to Blocks and weigh it on his hanging scale.

I've got some new parts for it on the way! I'm ditching the LX HTII crankset as I've never cared for the looks of it, it's going on wifeys bike as her bb and middle ring are done. On the way is an all black Middleburn DUO two ring crank. Also I needed a new rear mech as my XT had developed a lot of slop, XTR 952 short cage on the way. With these two additions the bike will be all stealth black. I'll post it up again when I get the parts.


Sounds Good :beer:



Regina:mad:

Well, it sure is nice to have some local boys to chat with here :beer: