I am 6'4" w/ a long torso. All of my last 1/2 dozen or so frames were XL's w/ top tube lengths that measured (actual) about 23.75". Seat angles were similar ranging from 71*-73*. Climbing or pedalling the flats I prefer an upright position from a straight Thomson post and my seat slid almost all the way forward. Run an 80mm stem. As of late, when descending I feel like I am on a tri-cycle . Came across a couple of newer trail / AM frames that sport 25" (actual) top tubes. Will I feel better on descents ? Worse for pedalling flats / uphill ? Thanx
Long vs. shorter top tube lengths ?
keen
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I am 6'4" w/ a long torso. All of my last 1/2 dozen or so frames were XL's w/ top tube lengths that measured (actual) about 23.75". Seat angles were similar ranging from 71*-73*. Climbing or pedalling the flats I prefer an upright position from a straight Thomson post and my seat slid almost all the way forward. Run an 80mm stem. As of late, when descending I feel like I am on a tri-cycle . Came across a couple of newer trail / AM frames that sport 25" (actual) top tubes. Will I feel better on descents ? Worse for pedalling flats / uphill ? Thanx
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My Blitz II is 22.5 & the Ibex Atlas is 22, something like a 24 or 25 would be a better fit for you size. I have not measured the actual TT length just what their claimed to be. The Blitz II XL has a TT of 24.5 you can call Versus & see if they have one available for testing. :thumbsup:
http://www.versuscycles.com/contact.html
http://www.versuscycles.com/contact.html
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That's an interesting question, and one I've been wrestling a little bit with lately. I'm becoming more convinced for my preference that the top tube can be as short as possible as long as there's room for my knees not to hit the back of the stem while pedaling or making other reasonable movements necessary on the bike. I'm somewhat like you in being longer torso/shorter legs, though I'm only 6 feet tall. My general comment is just that...general. Some frames really put a bias on their top tube to seat tube ratio, so you can't use a one size fits all method. And then those riders who are opposite of you and I...long legs/short torso...have other issues.
Now...it might seem that a longer top tube would suit a rider with a longer torso/shorter leg build, but usually it's the shorter legs that will work better with a shorter top tube. They don't smack the back of the stem with their knees, so they can usually fit well on a shorter top tube. It's more often the longer legged riders who need longer top tubes to avoid that stem smacking. Again...a generality with some occasional exception.
Another generality relevant to your question involves what affects descending. Most of the time, really long top tubes do not contribute to stable descending. That design will most often have the handlebar further to the front of the bike, hence putting the rider's weight more on the front tire. On such a bike, this can be negated to some degree by using a very short stem. Such juggling acts can work well in one respect but have a seriously negative influence elsewhere in handling or the way the rider fits the rest of the bike...like standover clearance.
There are so many variables when we're talking about general fitment and geometry issues that's it hard to make resonable recommendations. When you don't have all of the other geometry numbers available for a specific bike to compare, one can only discuss general principles. Like you, I prefer a more upright position on the bike except when really attacking a corner, standing for technical situations, and using body english to influence handling for a specific situation. So generally, I like to sit up in the middle of the bike and have a fair amount of neutral handling from that spot. Any aggressive moves that are required seem easier for me to do than for the bike to be set up where I'm heavily biased to the front, rear, low, or high. Another nice factor for being a long torso/shorter leg rider is that you can run the seatpost lower than long legged riders and therefore sit "in" the bike a little more and not have to be putzing with raising/lowering the seatpost frequently.
Now...it might seem that a longer top tube would suit a rider with a longer torso/shorter leg build, but usually it's the shorter legs that will work better with a shorter top tube. They don't smack the back of the stem with their knees, so they can usually fit well on a shorter top tube. It's more often the longer legged riders who need longer top tubes to avoid that stem smacking. Again...a generality with some occasional exception.
Another generality relevant to your question involves what affects descending. Most of the time, really long top tubes do not contribute to stable descending. That design will most often have the handlebar further to the front of the bike, hence putting the rider's weight more on the front tire. On such a bike, this can be negated to some degree by using a very short stem. Such juggling acts can work well in one respect but have a seriously negative influence elsewhere in handling or the way the rider fits the rest of the bike...like standover clearance.
There are so many variables when we're talking about general fitment and geometry issues that's it hard to make resonable recommendations. When you don't have all of the other geometry numbers available for a specific bike to compare, one can only discuss general principles. Like you, I prefer a more upright position on the bike except when really attacking a corner, standing for technical situations, and using body english to influence handling for a specific situation. So generally, I like to sit up in the middle of the bike and have a fair amount of neutral handling from that spot. Any aggressive moves that are required seem easier for me to do than for the bike to be set up where I'm heavily biased to the front, rear, low, or high. Another nice factor for being a long torso/shorter leg rider is that you can run the seatpost lower than long legged riders and therefore sit "in" the bike a little more and not have to be putzing with raising/lowering the seatpost frequently.
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As TNC mentioned body proportions are a big part of it, personally I'm 6' 3 1/2" with a 34" inseam, I ride a lot of very technical steep freeridey single track on rides that often run close to 3 hours. That being said I can't get used to short TT bikes which may be because I raced XC for 10 years, my 06 XL Nomad has a 24.5" TT (unlike the newer Nomads which have 23.8"
) and I do everything on it, including a fair amount of chairlifting (I live 5 minutes from a ski hill) and most of the time I run a 100mm stem, occasionally switching to a 70mm for some of the 3000+ ft descents we have around here.
I do like the longer TTs for big epic rides, they give you more room to move, and I like them on technical climbs. One area longer TTs suck, like most XL frames, is the resulting long wheelbase in tight twisty singletrack. I am currently considering switching to a Knolly Delirium T which has adjustable chainstays and a drastically laid back seat tube which allows the seat to be tucked up forward when you want the seat out of the way and stretches your position out when the seat is raised for longer rides.
The best idea is to try to ride one of the long TT bikes, which I know from personal experience is hard to do when you need an XL frame, a lot of shops don't seem to stock XLs. Toptube lengths are hard to 'pin down' for someone without knowing what type of terrain you are riding, what you have liked/disliked about previous rides you've owned, what type of rider you are etc...
) and I do everything on it, including a fair amount of chairlifting (I live 5 minutes from a ski hill) and most of the time I run a 100mm stem, occasionally switching to a 70mm for some of the 3000+ ft descents we have around here. I do like the longer TTs for big epic rides, they give you more room to move, and I like them on technical climbs. One area longer TTs suck, like most XL frames, is the resulting long wheelbase in tight twisty singletrack. I am currently considering switching to a Knolly Delirium T which has adjustable chainstays and a drastically laid back seat tube which allows the seat to be tucked up forward when you want the seat out of the way and stretches your position out when the seat is raised for longer rides.
The best idea is to try to ride one of the long TT bikes, which I know from personal experience is hard to do when you need an XL frame, a lot of shops don't seem to stock XLs. Toptube lengths are hard to 'pin down' for someone without knowing what type of terrain you are riding, what you have liked/disliked about previous rides you've owned, what type of rider you are etc...
I agree with TNC. I had the same problem( 6' tall with long torso/short legs) and initially had a Gary Fisher bike with the Genesis Geometry (long top tube) until I realized that shorter top tubes work much better for me (better control, more relaxed seating position)
I have ridden in XL's : 02' Enduro Pro, Bullit, Heckler, BLT , Nomad, VP Free & a couple K2's not woth mentioning. Of the bunch I had the hardest time climbing on the Bullit and Enduro - too slack of seat tubes kept too much weight on the rear tire. I am finding I am more comfortable and climb better w/ a shorter TT due to the upright positioning. Now for descents I feel like I am too far forward & upright, unless I bend my knee's & crouch to the rear of the bike almost like racer bmx style. My thoughts on a longer top tube would be that there is more bike in front of me stretching me out vs. a longer stem on a shorter top tube putting me farther over the front wheel - thoughts on this ?
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I'm taller than you and found my xl vp-free to be wayyyy to big. The top tube is just soo dang long. I grew up riding on smaller bikes so it feels more natural with a smaller top tube. The vp-free feels like a limo compared to a med heckler I used to ride.
Sounds like you didn't start out on 20 inchers, am I correct?
Sounds like you didn't start out on 20 inchers, am I correct?
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Hey keen, as you probably recall, I'm a moto guy too. I think it's part of the reason I like the shorter cockpit. You definitely sit more upright on a dirt motor, and the handlebars are higher. Yeah, crotch rockets are definitely more "lay down and reach" setups, but that's hardly suitable for off roading. I don't know, keen. The more you have to stretch toward the bar, the less ability it seems you'll have to move your body around on the bike to make controlling movements and apply body english to weigh the bike in technical situations...if that makes sense. Maybe if you have a higher bar/grip height with a slightly longer top tube reach, this would diminish the negative effects of a long reach while riding in technical terrain. Obviously you hear riders say they can go faster with a longer top tube and reach to the bar becasue it stretches them out a bit, and I would say that's generally true. But where are they going faster?...flats, climbs, non-technical terrain? I just don't think that position on a longer travel, bigger hit bike being ridden in technical terrain allows you to go faster...in technical terrain...because you can more easily move around on the bike to maintain control...move fore and aft...up and down...side to side...etc. If you're more generally "locked into" a specific position because of cockpit sizing, your lattitude for movement is diminished. So...once again it seems to come down to compromise for what kind of riding and conditions one is faced with and which elements of that riding are more important to a given rider.
For me this is where you really almost need two bikes...one with a more XC bias and one with a more aggressive AM layout. Then you use the bike that's more suitable for a given ride or trail conditions. Otherwise, you just compromise in the bike setup that suits what's generally more important to you as a rider. My compromise almost always leans toward a bike setup that won't get me into trouble in technical terrain.
For me this is where you really almost need two bikes...one with a more XC bias and one with a more aggressive AM layout. Then you use the bike that's more suitable for a given ride or trail conditions. Otherwise, you just compromise in the bike setup that suits what's generally more important to you as a rider. My compromise almost always leans toward a bike setup that won't get me into trouble in technical terrain.
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I went for a 20mm shorter stem in spring and felt that the steering became more "direct". Or ... how would I put it ... less effort needed to turn and also less tendency to oversteer.tiggles said:
But that was different stem on otherwise same bike and smaller frames tend to make more agile bikes too. Arrgghhh, there are so many things that affect handling and riding position. If a fork that is a different length affects the angles and handling, a different tyre must have a similar effect...
...
My legs are on the short side but much of their length is in the thighs. To position my seat well for pedaling I have to put it far back on my bike that has the seat tube at about 73 or 74 degrees. I have a new frame that has a 70 degree seat tube and should let me put the seat more forward on the post. With the seat more forward, I need some more top tube (measured horizontally) to have a good cockpit length. I think I have enough top tube on the new frame. I might even have so much that I can go for an even shorter stem on the new frame. That should be fine because the head tube angle will be a little slacker (more stable) too. There might be a flaw in my guesstimates but I think the new frame will eventually work out very well.
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I've been battling with setup for years on various different bikes.
As people have discussed; there are many factors to a good set-up.
I currently have a medium 6.6 with a layback post and a 90mm stem. I am 5ft 11" and ride a lot of trail/some DH courses etc.
My biggest problem is climbing position. If I move the seat further forward the cockpit gets cramped and if I run a shorter stem the seats needs to go back and I feel like I'm pedalling forward which uses the quads less hence less power on the climbs, all my weight over the back wheel and low effeciency!
On the plus side, the bike is great on the descents because the cockpit is shorter than I'd like and I can get my bodyweight back further.
You may point out that my problem is frame size and you could be right!
however, from what I've read on the forums, there seems to be a lot of people in the 6ft vacinity that have real trouble getting bikes to fit without a heavy compromise somewhere.
I used to have a 5.5 which had a longer top tube than the 6.6 but as we know this is not the whole story because to get the top tube length Intense seem to have put the seat about a foot behind the bottom bracket!
Ok I'm stretching the truth a bit, but the point I'm trying to make is that a very slack seat angle and a medium reach can lead to bad posture and low efficiency on a bike.
I think for successful trail riding up and down the seat shouldn't be any further back than the middle of the rails on a layback post (or using the plumline dangling from the front of the knee when the pedals are level - no more than half an inch behind the pedal spindle).
also, I think that anything more than a 100mm stem can compromise the way the steering feels and how much weight there is over the front, especially when you can gain or lose length by tilting the bars.
Just my 2 pence.
Cheers,
James.
As people have discussed; there are many factors to a good set-up.
I currently have a medium 6.6 with a layback post and a 90mm stem. I am 5ft 11" and ride a lot of trail/some DH courses etc.
My biggest problem is climbing position. If I move the seat further forward the cockpit gets cramped and if I run a shorter stem the seats needs to go back and I feel like I'm pedalling forward which uses the quads less hence less power on the climbs, all my weight over the back wheel and low effeciency!
On the plus side, the bike is great on the descents because the cockpit is shorter than I'd like and I can get my bodyweight back further.
You may point out that my problem is frame size and you could be right!
however, from what I've read on the forums, there seems to be a lot of people in the 6ft vacinity that have real trouble getting bikes to fit without a heavy compromise somewhere.
I used to have a 5.5 which had a longer top tube than the 6.6 but as we know this is not the whole story because to get the top tube length Intense seem to have put the seat about a foot behind the bottom bracket!
Ok I'm stretching the truth a bit, but the point I'm trying to make is that a very slack seat angle and a medium reach can lead to bad posture and low efficiency on a bike.
I think for successful trail riding up and down the seat shouldn't be any further back than the middle of the rails on a layback post (or using the plumline dangling from the front of the knee when the pedals are level - no more than half an inch behind the pedal spindle).
also, I think that anything more than a 100mm stem can compromise the way the steering feels and how much weight there is over the front, especially when you can gain or lose length by tilting the bars.
Just my 2 pence.
Cheers,
James.
long tube
I am 6' with long torso (29" pant inseam). I felt very comfortable with Fisher's Genesis geometry and have continued with longer TTs on other bikes as well. I am more comfortable on my current ride than any I have tried- an XL Santa Cruz Superlight (I believe it is listed at 25.2 ETT", and I'm running a 90mm stem)
I think the longer wheelbase is helpful for tracking and weight transfer but a bit less ideal for jumping and other stunts. The problem I have with shorter bikes is that I feel like I am "lifting" forward with the handlbars when I hit obstacles. On the longer TT I feel like my forearms are more horizontal and naturally absorb the shocks and twisting motions with less fatigue. I feel much less likely to endo, too.
Shorter stems are great most of the time, but I find that anything under 90 or so can be a challenge to keep on your line through slow rock gardens or off-camber waterbars. I run wide bars for the same reasons. The longer stems seem to carve turns a bit more gracefully and smoothly, but are not so great at "oh sh!t" corrections. Or horsesh!t corrections, for that matter.
Bear in mind that my riding is SLOW, tight east coast stuff. I bet I would like a shorter TT if I lived out in the wide-open high speed west.
I am 6' with long torso (29" pant inseam). I felt very comfortable with Fisher's Genesis geometry and have continued with longer TTs on other bikes as well. I am more comfortable on my current ride than any I have tried- an XL Santa Cruz Superlight (I believe it is listed at 25.2 ETT", and I'm running a 90mm stem)
I think the longer wheelbase is helpful for tracking and weight transfer but a bit less ideal for jumping and other stunts. The problem I have with shorter bikes is that I feel like I am "lifting" forward with the handlbars when I hit obstacles. On the longer TT I feel like my forearms are more horizontal and naturally absorb the shocks and twisting motions with less fatigue. I feel much less likely to endo, too.
Shorter stems are great most of the time, but I find that anything under 90 or so can be a challenge to keep on your line through slow rock gardens or off-camber waterbars. I run wide bars for the same reasons. The longer stems seem to carve turns a bit more gracefully and smoothly, but are not so great at "oh sh!t" corrections. Or horsesh!t corrections, for that matter.
Bear in mind that my riding is SLOW, tight east coast stuff. I bet I would like a shorter TT if I lived out in the wide-open high speed west.
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Heya,
Just curious, try this fit calculator out and see if it comes close to what your riding...
http://www.competitivecyclist.com/za/CCM?PAGE=FIT_CALCULATOR_INTRO&INTRO_LINK=NOREDIR&CLEAR_RESULTS=TRUE&SITE.CODE=
After reading this thread I was curious to see if I was long legged and short trunked and was trying to find some statistics on the matter when I found the above "fit calculator". I was initially impressed just because it sure seems like a well put together little AP with great instructions compared to others I've seen.
BUT, it gave me 24.6 - 25.0 inches for a horizontal TT, and get this, with a 125 to 130mm stem!!! ? that sure seems stretched out for anything but a pure XC race bike IMO. I'm kinda tall @ 73.5" and with a 35.5" inseam. But geeze, I bet any old roadbike calculator would throw out pretty similar stretched out numbers???
So I still haven't found any solid info on whether I'm long legged and short in the torso. I found someone quoting some article they read in which you divided your height by your inseam and if it was closer to 2.0 than you were long legged, and the closer to 2.2 you were short legged. so for me I'm at a 2.08 putting me solidly on the long legged side, so I assume I'm also proportionally short in the trunks?
Also I found that there are quite a few out there promoting 2/3's of your inseam as a good top tube measurement. I get a 23.6 for this which is pretty close to what I ride. But this is giving you a top tube measurement without any regard for whether you have a short/long torso or arm length...?
Also, TNC, what size stems are you running while trying not to hit your knees?
Just curious, try this fit calculator out and see if it comes close to what your riding...
http://www.competitivecyclist.com/za/CCM?PAGE=FIT_CALCULATOR_INTRO&INTRO_LINK=NOREDIR&CLEAR_RESULTS=TRUE&SITE.CODE=
After reading this thread I was curious to see if I was long legged and short trunked and was trying to find some statistics on the matter when I found the above "fit calculator". I was initially impressed just because it sure seems like a well put together little AP with great instructions compared to others I've seen.
BUT, it gave me 24.6 - 25.0 inches for a horizontal TT, and get this, with a 125 to 130mm stem!!!
? that sure seems stretched out for anything but a pure XC race bike IMO. I'm kinda tall @ 73.5" and with a 35.5" inseam. But geeze, I bet any old roadbike calculator would throw out pretty similar stretched out numbers???So I still haven't found any solid info on whether I'm long legged and short in the torso. I found someone quoting some article they read in which you divided your height by your inseam and if it was closer to 2.0 than you were long legged, and the closer to 2.2 you were short legged. so for me I'm at a 2.08 putting me solidly on the long legged side, so I assume I'm also proportionally short in the trunks?
Also I found that there are quite a few out there promoting 2/3's of your inseam as a good top tube measurement. I get a 23.6 for this which is pretty close to what I ride. But this is giving you a top tube measurement without any regard for whether you have a short/long torso or arm length...?
Also, TNC, what size stems are you running while trying not to hit your knees?
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stiingya, I think you touched on the fact that the calculator you linked there looks like a roadbike format which IMO is a real apples/oranges deal...as you well noted on the results.
My stem preferences are usually in the 70-90mm range, but like anything, that can vary depending on the bike geo. I run a 50mm on my Nomad, but the Nomad is a very different animal for geo numbers...long wheelbase, long chainstays, etc. I don't think I can see a situation where "I" would ever run a stem longer than 90mm. I think I'd be on the wrong bike if that was necessary. Do realize that my bikes are not racing hardtails or XC fullies. I like slack geometry and stable, slower handling is my priority. Dropping down rocky, ledgy trails with "adequate" climbing quality is my normal riding "type". I'm preparing to install a 650B front wheel/tire on my Nomad, and I'm going to try a 90mm stem on this setup to retain climbing capability and steering precision. Remember, I'm a longer torso/shorter leg 6 footer. I just don't have trouble with my knees hitting the stem with my relatively short cockpit setups.
My stem preferences are usually in the 70-90mm range, but like anything, that can vary depending on the bike geo. I run a 50mm on my Nomad, but the Nomad is a very different animal for geo numbers...long wheelbase, long chainstays, etc. I don't think I can see a situation where "I" would ever run a stem longer than 90mm. I think I'd be on the wrong bike if that was necessary. Do realize that my bikes are not racing hardtails or XC fullies. I like slack geometry and stable, slower handling is my priority. Dropping down rocky, ledgy trails with "adequate" climbing quality is my normal riding "type". I'm preparing to install a 650B front wheel/tire on my Nomad, and I'm going to try a 90mm stem on this setup to retain climbing capability and steering precision. Remember, I'm a longer torso/shorter leg 6 footer. I just don't have trouble with my knees hitting the stem with my relatively short cockpit setups.
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:yesnod: :yesnod: :yesnod: :thumbsup: :thumbsup: :thumbsup:TNC said:
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Yea it sure seems like the numbers are either for elite XC or road bikes. But the reason I even bothered with trying it out was that it is "supposedly" for mountain bikes, it talks about mountain bike horizontal TT vs actual TT sizing, and even gives suggested standover height for both full suspension and hard tails.TNC said:
At any rate, it never helped me find out if I was long legged with a short torso which was what I was looking for!
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