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Discussion Starter · #1 ·
I've been riding on XC bike frames for the past 12 years. I never thought a bike could be better until I got this new freeride frame. The only advantage I can see is that the seat tube is tall for powering your legs on XC bikes, that's all.

I just went out and made myself a custom seat post that's close to 20 inches long and stuck it on there. I goes plenty high up for some serious pedaling on XC trails and going up hill. I can move the bike seat back and forth on the fly to change my virtual top tube length.

In fact the new bike frame is much more riggid and compact than the XC frame, which equates to me being able to put power to the ground with more authority. On top of that the new frame makes turns twice as fast and can transition back and forth through turn after turn (left turn to right turn back to left turn: s curves) with no resistance whatsoever.

My new frame only weighs 4pounds 13 ounces. A wopping 8 ounces more than my Xc frame :rolleyes:

Not enough of a difference when pedaling, in that it doesn't slow me down, but it does take me much faster and safer through insane corners.

The question is..................... why would anyone want an Xc frame? If you bike in a straight line all your life and want less weight, I can see why.

but other than that

XC frames are much inferior in all the other aspects of biking.
 

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I don't know what "xc" frame your comparing your new one to, but they are generally designed for climbing efficiency and direct power transfer with super steep geometry, along w/ the light weight characteristics you mentioned. Not necessarily a tall seat tube, just depends on the size you choose. That K2 in the picture probably has a rather slack head angle esp. w/ the bomber, which will result in a slower steering, compared to a typical xc frame. Head angles of around 67deg on your K2 (I'm assuming) and around 71 on xc frame. The reason you probably feel it has faster steering is because it might have shorter chainstays and overall wheelbase than the other bike your comparing it to.
If you ever get a chance, go find a steep hill and try to climb it w/ your bike then try climbing it w/ an full on xc rig. You will feel a difference guaranteed.
btw- I wouldn't really classify your frame as a "freeride" bike. Nice ride though. I bet it manuals like a bmx bike.
 

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Discussion Starter · #3 ·
BikeSATORI said:
I don't know what "xc" frame your comparing your new one to, but they are generally designed for climbing efficiency and direct power transfer with super steep geometry, along w/ the light weight characteristics you mentioned. Not necessarily a tall seat tube, just depends on the size you choose. That K2 in the picture probably has a rather slack head angle esp. w/ the bomber, which will result in a slower steering, compared to a typical xc frame. Head angles of around 67deg on your K2 (I'm assuming) and around 71 on xc frame. The reason you probably feel it has faster steering is because it might have shorter chainstays and overall wheelbase than the other bike your comparing it to.
If you ever get a chance, go find a steep hill and try to climb it w/ your bike then try climbing it w/ an full on xc rig. You will feel a difference guaranteed.
btw- I wouldn't really classify your frame as a "freeride" bike. Nice ride though. I bet it manuals like a bmx bike.
It may not look like a freeride bik, but I do freeride it. The reason you don't see 3.0 tires and a 8 inch fork is because I have to work for my vertical (pedal up hill). It's a great compromise between up hill ability and downhill thrill. As you can see from the pic, it works just fine with tranny drops.

The steering with the Bomber is perfectly balanced. Not too fast--- not too slow--- just right.

On top of that, I've got ETA for steepening the head angle for up hill riding. It can really blast up the mountain like a scalded flyin monkey.

I think the only draw back from a frame like mine is that you have to make your own custom seat post. They don't make seat posts long enough for tall people like me (6ft4in) to use on smaller frames.

Other than that, it's all bonus!

BTW, I'll be upgrading to 185mm rotors front and rear pretty soon, so this baby can stop a bit better on the hard core stuffs.
 

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BudhaGoodha said:
It may not look like a freeride bik, but I do freeride it. The reason you don't see 3.0 tires and a 8 inch fork is because I have to work for my vertical (pedal up hill). It's a great compromise between up hill ability and downhill thrill. As you can see from the pic, it works just fine with tranny drops.

The steering with the Bomber is perfectly balanced. Not too fast--- not too slow--- just right.

On top of that, I've got ETA for steepening the head angle for up hill riding. It can really blast up the mountain like a scalded flyin monkey.

I think the only draw back from a frame like mine is that you have to make your own custom seat post. They don't make seat posts long enough for tall people like me (6ft4in) to use on smaller frames.

Other than that, it's all bonus!

BTW, I'll be upgrading to 185mm rotors front and rear pretty soon, so this baby can stop a bit better on the hard core stuffs.
Your an idiot.

-TS
 

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TheSherpa said:
Your an idiot.

-TS
haha

hah.'

yeah -- xc frames rule on the uphill. then again, maybe you're right, buddha! maybe the whole xc market is a sham-filled pot of inferior products! maybe racers and racing teams have no idea what the hell they're doing!

yes that must be it.
 

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Discussion Starter · #6 ·
TheSherpa said:
Your an idiot.

-TS
Gee you must be smarter than me. I'm always spelling it "You're an idiot", looks like I've been doing it wrong all along.

I'm an idiot for formulating a valid arguement? Responding with a 3 word phalacious response seems like the idiot wind is blowing back in your direction.

Here's the only reasons I can find as to why a person would want a XC frame:

1. The inherent bike geometry allows for a lighter bike by design. Having larger more obtuse triangles allows for much thinner and weaker tubing. A compact frame will always have to be heavier because the triangles are smaller, thus more stress is put onto the verticies of the head tube and BB.

2. They don't really make seat posts long enough to allow a person as tall as me to use a compact FR frame as a XC, uphill machine, but with a custom seat post the problem is solved.

3. Yes XC frames do have quicker steering, but not quicker turning.

Like I said before, if you ride on flat ground all the time and don't care much for corners and going downhill, then a XC frame is just right for you.

ON THE OTHER HAND

If you like riding EVERYTHING from flat ground to uphill to downhill and many turns and jumps inbetween, the extra slight amount of weight for a compact frame is well worth it.
 

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BudhaGoodha said:
1. The inherent bike geometry allows for a lighter bike by design. Having larger more obtuse triangles allows for much thinner and weaker tubing. A compact frame will always have to be heavier because the triangles are smaller, thus more stress is put onto the verticies of the head tube and BB.
As if there was any doubt before, you have gone proven Sherpa's statement. YOU ARE AN IDIOT. I would strongly suggest you learn to follow the phrase "it is better to be silent and thought a fool, than to open your mouth and prove it." Just out of curiosity, are you so stupid that you actually believe the bull*hit that you make up?

Just for laughs, here are some other brilliant thoughts from BudhaGoodha:

"I've done 30 ft horizontal gap jumps with it and have had no probs. As long as you land smooth and don't crash too hard this fork will do anything that any other 120mm fork can do."

"I'll get a pick of me going off the jump when my back starts feeling better. (tweeked it on a wheelie drop)"

"I'm sure most of you know that a bike with a head angle of 65" is going to turn very poorly in tight turns. THere's no way aorund it.

No use travel adjust and add 3 or 4 degrees to your head angle and your now able to turn on a dime, which is great for crowded city riding, tight single track, or wherever you need quick turning but not a lot of travel. Also, lowering the shock also helps in navigating uphill through rocks and roots, becasue the bike turns with more response.

I have an MX COMP ETA and use the ETA all the time. It's more than a climbing aid."
 

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Discussion Starter · #8 ·
CDMC said:
As if there was any doubt before, you have gone proven Sherpa's statement. YOU ARE AN IDIOT. I would strongly suggest you learn to follow the phrase "it is better to be silent and thought a fool, than to open your mouth and prove it." Just out of curiosity, are you so stupid that you actually believe the bull*hit that you make up?

Just for laughs, here are some other brilliant thoughts from BudhaGoodha:

"I've done 30 ft horizontal gap jumps with it and have had no probs. As long as you land smooth and don't crash too hard this fork will do anything that any other 120mm fork can do."

"I'll get a pick of me going off the jump when my back starts feeling better. (tweeked it on a wheelie drop)"

"I'm sure most of you know that a bike with a head angle of 65" is going to turn very poorly in tight turns. THere's no way aorund it.

No use travel adjust and add 3 or 4 degrees to your head angle and your now able to turn on a dime, which is great for crowded city riding, tight single track, or wherever you need quick turning but not a lot of travel. Also, lowering the shock also helps in navigating uphill through rocks and roots, becasue the bike turns with more response.

I have an MX COMP ETA and use the ETA all the time. It's more than a climbing aid."
CDMC--- and your point is???? Just because I use ETA on a Freeride hardtail means what? I never said a head angle has anything to do with what I'm comparing here. On my K2 I use the ETA to put me in a better climbing position and to quicken the steering. What's wrong with that? Just because a bike has quicker steering means it can go through all corners faster and more stable?

On the note of the 30 ft gap jump. It's a high speed low vertical gap jump that guys on BMX bikes and even target bikes can do with no problems. I probably don't get more than 6 - 7 ft off the ground. What's wrong with that? Like I said, as long as it's smooth, why is it required to have 9 inches of front and rear suspension? If I was doing 30 ft drops, then I would require a beefier bike.

You guys obviously have no reading comprehension skills what so ever. Why do you think road bike frames and XC frames look almost identical in geometry? It's because that's the lightest way to build a bike that still has some strength. Not only does the frame weigh less, but the seat post can be shorter for less weight.

I never claimed to be an expert at bikes, but I do know physics and engineering very well. That's why I posted it as a question. Why do people buy XC frames? How is that not a valid question? I'm talking from personal experience of riding XC frames all my life up till now. So yes I do have a valid background into what different bikes feel like, I'm just relaying my findings.

For those of you (who shall remain nameless) who don't know how to read or don't know slick dick about physics, maybe this will help:

Looking at the drawings below, imagine that you had to make the two figures out of tooth picks. The tooth picks being the same size.

Which one would be stronger? The XC frame of course, because ther are less lateral stresses on the weld verticies (arrow points). The FR toothpick frame would fall apart much quicker and allow for the BB to break and thus the seat tube will fall down.

That's why the more compact FR frame has to be built a bit beefier and heavier than the XC frame, it's inherently weaker. The Xc frame can get away with using lighter tubing becasue the geometry is stronger.

BTW, if I was an idiot, why would I have 3 utility patents to my name?
 

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Discussion Starter · #9 · (Edited)
This might help to visualize what's going on with different bike geometry.

Imagine that a constuction worker had to build a platform out of two 2x4 planks of wood 30 ft off the ground.

The first one (representing FR frame) would fall apart very quickly because much more stress is being put onto the points where the 2x4s connect to the wall. If he wanted the same geometry, but more strength, he would have to use 4x8 planks of wood.

The second setup (Xc frame) does just fine with a 2x4 because less stress is being put onto the connecting points.



For a bike though, having the weight lower and more compact is ideal for the way a bike should perform. Thus more weight is needed in the tubing to compensate for having weaker geometry.

Why do you think trials bikes and bmx bikes are made of heavy duty cro-moly steel? Because they have weak geometry, but need to have the weight down low for performance.
 

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You have it ass backwards. If you build two frames with the same tubes, one in a compact geometry and one with a more traditional seatube length, the compact frame will be stiffer horizontally (vertical flex is virtually nill in either frame), and lighter as less tubing will be required to construct the frame. This is because the tubesets are located closer to the bottom bracket (the primary source of flex) and the shorter seatube of the compact frame allows for less torsional flex.

You of course have also chosen to ignore a multitude of factors that are far more important than compact v. traditional in analyzing why your two frames handle so differently. Among those major factors are Head Angle, Seat tube angle, chainstay length, tubing thickness and butting, bottom bracket height, head tube length, and top tube length. But then of course you hold 3 patents so you know better. Engineer you are not.
 

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don't forget stem length and handlebar height. XC bikes typically do a longer front AND lower compartment, and ignore riser bars (unless they're very low rise ones), because you're trying to keep yourself stretched out and low and more weight over the front end, specifically for climbing. And did the shorter chainstay lengths get covered also (better climber) which is something you can't do if you want loads of tire clearance like on a freeride bike. By loads, I don't mean clearing a measly 2.35".

And that K2 frame, for its small size, is a good pound heavier than most similar quality XC aluminium frames, if not more (especially high end Al frames). As to strength of a frame, that's easily resolved by using a better alloy.
 

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Discussion Starter · #12 ·
As far as heads angles go. You can't really compare a XC bike that's got a steep head angle with a FR HT bike with a slightly slacker head angle.

Sure a steeper head angle will allow for a quicker movement of the front wheel, but in no way makes for an ideal carver through high speed turns. When I say "go thru a turn faster" that means speed wise, not how quick the front wheel responds.

FYI--- my bike has a HT angle of 70"

What I'm talking about really doesn't have as much to do with head angles as it does with having the weight of the bike down low and compact. A FR frame and a XC frame would handle completely different even if the head angle was exactly the same.

Just so you guys know, all of the components on my bike were switched over from my last XC frame, which gives me a pretty darn good benchmark to analizing the differences betweeen frames.

Of course a XC bike with 1.75 tires and light wieght components would haul circles around my bike going up hill, duh. but put the same compentents on two different frames and the difference comes down to the frame only.

I would consider my bike a light freeride bike. I would never take it on anything that would over stress my components, safety is number one in my book. Sure I could make up a 45 pound bike for smashing over logs and flatening hikers, but I needed something that could go uphill just as well as it can go downhill. My last Xc frame was good for going uphill but sucked nards for verything else. It was only a slight percentage better at uphill than my new frame.

If I was a racer weight wennie, then I would have the lightest XC frame I could buy.
 

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Discussion Starter · #13 ·
CDMC said:
You have it ass backwards. If you build two frames with the same tubes, one in a compact geometry and one with a more traditional seatube length, the compact frame will be stiffer horizontally (vertical flex is virtually nill in either frame), and lighter as less tubing will be required to construct the frame. This is because the tubesets are located closer to the bottom bracket (the primary source of flex) and the shorter seatube of the compact frame allows for less torsional flex.

You of course have also chosen to ignore a multitude of factors that are far more important than compact v. traditional in analyzing why your two frames handle so differently. Among those major factors are Head Angle, Seat tube angle, chainstay length, tubing thickness and butting, bottom bracket height, head tube length, and top tube length. But then of course you hold 3 patents so you know better. Engineer you are not.
Dood, what are you smoking man?!? Since when have you ever seen a light compact frame? Why would the most compact of all frames be made of Steel? (ie trials bikes, BMX)

I have it right, not backwards. The flex caused by pedaling is completely different from what I'm saying about the vertical pressures.

Imagine that the seat tube is your wall that you're build a platform off of. It's the height and size of the triangles coming off of that wall that determine it's geometrical strength. If two bikes are within an inch wheel base of eachother a more compact frame can be only more compact vertically, meaning the top tube and seat stays will have to be lower. By making them verically lower you are in essence placing mor stress on the both the tubes and welds, beacause there is more leverage being exerted on the triangles.

I sure as heck hope you never become an architect. :rolleyes:
 

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Actually, he's got a point...

BudhaGoodha said:
Dood, what are you smoking man?!? Since when have you ever seen a light compact frame? Why would the most compact of all frames be made of Steel? (ie trials bikes, BMX)

I have it right, not backwards. The flex caused by pedaling is completely different from what I'm saying about the vertical pressures.

Imagine that the seat tube is your wall that you're build a platform off of. It's the height and size of the triangles coming off of that wall that determine it's geometrical strength. If two bikes are within an inch wheel base of eachother a more compact frame can be only more compact vertically, meaning the top tube and seat stays will have to be lower. By making them verically lower you are in essence placing mor stress on the both the tubes and welds, beacause there is more leverage being exerted on the triangles.

I sure as heck hope you never become an architect. :rolleyes:
...ever notice how some companies who build custom frames will use extra tubes (more triangulation) and/or heavier gauge tubing on frames built for extra-tall riders?

One of the inherent disadvantages of compact (sloping top tube) road frames is the less-compliant ride that results from the smaller triangles (less flex).

A compact XC frame that has the top tube length and angles of a standard XC frame would make for an interesting ride. Lower center of gravity, possible lighter weight (though the longer seatpost might offset that somewhat), better standover clearance, and the extra comfort from the added seatpost flex due to the longer post might all be noticable advantages.

By the way, a 30-foot gap jump is pretty doable on most any bike if you can land smoothly. I used to do 20 foot gaps on my BMX bike and it was no problem. Just need a lot of speed, a good transition to land on, and a decent set of balls. Often on a gap jump you're never more than a foot or two off the ground, it's all speed.

Tommy
 

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BudhaGoodha said:
Dood, what are you smoking man?!? Since when have you ever seen a light compact frame? Why would the most compact of all frames be made of Steel? (ie trials bikes, BMX)

I have it right, not backwards. The flex caused by pedaling is completely different from what I'm saying about the vertical pressures.
So you are discussing vertical compliance. Guess what. Vertical compliance is probably the smallest variable between your two frames.

You ask why some frames are made out of steel? It is because some poeople prefer the feel of a steel frame. Also, steel tends to be more maluable than aluminium and accordingly less likely to suffer castistrophic failure.

Why are so many jumping bikes compact geometry? Because guys who jump like to be able to get their seats way down and out of the way.

Why does your new frame feel so different than your old one? LISTEN THIS TIME. HEAD ANGLE, SEAT TUBE ANGLE, BOTTOM BRACKET HEIGHT, CHAINSTAY LENGTH, HEAD TUBE LENGTH, TOPTUBE LENGTH, TUBE THICKENESS, TUBE DIAMETER, BUTTING METHOD, TYPE OF MATERIAL USED TO CONSTRUCT THE FRAME. The fact that your frame is a compact v. non compact is a the bottom the list.

You mention frames for tall people having extra triangles. This is to maintain lateral strength in the bottom bracket area. If the distance between the toptube and the bottom bracket gets to long, the bike will flex like a Mo-fo. Don't believe me, call Titus and ask them why they build their XXL frames this way.
 

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god you're a complete moron...

BudhaGoodha said:
Dood, what are you smoking man?!? Since when have you ever seen a light compact frame? Why would the most compact of all frames be made of Steel? (ie trials bikes, BMX)

I have it right, not backwards. The flex caused by pedaling is completely different from what I'm saying about the vertical pressures.

Imagine that the seat tube is your wall that you're build a platform off of. It's the height and size of the triangles coming off of that wall that determine it's geometrical strength. If two bikes are within an inch wheel base of eachother a more compact frame can be only more compact vertically, meaning the top tube and seat stays will have to be lower. By making them verically lower you are in essence placing mor stress on the both the tubes and welds, beacause there is more leverage being exerted on the triangles.

I sure as heck hope you never become an architect. :rolleyes:
#1 BMX and Trials bikes are made of steel alloys cause its CHEAPER. A "high end" BMX or TRIALS bike will sell for what a low end MTB sells for. But that's not to say no brand offers BMX/Trials bikes in other materials, Plenty offer Al frames and several offer titanium ones also.

#2 YOU'RE A MORON. Therefore you're always backwards and never right. You haven't a clue as to how frames flex while pedalling.

#3 Your analysis is flawed. Structures with a greater cross section are stiffer, not ones that are more compact. The stiffness of a structure like a tube goes up with the cube of its diameter. A 2" diameter bar is 8 times as stiff as a 1" diameter bar. This is why when they build houses, roofs, barns, hell, airplanes and bridges, they're trying to get the most efficient cross sections for a given restriction (usually weight or price).
 

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No he doesn't.

tommyrod74 said:
...ever notice how some companies who build custom frames will use extra tubes (more triangulation) and/or heavier gauge tubing on frames built for extra-tall riders?

One of the inherent disadvantages of compact (sloping top tube) road frames is the less-compliant ride that results from the smaller triangles (less flex).

A compact XC frame that has the top tube length and angles of a standard XC frame would make for an interesting ride. Lower center of gravity, possible lighter weight (though the longer seatpost might offset that somewhat), better standover clearance, and the extra comfort from the added seatpost flex due to the longer post might all be noticable advantages.
They need the extra tubes and heavier gauge tubing because extra tall riders also tend to be extra HEAVY riders. Ignoring genetically gifted folks with mutant metabolisms like myself who can't possibly gain weight, someone 6'6 who'd ride a 21" frame is not likely to weigh only 171 Ibs (I just stepped on a scale). Lance Armstrong is 5'11 and 165 Ibs in comparison.

Its not the sloping top tube that's the problem. Its the trend to larger diameter tubing that's the problem with ride compliance.
 

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I think someone was a wee bit too happy about his new bike.

Did you get that frame from eBay?

I got the funky monkey one. :) Still building it up. But I'm not going to come here and say its the end-all-be-all of XC frames. Because I would take an Epic or a SL frame over it anyday. ;)
 

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That's true, I suppose...

DeeEight said:
They need the extra tubes and heavier gauge tubing because extra tall riders also tend to be extra HEAVY riders. Ignoring genetically gifted folks with mutant metabolisms like myself who can't possibly gain weight, someone 6'6 who'd ride a 21" frame is not likely to weigh only 171 Ibs (I just stepped on a scale). Lance Armstrong is 5'11 and 165 Ibs in comparison.

Its not the sloping top tube that's the problem. Its the trend to larger diameter tubing that's the problem with ride compliance.
... I'd agree that larger riders tend to be heavier. You don't think that longer tubes are more flexy, though, as well? I'm not an engineer, but I know it's easier to flex a longer tube than a short one. Seems to me that it doesn't have to be either/or as the reason for the extra tubes and heavier gauges- maybe it's a bit of both, the larger riders have more weight as well as more leverage due to the longer tubes.

I'd say it's the same with the ride compliance issue. The compact design road frames tend to be oversized aluminum or carbon, as one usually sees steel in more traditional configurations. Probably both the tubing diameter and the frame configuration contribute to the ride compliance.

Are you really 6'6", 171 lbs? Wow. I'm 170 at 5'10", and I'm pretty lean. Bet you can climb like a champ...

Tommy
 

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yes I'm really that light and its also why I'm annoyed with the frame I ordered that the catalog claimed 6.0 Ibs frame + shock was actually 7.5 Ibs. Ok, even taking into account they weighed a 'small' frame for the catalog, the only reason the large is that much heavier is they like to lie to the customers, or they're shafting us tall folks with a heavier gauge tubeset.

And yes I do like to climb, which is why I had ordered a new frame that was to be lighter than my Giant Warp (which is what my all-mountain is built around) frame, and pretty much all frames this year have some sorta bob-resisting shock.

As to the longer tubes flexing more. Depends where you're applying the load, and what shorter tubes you're comparing them to. Given how just about every manufacturer today spec's beefier tubes for bigger frames as a second nature event (at one time, sure, 10 years ago, only custom brands did it), I doubt a 42cm version of a road frame is going to be any stiffer than the 60cm size of the same frame.
 
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