Road bikes sloping top tube, why?
02-15-08, 10:54 PM
#26
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If I read this correctly, you are stating that a more direct route from your headset to the bar center is not as good? From a STYLING view, yes reads "comfort" bike, aka $340. hybrid. Now the length is another story, if you cannot get the correct length with the rise, thats a supply problem.
Do note, I can ride a 2cm smaller frame with the same top tube on a 40's to 50's bike than a 70's frame as the saddle has a different dimension from rail to contact surface, but I like 8cm of drop from saddle to bars...old racers have a hard time doing otherwise. But I will admit, I ride on the hoods mostly, then get into the drops when the going gets Serious.
A distributor loves this compact geometry stuff, as noted makes the SKU's easier to manage, now there is a possible chance that a short top tube (effective horizontal length) MIGHT when mated to a long stem to get a good position will yield a better handling machine. I felt that way on an old criterium bike in the 70's, but NOT when going down hill, just around 90 degree turns.
Do note, I can ride a 2cm smaller frame with the same top tube on a 40's to 50's bike than a 70's frame as the saddle has a different dimension from rail to contact surface, but I like 8cm of drop from saddle to bars...old racers have a hard time doing otherwise. But I will admit, I ride on the hoods mostly, then get into the drops when the going gets Serious.
A distributor loves this compact geometry stuff, as noted makes the SKU's easier to manage, now there is a possible chance that a short top tube (effective horizontal length) MIGHT when mated to a long stem to get a good position will yield a better handling machine. I felt that way on an old criterium bike in the 70's, but NOT when going down hill, just around 90 degree turns.
And...I think that it looks ugly, too.
The real point of the note was that the (expensive) fork needs to be cut to length, and that may not work out for the next guy downstream. But, then again, the manufacturers probably don't want it to work out anyway.
02-15-08, 11:28 PM
#27
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I forgot to mention that a single spacer is useful, between the headset and the stem...at least 5mm, just ask those Trek mechanics after the P.R. fiasco, bar detachment.
Oh yes, the threadless stems are faster to assemble on the production line.
At NAHBS, there was a few external/internal threadless stems, the steerer inserted into the stem that had a pinchbolt like a seatpost binder, with that, one can get the height, have a level extension and look retro and cool custom and modern at the same time, whats money for a cool look.
Oh yes, the threadless stems are faster to assemble on the production line.
At NAHBS, there was a few external/internal threadless stems, the steerer inserted into the stem that had a pinchbolt like a seatpost binder, with that, one can get the height, have a level extension and look retro and cool custom and modern at the same time, whats money for a cool look.
02-16-08, 03:21 AM
#28
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I see that Thorn still list a horizontal frame, but their newer one's slope ...
02-16-08, 07:02 AM
#29
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It's cheaper for the manufacturer to build bikes that way. One frame can fit many different sizes of people by adjusting the seat post, and stem lengths. Personally I prefer a standard frame. I really dislike a longer than neccessary seat post. I suspect adults today who grew as bmx riders think it looks normal.
02-16-08, 10:28 AM
#30
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I forgot to mention that a single spacer is useful, between the headset and the stem...at least 5mm, just ask those Trek mechanics after the P.R. fiasco, bar detachment.
Oh yes, the threadless stems are faster to assemble on the production line.
At NAHBS, there was a few external/internal threadless stems, the steerer inserted into the stem that had a pinchbolt like a seatpost binder, with that, one can get the height, have a level extension and look retro and cool custom and modern at the same time, whats money for a cool look.
Oh yes, the threadless stems are faster to assemble on the production line.
At NAHBS, there was a few external/internal threadless stems, the steerer inserted into the stem that had a pinchbolt like a seatpost binder, with that, one can get the height, have a level extension and look retro and cool custom and modern at the same time, whats money for a cool look.
That's okay...because it takes a mountain of bikes to equal one consumable car. and there are always people like us fishing the bikes outta the trash.
05-29-08, 01:58 PM
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Why Not?
05-29-08, 04:17 PM
#33
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05-29-08, 05:02 PM
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Not solely based on economics; the desire to ride what the pros have is also there. It's why Americans starting riding racing bikes in the 70's in the first place. Of course, they had to have stem shifters and turkey levers, too.
My Orbea has a slight slope to the top tube; My Bianchi does not. The Orbea is a faster, more nimble bike but it is also lighter and has 19 more gears.
Definitely wouldn't kick this out of the garage:
Or this either:
slope, no slope; it's all good.
My Orbea has a slight slope to the top tube; My Bianchi does not. The Orbea is a faster, more nimble bike but it is also lighter and has 19 more gears.
Definitely wouldn't kick this out of the garage:
Or this either:
slope, no slope; it's all good.
05-29-08, 05:13 PM
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Why is a sloping top tube such a big deal? With the invention of the mountain bike longer seat post were invented. Bike maker decided to use them on road bikes. Not a big deal. I personally like the modern look but i have older bikes with traditional frames i like also. Go to any bike shop & buy the style you choose.
05-29-08, 10:08 PM
#39
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Why is a sloping top tube such a big deal? With the invention of the mountain bike longer seat post were invented. Bike maker decided to use them on road bikes. Not a big deal. I personally like the modern look but i have older bikes with traditional frames i like also. Go to any bike shop & buy the style you choose.
Showing my age here. but I even like MTB's with level top tubes, hehe.
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05-29-08, 10:32 PM
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Throwing another theory into the fire:
If you can't come up with a new way to reinvent the bicycle, you ain't going to sell any!
-Kurt
If you can't come up with a new way to reinvent the bicycle, you ain't going to sell any!
-Kurt
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05-30-08, 12:41 AM
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does proximity of the stem to the headset induce stresses that can eventually lead to steerer failure? thanks for the interesting feedback!
05-30-08, 01:22 AM
#44
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I haven't been around here for a bit due to injuries (face planted coming downhill at 40ish mph, pretty happy being alive), but this debate is always fun.
As you've said, it's for economics, aesthetics, and because it might fit some people better.
There are sloping (compact) frames, semi sloping (semi compact), and traditional geometry frames. If you look at todays pro peloton, all of these kinds of frames are present with no ill effect on the riders. It's just a matter of taste. Compact frames are supposed to be stiffer, but there have not been any real tests on stiffness vs efficiency yet (i.e. does frame flex with a steel frame make you 'waste' energy?).
Either way, ride what you like and the world will be a happy place
PS Bikedued, horizontal top tube mtb's? What are you, from the early 80's or something? You probably like rigid forks as well
05-30-08, 03:53 AM
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A road racing bicycle is designed for efficient power transfer at minimum weight and drag. Broadly speaking, the road bicycle geometry is categorized as either a traditional geometry with a horizontal top tube, or a compact geometry with a sloping top tube.
Traditional geometry road frames are often associated with more comfort and greater stability, and tend to have a longer wheelbase which contribute to these two aspects. Compact geometry road frames have a lower center of gravity and tend to have a shorter wheelbase and smaller rear triangle, which give the bike quicker handling. Compact geometry also allows the top of the head tube to be above the top of the seat tube, increasing standover clearance, and lowering the center of gravity. Opinion is divided on the riding merits of the compact frame, but several manufacturers claim that a reduced range of sizes can fit most riders, and that it is easier to build a frame without a perfectly level top tube.
THANKS WIKIPEDIA!
Traditional geometry road frames are often associated with more comfort and greater stability, and tend to have a longer wheelbase which contribute to these two aspects. Compact geometry road frames have a lower center of gravity and tend to have a shorter wheelbase and smaller rear triangle, which give the bike quicker handling. Compact geometry also allows the top of the head tube to be above the top of the seat tube, increasing standover clearance, and lowering the center of gravity. Opinion is divided on the riding merits of the compact frame, but several manufacturers claim that a reduced range of sizes can fit most riders, and that it is easier to build a frame without a perfectly level top tube.
THANKS WIKIPEDIA!
There is a difference in ride quality between the newer compact frame design and the traditional diamond frame. The larger frame provides a much "damper" ride. The slope or "rake" of the forks and head tube is old-school's answer to soft suspension.
The newer frames, have less metal and are lighter weight. Bicycle engineers have always chased the lightweight, strong, low-cost combination which the later compact frames offer.
