Is crossing cables underneath bike ok?
02-25-17, 09:45 AM
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Is crossing cables underneath bike ok?
Just picked up my new built Specialized Allez Sprint from local LBS for cable work. The cable crossing looks shoddy to me. What do you think?
02-25-17, 09:54 AM
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I think that you're looking at the wrong end. How does the cable routing look at the head tube? I'll often cross the cables under the down tube to get a smoother curve to the cable routing at the top. Looks and works better for some bikes but not for others.
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02-25-17, 10:05 AM
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This is the head tube.
02-25-17, 10:32 AM
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If they didn't cross the cables under the bike the cables would have had to make a much sharper turn at the front which would have affected both the function and aesthetics; I think they did the right thing.
02-25-17, 12:38 PM
#5
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Not at all uncommon to cross cables underneath to achieve better, smoother routing from the bars.
02-25-17, 05:06 PM
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On almost all bikes the cables should never have to cross.
Left shifter/brake cable stays on the non-drive side of the bike and right shifter/brake cable stays on the drive side of the bike.
Crossed cables is often a sign that someone didn't take the time to size the housings properly. It is an iterative process which most people are not willing to spend the time on.
Routed properly the cables can take a tighter radius without binding than most people think.
-Tim-
Left shifter/brake cable stays on the non-drive side of the bike and right shifter/brake cable stays on the drive side of the bike.
Crossed cables is often a sign that someone didn't take the time to size the housings properly. It is an iterative process which most people are not willing to spend the time on.
Routed properly the cables can take a tighter radius without binding than most people think.
-Tim-
02-25-17, 05:14 PM
#8
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There is nothing wrong with crossing the cables , as other said it look better and perform better .
02-25-17, 05:54 PM
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Some brifters have cable exits that make it difficult to avoid crossing without impinging on free movement of the cable. If it comes to a choice between aesthetically pleasing uncrossed cables and poor shifting versus crossed cables and decent shifting, I know what my choice would be.
02-25-17, 06:02 PM
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On almost all bikes the cables should never have to cross.
Left shifter/brake cable stays on the non-drive side of the bike and right shifter/brake cable stays on the drive side of the bike.
Crossed cables is often a sign that someone didn't take the time to size the housings properly. It is an iterative process which most people are not willing to spend the time on.
Routed properly the cables can take a tighter radius without binding than most people think.
-Tim-
Left shifter/brake cable stays on the non-drive side of the bike and right shifter/brake cable stays on the drive side of the bike.
Crossed cables is often a sign that someone didn't take the time to size the housings properly. It is an iterative process which most people are not willing to spend the time on.
Routed properly the cables can take a tighter radius without binding than most people think.
-Tim-
02-25-17, 07:35 PM
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I think bikes look better when the cables don't cross but thats just me.
Again, most people don't realize how tight a radius the cables can have before binding. Internal handlebar routing is a perfect example of very tight radius without binding.
Most binding and causing the brakes to grab is caused by housing cut too short anyway, and has little to do with how the cable curves.
Electronic renders the whole topic moot.
Again, most people don't realize how tight a radius the cables can have before binding. Internal handlebar routing is a perfect example of very tight radius without binding.
Most binding and causing the brakes to grab is caused by housing cut too short anyway, and has little to do with how the cable curves.
Electronic renders the whole topic moot.
02-26-17, 03:29 AM
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I reckon crossing is a bad idea, because when the cable goes around the head tube, sure, it was a wider radius - but a), turning the bars has more of an adverse effect on the housings, and b), you're using more housing and cable than necessary to get the job done, putting more friction back into the equation.
IME cables are much happier staying on their own side of the bike. It's neater and works better, IMO.
On the bike in the OP it looks like the cables should cross inside the downtube to create a straighter path, but they don't. Perhaps it wasn't designed to allow a gap between the cables if they're crossed in there.
Or perhaps the standard routing is just suboptimal, which is not uncommon these days; lots of makers going with the silly around the head tube idea.
IME cables are much happier staying on their own side of the bike. It's neater and works better, IMO.
On the bike in the OP it looks like the cables should cross inside the downtube to create a straighter path, but they don't. Perhaps it wasn't designed to allow a gap between the cables if they're crossed in there.
Or perhaps the standard routing is just suboptimal, which is not uncommon these days; lots of makers going with the silly around the head tube idea.
Last edited by Kimmo; 02-26-17 at 03:33 AM.
02-26-17, 04:08 AM
#13
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Some brifters have cable exits that make it difficult to avoid crossing without impinging on free movement of the cable. If it comes to a choice between aesthetically pleasing uncrossed cables and poor shifting versus crossed cables and decent shifting, I know what my choice would be.
Brad
02-26-17, 11:36 AM
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Very well said with minimal number of words. !
I recently reassembled our tandem (after a paint job with braze on changes. See this thread https://www.bikeforums.net/tandem-cyc...-comotion.html I chose the shift cable casing paths at the bars for the least tight curves (and steering influence), ran the cables parallel down the down tube then had then cross back along the boob tube so to enter the rear Bb shell guide tunnels cleanly and on the proper sides. Andy.
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02-26-17, 01:31 PM
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Very well said with minimal number of words. !
I recently reassembled our tandem (after a paint job with braze on changes. See this thread https://www.bikeforums.net/tandem-cyc...-comotion.html I chose the shift cable casing paths at the bars for the least tight curves (and steering influence), ran the cables parallel down the down tube then had then cross back along the boob tube so to enter the rear Bb shell guide tunnels cleanly and on the proper sides. Andy.
I recently reassembled our tandem (after a paint job with braze on changes. See this thread https://www.bikeforums.net/tandem-cyc...-comotion.html I chose the shift cable casing paths at the bars for the least tight curves (and steering influence), ran the cables parallel down the down tube then had then cross back along the boob tube so to enter the rear Bb shell guide tunnels cleanly and on the proper sides. Andy.
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02-26-17, 07:50 PM
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On almost all bikes the cables should never have to cross.
Left shifter/brake cable stays on the non-drive side of the bike and right shifter/brake cable stays on the drive side of the bike.
Crossed cables is often a sign that someone didn't take the time to size the housings properly. It is an iterative process which most people are not willing to spend the time on.
Routed properly the cables can take a tighter radius without binding than most people think.
-Tim-
Left shifter/brake cable stays on the non-drive side of the bike and right shifter/brake cable stays on the drive side of the bike.
Crossed cables is often a sign that someone didn't take the time to size the housings properly. It is an iterative process which most people are not willing to spend the time on.
Routed properly the cables can take a tighter radius without binding than most people think.
-Tim-
Ben
02-27-17, 03:29 AM
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Folks talking about smooth bends seem like they don't realise that even though tight bends cause friction and sponginess, so do long bends.
So it's gonna be close to same difference, depending on how much you can shorten the housing without tightening the bend too much.
And here's the thing: if you watch what happens to a cable that goes around the head tube as you turn the bars each way, on the side the bend tightens, it becomes a horseshoe shape. Turn the other way, and it goes more like an Ohm symbol: Ω
A cable that doesn't cross the head tube behaves the first way but not the second, instead straightening out and gently wrapping around the head tube instead of doing nasty little kinks at each end.
If there's a way to use less metal to do the job better, I'll take it every time.
Oh yeah - everybody's using die-drawn cables, right?
They may fatigue quicker, but not only do they dramatically cut down friction, the housing liners last better.
So it's gonna be close to same difference, depending on how much you can shorten the housing without tightening the bend too much.
And here's the thing: if you watch what happens to a cable that goes around the head tube as you turn the bars each way, on the side the bend tightens, it becomes a horseshoe shape. Turn the other way, and it goes more like an Ohm symbol: Ω
A cable that doesn't cross the head tube behaves the first way but not the second, instead straightening out and gently wrapping around the head tube instead of doing nasty little kinks at each end.
If there's a way to use less metal to do the job better, I'll take it every time.
Oh yeah - everybody's using die-drawn cables, right?
They may fatigue quicker, but not only do they dramatically cut down friction, the housing liners last better.
Last edited by Kimmo; 02-27-17 at 03:33 AM.
