why no cable housing on top tubes?
 

I am wondering why there are no bikes with cable housing along the top tubes? The steel cables could get damaged and same for under the down tube. You could have these housing items between cable bosses. Anyone know why?

Less friction.

older bikes have full length of cable housing from the lever to the caliper.

it's heavier and sloppier that way.

the cables, they're pretty strong.

My wife's Giant hybrid has cable housing along the top tubes. You can stop worrying about that cable getting damaged.
By the way, I don't remember having cable damage problems on exposed cable on any of our bikes.

Lots of bikes have braze-ons for top tube routing of cable housings...

http://4.bp.blogspot.com/_SZx2oaxuJS...BrCables03.jpg

I agree with not any damage on the cable. i was just theorizing as I am building a bike and I am to the cable installation and I dont find anything on road bikes with full length cable housing. Just pondering. It is answered, less friction and weight. Thanks all

Interesting. Is this a road bike? Looks like it from the size of the tire.

Friction and weight... bah!

Bike manufacturers don't eliminate the housings to save weight or reduce friction. They do it to save every penny that they can on their cost of materials. Four feet of housing times thousands of bikes adds up to a lot of cash saved.

Those naked cables enter and leave sections of housing along the way to the brakes... and each of those interfaces generates friction. I'd wager that the friction from an uninterrupted run of quality housing is lower than that from a cable that goes through four different cable/housing interfaces.

Look here. You'll see hundreds of road bikes with cable housing on the top tube.

A lot of older Italian steel road frames had housing guides on the top tube for the rear brake cable. My 83 Colnago does. Hydrated's bike looks like it may well be an older Italian frame too based on the Columbus tubing sticker I see on the seat tube.

Most current geared hub bikes I am aware of also have provisions for full length housing runs for both shifter and brake cables. My Swobo Dixon has them while my Civia Hyland Rohloff has provisions for two shifter cables and brake hydraulic hose. Full length housings do help keep dirt from getting into the cable housings IMO.

What is the price of brazing and painting 3 or 4 more cable guides on thousands of bikes?

says you. it's quite different to have to run +2m of housing as opposed to 1.2~1.4m of housing. front brake and rear brake are noticeably different because of the length difference.

About the same as brazing and painting those cable stops that go along with those naked cables on your top tube.

There is no realistic downside to exposed rear brake cables along the top tube, particularly with stainless steel cables. The minor weight, friction and cost savings are incidental and, what, if any, benefit is there to full length housing?

When you think of the huge expense some riders go to to save a few grams, the loss of 25 to 30 grams of cable housing weight at no cost or function penalty has to be a plus.

I prefer full housing, less slop to get in and dirty the cable run. Most of my bikes have full housing runs, But I have one that does not. I keep saying I am going to drill out the stops so I can run full housing but I have not yet. It seems to be alright. But I do have to replace the cable more often as it gets much dirtier.

2m of housing? What sort of bike are we talking about? I guess then it might make a difference? Never tried it. 1m certainly doesn't make any difference.......

Your housing is too long.

Now now... every system has its downside. And every system has its upside.

Exposed cables will be more susceptible to damage than housed cables. You probably won't rip exposed cables off of your bike under normal conditions, but they will get tweaked or pulled more often than housed cables... resulting in more frequent adjustments. And before it even gets posted... spare me the "I have exposed cables and I haven't had to adjust my brakes since 1998!" I know that some people are careful and will rarely bump or pull those cables... and that's good. No problem for you then.

Now to answer your question about the benefits of housed cables. The main reason that I like housings along the top tube is because housings make the top tube usable. What I mean is this: I ride my bike every day to work and to run errands. So I sometimes need to carry things, and sometimes I carry stuff by strapping bags or items onto the frame with velcro straps. If I use exposed cables, the straps may interfere with the operation of the cables running along the top tube. With housings I can simply strap the item on and go. No worries about cable travel or binding.

And I couldn't ride my favorite bike without housed cables. My 1984 Trek 520 rides like a Cadillac with its comfy position and stretched out frame that soaks up bumps. I like the longish top tube but it comes at a price... the standover height is too tall for me to stand comfortably with both feet flat on the ground. The frame fits me great when I'm in the saddle, but not when I'm stopped. When I stop, I tend to unclip one foot and stand with the frame leaned to one side. The back of my thigh rests across the top tube... if I used exposed cables, this would be a problem. But my housings don't care. I know that this is an odd benefit to using housings, but it is a benefit.



I know what you're saying about weight savings, but if you actually look at the numbers it starts to look kind of silly. Do you know that 30 grams equals 1.05 ounces? If saving 1.05 ounces is going to make that much difference to your performance, then go for it.

But almost every rider out there is carrying around more than 1.05 ounces of bad dietary choices. Hell's bells... a single fluid ounce of water weighs 1.04 ounces. Just go pee before you get on the bike. Or pass on that post-ride slice of pizza.

LOL... sorry I unintentionally misled you. That's not my bike. I just found that picture on the interwebz.

I've got an old Italian frame setup like that picture (slighly shorter cable, but still....). My new English frame (Mercian) would've been like that had I not opted for the internal routing. Haven't gotten that yet - not sure if I'll be feeding a housing all the way through or just the cable. Either way, it's housed.

Well, I agree that it's silly but there are a lot of folks out there who see $100/oz as a good deal. The big difference between a pair of Eggbeater C and Eggbeater 4Ti is 4oz and $400. With frames it's a lot more expensive than that. At those rates a free oz is priceless!

Is that really considered too long? I like mine about like that to keep the housing off the paint.

6 of 1, 1/2 dozen of the other. Makes no functional difference

If the cable stops are slotted, exposed systems are much easier to lube than full length housing systems.

One other comment on this topic. I notice from the pictures posted here and from my own '83 Trek 400 that full housed rear brake cables seem to be run along the top of the top tube (the 12:00 O'clock position) while open cables are routed on the lower left side (7:00 O'clock) of the top tube.

The 7:00 routing seems more out of the rider's way so I wonder why it isn't done with fully housed cables too.