Cables threaded inside frame... any downsides?
 

Howdy all. I recently got myself a 2007 Trek Soho as I work myself back into biking for commuting and general health. So far, I'm very pleased with this Soho, but already my mind is looking forward to my next bike as I gradually decide what I like and don't like, want, etc.

One thing I like about this Soho is how the cables for the deraillieur and brakes are threaded inside the frame to minimize the amount of cabling exposed on the outside. I've never had a bike like that, and it seems to be a great idea offhand. Less exposed cable means less opportunity to snag on it. If the need arose, I could wrap something around the frame to help carry something without interfering with the cable.

In looking at other bikes, like Cannondale for example, it seems this method of threading the cables inside the frame hasn't taken off with all bike manufacturers. At least in so far as I can tell from looking at the photos of their bikes. So... I'm wondering if there's any downsides to running cables this way? Offhand, I suppose water could seep inside through the openings and lead to rusting from the inside perhaps? Any other thoughts or insight?

Water in the frame is on issue, another is holes in tube makes the tube weaker... but size and placement are a large factor in that as well.

From Sheldon Brown:

Internal cable routing:
The practice of running gear or brake cables through the inside of a frame, instead of outside. This is usually done for the sake of making the bike look nicer. Unfortunately, internal cable routing usually degrades performance by increasing weight and cable friction. It can also make servicing the bicycle more difficult.

So its not a new idea by any means. I can see the advantage for an "urban" type bike - I have the snag issue when I carry my bike up the stairs - but it comes at a performance cost.

My Electra Townie has the rear brake cable routed through the frame. Fortunately its only the one cable.

If you eventually wore out the cable sheath it might be difficult threading a replacement through the frame. Although replacing the cable itself shouldn't be a problem unless theres a tight bend in the sheath where its inside the frame.

There is no cable "snag." External cables work just fine, it may not look as clean at first but that's what bikes SHOULD look like.

If u have been watching Chopper building at the Discovery Channel, there are two schools of thought (1) Build farings and hide all the mechanical stuff to make bike look slick, or (2) Classic bike building where all the mechanical stuff are on plain view. IMHO, the classic look is forever.

External cables and split stops allow easy cable maintenance.

The cables can be released in a snap...not so much with internal.

just be sure and know your wrench is familiar with such. Once a mechanic replaced by cables on my Klein. after he started he said he's never done one before. It took him a couple hours to run the cables through the tube. Since I rode in , i was afraid I'd not make it home before dark.

Thanx for all the input. I can certainly see how adding extra curves in the cabling to route it inside the frame can add extra friction on the cable when braking or shifting. I'm sure that if it's done right, it shouldn't be unreasonably more though. At least not for my needs. I found a web page that gives some tips on cables to use that minimize the friction.

The extra weight it may add... I can't imagine it'd add enough to bother me. Maintenance looks like the biggie issue. I read a couple tips on how to run new lines and while it sounds simple on paper, I'm sure in practice it's a whole different thing! I think all in all... it won't be a must-have feature on my next bike, but it won't be a deal-killer either.