Gear cable routing - backward steps

[raymondluxuryyacht]

Is it just me or does gear cable routing seem to be getting poorer on modern bikes?
Here are a few examples of what I see as strange changes/odd choices.
1) downtube gear cable routing
Surely the downtube is the worst place for a gear cable as it can be hit by flying debris and mud. Also if rear mech cable is routed that way then it would have to also be fed along the chainstay, which is nearer to flying debris and chain slap. I can see some merit to this routing on full suspension bikes though, but only where the relative movement of rear suspension would create problems for top tube and seat stay routed cables.
2) Full length gear cable outer. This is a possible source of unwanted extra cable friction. Possibly useful for full suspension bikes where design dictates cable is an exposed place but definitely should not be used on a hardtail (IMHO).
3) Why the heck gave shimano done away with the barrel adjuster on the latest rear mechs? I used to find this really useful when setting up gears. SRAM gave had this for a while which is why I don't buy their kit.

Grumpy old nan rant over.

 

[raymondluxuryyacht]

I just spotted the beautiful pace rc104 in mbr, but then I also spotted the cable routing. It's awful ! Exposed inner cable for the front mech on the down tube :-( Full length outer for rear mech cable at least but why did it have to be routed along the down tube and chainstay at all!!...and held on with a zip tie (sigh). Horrible modern mech with no barrel adjuster just for good measure.
I don't understand why the gear cables could not have been top tube routed on this hardtail. At worst the rear mech might have needed an outer along the seatstay (because too curvy for inner cable alone). This would have the benefit of no outer needed along the top tube. :?

 

[dbmtb]

Is it just me or does gear cable routing seem to be getting poorer on modern bikes?
Here are a few examples of what I see as strange changes/odd choices.
1) downtube gear cable routing
Surely the downtube is the worst place for a gear cable as it can be hit by flying debris and mud. Also if rear mech cable is routed that way then it would have to also be fed along the chainstay, which is nearer to flying debris and chain slap. I can see some merit to this routing on full suspension bikes though, but only where the relative movement of rear suspension would create problems for top tube and seat stay routed cables.

Not necessarily. I've never snapped a gear wire because it went under the down tube, in 20 years of MTBing. Have you? Personally I think it's the best routing for rear mech as it reduces cable length and when done properly, also friction. Top tube routing for front mech reduces clutter in B area where dirt will accumulate however....

Also with cable run down seatstays, moisture/debris is more likely to travel downwards into the cable housing when routed down from the seatstays, than it is horizontally when routed from chainstay.

2) Full length gear cable outer. This is a possible source of unwanted extra cable friction. Possibly useful for full suspension bikes where design dictates cable is an exposed place but definitely should not be used on a hardtail (IMHO).

Slight contradiction with point one there:
For sure - also N/C according to Shimano - and will be prone to collecting moisture under the bottom bracket shell. We saw this with Nexus and Torpedo systems here in Denmark, with huge problems in winters when that moisture froze to ice!

3) Why the heck gave shimano done away with the barrel adjuster on the latest rear mechs? I used to find this really useful when setting up gears. SRAM gave had this for a while which is why I don't buy their kit.

Probably because SRAM did and their market share keeps increasing!

I miss them too - and put an inline housing adjuster down there for the same reason. It's only really an issue for when you're adjusting on a workstand though. "on the fly" adjustments would be done at shifter anyway.

 

[dbmtb]

I just spotted the beautiful pace rc104 in mbr, but then I also spotted the cable routing. It's awful ! Exposed inner cable for the front mech on the down tube :-( Full length outer for rear mech cable at least but why did it have to be routed along the down tube and chainstay at all!!...and held on with a zip tie (sigh). Horrible modern mech with no barrel adjuster just for good measure.
I don't understand why the gear cables could not have been top tube routed on this hardtail. At worst the rear mech might have needed an outer along the seatstay (because too curvy for inner cable alone). This would have the benefit of no outer needed along the top tube. :?

It's because they made it Alfine compatible and Alfine runs a closed cable system. Neither can you run Alfine cable down the seatstays due to cassette joint.

RC104 is trying to be many things to many people and compromise has clearly had to be made.

See also this thread
http://www.retrobike.co.uk/forum/viewto ... sc&start=0

 

[FluffyChicken]

While I prefer top tube routing myself, there is really not much wrong with downtube other than forgetting to oil/clean the cable on the plastic guide and with the current shadow style mechs there is not the large loop to the rear mech any more.

As for 'friction' on full length. While I've never used it, I would expect the friction increase in length to be little.
Why, well the 'seals' or little o-rings in the furrels exert the most friction in the whole system couple that with dirt rubbing in these places you can see why it may be used as full length, that and
a) it'll match up with disc brakes
b) it's easier, just two cuts and that's it. Ziptie it on as per disc brakes
c) it really just a full blown cheap sealed 'goretext/dirtbuster/other fancy name for fully sealed system.
No I wouldn't use it unless I had too

I miss the mech adjuster, but it makes the mech lighter and you have an adjuster at the other end of the system anyway.

 

[hamster]

I miss the mech adjuster, but it makes the mech lighter and you have an adjuster at the other end of the system anyway.

Yep, when I'm riding I can always feel that 5g weight saving. :?

 

[MiniNinjaRob]

I've never had a single problem with down tube cable routing on my bikes in over 20 years. It looks better, you don't need as much outer cable, there's not many bends in the outer apart from at the mech. It's easier to lube the cables, takes 60s. Top tube routing looks ugly, your TT ends up getting scratched, the cable down the seatstay looks rubbish. If they are under the top tube it's harder to carry the bike. The cable stops snag your shorts/skin.

Down tube/BB routing every time for me!

 

[Andy R]

It's because they made it Alfine compatible and Alfine runs a closed cable system. Neither can you run Alfine cable down the seatstays due to cassette joint.

Actually, it can be (and frequently is) run down the seat stay

You just need to use anti-rotation washers to suit this positioning.

 

[Iwasgoodonce]

Again, I have never had a problem with under the BB route for a cable on a mountain bike. With the top tube however, if the guides go underneath it, shouldering the bike is horrible and I did once 'catch myself a nasty one' on a guide fitted to the side of the top tube.

Totally agree with you with regards the barrel adjuster. Plonkers.

 

[dbmtb]

You just need to use anti-rotation washers to suit this positioning.

There's always one.....

Yes - this is indeed true. But to get this far, you have have pretty in depth knowledge of Nexus/Alfine and a willingness to ignore Shimano specifications.

Frequently? I would say the unliklihood of fitting Alfine onto a bike that would need this routing makes "on occasion" perhaps more fitting than "frequently".

I've had hundreds (like as not over a thousand TBH) of Alfine/Nexus bikes pass through my spanners and never seen this configuration before.

I would also maintain that this routing "is a bit dodgy" as fragile cassette joint is a bit too close to the chain and not snugly hidden away under a protective chainstay.

I would however be interested in experimenting with this one day, to see if it would eliminate the frozen cable bugbear. Logically - moisture would run down and out of the system, which is not what happens with standard fitting.