Beginner Gear Cable Questions

[goodgabba]

Hi all. I just got a new (to me) Cyclocross bike and have some questions regarding gear cables, namely for the front derailleur.

1. Do i need to by specific cables/housings for this bike or do they sell 'universal' ones?
2. What's the plastic guard that routes the cables under the Bottom Bracket called?
3. The bar tape seems to cover where the gear cable enters the shifter - can i simply pull it up and re-lay it once I've replaced the cable or do i need new bar tape?
4. Overall, how difficult is it to replace the cables and housings?

Front Derailleur: SRAM Apex
Bike: Boardman CX Team 2012 (Link to details here)

Background: The front derailleur was seated too high plus was stiff to move. I've moved it down and adjusted the cable but it is now rather frayed and i daren't remove it until i have a spare replacement. I want to remove the cable, check the shifter moves freely, then replace the cable/housing/BB guard.

The bike itself:

 

[Pale Rider]

Gear cable is slightly thinner than brake cable, so you need to buy the right one.

Outers are also different, gear outer is 'compressionless', so once again you need to buy outer specced for gears.

Or you could use what's there, chances are there's nothing wrong with it as you say the cable now moves freely.

Roadie shifters are not my thing, but pay careful attention to the existing routing and copy it, particularly the way the cable enters the front derailer.

 

[boydj]

I'd just replace the inner. You should be able to thread it through without disturbing the outer or moving bar tape.

 

[Sea of vapours]

1. They're 'universal' in as much as you need a 'road bike gear cable set', which will have inner and outer cables and all the assorted ferrules. Alternatively, you could buy each of those bits separately. Search on a major on-line bike bits shop for 'gear cable set'.
2. That sounds as if you mean the bottom bracket gear cable guide. Again, available by searching for 'bottom bracket gear cable guide'.
3. Whether you can re-use the tape depends on the type of tape and your degree of care. In principle, yes. The tape I use tends to last 4-5 re-wraps quite happily, but I've also once used tape which was never going to survive removal. Probably best to have some available if you're going to be inconvenienced /if/ it can't be re-used.
4. Assuming you're mechanically competent, as you sound, and take note of how things come off, and hence can reverse the process, it's really very easy with a modicum of care.
(Note that the rubber cover on the brake/shift levers peels/rolls up from both front and back of the shifter You'll need to peel it up, away from the bars, to access the gear cable housing for removal and reinsertion of the gear cable.

 

[MichaelW2]

Cyclists routinely change the inner cables once a year but the outers can last for several years and do not need to be replaced. You may be able to re use bar tape but since you change outers once every couple of years, the tape can usually do with a refresh.
New cables are soldered at one end and you thread it through the gear changer hole and into the cable outer. You need to smear a little grease over the cable inner before fitting . Once attached you should cut off the excess length cleanly and squeeze a ferrule over the end to prevent fraying.

 

[SkipdiverJohn]

4. Assuming you're mechanically competent, as you sound, and take note of how things come off,.

Better still, use a phone camera for a purpose rather more worthwhile than just drunken selfies, and keep a photographic record of how things were set up before dismantlng them.

 

[alicat]

^^^ wot he said. Take pics as you go along.

 

[raleighnut]

+1 for just fitting a new inner cable.

 

[goodgabba]

What i might do it take it to my local bike shop and get them to check/set it up/replace cabling correctly. From then on i know it's been set up properly and hopefully they can shed more light on why the front derailleur/shifter is so stiff to move.

 

[raleighnut]

What i might do it take it to my local bike shop and get them to check/set it up/replace cabling correctly. From then on i know it's been set up properly and hopefully they can shed more light on why the front derailleur/shifter is so stiff to move.

Front shifters are always noticeably more difficult to move than rear shifters but they shouldn't be stupidly stiff, hard to tell from here how bad yours are.

 

[goodgabba]

Front shifters are always noticeably more difficult to move than rear shifters but they shouldn't be stupidly stiff, hard to tell from here how bad yours are.

It's very stiff - to the point where it aches your fingers after a few repeated shifts. Originally the front derailleur was over 1cm too high up over the big chain ring which i suspect was the original owners doing. What concerns me is if he had made that mistake he may slightly wired it up wrong and/or not replaced the outers or the bottom bracket guide properly (hence the stiffness).

 

[raleighnut]

It's very stiff - to the point where it aches your fingers after a few repeated shifts. Originally the front derailleur was over 1cm too high up over the big chain ring which i suspect was the original owners doing. What concerns me is if he had made that mistake he may slightly wired it up wrong and/or not replaced the outers or the bottom bracket guide properly (hence the stiffness).

A cm too high suggests a change in Chainset, what's it got on the front now?

 

[goodgabba]

A cm too high suggests a change in Chainset, what's it got on the front now?

Amazing insight! You are totally right i had forgotten that he he changed the front chainring from 50t to 46t! That must be the reason. The previous owner said he changed the cables too which i don't doubt but i wonder if the outers/bb guard was changed too

 

[Pale Rider]

Cable routing into the clamp could be the problem.

On a secondhand bike I bought years ago someone had looped the cable around the pinch bolt then through the clamp, presumably because they thought that would give a firmer grip on the cable.

The shifter was very stiff, cured by routing the cable straight into the clamp.

 

[the snail]

It's very stiff - to the point where it aches your fingers after a few repeated shifts. Originally the front derailleur was over 1cm too high up over the big chain ring which i suspect was the original owners doing. What concerns me is if he had made that mistake he may slightly wired it up wrong and/or not replaced the outers or the bottom bracket guide properly (hence the stiffness).

Change the inner and make sure the FD isn't seized, and check the guide under the BB isn't worn/gunged up. Putting a MTB crankset on a road setup could cause problems too.