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Changing shift cable set (Tiagra)

joewein

Maximum Pace
Oct 25, 2011
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Recently I've been having problems with shifting gears. My attempts at adjusting the shifting via the barrel adjuster at the derailleur did not resolve the problem. In some gears it works OK, in others it's noisy or jumps back and forth. The behaviour is different with different front chain rings, not sure why that is.

My suspect is the shift cable to the rear: It has been squashed a couple of times when it got caught on the hinge below the bottom bracket while unfolding my Bike Friday after a train ride. Coincidentally, the problem seemed to reappear every time I took the bike on the train again. The cable casing looks kind of flattened where it got caught before, with visible lines across the casing where it got pulled around the edge of the hinge :(

From the symptoms I am not entirely sure the problem is the shift cable (how much can a chain wear over 4000 km? I'm not very good about cleaning it), but I want to change the cable anyway because of the visible squeeze marks. So I got a new Shimano road shift cable set at Y's and was looking at installing it. It contains 1700 mm of casing, two 2100 mm cables and various end pieces.

My derailleurs are Shimano 105 and the brifters are Tiagra 9sp (4503), with the shift cables coming out towards the inside while the brake cables run under the bar tape.

I have figured out how to remove the rear shift cable: shift to the smallest sprocket, undo the cable at the derailleur end, squeeze the brake lever and push the wire from the derailleur end. I'm puzzled however how to change the casing, which is the part that's damaged in my case and I have not found any instructions anywhere yet. :confused: Any advice or useful links?
 
Two other possible reasons for poor shifting performance in your case could be

(1) Setting of the limiter screws at the rear derailleur. Did you check this? With the barrel you adjust only the tension, not the final position of the rear derailleur. You need to adjust tension, if the chain doesnt move from the smallest to the second smallest sprocket when you shift.

You could also have tensioned too much, so that the wire and not the limiter screw is deciding the position on the smallest sprocket.

(2) Bended rear derailleur adaptor. That happens quite often when travelling with the bike in a bag unfortunately.

You need a special tool to check, so it is better to ask a shop (Nagai-San at Positivo checks this quite frequently, he would be a good choice)

But for the original problem:

Do you want to change only the casing at the chain stay or the complete casing from the brifters to the rear derailleur?

If the former, you need a cutter and cut one of the casings to the same length as the one you have removed. You remove the complete cable from the rear derailleur to the brifters. It should come out from the brifters itself. Then you insert the new cable in the brifters. This can be a little bit tricky. But as the shift cable doesnt run below the handle bar in the 9 Speed version you can exchange that casing from the brifters as well if you like.

You will need end caps when you have holders or inserts. They should come with the set, however sometimes you need special ones like that, so use the ones that are already installed at your bike:

http://www.roseversand.de/artikel/shimano-metall-endkappen-119489/aid:119491

Then you lead the cable through the last piece of the casing to the rear derailleur (attach endcaps) und connect it to the screw. Cut the cable. Start to adjust the rear dearilleur.

Here are some additional infos from Shimano:
http://bike.shimano.com/media/techd...ST-4500/SI_6LP0A_En_v1_m56577569830607086.pdf

It just takes some practice and some time and I am sure you wil be able to handle that. You will need a good cable cutter to cut the casings and the cable.

You can also use the cable cutter to fix the end caps on the wire. Make two or three small "cuts) at the wire end caps below the rim.

Also, it is hard to cut the casings straight (although brake casings are more difficult because they are thicker 5 vs. 4 mm and spiral reinforced) so a sharp spoke wil be handy to adjust the opening of the casing.

Good luck and good shifting!
 
Joe,
Post up some pictures of the cable routing on your bike. You've probably got a few more pieces of outer cable compared to a conventional road bike to deal with the folding.

AW.
 
Perhaps the most common issue with poor shifting is worn casing and barrel ends.

1) The casing needs to be 100% rigid. Any flexing in it will affect the cable throw.
2) The casing ends need to be 'dressed' perfectly flat. You should use a carbide grinder or diamond grit file for this.
3) The casing 'barrels' need to be fitted perfect and I suggest using the alloy ones vs. the plastic ones for even less compliance at the casing end.

Then you can at least be assured that when you apply the shift lever - the travel will equal the cable throw required.

Then as other parts wear, the cable throw will vary and cause similar shifting issues. So, then you need to start looking at:

1) Derailler Jockey Wheels - as they get worn it takes more or less travel to effectively shift.
2) Derailler hanger mis-alignment.
3) Excessive play in the brifters. Unfortunately Shimano are not rebuildable (like Campy).
4) Worn chain links - takes too much side pressure to get them to jump to the next cog.
5) Worn inner cable - may have some broken strands.

etc, etc...
 
Thanks for the input, m o b, Alan and Tim.

I didn't think the limiter screws were the culprit because I don't normally touch them without necessity.

Alan, here are some pictures illustrating the cable layout. The casing is in one piece, from the shifter to the derailleur. There is no separate chainstay section and no exposed cable section, due to the requirements of the folding mechanism. I have heard that the cabling can be a bit of an Achilles heel on Bike Fridays, as it has to accommodate the geometry of the fold.

View of right brifter, with shifter cable to the right:

IMG_2630.JPG


Cable from shifter to bottom bracket:

IMG_2631.JPG


IMG_2632.JPG


Shift and brake cable around bottom bracket and hinge (with bolt on side):

IMG_2638.JPG


Along chainstay to derailleur:

IMG_2634.JPG


Damaged section that repeatedly got caught on the vertical portions of the rear triangle hinge. Ouch! :eek:

IMG_2639.JPG
 
Joe,

that flat damaged section in the last photo is 100% the culprit of all your woes - the inner housing off the cable housing is wrapped steel and where it has been flattened it is most probably pinching the inner cable and preventing it from slipping when shifting down gears.

I take it the issue only really arises when you are shifting down, no?

Unfortunately to resolve this issue you will have to replace the housing to the cable, also I would check the actual cable to make sure that there are no kinks in it as this can also cause some issues when shift up gears.

Also if you do replace it I would suggest for that piece of cabling switching out for a 100% metal housing – I've seen these at Y's and they are apparently designed to offer smother shifting but I think this would be perfect for your situation. Unfortunately it doesn't come cheap.

Look at Nokon Housing - its just one of many products that will resolve this issue.
 
Joe - I don't think you're too far away, so if you don't have the tools to hand I can help out. On the other hand, a good set of cable cutters is a handy tool in one's arsenal.

I would always replace the inner cable when replacing the housing, and I would always use a Shimano stainless-steel inner cable. There are some very minor benefits associated with Teflon-coated inners, but with Tiagra switchgear and all those curves I doubt it's worth the extra cost - better to save your money and get a spare cable for next time it happens.
 
I agree with James - that flattened section will ruin the shifting.

You'll need a full-length outer cable for each shifter and most of the Road Bike cable sets come with three short sections instead. I hope the set you bought has the 1700mm outer as one section.

The routing you have looks pretty good with respect to length and curve radius. When you install the new outer, you could look for a short piece of metal or tough, hard plastic tube to protect the section that was crushed, otherwise it's likely to get damaged again. It would be a lot cheaper than a full Nokon or I-Link outer. You could slide it over the cable outer before zip-tying the outer to the frame, then tape or zip-tie the tube in the right place.

I also refer you to Sheldon Brown's article on installation.

AW.
 
There are several types of reinforced housing:

cutting-cable-housing.jpg


Im guessing the one on the left is the one you are currently using?

This type is prone to poor shifting if crushed due to the wrap biting on the cable and causing friction or jams.
 
I tried alot of cables -

Shimano Cable Kit: No brainer. They just work.
GORE Ride-On!: Smoothest but a bit hassle to install and pricey.
NOKON: Best of both worlds (Gore and Shimano)
Yokozuna: Surpsingly good - and very corrosion resistant. Good price, too - but more expensive in Japan than US!!
JAG: I use their inners and Shimano outer all the time. Maybe my favorite combo.

Plus - I prefer the JAG Alloy endcaps to keep the cable ends solid and not 'mushy'.

Joe - Tiagra is a great set - easiest to change cable cause you just slide it in from the side. Make sure you are in your lowest gear. (front - small chainring and rear - smallest cog)

Adjusting Shimano is easy -

1) Always start with the cables slack.
2) Set the rear 'stop' so the derailler is perfectly aligned with smallest cog.
3) Spin your crank and slowly adjust the stop screw causing the derailler to shift up 1 cog. Then unscrew it to shift back down the smallest cog. Do this 1/4 screw increments. When it shifts, then screw another 1/2 turn out. The chainline should be smooth and noise free at this point.
4) Take up the slack in the cable and shift up to the largest rear cog (slowly cause you don't want to chance an over shift into the spokes)
5) Adjust the upper stop screw so the derailler is lined up perfect. And then unscrew only 1/4 - 1/2 turn for the 'over position'.
6) Shift back down to smallest cog. Now here's where you set cable tension.
7) Shift to cog 3 then adjust the cable tightener so it's running smooth. Shift up to 4, the cable adjustment should be such that you get crisp shifts up and down. Bear in mind you generally need it a little more tight to make the 'upshift'. The Shimano indexing is generally set at positions 3-4, or 2-5.
8) Run through your gears to make sure you get proper indexing and shifting up and down.

This is assuming you've got the front mainly in the big ring, btw. Adjust the front derailer,too. It's very simple.

1) Shift to smallest ring and make sure the stop screw is adjusted so the derailler won't let chain skip off ring and when you're in the little-big combo, the chain will just clear the outer shell of the derailler. (cable slack at this point)
2) Tighten the cable taking ALL the slack out. You want a firm cable.
3) Shift rear to smallest cog anf front to Big Ring. Adjust stop screw so chain is clear on the INNER side of derailler shell.
4) Shimano has a 'half step' position in the front derailler shifter - this is so you can avoid chain drag on the front derailler when running the little (front) little (rear) combo. Make sure that you just notice this. if you have the front stop screws and cable tension set properly, then you'll be able to have a clear chainline on both BIG BIG and LITTLE LITTLE positions. (Including the 'half-step') position.

Ride the bike. How it shifts while riding is always a little different than in the stand. Cables and housing will settle in and stretch a bit generally requiring some additional adjustment as you ride more and more.
 
Fastest way to set up rear derailleur:

1/. Before even installing cable set upper and lower limits so the Jockey wheels sit perfectly in line with the inner and outer cogs on the cassette.

2/. Run cable through to rear derailleur, pull cable tight to remove any slack along the length of the cable.

3/. When installing cable into rear derailleur manually by hand push derailleur so it is in line with second cog on outside and install cable and tighten.

4/. Ride away with perfect gearing.

I've lost of how many bikes I've built up.

Also a few other pointers:

On the adjuster barrel on the rear derailleur set it so it is halfway in and out - this will give you room to play with the settings if things aren't right. The amount of bikes I've had to fix at the road side on group rides where I couldn't slacken the tention due to the barrel being all the way in is unbeleivable and a real pain in the if you need to give the cable some slack.

Do not use cable cutters for the end stop - use a crimping tool. Thats what it's for and wwon't splay the cable ends or if you really want to go all out solder the tips of the cables and go without the end stops.

Do not be tempted to grease your cables especailly if you have open/bare segments such as the break lines along the top tube or more importantly on the down tube for your gears as a greased cable pulls dirt and other debris in to the cable housing and adds to wear and tear on the cable and housing it also negate the benifits of the teflon coating and inner housing coating.

If you ride all weather or off road then fully housed cable (No gaps in the outer between shifter and derailleur or brake callipers) is the way to go. If your fframe does not support this then a teflon sleeve can be slid over the cable and then passed through the outer casing terminating at the derailleur or calipers. Jagwire has some excellent solutions.
 
Might be worth just trying to UN flatten the section with a pliers. Not the best option, but really easy. Especially if you don't have time and have to ride the bike now.
 
There are several types of reinforced housing:

cutting-cable-housing.jpg


Im guessing the one on the left is the one you are currently using?

This type is prone to poor shifting if crushed due to the wrap biting on the cable and causing friction or jams.

The housing and cable on the left is for the brakes and the one on the right for shifting.

Brake cable housing have an outer diameter of 5mm, a "spiraled" reinforcement and are used with dia. 1.5mm cable. They are more sturdy and heavier.
The end piece to fix tem at the brake levers or brifters is different from the shifting cable and depends also on the purpose (say racing vs. MTB).

Shift cable housings on the right have an outer diameter of 4mm, a "twisted" reinforment of smaller wires and inside a 1.2 mm (standard) or sometimes 1.1 mm cable. They come with different end pieces.

You can use brake housings for your shifting as well but there is no apparent advantage. You should not use shifting housing as a replacement for brake cables as they are likely to collapse under cable tension.

Because of the end pieces you cannot switch between braking and shifting cables.

I agree with Alan and others that the flattened section is most likely the cause of your shifting problems. I also understood that you have bought already a shifting cable set at Ys. Provided that the 1.700mm length of housing is enough for your bike I would install the one you have. Sure, you can exchange that at Y against a better quality Nokon or Gore, but if you were OK with the origial performance than it shoudl work with the Shimano set as well.

I think you will manage the replacement of housing and cable with the advice from here, Sheldon Brown and Shimano instruction manual.
Good Luck!
 
Mob, actually depending on brand the one on the right is for both gears and brakes.
 
I think the NOKON might be a good choice for the Bike Friday cause you can twist them around funky curves more easily than standard wire wound housing. I know quite a few people use and recommend them for coupler bikes, for example, due the tight bends required when the frame is split.
 
Thanks everyone for your advice! Much appreciated! :)

As I wrote earlier, I already have the cable. It's not the PTFE (teflon) version but the regular one with steel cables (1480 yen at Y's). The outer cable is 1700 mm long, which should be enough. I think I'll study the hinge issue carefully to understand exactly when the cable gets snagged on hinge edges (it should be OK as long as it stays under the middle of the hinge, which has no sharp corners).

Encouraged by the explanations I got my hands greasy again today. I had wondered how the outer cable disconnects from the shifter, but it's really just pulled into the shifter by the inner cable and slides out easily if I loosen the inner cable from the derailleur end. If I remove the inner cable, the outer cable will no longer be held in place. That was my biggest question.

Mike, I may take you up on your offer to come over to your place and use your tools, since my tool kit is rather basic (I'm more equipped for messing with computers). The outer and inner cable replacement looks relatively straightforward now as long as I can cut both of them to size properly.
 
Mob, actually depending on brand the one on the right is for both gears and brakes.

Not that I've seen or used every brand out there, but I think mob is right; the one on the right is compressionless housing, which is intended for shift cables only. As per Sheldon Brown:

"Compressionless Housing
Cable housing consisting of a bundle of more-or-less parallel wire strands, instead of the single coiled strand of normal housing. This is used for handlebar-mounted shifters, because the effective length of the housing doesn't change significantly as the handlebars are turned and the cable flexes. This is part of what makes reliable indexed shifting possible.

Compressionless housing must not be used with brake cables. It is not strong enough, and can rupture, causing brake failure. See also my article on Cables."


Or Park Tools:

" Compressionless shift housing is intended for shifting systems only, not braking."

housingtypes.jpg
 
Not that I've seen or used every brand out there, but I think mob is right; the one on the right is compressionless housing, which is intended for shift cables only.

Phil, I use the Jagwire coloured housing - it's rebranded under Grunge I do beleive and I was very supprised when I found out that it was the same as the brake cable housing (Compressed cable)

In fact apart from the flash stuff out there like the Nokon it is the only one I have found that has this for both brakes and shifter - otherwise I wouldn't have mentioned it - its not like I haven't been working with bikes for the past 25 years or something.

Also just to point out that JAGWIRE ripcord does not use compressed cables for the brakes but Kevlar reinforced compression-less housing.

Lots of different styles out there and Im starting to find that good old Sheldon Browns is becoming a little dated.

Pete

In regards to the Yokozuna cables I personally don't rate them, I used them for a season on one of my bikes while the other I just ran the DuraAce PTFE and I honestly couldn't feel the difference - apart from in my wallet.
 
Lots of different styles out there and Im starting to find that good old Sheldon Browns is becoming a little dated.

This is getting OT so last from me on this, but lest we forget, we are talking about the picture you posted, which as mob pointed out, shows standard brake housing on the left and compressionless shift housing on the right. I'd be curious to see a link to the Jagwire stuff you are talking about, but until then, color me skeptical. :cool:
 
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