Need some Viagra for my Tiagra!

happycrank(s)

Hello all,

I've just bought a 2013 Giant Defy 2 excellent condition (or so I thought?) for £270. The bike is gleaming, wheels run true, BB is smooth, very little wear on the chainset, very little wear on the cassette, everything in general is showing very little or next to no wear. The tyres are original and still have some of that little rubber flap from the moulding process in the middle that the runs around the circumference.

When I took the bike for a test ride I noticed both (Tiagra 4600 10 speed) front and rear derailleurs were not changing smoothly, some rubbing at the front and hesitation with a little bit of jumping around in the low gears at the rear. For the price of the bike this didn't put me off.

I spent an hour and a half trying to sort the rear derailleur out this afternoon, I've set the limits, re-tensioned the cable and then worked on the adjusting barrel.

I've managed to get a fairly a smooth action from 10th to 2nd, but as soon as I adjust the barrel to allow the chain to move onto 1st gear everything is thrown out. Changing back upto 2nd moves from 1st to 3rd, there's hesitation around 5th and it jumps from 8th to 10th.

I've adjusted the barrel until my fingers hurt and can't find the sweet spot.

I feel like I have a faulty derailleur?

Any help would be appreciated.

Thanks,

Rob

penguin_of_death

Is the mech hanger straight?

happycrank(s)

Hello Penguin of Death,

To my eye the hanger looks straight (but I'm no expert).

I've noticed when the derailleur is in 10th to 4th gear it is perfectly aligned beneath the cog, but each time it moves towards 1st from 4th it moves a little bit further towards the wheel than it should?

Thanks for your post,

Rob.

chemicalviking

I've got the same bike , I've realised that indexing using the rear mech adjuster is sometimes not enough to dial it in . In that case I suggest using the adjuster on the cable going into
The rear shifter turning the barrel adjuster this was will allow for better indexing . Hope you're able to sort it :-)

jameses

What is the problem moving from 2nd to 1st (I'm assuming that's at the small sprocket end of the cassette)? Does it not quite move onto the smaller sprocket? Could be your H limit screw is set too far in, try loosening it a touch.

Another possible solution - are the jockey wheels and derailleur cage sufficiently tightened? I had a similar problem recently, the chain wasn't running cleanly through the derailleur in the lowest two or three gears and it turned out to be due to a slightly loose cage.

crankycrank

happycrank(s) wrote:

I've managed to get a fairly a smooth action from 10th to 2nd, but as soon as I adjust the barrel to allow the chain to move onto 1st gear everything is thrown out. Changing back upto 2nd moves from 1st to 3rd, there's hesitation around 5th and it jumps from 8th to 10th.

If everything is working as it should, mech functions fine, hanger not bent, limit screws set properly, B-tension set properly, cassette lockring tight, etc., then this sounds like a classic case of too much tension on the cable. Since your jumping up 2 gears in spots with one shift you need to turn the derailleur cable adjuster inward. Try 1/4 turns at a time until the shifting works well then go for a ride as sometimes it will need some slight tweaking. Basic adjustment tip: If it hesitates shifting to larger gears, you need more tension. If it hesitates shifting down to smaller gears (or skips a gear shifting to larger cogs), you need less tension. If you find that it works in all gears but is noisy try using 1/8 turns. Just turn adjuster in either direction to find which makes it worse or better.

happycrank(s)

Chemicalviking,

I'll give it a go, but I always thought those adjuster for when the gears are changing properly and need tiny tweeks?

JamesEs,

The limit screws are set properly and there's nothing lose on the derailleur.


CrankyCrank,

I adjusted the B tension and lowered the mech to ensure this wasn't stopping it moving onto 1st. I agree with you about it looking like a classic tension issue. I've been making some very small adjustment and there's definitely a tipping point that throws everything out and when I turn the adjuster back 1/8 the problems ease but I can't get the chain onto 1st?

As I've said in the post above: I've noticed when the derailleur is in 10th to 4th gear it is perfectly aligned beneath the cog, but each time it moves towards 1st from 4th it moves a little bit further towards the wheel than it should?

If there was too much tension would it no be mis-aligned in the higher gears also?

I'm frustrated with it at the moment and have left it alone today, but will have another go with relaxed frame of mind.

Thanks for the help from all of you,

Rob

crankycrank

happycrank(s) wrote:

As I've said in the post above: I've noticed when the derailleur is in 10th to 4th gear it is perfectly aligned beneath the cog, but each time it moves towards 1st from 4th it moves a little bit further towards the wheel than it should?

If there was too much tension would it no be mis-aligned in the higher gears also?

Rob

Yes, usually it will be off the entire range of cogs but not always. Some other things to check are a frayed cable, take a close look at the cable end in the shift lever. Maybe a good idea to remove the cable and give the entire thing a good check and test to see if it moves freely in the housings. With just the bare cable attached to the shift lever pull on it while shifting through the entire range to detect any sticking in the shifter. Check if the rear mech moves freely without the chain or cable attached. Are you absolutely certain the limit screw is adjusted properly? When it gets to the point of nothing will work it's best to check all parts involved to be sure they're all functioning OK. Being a secondhand bike even if everything looks OK it may just have several worn cogs or a worn chain (did you measure it?), bent hanger, missing spacer on cassette body, loose chainring bolts, etc., etc.

desweller

As it's a 2nd hand bike:

1. Check cable within shifter. You're looking for fraying, rust; anything that might affect the smooth action of the ratchet

2. Service the cables. If you want to be thorough, you can replace the housing and inner cable for a few quid, but it probably doesn't need this; I would zuzz the cable housings through with WD40 though.

3. Check that the mech hanger is straight and securely screwed on. If there's any marking on the derailleur body, perhaps it's had a tap. The hanger is designed to yield so it may be bent. The hangers are usually attached with one or two small screws, and it's not uncommon for those to come loose. It's also worthwhile checking that the hanger's not been fitted with debris between the mating faces.

4. Oil the chain.

5. Check that the wheel axle is properly seated in the dropouts.

6. Check that the cassette is not loose.

That would be my process, probably in that order...

happycrank(s)

Problem solved!

crankycrank:
Thanks for your cool thinking, you were correct it was a tension issue. I had turned the barrel completely in but the shifter must have been retaining a little tension, It took me a while to figure it out, but I had another go with a relaxed mind. It was simple in the end, I just gave the lever a couple of clicks to make sure all tension was released.

It's still not perfect, a little clunky moving up the gears towards from big to small cogs (1- 10), but it will do.

DesWeller:
Thanks for your help.

Everything was tight and as it should be, except maybe for a little bit of play in the cage. Although it doesn't seem to bother performance too much.

crankycrank

happycrank(s) wrote:

It's still not perfect, a little clunky moving up the gears towards from big to small cogs (1- 10), but it will do.

Just to get our terminology on the same page I assume when you say "big/large cogs" you mean those with the most teeth? Clunky moving from the large cogs to small could mean there is just a hair too little tension in the cable allowing the chain to overshift ever so slightly, slamming down to the next cog. If when you say it's "clunky" and you mean hesitation then the opposite for adjustment would be true, you need less tension. All you need are very small adjustments to get it perfect. Glad to hear it's basically sorted.

happycrank(s)

crankycrank:

"Just to get our terminology on the same page I assume when you say "big/large cogs" you mean those with the most teeth?"

Yes, 1st gear most teeth (biggest) - 10th gear least teeth (smallest).

Moving from the smaller cogs to bigger is smooth and quiet, but the other is more noisy, it tends slap down onto each cog (but it's not slow). I'll have another tinker with it and see what happens.

The front mech is just as poorly set up (by the last owner), it's rubbing on both small and large chainrings, the mech is also too far away from the big chainring. The cable has been cut too short and has just over 1cm to pull on after the clamp (I'll need a new one). Watch this space, I may well be grateful for your help again (I've done a few front mechs and never been happy with the results).

Thanks,
Rob

crankycrank

happycrank(s) wrote:

The front mech is just as poorly set up (by the last owner), it's rubbing on both small and large chainrings, the mech is also too far away from the big chainring. The cable has been cut too short and has just over 1cm to pull on after the clamp (I'll need a new one). Watch this space, I may well be grateful for your help again (I've done a few front mechs and never been happy with the results).

The front is a little easier to get right. First make sure that the mech outer side plate is 1-3mm above the outer ring. Then make sure the mech outer plate is parallel with the outer chain ring. If you have to make either of these adjustments it's best to undo the cable and chain. Reattach the cable and adjust so that it easily shifts to both chainrings in all gear combinations while turning the cranks. I like to do the limit adjusters last as it's near impossible to get it perfect without going out for a ride and testing. You want the limits to be as far out to either side as possible without dropping your chain so that you're less likely to get chain rub. There can be a little bit of leeway as far as getting the right cable tension. For instance if you frequently use several cogs in the middle of the cassette range and each time you change between them you have to adjust the front mech trim then you could use a little more or less tension so the mech sits slightly further in either direction for the trim position of your front shift lever. You'll figure out what works best after you ride it a few miles. Take it easy when you take a test ride in case the chain comes off due to the limit screws needing turning in a bit. You don't want to drop your chain and have it chew up your frame.