All the gear, no idea.

[ShiningWit]

Hello all, I've been lurking in this section for a while gaining a bit of knowledge here and there and (on the back of that) recently picked up a lightly used Voodoo Bizango for £330, i've already pulled a slight buckle out of the wheel, but am struggling to adjust the rear derailleur so need some help. When I click the gear change lever over it doesn't shift the chain - it needs me to just squeeze the lever a bit more before it moves over. I've looked on the 'net and there are plenty of guides, but none seems to address this particular problem.
Can anyone help? I'm guessing I may need to be more specific, so can update after tomorrows ride.

[Some Gump]

Plenty guides on yewtube, but if i understand you right...

If you have rear deraillier un smallest cog, and click, it doesn't shift.

If so, find barren adjuster on rear mech / inline on shifter cable. Undo 1/2 a turn. Does it shift? If not, repeat another 1\2 turn.

Once it shifts, go all the way up, and down again. If down doesn't work, tighten barrel 1/4 turn.

If it's ereatic / goes 1 way and not 'tother, you need a new gear cable.

[gazza285]

Some Gump said:

Plenty guides on yewtube, but if i understand you right...

If you have rear deraillier un smallest cog, and click, it doesn't shift.

If so, find barren adjuster on rear mech / inline on shifter cable. Undo 1/2 a turn. Does it shift? If not, repeat another 1\2 turn.

Once it shifts, go all the way up, and down again. If down doesn't work, tighten barrel 1/4 turn.

If it's ereatic / goes 1 way and not 'tother, you need a new gear cable.

Comedy gold there, fantastic speeling and the cable adjusting advice the wrong way round.

Here is a pretty thorough guide on Operation Yewtree...
https://www.youtube.com/watch?v=2j1gSwhsVN8

[deadtom]

gazza285 said:

Comedy gold there, fantastic speeling and the cable adjusting advice the wrong way round.

Here is a pretty thorough guide on Operation Yewtree...
https://www.youtube.com/watch?v=2j1gSwhsVN8

spelling was messy but advice was correct.

[gazza285]

If it didn't shift off the small sprocket I would be more inclined to tighten the adjuster, rather than undo it, as I would suspect that the cable needed more tension, not less.

[richardxjr]

I'd always fit a new inner cable anyway. Ensure shifter is actually in top gear too (smallest sprocket)

[gazza285]

richardxjr said:

I'd always fit a new inner cable anyway. Ensure shifter is actually in top gear too (smallest sprocket)

And what do you know about gears, you haven't got any!

[Soop Dogg]

Deadtom was right - undoing the barrel adjuster (like you're undoing a screw) increases tension on the cable.

Screwing the barrel adjuster clockwise (like you're tightening a screw) reduces tension on the cable.

[gazza285]

Soop Dogg said:

Deadtom was right - undoing the barrel adjuster (like you're undoing a screw) increases tension on the cable.

Screwing the barrel adjuster clockwise (like you're tightening a screw) reduces tension on the cable.

Ah, I see, so what you are saying is loosen the adjuster to tighten the cable, and tighten the adjuster to loosen the cable, while I'm looking at this in an illogical way and saying tighten the adjuster to tighten the cable because it isn't a screw but a cable tension adjuster?

[Kell]

If you're using indexed shifters then you only need to worry about where the derailleur sits when it's in the largest and smallest cogs. The shifter will take care of everything else.

Put it on the largest cog and adjust the barrel (not the screws) so that it runs dead centre and doesn't sound like it's trying to shift (I can't remember which way to adjust the barrel off hand, but you'll soon figure it out).

Check it runs true on the smallest cog and all your other gears will work.

The + and - screws are only there to stop the derailleur shifting your chain off the bottom cog or off the top cog and into your spokes.

It sounds complicated. But it really isn't. I spent years trying to line up every gear before watching a 'how to' online that explained all the above. The Park Tools ones are normally great if no one recommends anything better.

[louiebaby]

Soop Dogg said:

Deadtom was right - undoing the barrel adjuster (like you're undoing a screw) increases tension on the cable.

Screwing the barrel adjuster clockwise (like you're tightening a screw) reduces tension on the cable.

Agree.

[markoc]

richardxjr said:

I'd always fit a new inner cable anyway. Ensure shifter is actually in top gear too (smallest sprocket)

I'd do the cable outer too. Minimal cost and might as well if it is an older bike. Great tip on the shifter, which I have learned the hard way!

[Soop Dogg]

Kell said:

Check it runs true on the smallest cog and all your other gears will work.

Providing the cable has just become tense when it's sitting on the smallest sprocket.

Otherwise, if it's loose all you'll do is take up slack in the cable when you try to change to the next smallest sprocket. It then either won't shift to the next sprocket at all or it'll move only part way towards it. (Depending on how much slack it had to take up)

[Some Gump]

Yeah, apologies for that epic spelling.
In my defence, I was not just on an iPad, but considerably pissed at the time. Obviously yewtube vid now provided explains it better, my "unscrew" is w.r.t the barrel adjuster - counter clockwise makes the barrel longer and therefore tightens the cable (well in my head at least!)

[ShiningWit]

Thanks for the various conflicting posts, i'll have a go tomorrow. It doesn't need any new cables as it's practically a new bike, It changes up ok, it's going down where the problems are.

[deadtom]

ShiningWit said:

Thanks for the various conflicting posts, i'll have a go tomorrow. It doesn't need any new cables as it's practically a new bike, It changes up ok, it's going down where the problems are.

probably just cable stretch in that case.

As suggested, try winding out the barrel adjuster either on the shifter or the mech (either one, they both do the same thing)

gazza i can see what you mean that logically tightening should mean increasing tension, but when you look at the way the system actually works it is more intuitive and correct to say that unwinding the adjuster increases the tension.

[ShiningWit]

deadtom said:

ShiningWit said:

Thanks for the various conflicting posts, i'll have a go tomorrow. It doesn't need any new cables as it's practically a new bike, It changes up ok, it's going down where the problems are.

probably just cable stretch in that case.

As suggested, try winding out the barrel adjuster either on the shifter or the mech (either one, they both do the same thing)

gazza i can see what you mean that logically tightening should mean increasing tension, but when you look at the way the system actually works it is more intuitive and correct to say that unwinding the adjuster increases the tension.

There is only one adjuster and it's on the lever. Anyhow, I had a go and when I got it to change better it then wouldn't go onto the last cog. I'm presuming that I then have to use the stop screw to set that right? I ran out of time so will have a look at this later.

[Justin S]

Sounds like cables, regardless as to how old they are. Try by putting the chain on the largest sprocket on the back. Do not pedal, but click the shifter, so the cable goes limp. Then undo the cable outer from the frame dropouts and slide out around to see how mucky, rusty the cable is. Clean up and oil and put back together. Feel how smooth the cables are, as cheaper bikes usually come with galvanised cables and the coating can be course. If it feels rough/ looks rusty/ its galvanised , so consider swopping for some stainless smoother cables.

Edited by Justin S on Saturday 25th April 23:23

Edited by Justin S on Saturday 25th April 23:24

[Craikeybaby]

FWIW my bike needed a new gear cable after about 100km, so don't assume that it isn't to blame.

[ShiningWit]

Well I seem to have done it
I did it using the cable length adjuster, it was just a bit fussy and needed to be set in just the right place, a bit too much either way and it wasn't happy. It seems to have a SS cable and if I can't adjust it again I'll get a new one, but for now all is good.