Skipping chain on rear when downshifting

[geopat]

Hi all

I have the above problem on my Tiagra equipped bike. The gears I select don't seem to engage properly, especially on downshifts and it can miss a full cog on the rear cassette or chain slips under power. I usually have to upshift again or tap the lever to get the required gear. Only thing I done recently was tighen the cable on the front derailleur..maybe too much? Bike is only 6 months old.

Any advice welcome.

 

[Pauluk]

Sounds like a cable tension problem geopat especially as its a newish bike.

 

[rusty bearing]

Certainly sounds like cable tension. Bit too slack by the sounds of it.

 

[NotthatJasonKenny]

I had/have the same problem with my 9spd Tiagra, had a load of people look at the tension but no one could fix it.

In the end I sussed that it depends on the lever, I can drop 3/4 gears if I hold it but tapping it drops just the one.

Not sure if it was always like that or if it coincided with putting a new cassette on, either way I'm not going to mess anymore, I can live with it.

 

[Globalti]

Yawn.

Change the cable outer at the rear derailleur. Clean up of fit a new inner. Then re-adjust the cable tension.

(How many times do I have to pos this?)

 

[Hawk]

Can you select all your gears? You might've overtightened it so much that it's actually a full gear too high now, or similar

 

[geopat]

Can you select all your gears? You might've overtightened it so much that it's actually a full gear too high now, or similar

Am thinking this..I'll lossen off and see, thanks.

 

[geopat]

Yawn.

Change the cable outer at the rear derailleur. Clean up of fit a new inner. Then re-adjust the cable tension.

(How many times do I have to pos this?)

Clear as mud, sorry

 

[Mo1959]

Clear as mud, sorry

Not just me then. Lol. My hybrid does this too on the downshifts and as a 53 year old female with not a lot of mechanical knowledge nice clear steps as to what to try would be good.

 

[Hawk]

Not just me then. Lol. My hybrid does this too on the downshifts and as a 53 year old female with not a lot of mechanical knowledge nice clear steps as to what to try would be good.

Or I guess a patronising reply is good too :P

Yawn.

Change the cable outer at the rear derailleur. Clean up of fit a new inner. Then re-adjust the cable tension.

(How many times do I have to pos this?)

I imagine you guys have things called in-line adjusters on your gear system, basically you can tighten or loosen the cable tension really easily without having to unscrew your cable from where it's held to your derailleur. You'll need to tighten it a little bit over time as gear cables stretch.

They come in all shapes and sizes but basically they comprise of a screw thread that can extend the length of your outer cable and make the inner cable have to go a longer distance, increasing the tension. [The inner cable is the steel wire, the outer cable is the "casing" around it which looks plastic but is actual just more steel].

Playing around with this is an easy way to change the tension on your gear system. If the bike is new, you can use these to increase tension to take up slack as the gear cable stretches.

http://sheldonbrown.com/derailer-adjustment.html is probably a good starting point, it explains a few other controls as well. You probably don't need to touch the high/low limit screws or b-tension though!

 

[Mo1959]

Thanks Hawk. Would that be the black plastic adjusting screw I have tried to show here?

 

[Hawk]

Looks like that's it. So what I'd do would be put the derailleur to lowest tension setting (smallest cog, almost certainly). Then I'd pull the cable taught and clamp it with the bolt as it is already. After this, I'd tighten that cable barrel adjuster so the bike reliably changes up (to higher tension settings) and then maybe a half turn more. Should sort it for you

 

[Mo1959]

Looks like that's it. So what I'd do would be put the derailleur to lowest tension setting (smallest cog, almost certainly). Then I'd pull the cable taught and clamp it with the bolt as it is already. After this, I'd tighten that cable barrel adjuster so the bike reliably changes up (to higher tension settings) and then maybe a half turn more. Should sort it for you

That sounds quite straightforward. Many thanks.

 

[geopat]

Looks like that's it. So what I'd do would be put the derailleur to lowest tension setting (smallest cog, almost certainly). Then I'd pull the cable taught and clamp it with the bolt as it is already. After this, I'd tighten that cable barrel adjuster so the bike reliably changes up (to higher tension settings) and then maybe a half turn more. Should sort it for you

Many thanks, tighten the rear derailleur with the barrel adjuster and it seems fine now.

 

[MrJamie]

Looks like that's it. So what I'd do would be put the derailleur to lowest tension setting (smallest cog, almost certainly). Then I'd pull the cable taught and clamp it with the bolt as it is already. After this, I'd tighten that cable barrel adjuster so the bike reliably changes up (to higher tension settings) and then maybe a half turn more. Should sort it for you

Worth noting that to tighten the cable you turn the barrel adjuster anti clockwise. Also i think when you release the cable to reclamp it you should probably screw the barrel adjuster in by turning it clockwise pretty much all the way, then reclamp the cable, then turn it anticlockwise to add tension until it shifts correctly up all the gears.

Im sure Hawk can explain it better than me, but as Mo said she had no knowledge I think the extra info might be useful if someone can confirm it.