Gear not taking - shifting issue

I am having trouble with my bicycle when shifting from 5 to 6 (front sprocket 3 and rear sprocket 5 to 6).

When shifting from 5 to 6 (low to high) it takes several rotations until the gear actually takes. Essentially pedaling five or six revolutions without the gear engaging. It is not an issue for other combinations or shifting down from 6 to 5 (high to low). I do most of my cycling in 3 (front) and 5 (rear).

I am not sure what to tweak to fix it; or if it needs any new bits?

Chain is newish but when the chain was changed last the old cassettes stayed on.

How well do you do you know the bike? Did you install the cables too?

A while ago when very new to setting bikes up I accidentally used brake cable housing for the last loop from the frame to the rear mech. It mostly still shifted fine though sometimes had issues in the middle-range on the cassette.

How well do you do you know the bike? Did you install the cables too?

I had a "professional" do the work so working on the assumption everything was done properly. Are you suggesting I take a look at the ends of the cable (nearest to the derailleur) to ensure they are correct and not causing tension issues?

Check these?
http://www.bikeman.com/images/stories/RepairTechInfo/4and5mm.jpg

potential causes - worn cassette, chain worn at different rate to the cassette, mech hanger out of alignment poor cable run (kink in outer or inner cable)

it sounds like you have a one particularly worn sprocket (5th if you stay in that all the time)

Sounds like general cable stretch. Happens after a few weeks/months of bike set up with new cables. A bit of tinkering with a small screw driver on the adjustment screws should sort it.

WTF

If it is cable stretch then use the barrel adjuster to compensate. The screws adjust the limit stops - a completely different issue.

@darrinm81 please ignore @ColnagoDaft his name says it all.

weeks/months? Are you carrying your bike or something?

A common problem with bikes coming out of boxes (the majority of shop bought bikes) is the way they are packed - the cables are generally twisted right round. This is where cable stretch starts. DJ is sort of right to say barrel adjuster, but it's usually a combination of barrel adjuster/set screws and pinch bolt on the mechs that will take up the slack/sort the gear throw/fine tune.

Can also happen after a crash where the cable can get snagged or pulled through, or when the outer cable gets bent or distorted.

Rust in the outers (low end bikes won't normally have stainless cables) or dirt ingress accounts from about a third of bad changes - the only alternative is to change the outers. I'll change the outers on my bike about twice a year.

A final solution, where the mech might be slightly bent (see above) is to cold set the mechs back into alignment. Most mechanics will do this out of sight of the customer. You can generally do it by eye. I've had to do this on several bikes when all of the above failed.

Also if you have crashed, and on the gear side, there's a fair chance you might have bent the gear hanger on the drop out - this is generally a bike shop fix who will have an alignment tool to reset it.

So, DJ is about 15% right. Well done.

Thank you for the replies.

I ended up tweaking the rear derailleur barrel adjuster and it seemed to do the trick.

I did check the derailleur for damage but appears fine. Must have just needed an adjustment.

So I may have spoken a little too soon on this one (!) ...

I was riding home and the front chain set started making a noise - the chain rubbing against the front derailleur. I thought it was linked to the original problem and stopped to adjust the barrel adjuster. This made no different and the noise continued.

As I could still pedal I thought it may need a more technical adjustment and just kept cycling.

Got home and noticed this... a cracked frame! Time for a new bike after 8 years of daily commuting!

2 Attachments

Opps that would cause all manor of problems.

Apparently Ridgeback provide a lifetime warranty on frames. Hopefully I can dig out the proof of purchase.

Anyone ever had a successful warranty claim?

Not with Ridgeback. I've no idea what their warranties are like. I've had 4 Treks though, mainly because my mate services them and he's kicked off for me. His advice is to vastly undereport the abuse the bike has taken, and obviously the miles.

Otherwise they might well hit you up with 'excessive wear and tear'.

Oh, and give it a good wash and scrub up before you take it back!

Cracked frame will have likely been your issue in that...

You adjust to cater for the cable movement, then the frame cracks some more, pulls the cable, causes it to misbehave again

Your chain looks fucked, rollers are all over the shop, so can assume your cassette will also be worn and poss r.mech jockey wheels going on the state of your crusty front mech (sorry to be picky!), all will contribute to a bad shift.

As for warranty, you can clean it up as best you can, then spray it up gt85 to minimize the crusty ness of the bike then go and try. You won't get a new bike, you might get a frame but often if its that age you'll be footing the labour to swap the components over (typically £100 + cables), but if rest of your bike is pretty rotten then maybe not worth it unless you replace the whole drive chain in a oner.