Rear derailleur cannot shift to high gears

[ade234uk]

Ok hopefully you can shed some light on my issue. For the last few months I had completely lost my first three highest gears and my lowest gear on my racing bike, so as you imagine getting up the hills is a lot harder.

I have also lost the ability to use two rings on the front Derailluer as well

So the only gears I can use at the moment are 4567

My previous attempts at sorting out gears has always ended in failure so after some youtube tutorials I jumped in and had another go at it.

I decided to work on the back derailleur first. To prepare I made sure the I was on the lowest gear and I undid the nut the holds the cable. I pulled the cable tighter and tightened the nut.

No matter how tight I pull that cable I am stilling missing my three highest gears. I must have done this about four or five time snow. Do you have any tips you can suggest before I go running to the cycle shop. I hate being beaton by things like this.

Job is also harder since I don't have a proper bicycle stand to hang my bike either. Save money on the gears I can probably get a stand.

 

[MrJamie]

Try having a look at youtube guides/park tool videos, I found them really useful and learnt pretty quickly from them.

You can get one of the little stands that just lifts the bike off the ground by the chain/seat stays for like £15, not as good as a proper one but great for stuff like sorting out the gears.

 

[rusty bearing]

Sounds like a frayed cable to me. disconnect as you did before and holding the cable in one hand operate the shifter with the other, see if it pulls the cable the required number of clicks. Does the cable move smoothly or is it stiff? If it fails on either count it's time for a new one.
For the front mech, get a mate to hold the rear of the bike off the ground while you turn the pedals. Pull the shifter cable under the downtube and see if the mech shifts through its full range. If it don't then sticky cable is likely, test as rear.
There are other possibilities but lets start with the simple stuff first.

 

[ade234uk]

Sounds like a frayed cable to me. disconnect as you did before and holding the cable in one hand operate the shifter with the other, see if it pulls the cable the required number of clicks. Does the cable move smoothly or is it stiff? If it fails on either count it's time for a new one.
For the front mech, get a mate to hold the rear of the bike off the ground while you turn the pedals. Pull the shifter cable under the downtube and see if the mech shifts through its full range. If it don't then sticky cable is likely, test as rear.
There are other possibilities but lets start with the simple stuff first.

Thanks for the info. Time for a new cable I think. Where I was messing around with it earlier, the end of the cable is now frayed as the pliers slipped and I knocked the cable end off lol.

These are the original cables that came with the bike, so I think the next step is to get a new one. New cable fitted and I reckon it will solve my problem.

 

[fido]

Have you checked the limit adjustment screws?

 

[rusty bearing]

Limit screws are unlikely to be the problem. They might need a quarter turn adjustment now and then or resetting after some major work but to go so far out of alignment? We get so many bikes in where peeps have fiddled with the limiters when all that's need is a little cable tension adjustment. Even when you tell them not to touch those screws there seems to be some otherworldly power that says
"go on, just a quick turn. You know you want to!"
The symptoms described suggest the cable is fraying and snagging inside the outer somewhere resulting in limited movement and loss of gears

 

[ade234uk]

Limit screws are unlikely to be the problem. They might need a quarter turn adjustment now and then or resetting after some major work but to go so far out of alignment? We get so many bikes in where peeps have fiddled with the limiters when all that's need is a little cable tension adjustment. Even when you tell them not to touch those screws there seems to be some otherworldly power that says
"go on, just a quick turn. You know you want to!"
The symptoms described suggest the cable is fraying and snagging inside the outer somewhere resulting in limited movement and loss of gears

Today I am going down to Halfords to get a new cable. Does not matter how tight I make the cable, I cannot get to the low gears, 1,2 or 3.

The cable has been on the bike since I bought it and where I have been messing with it, I ended up knocking off the little gubbin at the end of the cable. The end of the cable is now frayed.

New cable, fresh start. As you correctly point out, the limit screws high and low are for small adjustments. I tried that and it made absolutely made no difference.

Hopefully once I get this new cable in, I can get those missing gears back. I can then use the high and low limit screws to make fine adjustments.

 

[accountantpete]

I don't think you are setting up the gears right in the first place.

Install new cable to front right but dont attach to mech.

Click through the gears on the lever/thumb - seven clicks down and seven clicks up.

Then get to the bottom of the lever clicks and press the thumb switch 3 times. That should put you on the 4th biggest cog.

Finally thread the cable, squeeze the rear mech so that the top jockey wheel is in line with the 4th cog and tighten up on the cable so that the mech does not move away from that position.

You may find that a little adjustment to the rear mech is needed to fine tune everything.

 

[ade234uk]

I don't think you are setting up the gears right in the first place.

Install new cable to front right but dont attach to mech.

Click through the gears on the lever/thumb - seven clicks down and seven clicks up.

Then get to the bottom of the lever clicks and press the thumb switch 3 times. That should put you on the 4th biggest cog.

Finally thread the cable, squeeze the rear mech so that the top jockey wheel is in line with the 4th cog and tighten up on the cable so that the mech does not move away from that position.

You may find that a little adjustment to the rear mech is needed to fine tune everything.

Ok that seems to make more sense as well along with a new cable suggested by other users.
The examples that I viewed online all started from the smallest gear.

 

[accountantpete]

Ok that seems to make more sense as well along with a new cable suggested by other users.
The examples that I viewed online all started from the smallest gear.

You can start anywhere you like - it's down to personal preference. Just as long as you match the gear at the lever with the gear at the back.

 

[Hawk]

Are your jockey wheels (on the pivoting derailleur arm) clear of the cassette sprockets themselves? I was unable to shift up yesterday as my derailleur jammed against my cassette..... Stupidly ended up breaking the hanger and derailleur

 

[rusty bearing]

You can start anywhere you like - it's down to personal preference. Just as long as you match the gear at the lever with the gear at the back.

True but an uncabled rear mech rests naturally under the highest gear (unless you have a low normal setup) and is easily lined up with the outer limit screw if necessary so it just seems easier to start there.

Just as an extra point to the original post, when you've fitted the new cable operate it a few times to let everything settle, assuming you take the outers off and put a bit of spray grease down them. Take out any slack in the system before final adjustments.

 

[ade234uk]

Thought I would give you an update. I bought the cables and got my gears working again apart from 1:1 the easiest. I'm happy with it now. Getting up those hills, is a hell of a lot easier now.

I might actually consider getting my self a complete new set of levers, and gears. Probably looking at £300-£400. Wonder if it is worth just handing it over to the bike shop and saying do the lot or just getting another bike. I have 24 gears on my bike, well 23 with 1:1 missing.

Love my Halfords Carrera special. It has served me really well.

This is what the bike looks like. Courtesy of the internet