Rear derailleur adjustment?

[The Bear]

Any suggestions for my rear derailleur problem pease?

My Shimano Deore XT rear derailleur on my Cube Reaction Race bike got twisted so I've fitted an identical replacement.

Problem is, I can't get it adjusted correctly. I can change up into each gear fine, but can't get it onto the largest gear. I run out of clicks in my gear change lever.
The stop screw isn't restricting it, as there's still a gap (see photo).

Also, when changing down the gears I can get it into the smallest gear, but there's still one click left in the lever, but the chain doesn't move any further. Again, it's not the stop screw limiting it as there's a gap on that one too.

Any suggestions please? Could the cable tension need adjusting?

 

[Deleted member 33385]

Any suggestions for my rear derailleur problem pease?

My Shimano Deore XT rear derailleur on my Cube Reaction Race bike got twisted so I've fitted an identical replacement.

Problem is, I can't get it adjusted correctly. I can change up into each gear fine, but can't get it onto the largest gear. I run out of clicks in my gear change lever.
The stop screw isn't restricting it, as there's still a gap (see photo).

Also, when changing down the gears I can get it into the smallest gear, but there's still one click left in the lever, but the chain doesn't move any further. Again, it's not the stop screw limiting it as there's a gap on that one too.

Any suggestions please? Could the cable tension need adjusting?

View attachment 41904

Adjust the restricting screws for highest and lowest gear, if needed increase cable tension, till you can get all gears, then fine tune using the tensioning screw on the derailleur and the tensioning screw on the gear changer.

 

[soundwave]

and get a new cable

 

[vfr400]

Your problem is that the cable is too slack in top gear.

You put it in the highest (smallest) gear, adjust the derailleur's position with the end-stop screw, then fully screw in the cable adjuster and adjust the cable clamp position until it just has some tension, but not enough to move the derailleur. After that, you screw out the cable length adjuster until you can see that it is starting to move the derailleur and you can hear it, then back it off until the chain runs without noise. As soon as you move the shifter, you should see the derailleur moving with it. After that, you can check the other gears and make fine adjustments with the cable length adjuster.

 

[JPGiant]

And check the hanger isn't bent.

 

[The Bear]

Adjust the restricting screws for highest and lowest gear, if needed increase cable tension, till you can get all gears, then fine tune using the tensioning screw on the derailleur and the tensioning screw on the gear changer.

Thanks, I'll give those videos a watch

And check the hanger isn't bent.

Yes, it does need replacing but it threads through the frame so I need to learn how to do that.

 

[The Bear]

Your problem is that the cable is too slack in top gear.

You put it in the highest (smallest) gear, adjust the derailleur's position with the end-stop screw, then fully screw in the cable adjuster and adjust the cable clamp position until it just has some tension, but not enough to move the derailleur. After that, you screw out the cable length adjuster until you can see that it is starting to move the derailleur and you can hear it, then back it off until the chain runs without noise. As soon as you move the shifter, you should see the derailleur moving with it. After that, you can check the other gears and make fine adjustments with the cable length adjuster.

Thanks. By coincidence I think I happen to have done some of that just now. I loosened the cable clamp and pulled a few more mm of cable through, then nipped it back up again. It now goes into every gear. I'll give it a test ride tomorrow.

 

[Deleted member 33385]

Your problem is that the cable is too slack in top gear.

You put it in the highest (smallest) gear, adjust the derailleur's position with the end-stop screw, then fully screw in the cable adjuster and adjust the cable clamp position until it just has some tension, but not enough to move the derailleur. After that, you screw out the cable length adjuster until you can see that it is starting to move the derailleur and you can hear it, then back it off until the chain runs without noise. As soon as you move the shifter, you should see the derailleur moving with it. After that, you can check the other gears and make fine adjustments with the cable length adjuster.

That's brilliant! I've just done as you've suggested and my gears work great - good tip about gear tension at the start, especially. Saves a lot of fiddling.

 

[slowcoach]

An excellent video on derailleur adjustment by Park Tools.

Rear Derailleur Adjustment

The article will discuss adjustment of rear derailleur limit screws and indexing.

www.parktool.com

 

[soundwave]

the mech hanger will bolt in to the frame, so you need the right one that will fit what you have but i went from 11spd to 12spd cassette even tho it worked bent like that couple of mm it would not work with a 12 spd cassette.

if you dont replace it then it will wear the chain and cassette faster you can get a tool to bend them back in to shape but not recommended.

Stainless Steel Alignment Tool Cycling Maintenance Rear Derailleur Hanger | eBay

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[The Bear]

The hanger that came with the derailleur was the wrong type, but I used my existing hanger.

I now need to figure out how to change the cable as most of it is concealed inside the bike frame. Not sure how a new cable is fed through, im guessing some kind of pull through is needed to act as a guide?

 

[Nealh]

simply attach some light string or fishing line to the cable with tape and gently pull it through, repeat process to re thread it back through again.

 

[Deleted member 33385]

Not appropriate for this situation but... a strong sheath and lots of lube, can keep you out of trouble

 

[vfr400]

The hanger that came with the derailleur was the wrong type, but I used my existing hanger.

I now need to figure out how to change the cable as most of it is concealed inside the bike frame. Not sure how a new cable is fed through, im guessing some kind of pull through is needed to act as a guide?

You don't need to replace the cable if it's working. It's a fallacy that cables stretch. That's what bike shops tell you when they want to make extra money out of their customers. You repla e cables when they're visibly damaged or rusty.

 

[Deleted member 33385]

You don't need to replace the cable if it's working. It's a fallacy that cables stretch. That's what bike shops tell you when they want to make extra money out of their customers.

Some new cables are even sold "Pre-stretched", so you don't end up having to adjust the gears all over again soon after, as the new cable inevitably stretches:

Transfil Campagnolo Stainless Steel Gear Wire, 190 cm : Sports & Outdoors

Shop Transfil Campagnolo Stainless Steel Gear Wire, 190 cm. Free delivery and returns on all eligible orders.

www.amazon.co.uk

...it's a pity those were too short for my bike. They should have stretched them some more.

 

[soundwave]

you just change the inner cable but when you remove the old one give the outer cable a blast with some wd40 and then put the new cable in the shifter.

 

[The Bear]

you just change the inner cable but when you remove the old one give the outer cable a blast with some wd40 and then put the new cable in the shifter.

That makes it sound a bit easier than I thought, thanks. My cable is quite badly frayed where it clamps to the derailleur so I ought to replace it.

Would I need Shimano cable, or will any cable do as long as it's long enough? are they different thicknesses?

 

[soundwave]

GEAR CHANGE DERAILLEUR INNER CABLE BIKE 2200mm MTB SHIMANO SRAM 7 8 9 10 11 12 | eBay

Length 2200mm. Inner gear change cable.

www.ebay.co.uk

just look inside the shifter and make sure the end matches what you have.