Derailleur causing issues

[Mohammed]

Hello there,

I had managed to replace my inner tube and outer tyre successfully, however since then I have been trying to re-fit my rear tyre back onto the frame to no avail.

Initially I thought the axel was at an angle. I have undone the nuts and bolts many times, rode the bike, then either the tyre starts rubbing with the frame, or the pedals become really stiff to rotate. But today I have realised its the derailleur that is the main issue. Basically, as soon as I attach the derailleur, the rear wheel becomes very difficult to rotate using the pedals. Once the derailleur is off, the wheel rotates as normal.

Please can you help me with this problem, I have been walking to work for about a week now and not cycling really is a hinderance! Thank you.

[ReapThaWhirlwind]

Do you mean the rear derailleur?

To adjust this from scratch, shift the derailleur down into the highest gear. This will cause it to descend into the smallest cog in the back (not up into the larger ones). Now unhook the cable. Dial the barrel adjuster all the way in (screw inwards—clockwise).

Undo the cable. Pull it just lightly so that it's fixed in the clamp grooves. Refasten the bolt while holding it in place. If you pull the cable too much, or too hard when you refasten it, then you will have too much pretension on the cable and it will mess with the shifting accuracy. Once it's refastened tight, now begin to dial the barrel adjuster out until it's indexed. Checking each little bit by turning the crank and attempting to shift up.

Also check to see the high and low limit screws are screwed in just enough that they touch and hold against the hammers in the top and bottom gear.

If you are still having issues, then it's something more technical, such as the size of the chain maybe.