Rear derailleur problem or not?

[MBosh]

I don't know if this is a problem or not so thought I'd better ask here. I have a Giant road bike and the rear derailleur is a Shimano Claris. I've just tried adjusting my gears after they started to jump a gear when I shifted to the largest sprocket on the rear cassette. It seems to be working alright now but here's the bit I don't understand. I adjusted the higher limit screw when my chain was on the smallest sprocket at the front and back and that seemed to work out fine. However, when I then started to do the lower limit adjustments with my chain on the largest sprocket on the rear cassette, I found that I was having to turn the lower limit screw anticlockwise instead of clockwise to get it to stay on the larger sprocket on the cassette.

Can someone tell me if this is normal because I thought turning the lower limit screw clockwise is what pushed it towards the rear wheel and not away from it. The YouTube video I watched also showed the guy adjusting it clockwise to pull it towards the rear wheel, so I'm just wonder why I had to turn it anticlockwise to get it to pull towards largest sprocket on the cassette. Cheers!

 

[Ajax Bay]

Turning the lower limit screw clockwise (screwing it in) limits how far it can move left. Screw it in and it won't allow the RD to move far enough to get the chain to climb onto the largest sprocket. And vice versa.
The limit screws H and L both have a 'limit' function: they don't push or pull anything.

 

[Illaveago]

You can sometimes see the screws projecting from the other side of the mechanism . The screws are limit screws which act on the parallelogram and prevent it going too far in one direction or the other . The high screw prevents the chain from coming off towards the chain stays and the lower stop screw prevents the parallelogram going into your spokes. By turning the screws you should see what effect they are having .

 

[Shearwater Missile]

I just wonder why there was a need to adjust the limit screws, they don`t normally go out of adjustment IMO. Sometimes if the RD has taken a knock it might put shifting out and you are just compensating for that knock. If the bike is new then perhaps it was`nt adjusted correctly in the first place.

 

[Cycleops]

Disconnect the cable and then move the derailleur across by hand and you'll be able to better see what effect the limit screws are having. Turn the cranks, when the it runs smoothly without chatter on the small and big things you're done. Then refer to a YouTube video for the other steps in adjustment.
If it's s new bike take it back to the dealer.

 

[MBosh]

My bike did fall over when I had it rested on the curb so this might be the reason for the gears getting messed up. If it was then I didn't notice until later on because I don't use that gear much unless I'm cycling up a hill. After looking at these comments the gears seem to be working fine now after a few more adjustments.

Can these derailleurs take a bit of a knock or are they usually no good once a bike has toppled over. Cheees!

 

[iluvmybike]

The derailleur is probbaly ok but it may be the hanger that is now slightly after alignment after it fell over - with indexed gears it doesn't take much to cause them to not work ideally. Take it to an LBDS who should be able to bend the hanger straight for you if it is just a tad out - if badly bent then it might require new one - they are not expensive and it is a good idea to always carry a spare anyway. You just need to get right one fro your make and model of bike. Look at the bike from the rear and check the alignment - should all be nice and straight. Be very wary if it is bet inwards as it the lowest gear it may contact the spokes running the risk of catching the rear mech which can do a lot of damage

 

[Shearwater Missile]

My bike did fall over when I had it rested on the curb so this might be the reason for the gears getting messed up. If it was then I didn't notice until later on because I don't use that gear much unless I'm cycling up a hill. After looking at these comments the gears seem to be working fine now after a few more adjustments.

Can these derailleurs take a bit of a knock or are they usually no good once a bike has toppled over. Cheees!

The derailleur will be fine, it`s the hanger that usually gets bent albeit a small degree perhaps. So what you have done is compensate for the bend/twist which may not be that obvious.

 

[Shearwater Missile]

I should have added that if you try and bend it back (if you can see it is out) then you`d need to readjust the limit screws again. As @iluvmybike said may be best to take it to a LBS to align the hanger.

 

[MBosh]

Thanks Guys, I'll get it checked out at the LBS.