Hi, I've tried tuning my rear derailleur on my own according to this video: https://www.youtube.com/watch?v=ZTprZHCwoNc (first time doing it)

And yet, after finishing the step of adjusting the high limit screw, I can't by any means get the chain to move up to the low gear. Here's what I do:

1) I turn the barrel adjuster so that it goes in, loosening the gear cable
2) Loosen the anchor bolt and tighten the wire almost as far as I can pull
3) Take off the wire tension by pushing on the derailleur to put it in the easier gear and then pulling the wire out of the wire stop
4) Setting the high limit screw so the chain can come to the smallest (highest) gear easily
5) Reattaching the cable in the wire stop
6) Making sure the chain still falls on the smallest gear

And it's at this point that I can't get the chain to move up to the lowest gear. Intially when I shift using the gear shifters it clicks all the way easily and I see the wire tightening, but nothing happens to the chain. Then I keep turning the barrel adjuster so that it goes out, tightening the cable. And still the chain doesn't move when I shift to the lower gears with the shifter, and now, the more I loosen the barrel adjuster (moving it out), the more difficult it becomes to use the shifters, until it becomes really difficult to even click one gear lower. And yet the whole time the chain doesn't move.

I would appreciate any advice. Thanks.

Loosen the low limit and repeat step 2?

+1 also make sure the shifter in the highest gear before you connect the cable to the derailleur .

+2

Very important.

So I tried all this and still nothing. Here's a video of me explaining what I did. Please note that at the end, I say the high limit screw was loosened; i actually meant low limit.

And forgive me if I don't use the right terminology. I'm new to this

https://youtu.be/laWKmtxAryE The only other thing I could think of is that I didn't put the bolt back properly. Here's a picture of it. Is the thing behind the bolt in the right position, and is the wire positioned properly? When I loosened this the first time, I didn't pay attention to how it was set up.

And tight on the RD cable is really *tight* before attaching the fixing bolt...odds are backing off even a faction from, "as hard as you can pull" will get these symptoms. Could also be as a result of excess housing (bends too big) or too little housing (too small)....OP didn't say if he was messing around or installing from scratch.

No matter what, there is excess cable that is slack above what you're plucking in the video, OP...and the shifter's index ratchet is taking that slack up instead of pulling on the RD.

OK, here's two steps that should help you solve the problem.

First set the low gear limit properly. For the moment leave the cable where it is, and shift by pulling the bare wire away from the frame like a bow string. Back off the low limit until you can overshift the chain beyond low. (go easy here so you don't jam the wheel or RD). Once you can overshift, bring the limit in by degrees until you can't and stop there. Double check by backing off a half turn which should allow an overshift, then back to prevent. Now repeat shifting a number of times until you're 100% bullerptoof sure it's impossible to overshift. --- Now the Low Limit is correctly set.

[EDIT --- I think you're already covering this part OK, so it may not be relevant] Now to attaching the cable properly, and setting trim and shifting. I suspect your problem may be inability to pull up enough slack, so here's a trick. Shift to a middle gear, such that when you shift back to high without pedaling, the RD hangs inboard of the high gear limit. Now, with the lever in high position and the RD inboard of high, and with the adjuster all the way down, reattach the cable pulling all the slack out, and tighten the pinch bolt.

Having the RD inboard should help you get all the slack out, and with any luck a all, when you turn the pedals the RD should drop to high, with only vestigial slack in the wire. Now shift one click to second high. While pedaling, adjust the trim (barrel) until the RD completes the shift and fine tune the trim. Now you're almost home, shift through the gears and if 2nd high trimmed and shifted properly, all the others will too, except for some minor fine tuning.

The key is to get all the slack out, so if my trick of hanging the RD up inboard isn't enough, push it in by hand as you pull the cable down and cinch it. Also, using these methods, may cause you to over tighten the cable, so double check that you can shift to high, and if not, slowly loosen the pinch bolt until the cable slips enough to let the RD go to high.

Good luck.

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I pull it pretty, pretty tight, to be honest. And it's when I pull it so tight that the gear shifter becomes very difficult to move up one or two, and impossible to shift into the rest.


Inboard... RD.... Gotta go search what these mean

Inboard --- toward the bike's central plane, or wheel. Outboard -- away from bike or wheel -- on a 4 engine jet, the two engines nearer the fusilage are the inboard ones, the other two outboard.

RD -- shorthand for rear derailleur

It will get increasingly difficult to shift the rest...unless you're turning the cranks. Fact of life. As true on your bike as on my Campagnolo Centaur 10s shifters.

First make sure your chain length is right.

Then dont overlook the much misunderstood "B" screw adjustment. It is NOT a tension screw, it is adjusted for clearance between the jockey wheel and the largest sprocket on the cassette. The spec on my Sram 7 for instance is 6mm. The best way to measure that clearance is with the end of a 6mm allen wrench.

THEN do all the adjustments in order described above.

Seems like you're getting your high and lows, and ups and downs mixed up. Low gear is biggest cog. You shift down to get to the lowest gear. High gear is smallest cog, you shift up to get the the highest gear. The low limit screw prevents the derailleur from moving past the largest cog and into the spokes. The high limit screw prevents the derailleur from moving past the smallest cog and into the frame/dropout.

I'm turning the cranks when I'm shifting. Even then, it's impossible to go from the highest gears to the lowest ones.

Thanks

K, will play with the B screw adjustment. My chain length should be OK. The gears were shifting better before I started touching them A month ago they were OK, but then it became increasingly difficult to switch from high to low, and 4 and 3 would be skipped and it wouldn't go into 1, but at least it worked better than now

Yup, probably. But I got it now. Thanks.

OK, will give it another shot today. Thanks everyone.

Do everything everyone was saying above. If that doesn't work, this is what I do when I get a troublesome bike. Loosen the high and low limit screws all of the way. Shift the shifter down to the highest gear (smallest cog) or as far as it will go. Now, shift DOWN one (to the next bigger cog). It doesn't actually have to shift on the gears, just change the shifter to the second position. Adjust the tension (either by repositioning the wire or using the barrel adjuster) so that the bike shifts to the second smallest cog and doesn't sound like it's rubbing. Now shift back and forth between the smallest and second smallest cog to make sure it works. It's very likely that it'll shift off of the outside of the smallest cog at this point, so screw in the high limit screw so this doesn't happen. Now shift through the entire cassette and adjust the low limit screw so it doesn't shift off of the biggest cog into the spokes.