Bicycle Tutor

I'm so dumb I don't even know what I did wrong. I had a flat rear tire. I changed the tire. No problem. But when I went out to ride my front derailleur would hardly move. It was so tight I thought I would break it trying to shift. It would no longer shift all the way up. I went through the videos on this subject on this site and nothing seems to address an issue like this. Does anyone have any suggestions for somebody who apparently has no idea what he's doing?

Thanks

Cannot see how removing/reinstalling the rear wheel would affect the front changer unless you have somehow moved it out of position or managed to trap the cable?

The only other thing I can think of is that if you have lever type shifters the front shifter lever has been knocked and is catching on the brake lever, seen this several times.

(Jun 28, 2010 07:26 AM)trevgbb Wrote:  Cannot see how removing/reinstalling the rear wheel would affect the front changer unless you have somehow moved it out of position or managed to trap the cable?
The only other thing I can think of is that if you have lever type shifters the front shifter lever has been knocked and is catching on the brake lever, seen this several times.

No, I stated it wrong!!! It is the rear changer that has the problem. See, I told you I was dumb. ;-)

I'm gonna guess that you didn't get the chain looped around the rear sprockets correctly. Post pictures, they help!

Find a way of working on the bike with the rear wheel off the ground, if you don't have a workstand, a very basic system I have seen used for simple repairs is to hang a rope with a loop on the end from the garage roof and hook the saddle into the loop.

The most likely cause is in the cable, either too much slack or not running through the guides properly or even rusted inside the outer cover, you should be able to check this visually or by pulling on the bare wire somewhere along its length while operating the shifter.

Correct any problems with this and continue.

Now rotate the pedals and operate the gears, does the chain run through all the gears properly, no jumps or catches?

No, first is it running over the jockey wheels properly, if not, this is usually just a matter of pushing the chain into position.Still problems? then disconnect the cable from the rd, noting how it is connected and where it runs before you do so.

Now again rotate the pedals slowly and push the rd through it full stroke by hand, ( this is also a good time to check that the high/low gear stops on the rd are set so that the chain doesn't fall off the top or bottom ring).

Make sure that the cable runs properly through all its guides except it is not clamped up in the rd, grasp the end of the wire and operate the shifter, you should feel it working, Reconnect the cable to the rd making sure that the chain is on the high gear (smallest ring) and the shifter in the same gear position, eliminate any slack in the cable using the adjustment barrel if necessary and run through the gears.

(Jun 28, 2010 01:44 PM)Billy Wrote:  I'm gonna guess that you didn't get the chain looped around the rear sprockets correctly. Post pictures, they help!

I'll try to get out there in the next couple of days and get some pictures. Thanks for the tip.

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(Jun 29, 2010 01:39 AM)trevgbb Wrote:  Find a way of working on the bike with the rear wheel off the ground, if you don't have a workstand, a very basic system I have seen used for simple repairs is to hang a rope with a loop on the end from the garage roof and hook the saddle into the loop.

The most likely cause is in the cable, either too much slack or not running through the guides properly or even rusted inside the outer cover, you should be able to check this visually or by pulling on the bare wire somewhere along its length while operating the shifter.

Correct any problems with this and continue.

Now rotate the pedals and operate the gears, does the chain run through all the gears properly, no jumps or catches?

No, first is it running over the jockey wheels properly, if not, this is usually just a matter of pushing the chain into position.Still problems? then disconnect the cable from the rd, noting how it is connected and where it runs before you do so.

Now again rotate the pedals slowly and push the rd through it full stroke by hand, ( this is also a good time to check that the high/low gear stops on the rd are set so that the chain doesn't fall off the top or bottom ring).

Make sure that the cable runs properly through all its guides except it is not clamped up in the rd, grasp the end of the wire and operate the shifter, you should feel it working, Reconnect the cable to the rd making sure that the chain is on the high gear (smallest ring) and the shifter in the same gear position, eliminate any slack in the cable using the adjustment barrel if necessary and run through the gears.

That's all great advice; especially the rope idea to get the rear tire in the air. I'm going to try to get back out to work on this in the next couple of days. I miss riding already!

Thanks,

Jim Patton

(Jun 28, 2010 01:44 PM)Billy Wrote:  I'm gonna guess that you didn't get the chain looped around the rear sprockets correctly. Post pictures, they help!

Here are some pictures; do these help?

   

   

   

Can't see anything drastically wrong, the only thing I can suggest is you have too much slack in the cable, as I have suggested before, try pushing the rd by hand through its full stroke, if this works the fault must be in the cable or the shifter, if it doesn't, then the rd stops need resetting.

Too much slack is easy to remedy, disconnect the cable, screw in the adjuster on the rd, it's fully out at the moment,check that the cable is properly routed and that the shifter is in the proper position and reconnect the cable, keeping it taut as you do so.

Now operate the shifter, using the adjuster for fine tuning. If this doesn't solve it, you have a fault in your shifter, which may mean replacing it.

OK, I guessed wrong. I agree with trevgbb in that the cable is the next likely suspect. The only thing I'd add to his suggestion is: while the cable is disconnected at the rear, operate the shifter to verify that it's not jammed or otherwise broken. If it operates normally, then follow trevgbb's advice and get the cable sorted.

(Jun 30, 2010 10:06 AM)jimpatton63 Wrote:  

(Jun 28, 2010 01:44 PM)Billy Wrote:  I'm gonna guess that you didn't get the chain looped around the rear sprockets correctly. Post pictures, they help!

Here are some pictures; do these help?

Forgot this one from the back.


   

(Jun 30, 2010 06:02 PM)Billy Wrote:  OK, I guessed wrong. I agree with trevgbb in that the cable is the next likely suspect. The only thing I'd add to his suggestion is: while the cable is disconnected at the rear, operate the shifter to verify that it's not jammed or otherwise broken. If it operates normally, then follow trevgbb's advice and get the cable sorted.

I disconnected the cable and turned the shifter on the handle bars back and forth and the cable seems to move easily. But when I try to push the derailleur at the back of the bike it won't even go all the way to the inside; that is the bigger gears. There are 8 gears but I can only force it to go to the 6th one leaving 7 & 8 inaccessible. But with the cable re-attached I can't get the derailleur to move at all with the shifter on the handelbars. I'm not good enough at this to know what might be wrong but that derailleur either needs some kind of adjustment or something.

What I can't figure out is how this happened. All I did was put on a new tube and tire. I didn't mess with any of the gears or cables. I have since then because I'm trying to get it to work. Could I have something so terribly out of adjustment now that it just won't work?

(Jul 6, 2010 07:26 AM)jimpatton63 Wrote:  

(Jun 30, 2010 06:02 PM)Billy Wrote:  OK, I guessed wrong. I agree with trevgbb in that the cable is the next likely suspect. The only thing I'd add to his suggestion is: while the cable is disconnected at the rear, operate the shifter to verify that it's not jammed or otherwise broken. If it operates normally, then follow trevgbb's advice and get the cable sorted.

I disconnected the cable and turned the shifter on the handle bars back and forth and the cable seems to move easily. But when I try to push the derailleur at the back of the bike it won't even go all the way to the inside; that is the bigger gears. There are 8 gears but I can only force it to go to the 6th one leaving 7 & 8 inaccessible. But with the cable re-attached I can't get the derailleur to move at all with the shifter on the handelbars. I'm not good enough at this to know what might be wrong but that derailleur either needs some kind of adjustment or something.

What I can't figure out is how this happened. All I did was put on a new tube and tire. I didn't mess with any of the gears or cables. I have since then because I'm trying to get it to work. Could I have something so terribly out of adjustment now that it just won't work?

New info: I got a book on mountain bike maintenance and repair. I figured out how to adjust that rear derailleur so that it moves from top to low gear and back by hand. The cable still moves fine when not connected. But when I connect it it won't move. I'm still trying to figure it out from the book but any advice would still be appreciated.

Thanks.

(Jul 6, 2010 08:03 AM)jimpatton63 Wrote:  I got a book on mountain bike maintenance and repair. I figured out how to adjust that rear derailleur so that it moves from top to low gear and back by hand. The cable still moves fine when not connected. But when I connect it it won't move. I'm still trying to figure it out from the book but any advice would still be appreciated.

Thanks.

Well, at least that's some progress, keep trying!

If it isn't already, then shift the front gear onto the smallest chain-ring. Manually put the chain onto the smallest rear cog and Loosen the cable on the rear derailleur. Verify that the shift lever is set to the highest number. From the rear, pull the cable until the rear derailleur almost moves, but the cable's still a little slack. Tighten the bolt while holding the cable at that somewhat-loose position. Test it again.

Loosen the cable at the derailleur and pull on it tightly with one hand.
With the other hand, operate the gear shifter and you should feel the cable move relative to the shifter position.

Ok, thanks everybody. With all of your help and the repair book I have, finally, not only got it working but it's better than it's been in a long time. One of the things that really helped was disconnecting the rear cable and then adjusting the two screws on the rear derailleur to make sure it would go through all of the back gears. Then all the other things came easier.

So I went for an 11 mile ride in the heat of the day (big mistake, I am, after all 60 and the East Texas weather is murder this time of year). The bike worked fine but I forgot my water and I'm a bit tired this evening. Still, thanks to you all I am riding again. Yeaaa!!!

Thanks guys,

Jim Patton