Weird (and annoying) problem!

[Rabsh]

Hey guys, been watching BicycleTutor's videos and they've really helped so far, and I learned a lot of stuff about maintaining and tuning my bike. However, I have this problem with the rear derailleur which, I don't suppose, others might have. Perhaps they do.

Basically, when on the middle front gear, the derailleur won't let me access all the rear sprockets. With a little barrel adjusting, I can use the gears 1 - 6. With another barrel adjusting, it allows me to use gears 2 - 7 (never all 1 - 7). However fine my tuning is, it's either too much tension or too little. So I've decided to retension my shifter cable.

After much trying and getting tired (I don't own a repair stand, these aren't too common in where I live), I finally got it to work, but the problem's not gone :/

I'm using a Shimano Tourney, by the way. I'm guessing it's some really basic stuff, but I'm not what you'd call a professional cyclist :p but that the derailleur sucks and its annoying. I called the place I bought it from and they told me to do exactly what I did, which sort of confirms I was right.

Help appreciated!

[Rabsh]

P.S.
Gah few typos in the post but it won't let me edit it after 60mins.
Anyway, if it can be of use, it actually shifts from gear to gear *very* well, but the smallest/biggest gear is always left out. I cannot get the chain to go on the first/last gear without adjusting the barrel and tension, but when I do, the last/first gear becomes inaccessible, no matter how small the increments I made are I'm guessing that on the other front sprockets, it would work worse, but I haven't tried yet.


Checked the chain, one of the links is slightly bent but not enough to tamper with the derailleur. It's not worn out either, as in, the other chain links are in good condition. Front derailleur is working fine, too.

[X-RAY]

sounds like maybe the limit screws need adjusted.

[dave_sd]

Clean the rear derailleur really well and re-lube it. What's probably more likely is that the cable housing is worn out or so dirty that there's so much friction that it's keeping the derailleur from working correctly, so replace both the cable and the housing. It's a good practice to replace all your cables and housings once a year to keep them in tip top condition and minimize the chance of them breaking at a less than optimal time.

I also had a similar problem where i missed the eyelet in the shifter when i replaced a cable and it was acting all screwy. Had the shifter apart multiple times and took it to the shop once to try to find the problem. They told me the pivots in the derailleur were worn out, and it's a good thing I took one last look at it before I dropped the $$$ on a new derailleur.

Good luck!

[cyclerUK]

Check alignment of the dérailleur and hanger:-

http://bikeride.com/derailleur-hanger-alignment/

http://www.parktool.com/blog/repair-help/rear-derailleur-hanger-alignment

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

You don't need the special tool, just do it by eye to see if it's out of alignment.

You also don't need a stand. Turn the bike upside down and rest it on the saddle & bars if possible.
Or hang the bike by the saddle.
Lets you turn the pedals/wheels etc.

[Rabsh]

Well it's definitely not the limit screws, and I tried doing it upside down already, but I think that with gravity, the derailleur works better when upright, implying that it may seem to function properly upside down, but in it's original position, it doesn't work as it should. Besides, even upside down, it doesn't reach the 7th (smallest) gear (or 1st if i adjust the barrel).

Might be the hanger alignment, i dunno, although, that, too, looks fine.
Thanks for the advice Will try it out the hanger adjustment asap

[cyclerUK]

1st daft question = I assume you have a 7 speed changer to match the dérailleur.?
2nd = check that the cable is clamped in the correct position on the dérailleur.
Usually there is a grove where it goes.
3rd = check that the jockey wheels haven't been swapped. Usually the top jockey can slide sideways a bit to help alignment of the chain.
The bottom one can't slide and is fixed. I don't know if the Tourney is the same as others?.

Do you know the model number of the Tourney?

[Rabsh]

Yuppers, it's a Revoshift grip-shift shifter with 7 shifts.

2nd, i checked, it's all right

3rd, still fine, i'm 100& sure

and lastly, well it's that one, in the picture (don't mind the silly labels >.> )

[JohnnyCO]

Check limit screws. Shifter and derailleur compatible? same number of clicks(indexed) on shifter as number of cogs on the cassette. Also a good source for info is park tool webpage and sheldon brown.

[Rabsh]

Definitely not the limits. Anyway, I dropped it at the shop i bought it from, and they say something in my shifter was damaged and to access all gears, i had to loosen tension, and use the before-1 setting (i can turn the shifter from 1 to 7, but there's a "setting" before 1) to access the largest gear.

Thing is, i can now use all of my 7 gears, but there's some play in the setting and it annoys me >.<

but some advice here really helped thanks mates