Bicycle Mechanics - Problem adjusting tiagra rear derailliur.

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA
pagh
06-20-09, 02:09 AM
Hi,

I have recently gotten gotten hold of an older Merida 901 road bike. It has full Sora 8 speed, and tiagra rear de. Problem is that when i adjust the rear derailliur, it works perfect when going from the small coq (small amount of teeth) to the largest coq, but when i then return it downwards, then halfway it doesn`t match up anymore. If i start at the bottom again, it matches perfectly. What is the solution here?

I have tried giving the cables some lube, lubed the deraillur a bit. Had the drop off, and that looked ok to me.

Regards, Michael

chas0039
06-20-09, 06:17 AM
You need the cable tight enough to go to larger cogs and loose enough to go to smaller cogs. So, assuming that your RD is aligned correctly and otherwise working, your cable is too tight. Use the cable adjusting screw assembly and tighten clockwise in small increments.
bikeman715
06-20-09, 09:29 AM
you'll need to start by replacing the cable & housing (which will fix 90% of this problem) if it doesn't then have dropout check. (being bent just a little ) can also cost this. all of this can also be cost by a worn out dérailleur too so it would need to be replace.

z415
06-20-09, 04:22 PM
There can be many problems that can be solved anywhere from dripping some cable lube down there to replacing the whole thing. Check out Parktool.com.
pagh
06-21-09, 08:20 AM
Chas ->
That is what i done and played around with. I think something is either very worn (derailliur - can i check that?) or drop isn`t straight.

Bikeman ->
I had a good play yesterday and it now shifts better, but still not perfect. Will try a new cable and housing. If that still doesn`t do the trick, i will just ride the bike and wear it down and then replace with new components when needed.

Z415 ->
I lubed everything - even myself, that didn´t help either. Did a 10km ride this afternoon, and it is ok to ride. But hey, it is just a winter-beater, so I`ll just have to cope.

Thanks for your replies. :-)