Raleigh Chopper

Hi all,

I am having problems with my rear derailleur in that it is skipping and making "clunking" noises.

More specifically, I have a newish Giant FCR 3 road bike, with Shimano 105/Ultegra groupset with a 10 speed freewheel 12-25, I think, off the top of my head!) and since it is a flatbar bike, it has thumbshifters as opposed to the kind that fit standard road bike bars (I come from MTB, I tried standard road bars but I could not get used to them! Hence I chose a flatbar bike).

Anyway, I digress.

I installed and tensioned the front deraileur with no problems at all. The rear deraileur, however, has proved to be a pain in the arse!

When I adjust the hi/lo tensioners so that the gear changes are smooth through the middle sprockets, the chain skips off the smallest and largest sprockets.

When I adjust the hi/lo so that the chain is correctly positioned on the smallest and largest sprokets, it skips about on the middle sprockets (I notice that the derailleur arm is infact not quite lined up correctly with the middle sprockets).

I worked on the sod for two hours before achieving something that I can ride with comfortably(ish); any slight adjustment to the hi/lo tensioners upsets the whole thing and I have to start all over again! The third tensioner (the one that puts the deraileur arm further away or closer to the sprocket) seems to have no effect at all.

This is my first road bike; I have built a couple of mountain bikes before with no such problems and the big difference I have noticed is that MTB rear derailleurs (LX, XT and old DX) are chunky and the sprockets are much more widely spaced than the delicate little Ultegra thing on my road bike! This chunkyness makes MTB rear derailleurs dead easy to set up!

I thought perhaps that they (Giant) had shipped the wrong thumbshifters by mistake but they haven't.

Anyway, any suggestions would be greatly appreciated!

squirtdad

Sorry...no help....but Skippy the Kangaroo brings back old memories.....Australian shows on Canadian TV, viewed in northern Montana.... The Magic boomerang was right up there also

BikeGarage

Are you thumb shifters 10 speed? I am not aware of any available except Paul's.

Raleigh Chopper

Yep - they ship with the bike - I tested them with no load and there are 9 clicks - hence 10 positions!

EDIT: The rear shifter is the same as the one shown here: https://www.chainreactioncycles.com/M...?ModelID=26702 - the rear derailleur is a 6600.

orangepaint

They're probably Shimano rapidfire or something of that sort.

Check out either Sheldon Brown's site or the parktool site, they both have good tutorials for adjusting your derailleurs. Make sure you set up the limit screws with the rd cable fully slack. Then adjust shifting by playing around with cable tension. Unless you have mismatched shifters(all current shimano shifters and derailleurs are compatible), a bent derailleur hanger, or a damaged derailleur, adjusting cable tension should be easily fix your problem

Raleigh Chopper

Thanks, I'll give it a go

larry_llama

The limit screws should not affect the middle gears. All the limit screws do is set the furthest reach inward and outward -- i.e. they need to be set so that the derailer can reach the extreme cogs but not go so far that the chain goes off the other side. you can theoretically set the limit screws without even having a cable attached.

Then once those are set, shift the derailer to the smallest cog, tighten all of the barrel adjusters in all the way, connect the cable as snugly as you can (should be ok to just use your hands at this stage, no need for pliers). then shift to the second-smallest cog. the derailer probably wont move far enough. thats ok, keep pedalling and back out the barrel adjuster until the chain shifts. then make sure it shifts back ok. at this point you should be pretty much adjusted. take it for a ride and you will be able to tell if the cable needs a little more or less tension. all the fine adjustments can be done at the barrel.

Raleigh Chopper

Thanks for all your advice - Sheldon Brown's site is great! Everything explained in thorough detail. What I know about bikes has been mostly picked up from friends, reading really confusing books and/or just figuring it out for myself. Sheldon has it nailed down nicely

After reading his page on derailleur adjustment I see what I've done wrong with my road bike; also I think my mountain bike RD is screwed (I tend to beat the crap out of my MTB!)