Shimano 105 Biopace 52/42

[nrsmd]

I am resurrecting my Cannondale road bike I have had since about 1985 that has Shimano 105 Biopace 52/42 gears up front (2 rows) and 6 rows in the rear. No matter how I adjust the barrel screw in the rear, the gears in the rear will not shift smoothly between all 6 gears, but jumps over one or more. Each turn of the barrel screw in or out provides new options, but no matter what I do, only 4 or 5 gears are operative (at least skips over, and this in the middle (my useful range) gear range. I can live with it the way it is, but looking at videos, the adjustments seem fairly straight forward.

Any ideas?

Also, the crankshaft is somewhat corroded (fully functional), not sure what it is made out of or how to remove the tarnish?

[GeorgeET]

Its possible the problem is in the worn shifter not in the derailer.

[Painkiller]

as george states one possibility, and I would also replace the cables and housing for that could be the culprit. If you have not done so yet. Bad shifter or not If you have not done the cables and housing yet you still need to. so I say start there and rule that out first. If it takes care of your problem after proper adjustment you are good to go. If not, try to find a shifter and you have not wasted money because you need new cables and housing anyway to do a nice job on your refurb. Also inspect your chain for any damaged links and your cassette for bad teeth. It sounds like a cable/housing issue to me though. and one other note, make sure that your derailleur hanger is not out of alignment. One should true the wheel and make sure the axle is tight before checking the hanger. Good luck and let us know what you came up with

[nrsmd]

I inspected the rear cogs and there are some teeth broken off on the third one up. All the others are OK. I wonder how can I find a replacement, if it is even available??

[GeorgeET]

Replacements are available, just google it or go to Amazon. Is it a freewheel or cassette?

I may have a freewheel cogs here and Robs Garage check for sale on this site has lots of old stuff.

[nrsmd]

(03-17-2012, 10:35 PM)GeorgeET Wrote:  Replacements are available, just google it or go to Amazon. Is it a freewheel or cassette?

I may have a freewheel cogs here and Robs Garage check for sale on this site has lots of old stuff.

I have never even heard these terms. It has 6 rows of cogs, and as Schultz said..."I know nothing."

[Bill]

To help out with the great advice these young gentlemen are telling you I will asked if there is a way you could take a picture(s) of your "6 rear straight rows" (known as cogs) and post it here? This way we can help to determine what kind of assembly of cogs (known as a freewheel or cassette) you have. If you have access to Alex's videos I would suggest you watch all of them which will help your understanding of the parts terminology. As I said just a suggestion. Here is also a cool link to terminology that may assist to break the language barrier .... http://sheldonbrown.com/glossary.html . Hope this helps Bill

[GeorgeET]

Oh so, Schultz. Kind of amazing concept. Funny Nazis. Only in USA.

Check to photo of freewheel and cassette hub. Note on a cassette there is s thickening of the hub diameter at the cassette. That's a good way to tell .

http://sheldonbrown.com/gloss_ca-g.html#cassettejoint

BTW may be a good idea to get friendly with a local bike dealer, he may have the parts you need, and give you the right ones, and tools you will need.
Good luck. Nice project.

BTW Bill thanks for calling me young. :-))

[Bill]

Your welcome lol.