Bicycle Mechanics - Sora to 105 question?

I have a redline R740 with Sora components. 8speed in back and triple up front. IFSA vero crankset. I would like to upgrade to 105 shifters and front and rear derailers eith 10 speed. Will I be able to put a 10 speed cassette on rear and will the crank and chainrings in front work or does everything need to be changed?

That should work. You may not even need to replace the derailleurs.

Will need a ten speed (narrower) chain.

Minimum amount needed to go 10 speed is chain, cassette, and right-hand shifter. Crankset will probably be OK. Changing the front derailleur could improve shifting with the narrower chain, but the difference may not be noticeable. Changing the rear derailleur will be the least necessary, and will probably only achieve a reduction in weight and no functional difference.

Depends how old the Sora derailleur is.

I'm not real impressed with the quality at that level, at least when Sora just came along... 105 derailleur is likely to have less play for much longer, even out of the box.

This would translate to crisper and more reliable shifting, a functional difference.

But depending on how resourceful you are, it can be possible to tweak much of the play out of a derailleur.

Depends how old the Sora derailleur is.

I'm not real impressed with the quality at that level, at least when Sora just came along... 105 derailleur is likely to have less play for much longer, even out of the box.

This would translate to crisper and more reliable shifting, a functional difference.

But depending on how resourceful you are, it can be possible to tweak much of the play out of a derailleur.

Wait, I bought an 8 speed Sora front derailleur that I intend to use in friction mode (from what I know, I think front derailleurs only work in friction mode EDIT: WHOOPS! lol, I forgot when I shift down on my CCM, I "click" down). Anyway, I BELIEVE (not sure) that this Sora front derailleur was from 1999 (bought on eBay FD-3304 if I remember correctly). You're saying it won't work as well as a 105? I was kind of contemplating using an FD-R443 but I changed my mind about using mountain bike shifters and bought Ultegra bar end shifters instead (that I want to install on Paul Thumbies).

Friction shifters are certainly the best way to control front derailleurs, and are what I use on all of my bikes (a selection of down tube, barend, and thumb shifters). They certainly can be operated with an indexed shifter, and that is the more common technique, but then you do need to worry about compatibility between the shifter and derailleur. With friction shifters, there is almost no compatibility issues between shifter and derailleur, so you can just choose whichever FD matches the sizes of your chainrings the best - if it is a triple crankset then pay special attention to the difference in size between the large and middle rings and try to use a FD designed for this difference when possible to ensure smooth shifting. Size of the inner ring is far less important.

My comments were in relation to rear derailleurs. I wouldn't worry about front derailleur quality, except as a matter of aesthetics.

If I decide to go Double or Compact will the FD need to be replaced. I have seen double and triple specific FD while searching around.

If I decide to go Double or Compact will the FD need to be replaced. I have seen double and triple specific FD while searching around.

You may be able to get the front derailleur to work with a double set up, but they are built with double or triple in mind. Generally, a triple FD won't work as well with a double crank as well as a double FD will, meaning sloppier front shifting and some chain rub on the FD in certain gears. The triple FD has a different cage design, allowing it to work better with the small chainring of a triple, but not work optimally with a double set up.

Also, using the 8spd chainrings with 10spd chain will also cause a couple problems. The 10 speed chain has a narrower width than the 8 speed chainrings, meaning you'll get sloppier shifting in the front than with using 10 speed chainrings. Also, since the width of the rings is wider than the chain, the chain will wear faster than normal.

If you can afford it, its generally recommended to switch out shifters, cassette, chain, derailleurs, and crank or chainrings all at once to get the best shifting options. Again, you may be able to get it work, but your front shifting won't be spot on, and could wear the chain prematurely.