Soberone

Not even going into the reasons I am sick of this Sora front derailleur. I am thinking of upgrading to 105 front derailleur. I have Sora STI shifters, triple chain ring with a 52. Can I swap the Sora front derailleur for 105 Triple with no problems, or is it incompatible with something? Its an 8 speed cassette.

Thinking of doing this tomorrow so any tips on adjusting the thing would be greatly appreciated too.

Later, Russell

Place Sora front derailleur here ->

pokey

Sure you can swap,but your problen is not likely the sora derailer.If you are whoever else is fiddling with it cannot adjust the sora,the 105 will be no better.No sheet!

Soberone

Thanks. This is the answer I was looking for.

Adjustments are a pain, but I don't think it is related to why I don't like my Sora front. Others that I have used are crisp and responsive, no waiting around for the clunking to stop. I sometimes feel like I am shifting manually with a crowbar. Feels and sounds more like a train derailling than a simple gear shift.
(I promised myself I wouldn't talk bad about the equipment. It works fine, when adjusted properly, just not to my personal satisfaction.)

Thanks again Pokey.

mechBgon

Before swapping, you might want to see if Sora is inheriting a problem that RSX had before it.

With RSX triple-chainring systems, the shift from the granny to middle was particularly afflicted because the shifter simply moved the front derailleur cage to its final resting position over the middle chainring and stopped there. At that point, it was up to the middle chainring to grab the chain using its ramps.

Other STI shifters of that generation were able to overshoot the final position momentarily, then fall back to the running position, and this helped the chain climb the ramps onto the chainring. This is not to be confused with the trim positions that many STI shifters also have.

So maybe take a look at how your front derailleur moves when you make the shift. If you push the shift lever to the stop, does the derailleur cage fall back a bit when you release the shifter, or does it stay precisely where it is?

Hope I'm not leading you on a wild goose chase, but I can't remember if Sora acts this way or not. At any rate, if it does, the shifter may be deserving of some or all of the blame.

chewa

Ditch the Shimano and go for Campag. Come on, you know you want to!

(Currently using a mix of 105, 600 and Campag on my Scot)

pokey

mecBgone............possibly good points but I have never experienced a problem with RSX. and, when speking of the RSX,one has to remember the 7 speed fronts would shift a double or trople, and the 8 speed RSX ras essentially rebadged rx-100/105 that whad double or triple specific front sifters. I have noticed a slight overshift to the big ring,but not the middle on 7 and 8 speed sti systems.

WoodyUpstate

When my Ultegra front started shifting sluggishly and requiring more effort than usual I discovered that the cable guide under the bottom bracket was all ****ered up with road grime, spilled sports drink, etc. Some bike love helped the problem immensely. A good cleaning was all that was required.

You may want to check your cables and their routing. Perhaps new cables or housing are in order. Lubing the cable may help, too.

I'm inclined to agree that Sora isn't the reason for your shifting problem (though you may have other issues, and that's fine).

A 9-speed 105 front will work fine with your 8-speed drivetrain.

Soberone

WoodyUpstate, thats what I first thought. Some cleaning up and an adjustment here & there and it would shift again like,, "clunk, clang, what tha !?@". Well, I slid down to my LBS and looked at a new Sora fd and realised that, when viewed fron the top, they don't make an "S" shape! The guy said that was not uncommon. I think "malliable" (sp) was the word he used to describe them. I thought I was going easy on it but maybe I shift harder than I realise.

Anyway, 105 front will work with my 8 speed. Thats good news.

ps. I like the Sora rear. Its a bit noisy, but who cares.
I ain't hunt-n squirls.

Thanks everyone.

jbinbi

I too could use help adjusting a sora sti triple.

I purchased a new trek 1k last oct, rode it about 10x for 200 mi since then, and on every ride the following happens:

high to mid front downshift: fails to make the shift, or every once in a while makes it after 5-10 crank revolutions;

low to mid upshift: chain falls off 1/10 times.

Any help on adjusting? Thanks

mechBgon

Maybe some of these ideas will help:

• Put the chain on the middle chainring and sight down on the derailleur from above. Its outer plate should not be more than a couple degrees out of parallel with the outer chainring. If so, it can be realigned by loosening its clamp bolt and rotating it.
  
• As you're checking this out, also get down next to the crank and pull on the front derailleur cable while observing how close the derailleur cage approaches the tips of the outer chainring's teeth at the minimum. It should be about 1-2mm. Note that many chainrings have short teeth at certain positions, so make sure you're looking at the taller teeth. If the gap is 3-4mm or more, it may help to lower the derailleur.
  
• I would also try rotating the derailleur about 1-2 degrees tail-out, because this will swing the front of the outer cage plate inwards (it's responsible for bumping the chain off the big ring) while swinging the rear of the inside cage outwards (it's responsible for persuading the chain up-and-out on the upshifts). Make certain that this cannot bring the tail of the derailleur cage too close to the inside of the crankarm as it comes around, or it may get damaged.
  
• As a former shop mechanic, I routinely tweaked the nose of the derailleur's outer plate inwards if needed to assist downshifts, and occasionally did similar stuff to the inner plates if necessary. You might try this a little bit at a time if the previous steps aren't helping.
  
• The indexing of the derailleur could also have a lot to do with this. If you want to check for indexing problems, shift the rear derailleur to the big cog and leave the chain on the front chainring. The next bit will depend on whether your Sora shifter has a mini-click to allow for trimming the derailleur... press the downshift lever lightly and see if the derailleur tics inboard a little. This is the more inboard of the two middle-chainring positions on an STI shifter.
  
  Now look at the gap between the chain and the inner FD plate. It should nearly touch. If it doesn't, you can use the adjuster barrel on the downtube to move the cage outwards, strengthening the upshift. If it begins to graze the chain and make noise while pedalling, you've gone too far.
  
  With the "traditional" style of derailleur used on your bike, the inner limit screw controls how far in the derailleur can swing, and the outer... right. These should limit the stroke to the minimum excess needed for good shifting, so that the chance of chain drop is minimzed.
  
• Your LBS can also help if these steps aren't getting the job done. The typical charge for this is probably around $10.

By the way, it seems unusual for the chain to fall off when upshifting from granny to middle. Is that intended as written?

jbinbi

thanks for the super quick reply!!!

you did read correctly. I lose the chain when upshifting from small chainring to middle chainring.

About 20 years ago, I used to be a bike mechanic, but this is the first bike I have with index shifting. It was much easier to adjust with friction shifters!

I did adjust on the downtube cable adjuster, after which it downshifts occasionally, but still takes too long, and still doesn't happen sometimes.

I will try angling the drlr inward, a trick I used to use, but didn't know if it was still ok with indexing.

I would love to find a book, or manual for the sora sti set, which would give the manual for setting up. this shouldn't happen on a brand new bike.

mechBgon

These days, the system seems to rely a fair amount on the "pickups" on the inboard faces of the chainrings, too. Sora uses steel rings and they are not the ultimate in shifting, so I wonder if weak, worn or damaged pickups could be responsible for the inner-to-middle upshift problem... or maybe a bent chainring tooth is giving the chain the heave-ho?

John E

This thread further supports my position that indexed shifting on the front derailleur is an utterly stupid, counterproductive, meritless concept. It is sad that the engineers at Shimano cannot comprehend that the rider needs full, fine-grained control over the motion of the front derailleur cage.



-- Very happily friction-shifting (downtube, barcon, or thumb lever) since 1962!

WorldIRC

i luv friction in the front.. its always silent cuz u can control it.

mechBgon

What kind of bike do you ride, John E? Do you feel that Campagnolo's approach with many fine detents is any better than Shimano's implementation?

I remember when I first heard about the hot new 600 and Dura Ace SIS from Shimano, and I remember thinking, "wow... I'll never have anything that advanced." I was 14 at the time. Now indexed systems are ubiquitous.

Front shifting is lagging the precision of rear shifting, that's for sure. I can power-shift the rear derailleur like a madman while accelerating, no worries. Trying to punch up to the big ring while accelerating hard out of the saddle is asking for a dropped chain and possibly a crash. Moral of the story: I try to be in the chainring I want first.

John E

1) 1959 Capo "Modell Campagnolo" with original friction Campag. NR downtube levers

1980 Peugeot "Competition/PKN-10" with 1970 friction SunTour downtube levers

1982 Bianchi "Campione d'Italia" with original friction Campag. NR downtube levers

2) Yes, the Campag. Ergo front shifter is vastly superior to anything from Shimano, precisely because of the fine-grained control over the position of the cage.

John E

In the picture of Lance on the final climb of Stage 11, one can clearly see the left-side downtube shift lever with which he avoids the indexed front derailleur problems we have been discussing. (He does use a conventional indexed integral brake-shift 9-speed high-end Shimano unit on the right side.)

mechBgon

Does he run that setup just on the climbs, or all the time? Might be a weight-reducing measure, too.

SteveE

JohnE -

I think that Lance just ought to bite the bullet and switch to Campy --- problem solved!

Steve