Front derailleur on V20

[Max Id]

Hi guys, so I am currently assembling a V20 with Shimano 105 groupset. I am confused about shifter cable guidance through the pulley. The horizontal distance between the pulley and that bolt on FD which I attach the cable to is about 0.5 cm. That is, the cable pulls the FD almost vertically downwards, so there is insufficient leverage to actually move the derailleur. There is another setup possible, with wrapping the cable around the bottom bracket. Could you please post a few pictures with detailed view of the your cable guidance near that pulley?
That would help a lot!

 

[Doug Kline]

If it helps, here are a couple shots with a SRAM derailleur.

 

[Max Id]

Hi Doug, thanks a lot for the photos, they really helped!
So far I am doing in exactly the same way, but I have some concerns about the durability of that thin thing the front derailleur is attached to... I guess the tension in the gear cable is quite significant?

 

[Doug Kline]

I have some concerns about the durability of that thin thing the front derailleur is attached to

The front derailleur attaches to a derailleur bracket that is the same as a braze-on bracket you'd find on all carbon framed bikes. It should not give any trouble. If your cable pull is that hard, then something else is wrong.

 

[Max Id]

Well, I don't have experience with road type brifters, so can't say if the pull is harder that usually...
The is a standard Shimano 105 front derailleur, I think multiple people reported successful builds on this forums.
Once I attach the cable properly, will drop a picture so you could perhaps advise if it looks fine.
One question - could you please make a picture of the derailleur from the rear, so that both the derailleur and the braze-on bracket are in view ( I'd like to see the angle of the cable from FD to the pulley ), while the derailleur is on the smallest gear?

Thanks a lot!

 

[Doug Kline]

could you please make a picture of the derailleur from the rear

Here's a few more angles.

 

[pedlpadl]

I had difficulty with the FD also. The plastic pulley is strong enough. I had to pull really hard on the cable while tightening the cable clamp bolt in order to get all the slack out of the cable. That was the only way I was able to get the FD to shift to the big ring.

 

[ratz]

A third hand tool is highly recommended for getting the cable tight enough. Also useful for zip ties.

The stalk is sturdy enough for us on RAAM. You won't have any problems with it.

 

[Doug Kline]

The stalk

Oh, I'm learning some new jargon. I could use a Cruzbike glossary of terms.

I don't remember it being difficult to install the FD, but then I've done it many times on many bikes. I wouldn't think you'd have to pull all that hard on the cable to set it and you do have some adjustment with the barrow adjuster. I've always used compressionless cable housing, which might make a difference.

And to be clear, Shimano does make some 105 derailleurs as top pull. Just check to make sure you have a bottom pull.

 

[Doug Kline]

I should also say that with SRAM derailleurs, the cable goes on the clamp on the outside of the pull arm which means while you're tightening the clamp bolt, the rotation is also pulling the cable tighter.

 

[super slim]

Are you using an inline gear cable adjuster like this, to take up the slack?
http://www.chainreactioncycles.com/...exed-inline-gear-adjuster-4-5mm/rp-prod150980

Have you followed the Shimano adjustment instructions, which assumes an in line cable adjuster?
http://www.parktool.com/blog/repair-help/front-derailleur-adjustment#article-section-9

 

[Max Id]

Hey I really like the community here, the answers are really quick and helpful!

Unfortunately I've got another issue, and this one I believe is even more serious:


As you can see, I already moved the cage to the lowest position allowed by the braze-on bracket , but it is still too high above the biggest chainring. Shimano recommends the distance to be around 1-2 mm, but here I have exactly one centimeter, so most likely it won't shift properly, and also the chain will rub the bottom of the cage.

Am I doing something wrong? On CRC there was just one Shimano 105 braze-on front derailleur for double chainring, so I believe it should match the crankset.

Would be very grateful for any suggestions. To be fair, I don't want to buy another groupset from SRAM.

Thanks!

 

[Jeremy S]

Is your lower limit screw perhaps screwed in, forcing an upshift?

 

[Max Id]

Is your lower limit screw perhaps screwed in, forcing an upshift?

It is screwed in ( not fully ), but that bolt mostly controls how far (left-right) the cage can move horizontally, not vertically. I haven't tried the shifting yet because some components are still on the way. What I say is that the cage is tool high above the ring, around 5-7 mm too high.
I actually asked guys on other forums, they say that the bracket might be welded too high, which is really bad news.

 

[Jeremy S]

It is screwed in ( not fully ), but that bolt mostly controls how far (left-right) the cage can horizontally, not vertically

I would suggest backing it out since it should only take a second to try. The derailleur moves in both directions when you shift.

 

[Max Id]

Just tried screwing it out almost completely. I think it became around 1mm closer to the cage. However, it is still too far, unfortunately...

 

[Jeremy S]

Just tried screwing it out almost completely. I think it became around 1mm closer to the cage. However, it is still too far, unfortunately...

Ah well, I figured it was a long shot.

Your second photo above does look odd to me though, like the derailleur is already shifted up. However I am comparing to my SRAM FD.

 

[Doug Kline]

SRAM front derailleurs come with two mounting holes to attach to the braze-on clamp. One for standard cranks and one for compact cranks. Does Shimano do the same thing?

 

[Jeremy S]

Move your tape down to match inside flange. My bet is it will shift just fine as is. I could be wrong but I think its the inside flange that is 1-2 mm not the outside. Probably can move the dr up some.

No.

http://si.shimano.com/pdfs/dm/DM-FD0002-05-ENG.pdf

And other sources (Google it).

 

[Jeremy S]

The tape on the chain ring and the camera angle has me a bit confused as to the spacing on his bike. It looks very similar to all my cruzbikes. Just for giggles I measured the distance on all of my Cruzbikes and they were all +- 1.8 CM. Translation, I think this DR will work fine on my bikes. Based on the Cruz angle no way it drags the bottom of the cage. I suggest trying it before making a new mouse trap.

Are you shifted to the big chainring or the small chainring when you measure? (Except for Yaw, FD setup is initiated in the small chainring position since there is no cable tension.) Yes, I looked at my bike too.