wheelhot

Hi,

So I have a Roubaix set up on a 50/34 and 11-32. The FD and RD are both Ultegras but the crankset is a Praxis Zayante.

The issue I have now is, the FD won't upshift (small to large cog), unless the FD is set up in such a way where if I ride on big front and mid rear cog, it'll rub the chain.

I can accept if there's chain rubbing if I'm cross chaining big-big but this is big-mid. Advice?

And to adjust the FD inwards (to avoid chain rub), I guess I need to tighten the H limit screw?

Hondo Gravel

I have Ultegra 50-34 on my gravel bike and when I’m in the large front chainring and I shift to far to the lower gears the chain will rub but as you say in the middle gears it shouldn’t rub. Sounds like a simple adjust of the FD. Try tensioning the cable that has always fixed my FD with chain rub and poor up shifting. Most of time I tinker with it until it works and I forget what I did lol. Turn the H/L screws in small increments that may help. Someone who is a professional wrench on the website will probably chime in to help you out.

Iride01 

This is after you trim? Although something still seems out of adjustment. I don't have any rub to trim out until I'm in the big front and second largest rear on my 105 5800. Sometimes the third gear.

I'm on a 52/36 front with an 11-32 rear. Seems like that would be more extreme but maybe I'm visualizing it wrong.

What version Ultegra? 6800?

wheelhot

Yes, the 6800 ones.

It's odd in a sense that if tuned on a bike stand, it will shift without any rubbing and stuff, but the moment you actually ride it, going from the front small cog to the large cog becomes almost impossible, unless you tune it in such a way where the chain rubs on the middle rear cog.

smashndash

See if my issues are anything like yours:

https(colon)//www(dot)bikeforums(dot)net/bicycle-mechanics/1136242-my-bike-defective-how-s-supposed(dot)html

wheelhot

Hmm, does seem like it but it seems there's a no clear answer either :/

pesty

Sounds similar to @smashndash's issues. Did the shifting degrade to this point, or was this after initial setup? 5800/6800/9000 FD's are a PITA to setup.

The below link is what I used to get my 5800 setup and working good... the key is you MUST have a barrel adjuster for your FD. If you don't, it's not impossible as I've gotten it to work, but it's pretty damn close to imposible.

Moonigan's How to Setup 11s FD

wheelhot

@pesty, hmm, the original bike setup was fine, but after its first maintenance service, I think someone adjusted the FD and since then it has not been "perfect"

The Roubaix does come with a barrel adjuster and since it's direct mount type, I guess there are no rotational misalignment issues?

And thanks for the link, I'll take a look at it

EDIT: Wish there was a video or photos explanation alongside it, some parts isn't that clear

pesty

What do you mean "direct mount"? To my knowledge there are direct mount road front derailleurs, at least not from Shimano. Do you mean band clamp type as opposed to braze on? [that's what I'm going to assume]

So I'm assuming they wouldn't adjust the angle or height of the FD during a servicing unless there was a problem. I could see them adjusting or replacing cables, which if done the way you would the previous generation Shimano FD's would put you in the situation you're seeing.

If you're adept at doing any of your own maintenance, should be fairly simple and straight forward. Again, this is assuming nobody messed with the height or angle of the FD, and hopefully not the limit screws.

First, put it in the smallest front ring, biggest rear cog. Hit the front downshift 3 or 4 times to make sure you're not in the trim position. De-tension the barrel adjuster all the way. The inside of the cage (nearest the seat tube) should be about .5mm from the chain. If not, adjust the low limit screw accordingly.

Next, loosen the cable clamp bolt, take up any slack, and re-tighten. The cable should be below the bolt and inside of a small black peg. There is a white arrow on the side of the arm that shows the proper cable routing. This peg adjusts the pull ratio, I'm also assuming nobody moved that as well.

3rd, tension the cable with the barrel adjuster until it's tight, but not so much that it pushed the derailleur into the chain. This is backwards from the instructions in the link, but this was the order I did it in.

Assuming the high limit screw has not been adjusted, you should be able to shift into the big ring without issue, but you may need to adjust accordingly.

The barrel adjuster I have only takes up about 3-5mm of slack and I had to screw it all the way tight to get it to work on mine. Really bad design on Shimano's part IMHO on this one. The newer 5801/8000/9100 design, while mechanically more complex, does look to be a bit easier to work with. Not certain on this, but it looks like it might be another trickle down from their MTB line similar to the 8000 and 9100 rear derailleurs.

wheelhot

Yeah, braze on. And thanks for the tips! So far the only issue is when riding, it wont shift from small to large but mounted on a maintenance stand, it shifts fine.

I'll probably look at the gap as I think the main issue now is the FD barely moves in the big cog trim position.

Talking about that, what affects the trim position? Is it the cable tension so I'll have to use the barrel adjuster to adjust the trim?

pesty

Trim position is determined in the shifting mechanism in the lever and isn't adjustable as far as I'm aware. There are two trim positions, one going up from the small ring, and one coming down from the big ring.

You might try letting the high limit out a touch and see if the cage comes out a little farther.

Racing Dan

The position of the cage in either of the two trim positions is determined by the cable tension. Adjusting the barrel will move the cage in or out. In the non-trim positions (outer or inner most positions) the cage position is either determined by the L or H stop screw >or< the cable tension. It can be a bit confusing the first few times.

wheelhot

Hmm, right now it shifts fine, just that it rubs the rear cog, so I think I need to adjust the barrel adjuster and see if the trim moves back like how it used to, cause right now I don't see the FD move in the trim position whereas previously, I am able to see some movements.

wheelhot

Hmm, so with the barrel adjuster, if I rotate it clockwise, it'll tighten the cable and vice versa right?

smashndash

"Clockwise" depends on how you're looking at it. To tighten the cable, you want to make the barrel adjuster longer as a structure, which feels more like unscrewing something. To loosen the cable, make the adjuster shorter, which should feel like screwing something in.

Racing Dan

This is clear a mud. What "it" rubs which cog? And in that lever position does it do it?
. - Remember there is 4(!)

fietsbob

Bring it by & I can look at it.

wheelhot

Thanks! I'll give that a try

wheelhot

Haha, if only I was in the States

wheelhot

The chain rubs the front derailleur trim side when the setup is front large cog, middle rear cog.

And it rubs even if it was shifted to "trim" position

Racing Dan

Sounds like too much cable tension. You should be able to cross chain big-big in the high trim position. Too much tension pushes the cage out making the chain rub on the inside of the cage.

pesty

The cable isn’t clamped over the top of the bolt is it?

wheelhot

Hello all, apologies for the lack of update but I've decided to go for a few rides while doing the barrel adjustments but no go, if I loosen the cable tension to prevent the chain from rubbing, FD won't shift from small to big cog, I need to shift both the FD and RD simultaneously to get the FD to upshift.

So I decided to adjust the H limit screw, but it seems that I can't get the FD to push the chain off the big cog. I even loosen the H screw till it's not touching and I still can't get the FD to throw the chain off the big cog.

Here are some photos


As you can see here, the H screw is totally loosen

And @pesty;, here's how the cable is clamped


Lastly, I checked the FD and it seems to be parallel with the cogs, then I check the height as I read there need to be a gap of 1-3mm, I'm not sure if this is because of Praxis cogs, but I notice some of the teeth height are different? Some look within the 1-3mm while some do not, so which I should reference then?





And what do you guys think of this setup video, it sounds about right

pesty

@wheelhot
That all looks right, and the video covers about everything. Only thing I can think of is if the cable alignment pin thing just below the cable clamp needs to be flipped, but it looks like it’s in the position that gives the most leverage.

I’m at a loss here, only thing I can think of is barrel adjuster/cable tension issue.

On a side note, I did get my 5801 installed finally, and while it’s no fewer or less complex instructions, it isn’t easier to, how should I say.... not get wrong?

wheelhot

Oh, so the FD should not be able to push the chain further out causing the chain to drop outside of the big ring? Cause what I'm thinking is there's not enough leverage or tension which is causing it to shift smoothly while on a stand but once ridden, not enough force.