Road Bike, Cycling Forums banner
1 - 17 of 17 Posts

·
Registered
Joined
·
318 Posts
Discussion Starter · #1 ·
I have take my BMC to 4 different bike shops and it still has issues. Whenever I shift from small to large chainring, it's not smooth the way Di2 is intended. The bike shops stated so but can't seem to fix the issue. The way it's shifting now is that it tries to catch the big chainring but it takes much longer than it's supposed to. What could be the issue? The crankset is a dura ace 7900 and it only has 300 miles.
 

·
Registered
Joined
·
1,109 Posts
Make sure that the support bolt and the protector plate is installed and the support bolt has been extended to the frame. I've found a number of installs by supposedly experienced shops that have not used the support bolt. It stiffens the FD and improves shifting. Also check that the FD hanger is not loose.
 

·
'brifter' is f'ing stupid
Joined
·
15,670 Posts
Make sure that the support bolt and the protector plate is installed and the support bolt has been extended to the frame. I've found a number of installs by supposedly experienced shops that have not used the support bolt. It stiffens the FD and improves shifting. Also check that the FD hanger is not loose.
^This...i'm amazed at how many Di2 bikes i've seen from other shops that were sold w/o the support bolt ever being touched. It can make a huge difference.
 

·
Registered
Joined
·
318 Posts
Discussion Starter · #7 ·
^This...i'm amazed at how many Di2 bikes i've seen from other shops that were sold w/o the support bolt ever being touched. It can make a huge difference.
They did not install the protector plate and I did bring this up. However, on this particular frame, the supporting bolt is actually sitting on the braze-on plate of the bike. Therefore, they said the protector plate is not needed. I'm going to mess around with it myself tomorrow.
 

·
'brifter' is f'ing stupid
Joined
·
15,670 Posts
They did not install the protector plate and I did bring this up. However, on this particular frame, the supporting bolt is actually sitting on the braze-on plate of the bike. Therefore, they said the protector plate is not needed. I'm going to mess around with it myself tomorrow.
As long as the bolt is pushing on something other than carbon you're ok. Just about every Trek frame is like that, the support bolt hits the braze-on mount so you don't need the stick-on plate.
The only reasons for the poor shifting in this case are poor derailleur positioning and/or the limit screw is too tight. Remember the 'high' limit screw works backwards from a regular derailleur. When you tighten the screw it moves the derailleur cage out.
 

·
Registered
Joined
·
282 Posts
I've installed Ultegra Di2 on 2 Cervelo's and both have shifted perfectly, even standing up grunting up a step inclines and I have just upgraded one of the bikes to DA9000 Di2 and its just the same, perfect changes every time.

I suggest you go to Shimano's tech website and download the Di2 installation instructions (pdf format). Installation and adjustment is really easy when you get the hang of it.

As others have already said, it is very important that the initial mechanical install instruction are followed in respect to the additional support bolt and its adjustment before you move onto the actual small ring, big ring adjustments.

Good luck
 

·
Registered
Joined
·
40 Posts
Did you make sure the angle adjustment is correct? There's a bolt that's hard to see that moves the cage in/out so you can set the cage parallel to the chain rings. Other than that there is only the limits. If you set the limits too loose (like to far away from the chain) it might have issues too.
 

·
'brifter' is f'ing stupid
Joined
·
15,670 Posts
Did you make sure the angle adjustment is correct? There's a bolt that's hard to see that moves the cage in/out so you can set the cage parallel to the chain rings. Other than that there is only the limits. If you set the limits too loose (like to far away from the chain) it might have issues too.
That is NOT an adjustment bolt. It's a support bolt. You need to align the derailleur correctly and then adjust that bolt to support it, not change the adjustment.

Shimano does refer to adjusting the angle of the derailleur cage using the support bolt, but it's a very very minor adjustment, like half a degree. i rarely use the support bolt for anything other than giving the derailleur something to push against.
 

·
Registered
Joined
·
318 Posts
Discussion Starter · #13 ·
Just an update. It's been several rides now and it's been perfect. I think the key (as mentioned) above is to make sure the support bolt is well seated on the backing plate. The other key thing is to make sure the outer plate of the derailleur is absolutely parallel to the big chainring like the video above. I follow the video to a T and it worked out great. Surprising so many bike shops couldn't get this thing right.
 

·
'brifter' is f'ing stupid
Joined
·
15,670 Posts
Just an update. It's been several rides now and it's been perfect. I think the key (as mentioned) above is to make sure the support bolt is well seated on the backing plate. The other key thing is to make sure the outer plate of the derailleur is absolutely parallel to the big chainring like the video above. I follow the video to a T and it worked out great. Surprising so many bike shops couldn't get this thing right.
It really is surprising, yeah? Good job on getting it dialed in and working like it should. :thumbsup:
 

·
Registered
Joined
·
282 Posts
Its really good to hear you have everything worked out now.

Properly installed and adjusted, Shimano Di2 be it Ultegra & Dura Ace is just fantastic technology, having had both, I would never want to go back to mechanical ever again.

What really annoys me though is that there are bike shops out there who just don't have a clue about what they are selling, is it any wonder that so many are finding it hard to compete in the world with the likes of the big online retailers and users who are now "doing their own thing" because there have been bitten once to often by LBS who are incompetent.
 

·
Registered
Joined
·
1,109 Posts
I think Di2 and 9000 are different enough in the setup on the FD in particular, that these installs are where I find the most issues of shops not doing it right. The users keeps going back to them when they have issues and the shops are ignorant of the proper procedure and just throw up their hands. All I do is read the manuals and follow the instructions and I'm called a "miracle worker". Go figure.
 

·
Registered
Joined
·
265 Posts
I'm having the same problem at the moment :mad2:

Is it the screw that's shown on the 1 min mark that's the culprit for the overshift?

I'm certain the mechanic played with the upper and lower limit screws before handing the bike to me, but I think he forgot to allign it. I'm coming from an Ultegra crank to a Rotor 3D w/ BOR chainrings. I thought it was ok the other day but when I brought it back to him for a different issue, the shifting wasn't as crisp last night.

Thanks.
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top