Good morning fellow tinkerers.
So today I was upgrading my 2015 Boardman team FS 650 B to a one by 11 drivetrain. The derailer is a Shimano Dior 5100 and the cassette is 11 to 51 teeth. On paper you should work however you can see the top jockey wheel is making contact with The cassette.
Please confirm my suspicion that this is because the Boardman was originally a 2 x 10 drivetrain if I recall correctly, so I should get something similar to a wolf tooth GOAT to extend the derailer below its current position.
If I’m missing anything, please tell me so.
by Returning2Riding
10 Comments
ain’t nothin’ but a heartache
Adjust the B screw
I would probably start with making sure the cable tension is set correctly and check the chain is the correct length. Looks like b tension is maxed out.
learn how to set up a derailleur.
this is just the B screw that you need to turn to make the derailleur go lower to clear the cassette
> Please confirm my suspicion that this is because the Boardman was originally a 2 x 10 drivetrain
Nope, that’s not the cause.
> On paper you should work however you can see the top jockey wheel is making contact with The cassette.
What installation instructions are you following? How have you adjusted the B-tension? How have you sized the chain?
You should be following the [dealer’s manual](https://si.shimano.com/en/pdfs/dm/MARD001/DM-MARD001-05-ENG.pdf) step-by-every-step.
Check the derailleur spec online, it should have a maximum cassette size listed – but m5100 should support the cassette size.
I also see the chain is not on the chainring so the cage has nothing pulling on it. Put the chain on the front chainring to pull the derailleur cage, which will pull the jockey wheel out of the way of the cassette. If the chain is not tensioned the top jockey wheel will hit the cassette.
[si.shimano.com](http://si.shimano.com)
Follow the directions.
A couple of possibilities:
(1) The Deore had a spacer with 2 tabs on it. One tab rests against the tab on the derailleur hanger. The other is what the B screw presses on. If that spacer is turned around so that it isn’t contacting the hanger tab, the B screw has nothing to press against. This seems likely here.
(2) Your chain is way too long.
Your chain is too long. The geometry of high range derailleurs requires chain tension/length to be within a specific range to position the cage correctly for the larger gears. Like everyone else has said, follow the shimano instructions to a T.
in your second picture you can see the black tab sticking up in front of the b tension screw. the b tension is supposed to use that tab to set the derailleur position. loosen the derailleur on frame, spin that tab down under the b tension screw and try again.