Ok, so I have a ‘history’ with BB bracket spacing on my bike so pardon any stupidness.

I have an on-one inbred, until now I have had a chain guide mounted on the BB where I had one spacer on the BB on each side (as per instructions for the BB shell width) with SLX cranks, no bash.

I now am putting on a front mech so have decided to put the slx double cranks back together as nature intended i.e. 2 chainrings and bash.

First off, the shimano mech 2×9 (m665 top swing) mech instructions say to mount it on the inside of the bash.

In order to do this I have to put both BB spacers on the drive side or it rubs the bash – is this ok???

Second question (and this is dumb) is it the case that when I then put the cable on, pulling the cable taught will move the mech inward (toward the frame) – this is just the opposite to how I thought they worked (but is this because it is top swing?) – otherwise this is doomed already!

Cheers

The default position for the front mech is on the granny ring, so it should move out, away from the frame when the cable is pulled. just take the slack out of the cable and use the barrel adjuster on the shifter to get it shifting.

You need to mount the front mech with about 2mm clearance of the bash ring or it wont shift up into the top of the two rings… or at least mine wouldn’t.

All front mechs use cable pull to move the mech AWAY from the frame..!

ok, good, atleast i am not going mental

in that case should the mech, when mounted with no cable be over the granny ring? as if so, mine isnt. I cannot space it out anymore on the BB amd the limit screws are all the way out at the moment?

i had lots of spacing problems before with my chainguide, is maybe the inbred BB a slightly odd size?

anyway – advice welcome, especially if you have an inbred with this setup!

The Inbred has a 68mm shell so you need the 3 spacers (or 2 and a chain device) for an MTB BB to fit.
Normally you have 2 on the drive and one on the NDS.
So, fit the 3 as above and the front mech will fit as intended.

Hopefully you have the instructions (in 17 useful popular languages) with the front mech….I suggest you read it in the comfort of the settee before work.

PaulD

ah thanks paul – i see my error duh

cheers

hi, i am resurecting this as still having an issue.

in the instructions for the mech it says (or says to me) to install the mech on the inside of the bash i.e.

adjust the height of the frontderailleur so that the outer edge of the bash guard is within the specified range on the Pro-Set gauge. Also adjust so that the flatpart of the outer plate is parallel to the inner surface of the bashguard.

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SLX/SI-5KY0A-002/SI_5KY0A_001/SI-5KY0A-002-ENG_v1_m56577569830655481.pdf

however, if i do this the mech always hits the bash on shift, so i set it higher than the bash so there is about a 1mm gap between the bottom of the mech and the top of the bash

it seemed to shift ok but after on big ride it became really hard to shift, so hard I had to shift it with the palm of my hand (on the lever). however, when not under load the mech shifts fine and the shifter pulls the cable through fine.

i guess my main question is, have i set the mech up wrong and am trying to pull too much cable through i.e. trying to shift it too much making it tough to shift? if so how the heck do i get the mech to sit within the bash?

cheers as always

normally you would set the deraillieur so that the cage is about the thickness of a 2p coin off the top of the teeth – set the height by wedging something in the mechanism to lock it out (they give you a plastic wedge with new ones to do this).

If it’s hard to shift at the end of motion you may have the high end stop set far enough away for the shifter to click? or is it hard to push the shifter all the way through the movement?

hi andyl

cheers for the reply – i usually go for a similar height from the teeth but the shift over onto the large ring just drives the mech into the side of the bash

the shifter is hard to move through the whole movement as if the cable was too tight, however the cable was pretty slack on the small ring.

have you set the end stop to preven the cage hitting the bash and then indexed the cable using the barrel nut?

And are you sure its a 2×9 one and not the 3×9 one?

and you are using the 36T chainring not a 32T?

yup to all, though i do have a 3x shifter but that shouldnt be an issue – however, obviously didnt do it right so will start from scratch again and let you know how it goes!

chheers

that’s your best bet. Remove it all check the pivots are night tight, ditto for cables and shifter and that the cable routes correctly around the deraillieur as some that are multi (top or bottom) pull need to have the cable routed correctly.

ok seems ok, not sure why but works better, see how it goes on a ride now, cheers:)