Setting up front and rear mech’s

[Twozaskars]

RD is pretty straightforward.
Set H limit screw so the top jockey wheel lines up with smallest cog and will not come out any further.
Then grip mech, pull back and push towards the wheel as far as you can and set L screw so it will not go in further than biggest cog.

Credit to winjohn, no point anyone else writing it again.
People often think (not necessarily you, but some people) that those H and L screws are for some sort of fine tuning of the gears but they are there purely to restrict the maximum travel of the derailleur.

You say it stops at 3. With tension on the cable, either by slight force on the lever or grab it under the downtube and pull down, so that the mech moves toward the wheel.loosen the L screw (lefty loosey righty tighty) until it goes as far as needed.

 

[Monkeeee01]

T

Credit to winjohn, no point anyone else writing it again.
People often think (not necessarily you, but some people) that those H and L screws are for some sort of fine tuning of the gears but they are there purely to restrict the maximum travel of the derailleur.

You say it stops at 3. With tension on the cable, either by slight force on the lever or grab it under the downtube and pull down, so that the mech moves toward the wheel.loosen the L screw (lefty loosey righty tighty) until it goes as far as needed.

Thank you, that’s really helpful!

 

[7Speed]

Mech set-up still evades me sometimes after 30+ years…

 

[bikeworkshop]

Old front mech sometimes needs a touch of voodoo

 

[winjohn]

Remember when I said that the RD is usually fairly simple to set up (caveat as long as the cage is long enough for cog size and range.) I did say the front was a different matter though.
In practice it is simple.
Fit mech to seat tube ensuring that the height is right to give the correct clearance above the largest chainring. Check the cage is parallel with the chain ring.
Set H and L screws to the right ball park then fit chain.
Move chain to largest rear cog and smallest chainring. Set L screw so the cage just clears the chain with no rub.
Attach cable and take up slack.
Move to smallest rear and largest front and set H screw so chain engages on chainring without rubbing but the cage cannot move too far out and take the chain right off the chainring.
That's the basic theory, then it's "just" a case of tinkering with cable tension until everything runs sweetly...good luck!
Sometimes it works just like that but other times it will not work well, no matter what you try.

Case in point yesterday...
Sorting the 2002 Lava Dome frame with lovely LX bits including front mech.
Fit front mech and align as above.
Go to fit cable...damn it's a bottom pull and I need a top pull.
Place ad on Retrobike for suitable top pull mech.
Rummage through boxes in the garage and find a top pull LX mech for 31.8 seat tube and, miracle of miracles, also find a shim.
Happy days!
Fit new front mech as above but it just will not work.
Spend an hour or two tinkering.
Then the light bulb moment hit me, the BB is too narrow.
Remove pedals, remove BB. Measure BB, 111mm
Rummage in old BB box, find wider BB.
Fit BB
Fit pedals
Go through the steps above.
Spend an hour tinkering
No good, try an SLX mech, and still no good.
Light bulb moment, new BB is too wide.
Remove SLX mech, remove pedals, remove BB. Measure BB. 120mm.
Decide to split the difference and find something around 115 mm.

Repeat to myself, "Front mechs are a right pain" !

 

[Monkeeee01]

Remember when I said that the RD is usually fairly simple to set up (caveat as long as the cage is long enough for cog size and range.) I did say the front was a different matter though.
In practice it is simple.
Fit mech to seat tube ensuring that the height is right to give the correct clearance above the largest chainring. Check the cage is parallel with the chain ring.
Set H and L screws to the right ball park then fit chain.
Move chain to largest rear cog and smallest chainring. Set L screw so the cage just clears the chain with no rub.
Attach cable and take up slack.
Move to smallest rear and largest front and set H screw so chain engages on chainring without rubbing but the cage cannot move too far out and take the chain right off the chainring.
That's the basic theory, then it's "just" a case of tinkering with cable tension until everything runs sweetly...good luck!
Sometimes it works just like that but other times it will not work well, no matter what you try.

Case in point yesterday...
Sorting the 2002 Lava Dome frame with lovely LX bits including front mech.
Fit front mech and align as above.
Go to fit cable...damn it's a bottom pull and I need a top pull.
Place ad on Retrobike for suitable top pull mech.
Rummage through boxes in the garage and find a top pull LX mech for 31.8 seat tube and, miracle of miracles, also find a shim.
Happy days!
Fit new front mech as above but it just will not work.
Spend an hour or two tinkering.
Then the light bulb moment hit me, the BB is too narrow.
Remove pedals, remove BB. Measure BB, 111mm
Rummage in old BB box, find wider BB.
Fit BB
Fit pedals
Go through the steps above.
Spend an hour tinkering
No good, try an SLX mech, and still no good.
Light bulb moment, new BB is too wide.
Remove SLX mech, remove pedals, remove BB. Measure BB. 120mm.
Decide to split the difference and find something around 115 mm.

Repeat to myself, "Front mechs are a right pain" !

Thank you for all your help. Got my Hot with my FD-M953 and RD-M952 running perfectly

Going to have a play with the Kula with the bottom pull FD-M770 later!!