44 to 48 chainring, new front mech required?

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Bodhbh

Guru
Just wondered if I swap out a standard 44/32/22 MTB chainset for a 48/36/26 the existing front mech will work okay?
 

Will1985

Über Member
Location
South Norfolk
You're just moving up 4 teeth on each ring, so just put the derailleur higher up the seat tube - the difference between inner and outer is still 22t

You might have to add a link or two to the chain as well.
 

yello

Guest
It might not be quite as easy to set up (i.e. it might need to be 'just so'), and/or may not change quite as cleanly, but I would have thought it would work.

The reasons for my 'mights' is that the 48 outer will have a larger circumference and so a slightly different shape to the 44. If your mech was designed for the smaller circumference of the 44 then it might not work as smoothly.
 
OP
OP
Bodhbh

Bodhbh

Guru
Cheers Will, Yello. I'll give it a go at least. I just had a rummage around on SJS website and - when they are specced - most of the MTB front mechs seem to go up to 48t outer ring. Mines a Deore one not sure of the exact vintage but will suck and see.
 

yello

Guest
Hmmm, that's odd. I felt sure I added a final line to my post... something along the lines of

as always, my advice in such situations is 'suck it and see'

kind of coincidental you've used exactly those words bod! best of luck, setting up a rear mech is perhaps the most frustrating thing I've done on a bike.

There are a number of different design parameters for a front mech (span, chainwheel size(s), frame angles, curvature, etc etc etc) that make it quite difficult for the uninitiated (like myself!) to know whether you're not setting it up correctly OR it's the wrong mech design and it will never work!
 
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Bodhbh

Bodhbh

Guru
yello said:
Hmmm, that's odd. I felt sure I added a final line to my post... something along the lines of

as always, my advice in such situations is 'suck it and see'....

There are a number of different design parameters for a front mech (span, chainwheel size(s), frame angles, curvature, etc etc etc) that make it quite difficult for the uninitiated (like myself!) to know whether you're not setting it up correctly OR it's the wrong mech design and it will never work!
Yes, I know have a go and find out is the only way :tongue:. But I have found the hard way, like you say, buying stuff too much without thought can result in stuff not working and ending up with too many variable to work out easily why. I could afford that last year, now I need to be more careful !
 
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Bodhbh

Bodhbh

Guru
peanut said:
what are you trying to achieve Bod ?
Well the BB on the runabout is offering up a fair bit of resistance, the BB was 2nd hand off eBay and has not lasted long. Rather than messing about with more false economies thinking just to buy a new chainset and go to 48/36/26 which seems more suitable gearing for the use it's getting.
 

peanut

Guest
Bodhbh said:
Well the BB on the runabout is offering up a fair bit of resistance, the BB was 2nd hand off eBay and has not lasted long. Rather than messing about with more false economies thinking just to buy a new chainset and go to 48/36/26 which seems more suitable gearing for the use it's getting.

ah I see. I thought you might be trying to achieve higher gearing which of course would be cheaper and easier to achieve by modifying or changing your cassette.
 
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