Chainset change

Justinslow

Lovely jubbly
Location
Suffolk
Hi, I've just come across a new Chainset cheap, suntour xcr 6, in 22 32 44 rings, however my old set is 24 34 42 and is 7 speed, the new one is listed as 9 speed. Is this a no no or will it work?
 
Location
Loch side.
Cheap is your clue. Do it. If it makes you feel better, 7 speed and 8-speed chains are the same width, so you're only going down one size on the rings and you will not even notice it. Further, a 22 is pretty ridiculous, so you'll score on the 24 smallest ring being more useable too.
 

shadow master

Well-Known Member
Yeah be OK,if it the same bb offset which i doubt and have to move front mech up a bit,probably find thering the 44t a bit better 42 on seven speed is a bit flat on open tracks or road!
 
Location
Loch side.
Yeah be OK,if it the same bb offset which i doubt and have to move front mech up a bit,probably find thering the 44t a bit better 42 on seven speed is a bit flat on open tracks or road!

I get the drift but punctuation is your friend. It is the difference between: helping your uncle, Jack, off a horse and; helping your uncle jack off a horse.
 
OP
Justinslow

Justinslow

Lovely jubbly
Location
Suffolk
Thanks, I'm struggling to find a like for like replacement for what I've got at the minute another option is 22 32 42 which seems more popular? Not much in it really is there.
 

shadow master

Well-Known Member
Thanks, I'm struggling to find a like for like replacement for what I've got at the minute another option is 22 32 42 which seems more popular? Not much in it really is there.
At least with that option,22,32,42t you won't have to move the mech height,if your happy with the top speed stick with it.
 
OP
Justinslow

Justinslow

Lovely jubbly
Location
Suffolk
It's an old mtb so top speed not really important, more important would probably be the middle ring, so on 7 speed 32 or 34, I guess still not much in it, I'll just be using slightly different gears on the rear as opposed to what I'm used to.
 

shadow master

Well-Known Member
Yeah,drop down a cog on the back to get the equivalent gear.
 
OP
Justinslow

Justinslow

Lovely jubbly
Location
Suffolk
Ok we may have a problem or two, front mech may not be big enough (long enough) to cope with a smaller small ring and a larger big ring during changes, and the offset maybe too much so that the chain angle is pretty bad, big front to big rear etc. oh and chain length obviously needs to be a bit longer for the bigger front ring but slightly shorter for the smaller front rings? Maybe I should just stick to the like for like cheapo shimano fcm 171.
 
OP
Justinslow

Justinslow

Lovely jubbly
Location
Suffolk
Wouldn't work, stuck out too far so everything was wrong, chain run, front mech, took it back for refund, shame as it was over 300g lighter than my old crankset, shimano fcm171 it is then as that's about the only crank retaining my original crankset ratios.
 

shadow master

Well-Known Member
I suspected this problem in my first post "if the bb off set is the same which I doubt" The ratios are a secondary problem,the stand off of the chain wheel is always the tricky bit for a diy job
 
OP
Justinslow

Justinslow

Lovely jubbly
Location
Suffolk
Yes you did mention it, do you think it could also be a problem with a new like for like shimano item, I guess there is no way to find out. I'm replacing an old "no name" crankset, (approx 15 year old) if it is off set too much then I suppose I have to change the bb width but am limited by arm clearance with frame on the other side?
 
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