Flip the chain wheel so that it sits on the inside of the crank arm bolts
11-22-21, 03:47 PM
#26
Method to My Madness
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,675
Bikes: Trek FX 2, Cannondale Synapse, Cannondale CAAD4, Santa Cruz Stigmata GRX
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1953 Post(s)
Liked 1,475 Times
in
1,022 Posts
Yes, a single chain ring looks best mounted on the outermost position (i.e., in front of the crank spider).
11-24-21, 11:55 AM
#27
Senior Member
Join Date: Mar 2019
Posts: 1,606
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 581 Post(s)
Liked 921 Times
in
518 Posts
I/m not convinced this is necessary on your bike - you need to measure the chainline on the front chainring and on the rear cog to be sure. The person who wrote the comment you read may have had a bike that was incorrectly assembled or had a wrong part installed at the factory This does not necessarily mean your bike needs the same thing.
To measure chainline on the rear, you need to know the 'Over Locknut Dimension' (OLD) of your bike's frame - the width between the rear dropouts where the axle is fastened. On a single speed or fixed gear bike this might be 120mm or so.
Take the OLD dimension and divide by 2, then subtract from that the horizontal distance from the middle of the rear cog to the inside edge of the dropout.
To measure chainling on the front you only need to measure the horizontal distance from the centre of the front chainring to the centre of the seat tube.
The two dimensions - F chainline and R chainline - should be very close to eachother, like within a mm or two. You only need to do the mentioned modification of moving the chainring to the inside of the crank if the F chainline measurement is significantly larger (like 6 or 8 mm) than the R chainline measurement.
I have created a sketch that shows a top view of a bike frame with a chainring and rear hub with a cog. The blue lines represent the measurements you need to take - X, Y, and OLD. The red line is the centre line of the bike that should run through the centre of the seat tube and directly through the centre between the dropouts.
To measure chainline on the rear, you need to know the 'Over Locknut Dimension' (OLD) of your bike's frame - the width between the rear dropouts where the axle is fastened. On a single speed or fixed gear bike this might be 120mm or so.
Take the OLD dimension and divide by 2, then subtract from that the horizontal distance from the middle of the rear cog to the inside edge of the dropout.
To measure chainling on the front you only need to measure the horizontal distance from the centre of the front chainring to the centre of the seat tube.
The two dimensions - F chainline and R chainline - should be very close to eachother, like within a mm or two. You only need to do the mentioned modification of moving the chainring to the inside of the crank if the F chainline measurement is significantly larger (like 6 or 8 mm) than the R chainline measurement.
I have created a sketch that shows a top view of a bike frame with a chainring and rear hub with a cog. The blue lines represent the measurements you need to take - X, Y, and OLD. The red line is the centre line of the bike that should run through the centre of the seat tube and directly through the centre between the dropouts.
12-04-21, 02:57 PM
#28
Elco
Join Date: Nov 2020
Location: Netherlands
Posts: 14
Bikes: aluminium Concorde Cipressa roadbike , my homebrew/rebuild Trek District (hybride) TT aluminium /magnesium fixed roadbike, Giant Boulder team aluminium /magnesium A.T.B. and last yet definitely not least Scapin Enki full carbon roadbike
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked 1 Time
in
1 Post
good trick
good trick ...it's let's the chain have a better line.
same cranks have this option i would post a picture ...
but its pretty simple...and very effective
if you look at the chain from the back-end of the bike to the front ...
and turn the crank you can see the movement of the chain ..
if it is straight it wil have less rub...
it has to be mostly straight ...and this change to the position of the front sprocket can make just that little difference.
or you are obligated to put your back cog in a different place on the back axle ...with a freewheel or whatever..
fixed cog's can be moved but not al of them.. there are screw on's that's the best if you ask me..
there are rules in this essamble ..
it involves angles ...from sprocket to cog ...and from crank to sprocket ...if you see a regular bike it would always be perfect straight and mostly horizontal ..
both things can be avoided ..
it can be at a angle .....like gravel bikes ..
and it can be tottaly not horizontal it's all up to gear ratio and ..this Angle ...this damn angle ..
lot's of idea's for bike's I tried to build....
didn't work because of that angle ..
succes ..and make it work bro
same cranks have this option i would post a picture ...
but its pretty simple...and very effective
if you look at the chain from the back-end of the bike to the front ...
and turn the crank you can see the movement of the chain ..
if it is straight it wil have less rub...
it has to be mostly straight ...and this change to the position of the front sprocket can make just that little difference.
or you are obligated to put your back cog in a different place on the back axle ...with a freewheel or whatever..
fixed cog's can be moved but not al of them.. there are screw on's that's the best if you ask me..
there are rules in this essamble ..
it involves angles ...from sprocket to cog ...and from crank to sprocket ...if you see a regular bike it would always be perfect straight and mostly horizontal ..
both things can be avoided ..
it can be at a angle .....like gravel bikes ..
and it can be tottaly not horizontal it's all up to gear ratio and ..this Angle ...this damn angle ..
lot's of idea's for bike's I tried to build....
didn't work because of that angle ..
succes ..and make it work bro
