Lowest and highest gears... extreme chain angles and don't use?

nufo

Member
Hi everyone,

I recently received my NCM Moscow and have been adjusting the rear derailleur since I was unable to shift into higher gears (4-7 in the rear; front works fine). After some cable tension adjustments all seems fine, mostly. Now the chain hits the metal cage part of the front derailleur when in highest gear (21st; smallest cog in front, largest in rear). A bike mechanic advised me to just not use the lowest and highest gears due to the chain at extreme lateral angles and because some rubbing will happen in the highest gear. Ideally I would like to use the highest gear possible at higher speeds. Has anyone received similar advice? Would greatly appreciate any feedback. Thanks and ride safe!
 

GenXrider

Well-Known Member
Crazy. My Trek has the same size chainring (48T) and cassette cog (11T) and have never had a problem using them together. That's actually one of the advantages of the Moscow "Plus" version from what I read to have that higher maximum gearing. Anyway, different hardware in my case. You might want to ask on the NCM subforum here.
 

Nova Haibike

Well-Known Member
Hi everyone,

I recently received my NCM Moscow and have been adjusting the rear derailleur since I was unable to shift into higher gears (4-7 in the rear; front works fine). After some cable tension adjustments all seems fine, mostly. Now the chain hits the metal cage part of the front derailleur when in highest gear (21st; smallest cog in front, largest in rear). A bike mechanic advised me to just not use the lowest and highest gears due to the chain at extreme lateral angles and because some rubbing will happen in the highest gear. Ideally I would like to use the highest gear possible at higher speeds. Has anyone received similar advice? Would greatly appreciate any feedback. Thanks and ride safe!
 

nufo

Member
Thanks for the quick reply GenXrider. I'm realizing know that the extra gears of the Plus version would be beneficial. I can get by without using the highest gear but it would help at the higher speeds.

And thanks for the suggestion about posting over in the NCM subforum. I figured this may be a common "problem" with all bikes so figured I should post in the General forum. If there isn't much other feedback here I will post in NCM. I don't want to cross post and make anyone mad :)
 

Nova Haibike

Well-Known Member
Hi everyone,

I recently received my NCM Moscow and have been adjusting the rear derailleur since I was unable to shift into higher gears (4-7 in the rear; front works fine). After some cable tension adjustments all seems fine, mostly. Now the chain hits the metal cage part of the front derailleur when in highest gear (21st; smallest cog in front, largest in rear).

Just to clarify, the front are referred to as chainrings, and the smallest chainring and largest cog in the rear is 1st gear, or the lowest gear, not the highest.

A bike mechanic advised me to just not use the lowest and highest gears due to the chain at extreme lateral angles and because some rubbing will happen in the highest gear.

Your mechanic is correct; this is commonly accepted advice. Do not use the combination of #1 on the left and #7 on the right, and do not use #3 on the left with #1 on the right.

Ideally I would like to use the highest gear possible at higher speeds. Has anyone received similar advice? Would greatly appreciate any feedback. Thanks and ride safe!

The highest gear is the largest chainring in front and small cog in the rear i.e. #3 on the left, and #7 on the right.
 

GenXrider

Well-Known Member
Thanks for the quick reply GenXrider. I'm realizing know that the extra gears of the Plus version would be beneficial. I can get by without using the highest gear but it would help at the higher speeds.

And thanks for the suggestion about posting over in the NCM subforum. I figured this may be a common "problem" with all bikes so figured I should post in the General forum. If there isn't much other feedback here I will post in NCM. I don't want to cross post and make anyone mad :)

Sorry, I actually misread your post. For one, I was thinking you had the Plus version, even though you didn't state that, so the chainring and cassette/freewheel don't match up with mine. And when you said "(21st; smallest cog in front, largest in rear)", I read that as "(21st; smallest cog in rear, largest in front)", which would be 21st, not 1st. I always ride on the largest chainring.
 

nufo

Member
Nova Haibike: Thanks for correcting my terminology and the error of the size of the chainring and cog (I've corrected them in my original post). And appreciate the feedback; guess I'll have to make do with not shifting to the highest gear.

GenXrider: yes, I meant largest chainring (sorry for the confusion).
 

GenXrider

Well-Known Member
Nova Haibike: Thanks for correcting my terminology and the error of the size of the chainring and cog (I've corrected them in my original post). And appreciate the feedback; guess I'll have to make do with not shifting to the highest gear.

GenXrider: yes, I meant largest chainring (sorry for the confusion).

Your original post still says, "smallest cog in front." You certainly should be able to use the HIGHEST gear, largest chainring in front and smallest cog in the rear.
 

Nova Haibike

Well-Known Member
I'll have to make do with not shifting to the highest gear.

Just to add additional information/clarification, there is no need to use the extreme combinations of gears. Even though the bike physically has 21 combinations of gears, there is overlap in the actual ratios. So if you like the feel of the the extreme "cross-chaining" gear, there is another combination that feels the same or close to it.

Your bike's crank has chainrings of 28, 38, and 48T. The freewheel has cogs of 14, 16, 18, 20, 22, 24, and 28T. The combination of the 48T large chainring (#3 on the left) and 28T cog (#1 on the right) is a gear ratio of 1.71. This is virtually the same as using the 38T middle chainring (#2 on the left) and the 22T cog (#3 on the right), which is a ratio of 1.73.
 

Sierratim

Well-Known Member
Region
USA
City
Nevada City, CA & Paradise Valley, AZ
Our mech bikes have 3 chainrings and 9 cogs on the cassette. Dealers like to call this combo a 27 speed (3x9) but as @Nova Haibike detailed there are over lapping gear combinations that reduce the useful range of gears. As a normal practice I only use 3-4 cogs per chainring to minimize 'cross chaining'; the largest ring uses the 3-4 smallest cogs, the center ring uses the 3-4 center cogs and the smallest ring the 3-4 largest cogs. Helps with chain and gear life while using the full range of gear ratios.

Our ebikes have a single chain ring so no issues there!
 

nufo

Member
The feedback is much appreciated! I should have done some homework about gear ratios, chainrings, cogs, etc before posting. I went for a ride last night and realized that I really don't need to use so many gears (like several people have stated). So again, thanks for the help :)