Opinion on my chainrings please

For discussions about bikes and equipment.
cycle tramp
Posts: 1076
Joined: 5 Aug 2009, 7:22pm

Re: Opinion on my chainrings please

Postby cycle tramp » 25 Jun 2018, 6:36pm

Fraz101 wrote:
rjb wrote:It looks like the small chainring is worn the most. If this is used with the small sprockets frequently the "cross chaining" as it's called could have led to early failure. Try to use the middle chainring and bigger sprockets more. :wink:

Yes small cog front and rear is a habit i'm going to need to change.


If you spend alot of time on your small front ring, have you ever considered just using one front chain ring, perhaps somewhere between the size of your existing smallest and middle chain ring?

Fraz101
Posts: 146
Joined: 15 Feb 2018, 12:47pm

Re: Opinion on my chainrings please

Postby Fraz101 » 25 Jun 2018, 7:07pm

cycle tramp wrote:
Fraz101 wrote:
rjb wrote:It looks like the small chainring is worn the most. If this is used with the small sprockets frequently the "cross chaining" as it's called could have led to early failure. Try to use the middle chainring and bigger sprockets more. :wink:

Yes small cog front and rear is a habit i'm going to need to change.


If you spend alot of time on your small front ring, have you ever considered just using one front chain ring, perhaps somewhere between the size of your existing smallest and middle chain ring?

Not something I’ve ever thought about but an interesting point you raise.
Would it be a part I could pick up fairly easily?
And would it help with chain angle?

Brucey
Posts: 43055
Joined: 4 Jan 2012, 6:25pm

Re: Opinion on my chainrings please

Postby Brucey » 26 Jun 2018, 10:35am

you most likely have all the gears you need on the chainrings you have; you probably just need to use them differently.

Single chaining setups are all very well but the chain tends to fall off (and there is no FD to help it back on again), you have a narrower gear range and/or wider gear intervals, you are forced to use a bad chainline to access the full gear range... I could go on but suffice it to say that there are reasons why single ring setups were not commonly used before now and not all of these problems have been solved.

To help you work out how to use the gears you have better, see

http://www.ritzelrechner.de/?GR=DERS&KB=48,24,36&RZ=14,16,18,21,24,28&UF=2075&TF=90&SL=1.7&UN=MPH&DV=gearInches

I have guessed at a 3x6 setup with 24, 26, 48 chainrings and a 14-28 6s freewheel. You can alter these values by dragging and dropping various things and you can copy the link to your revised setup using a box at the bottom of the screen.

in the setup I put into the gear calculator the 24/14 gear is the same as 36/21 or 48/28. Of these 36/21 is the best choice, 48/28 is worse than that because the chainline is terrible and 24/14 is the worst choice of all because it uses both a bad chainline and a small-sized sprocket (which itself wears quickly and wears the chain faster than normal too).

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

cycle tramp
Posts: 1076
Joined: 5 Aug 2009, 7:22pm

Re: Opinion on my chainrings please

Postby cycle tramp » 29 Jun 2018, 11:32pm

Fraz101 wrote:
cycle tramp wrote:
Fraz101 wrote:Yes small cog front and rear is a habit i'm going to need to change.


If you spend alot of time on your small front ring, have you ever considered just using one front chain ring, perhaps somewhere between the size of your existing smallest and middle chain ring?

Not something I’ve ever thought about but an interesting point you raise.
Would it be a part I could pick up fairly easily?
And would it help with chain angle?


Apologies for the lack of reply until now, i was thinking about the questions you raised...
To answer your last question first... it may help your chain angle, but only if you know what your favourite gear ratio is for most circumstances, and if you can space your chainring to the cog to match it... and it depends on the width of your [edit] freewheel/ sprocket cluster. The wider (more gears) that you have on the back wheel the greater the angle the chain will be in the highest and lowest gears

To illstrate the point, i'll talk about my set up. I currently ise a 36 tooth chain ring* with a 5 speed freewheel (13 to 28 teeth) which gives me a high of 72 inches and a low of 33 inches (chainwheel teeth divided by sprocket teeth multipled by the size of the wheel)
However this means that for normal road riding my chain is going to be at the high end (smaller sprocket end) of my freewheel. So i mounted my chain ring (on my crank) so my chain runs straight when its on the second smallest cog on my freewheel. By doing this the chain has a slight defection when i use the smallest cog, which i do most of the time and a large defection when i use my low gears, which i use very little.
In answer to your first question, you may need to buy new crank arms and a chain ring, as well as something to keep the chain on the chain wheel. I used a chain guard from SPA cycles, some spacers and a set of long chain ring bolts. Because i was only using one chainring i used a stainless steel one from surly bicycles, as they last longer (and when worn, you can flip them over and use the other side!)
However using just one chain ring does reduce the range of gears that you have which means that you may have to freewheel more often down the hills, go slower if you have the wind behind you, and get off and walk on steep or long hills.
On the plus side having only one gear control does make it easier to use the bike, there's less things to go wrong, and if you use a friction gear control there is less maintenance too :- )