Thorn Cycles Forum

Community => Thorn General => Topic started by: scottymac on March 05, 2007, 01:50:04 am

Title: Chain ring size for Rohloff
Post by: scottymac on March 05, 2007, 01:50:04 am

Hi, i would just like some recomendations please.

I am soon to set up my audax bike with a Rohloff and would like some advice on what may be an approprate sized front chain ring. I am thinking a 39 due to the the ability of the ratios to be relatively close as well as the ability to have a gear suitable for mountains. Also when i am riding even in audax rides i do not ride in a bunch so i dont draft at all, i am thinking however a 39 may be to small for those times a have decent tail wind and can rev out a gear.

 I also do not push any gears but sit on a rev range of 85 +.

Thanks for your time in reading this email, any advice would be great. Cheeers Scott [:)]

Title: Re: Chain ring size for Rohloff
Post by: pdamm on March 05, 2007, 03:35:36 am

I suspect that may be too small.  I have 42 teeth on the front and 17 on the rear with 26 inch wheels.  I run out of peddles at about 50 km going down hills but have some nice low gears for steep hills when fully loaded.

When I made my choice I carefully compared what I was getting on my Thorn with what I had on my current bike at the time.  I compared the distance I would travel in one peddle revolution in the lowest and highest gears.  I choose a slightly lower top gear and a much lower bottom gear for my Raven Tour.  This worked well for me and I haven’t felt the need to change my gear range on my new Thorn.

Peter Damm

Title: Re: Chain ring size for Rohloff
Post by: stutho on March 05, 2007, 09:41:22 am

Hi Scottymac

This topic comes up quite often on the list - it might be worth searching through some of the older posts to see some other opinions.  

I thing it is probably impossible for anyone on the list to recommend (with certainty) a gear combination to another.  There are just too many variables - fitness, weight carried, riding surface, local geography, riding style, etc.  

I can tell you that for me 42 by 16 is great for general on road use.  Like PDAMM  I compared my previous bike gearing with the Rohloff.  I wanted gearing slightly lower than I had then.  I do find that if I load the bike up  (16.5kg) then an even lower ratio would be advantageous - but 95% of my mileage is unloaded.  

The good news is that if you do decide to change the gearing range then it is not too expensive – just one chain ring!