Recommended triple -> single chainring sizing

[moorfield]

Hello All

As a mini project I am looking to replace the front triple chainring on the missus's (Halfords) bike with a single - she struggles with the left hand friction shifter, can't really be bothered with it and it occasionally slips so I'm going to take it off. It is relatively flat round our way and she typically uses it for short local trips 3-5 miles, ie. no long hills.

Any recommendations on size ie. number of front teeth for a 1x6 setup?

Thanks
M

[redsturgeon]

Are you looking to replace the rear cassette as part of this?

If not then surely the answer lies in looking at which current front ring she uses most of the time and replicate that.

TBH a 1x6 set up might be a bit tricky to give a decent range unless you are pretty flat.

Why don't you just remove the LH shifter and front derailleur and leave the three rings on for the moment. See which she is happiest with (I'm guessing it will be the middle ring)

John

[moorfield]

Why don't you just remove the LH shifter and front derailleur and leave the three rings on for the moment.

Yes in fact that's what I'll probably do just to KISS. Really I'm just getting curious/geeky about gear ratios I suppose ...

[redsturgeon]

Why don't you just remove the LH shifter and front derailleur and leave the three rings on for the moment.

Yes in fact that's what I'll probably do just to KISS. Really I'm just getting curious/geeky about gear ratios I suppose ...

Ah, why didn't you say so.

You need this

http://www.sheldonbrown.com/gear-calc.html

prepare to disappear into a whole world of cycling geekdom!

John

[Ashfordian]

Why don't you just remove the LH shifter and front derailleur and leave the three rings on for the moment.

Yes in fact that's what I'll probably do just to KISS. Really I'm just getting curious/geeky about gear ratios I suppose ...

What are the ratios on the back?

I'm guessing it is something like 25-14

I would go with the kiss approach, but only remove the front shifter and leave the front derailleur so it assists in keeping the chain on the pre-selected cog

[redsturgeon]

I would go with the kiss approach, but only remove the front shifter and leave the front derailleur so it assists in keeping the chain on the pre-selected cog

You have to take off the actual derailleur since when you remove the cable and shifter the derailleur is spring loaded to default to the smallest ring.

The front derailleur, once the gear selection has been made, plays little or no part in guiding the chain onto the chain ring.

John

[bombat]

You have to take off the actual derailleur since when you remove the cable and shifter the derailleur is spring loaded to default to the smallest ring.

That's not quite true. You can just use the limit screws to keep the derailleur in the desired position.

[redsturgeon]

Ha ha that's true...I think...do the limit screws allow that much "limiting" never tried it myself.

John

[bombat]

Yes, it works. I've done it on my station bike (when the front shifter broke and I couldn't be bothered fixing it).