Converting 3x9 to 2x9

jamski

Sorry if this has been asked. I have searched but can't find what I'm after.

So I think I can remove my biggest chainring. I never use it these days but very occasionally use the granny ring, so would like to keep that on my hardtail. A couple of questions.

Is it just a case of removing the chain ring and adjusting the limit screws on the front mech?

Will the 3x shifter be ok to use?

Should I replace the outer chainring with anything? A guard of some kind?

Thanks.

jamski

I guess the main question should be, if I can get an Alan key in here, does this mean I can remove the outer ring? If no it's a completely pointless post!

https://www.dropbox.com/s/ielioobhnr3dc ... 1.jpg?dl=0

LimitedGarry

Looks removable enough to me. At least by the picture. You should be able to take it off without removing the crank (again, judging by the picture).

As for the conversion process, I'm certain there's several very good videos covering it on Youtube. Go check them out.

Harry182

I've done this on mine (or rather, the previous owner had.)

Caveat - If you remove your outer chainring then your chainring nut/bolts will be too long, ie they'll tighten against themselves before they'll securely hold the remaining single chainring in place. Mine's solved this by fitting a bash guard in place of the outer chainring. There's also the option of getting a set of shorter chainring nuts/bolts but i reckon bashguard is the more elegant/better looking solution.

jamski

Ok great, so next question.

How do I know what bash guard will fit? Middle chain ring is 32t, but how do I know what the correct 'bolt circle' is?

LimitedGarry

You can look up the exact cranks you've got and check manufacturer's specification or you can measure it yourself.



Bolt patter is either symmetric or asymmetric.

jamski

Thanks all. HAve just removed my chainring, really easy. Measured just over 100mm and looking around 104mm seems to be the closest match, there aren't too many options by the looks of things. Should be a really easy change.

The Rookie

Be warned that plastic bashes need longer bolts as they are thicker, get a metal one and you should be fine.

jamski

The Rookie wrote:

Be warned that plastic bashes need longer bolts as they are thicker, get a metal one and you should be fine.

Thanks. Struggling to find a 'cheap' one at the moment. £23 from superstar components is the best I've found, but they don't have a black one.

cooldad

Bash rings are stupid prices for what is essentially a flat bit of alloy.

Have a look on Ebay for a used one.

cooldad

Or get some carbon fibre

http://www.ebay.co.uk/itm/Truvativ-Bash ... SwnHZYWUmD

I have one of those on mine. Can't see any weave though, so it just looks like cheap plastic cr4p.

Unless that's an alloy one - hard to see in the pic.

The Rookie

DIY
http://www.ebay.co.uk/itm/Single-Layer- ... Sws65Tmssi

I shaped mine similar to a chainring on the inside, it weighs just 26g.

EDIT, just noticed the dimensions on that are wrong for A5 and not big enough, other CF sheets can be had (mine cost me £8).

Or a Hope for £15
http://www.halfords.com/cycling/bike-pa ... uard-104mm

jamski

The Rookie wrote:

DIY
http://www.ebay.co.uk/itm/Single-Layer- ... Sws65Tmssi

I shaped mine similar to a chainring on the inside, it weighs just 26g.

EDIT, just noticed the dimensions on that are wrong for A5 and not big enough, other CF sheets can be had (mine cost me £8).

Or a Hope for £15
http://www.halfords.com/cycling/bike-pa ... uard-104mm

You got me excited with that Hope one, but it's not available anymore.

jamski

Any idea if the bolts I've removed will be ok with this guard?

Have found someone with one, so hoping to get it cheap!

http://www.ebay.co.uk/itm/Shimano-SLX-F ... 2119977455

The Rookie

Nope, it's plastic very thick and needs longer bolts.

jamski

The Rookie wrote:

Nope, it's plastic very thick and needs longer bolts.

I figured. Bit the bullet and ordered a hope one. £30 though, but looks nice.