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FD three blade adjustment for a two blade system?


Palaeodom
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Just removed the outside large blade on my MTB crank and am hoping I don't also need to change my FD. I'm mostly in the middle ring but occasionally down on the inner.

 

On a couple of changes the chain popped off over the middle ring when changing from the inner. Is there any adjustment that I can make to the FD settings to ensure this doesn't happen?

 

Otherwise, If the three blade FD doesn't work so well, will a 10 X 2 FD work with a 9speed cassette and chain?

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Shorten chain accordingly.

Use bash guard.

 

Or get yourself a different FD, one with clamp above FD mechanism which then surrounds the chain better.

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I could get a new FD and two blade shifter, but I'm trying to get away with not getting them if possible.

 

I am hoping its not entirely necessary otherwise its just cheaper for me to sling the outer blade back on and ignore it. The two blade system gives me much better clearance for those technical bits.

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Guest agteros

erm... why all the weird advise, what about the limit screws?

Edited by agteros
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yip. If you dont know whats going on, please dont tell people to go out and buy a truck load of new equipment! :thumbdown:

All you need to do is adjust the limit screws so that the FD can only go between the 2 chainrings that you have. On my bike I have a gripshifter and FD for a triple crankset, but I'm only running a large and middle ring, and it works perfectly....

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yip. If you dont know whats going on, please dont tell people to go out and buy a truck load of new equipment! :thumbdown:

All you need to do is adjust the limit screws so that the FD can only go between the 2 chainrings that you have. On my bike I have a gripshifter and FD for a triple crankset, but I'm only running a large and middle ring, and it works perfectly....

 

 

 

Thanks mate will try that immediately, i'm sure that with the shortened chain will do fine.

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Guest agteros

Thanks mate will try that immediately, i'm sure that with the shortened chain will do fine.

 

There is no need to shorten the chain. Try it with the chain in stock length first. RD will still take up slack in the chain as it used to do before.

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My understanding is that you don't really want excess length in the chain. The measurement i've always used is that the chain should reach around the largest front cog and the largest back cog with one or two links extra. Now that my largest front is significantly smaller the chain should also be smaller. If I have excess chain length i've found it more prone to jumping off the middle blade on especially bumpy areas or landing when the RD is pushed forward and the chain slackens.

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Guest agteros

My understanding is that you don't really want excess length in the chain. The measurement i've always used is that the chain should reach around the largest front cog and the largest back cog with one or two links extra. Now that my largest front is significantly smaller the chain should also be smaller. If I have excess chain length i've found it more prone to jumping off the middle blade on especially bumpy areas or landing when the RD is pushed forward and the chain slackens.

 

You did not change the RD?

You did not change the FD.

You did not change the rear cluster?

You ONLY removed the front big blade?

 

Why change the chain? Because of an "IF" and some 'rule' you found on the net? You sure you NEVER, EVER going to put the big chain ring back? You tried it with the stock chain yet?

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I have only removed the large chainring.

 

I didn't say anything about 'rules' I just put down my experience, which is about the only thing I have to go on and why I ask these questions in the first place.

 

To clarify my current setup.

 

I have removed my large chainring for some added clearance and it only functioned as a pointy bashring. I have not changed anything else at all. I'm still running the stock chain length, cluster, 3 x 9 shifters, FD and RD. Changing the chain length makes sense to me as it will make the system tighter since I don't have a large chainring to ensure it doesn't pop off the middle and around the crank when bouncing around. I am hoping I don't need to buy a new FD because the limiter screws may allow me to stop it moving past the middle chainring when shifting from small to middle. I will now check this out.

 

If I do need to buy a new FD, my question is will a 2 X 10 accomodate a 9 speed chain?

 

and lastly I have a number of chains so if it turn out i want a large chainring back then I will simply put to old large chainring back on and put on an old chain.

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Nah dude, first thing to do is screw in the top stop limit screw.

 

The chain WILL be fine as is because all that you are doing now is removing the extreme stretch of the big chain ring. If you want to, make the chain shorter. Yes it'll make the chain tauter over the chain ring, jockey wheels and cassette = less chain slap. Just make sure you don't make it too short.

 

All sorted. Now go ride! :thumbup:

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Guest agteros

I have only removed the large chainring.

 

I didn't say anything about 'rules' I just put down my experience, which is about the only thing I have to go on and why I ask these questions in the first place.

 

To clarify my current setup.

 

I have removed my large chainring for some added clearance and it only functioned as a pointy bashring. I have not changed anything else at all. I'm still running the stock chain length, cluster, 3 x 9 shifters, FD and RD. Changing the chain length makes sense to me as it will make the system tighter since I don't have a large chainring to ensure it doesn't pop off the middle and around the crank when bouncing around. I am hoping I don't need to buy a new FD because the limiter screws may allow me to stop it moving past the middle chainring when shifting from small to middle. I will now check this out.

 

If I do need to buy a new FD, my question is will a 2 X 10 accomodate a 9 speed chain?

 

and lastly I have a number of chains so if it turn out i want a large chainring back then I will simply put to old large chainring back on and put on an old chain.

 

Nah dude, first thing to do is screw in the top stop limit screw.

 

The chain WILL be fine as is because all that you are doing now is removing the extreme stretch of the big chain ring. If you want to, make the chain shorter. Yes it'll make the chain tauter over the chain ring, jockey wheels and cassette = less chain slap. Just make sure you don't make it too short.

All sorted. Now go ride! :thumbup:

 

 

Asking questions is cool :thumbup:, but do not get too caught up in all the detail. In principle a shorter chain might be the prudent thing to do if you had problems with a skipping/slipping chain / chainsuck etc... personally I doubt that it will be 'really' necessary, but if it gives you a greater sense of comfort, go for it!

 

Bicycles are simple beasts in design and they just want to be ridden, so make as Tiny K says, go ride your bike! (maybe report back?)

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I will definately go ride as soon as I can get out of this damned office.

 

OK, now what are you doing in an office on a Sunday? Definitely not ayoba :thumbdown:

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