MTB front mech

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thiscocks
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MTB front mech

Postby thiscocks » Fri Nov 09, 2012 16:04 pm

Hi,
A friends bike needs a new front mech as I have tried to adjust it but it wont go onto the large chainring, so I think its bent. I have set up some road bike front mechs but this one looks a bit odd so I dont know which to get.

It is quite an old Shimano Altus, and looks like it fixes to the BB. Its a 7 speed gear set.
Pics:
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Anyone know what one I need to order?

Thanks for any help,
T

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benpinnick
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Re: MTB front mech

Postby benpinnick » Fri Nov 09, 2012 18:25 pm

You have an e type mech currently, but for no good reason. You'll need to remove the bob cup to take it off. To replace, either an etype of similar spec, or my preference would be a band on mech with down pull. There's so many options , plus you need the right size... I think it's probably bike shop time.
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cooldad
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Re: MTB front mech

Postby cooldad » Fri Nov 09, 2012 19:23 pm

By bob I think he means bottom bracket.
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The Rookie
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Re: MTB front mech

Postby The Rookie » Fri Nov 09, 2012 23:14 pm

There may be a good reason like non standard tube diameters......

why won't it go onto the top chainring, what have you done to try and fix it....have you setup and indexed front mechs before?

thiscocks
Posts: 529
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Re: MTB front mech

Postby thiscocks » Fri Nov 09, 2012 23:56 pm

Thanks for replies. Well the cable was already tight on the bottom ring but it wouldn't index up to the top. I tightened it literally as tight as I could(never had to do before on other mechs) on the bottom ring and it did just click up to the big ring but wouldn't shift over far enough to stop rubbing on the outside of the chain... the limit screw is wound right out, so It's not that. The spring looks slightly bent and the whole mech seems to move a fair bit on the mounts to the bb so I assumed something is inherently wrong with the unit... any ideas?

If I need another, searching for etypes, would something like this work with 7 speed?

http://www.google.co.uk/shopping/produc ... c:overview

Cheers

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jimothy78
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Re: MTB front mech

Postby jimothy78 » Sat Nov 10, 2012 00:27 am

If you want to try replacing the mount, I have an e-type Altus 6/7/8speed mech (FD CT91) I removed from my bike when I upgraded to 9-speed. It's the top-pull variant, but the mount is the same, and attaches to the upper part of the mech with two bolts, so you should be able to swap it over.

Give me a pm if you're interested.

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nicklouse
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Re: MTB front mech

Postby nicklouse » Sat Nov 10, 2012 00:29 am

thiscocks wrote:Thanks for replies. Well the cable was already tight on the bottom ring but it wouldn't index up to the top. I tightened it literally as tight as I could(never had to do before on other mechs) on the bottom ring and it did just click up to the big ring but wouldn't shift over far enough to stop rubbing on the outside of the chain... the limit screw is wound right out, so It's not that. The spring looks slightly bent and the whole mech seems to move a fair bit on the mounts to the bb so I assumed something is inherently wrong with the unit... any ideas?

If I need another, searching for etypes, would something like this work with 7 speed?

http://www.google.co.uk/shopping/produc ... c:overview

Cheers


looking at the wire i would be removing it (as it needs replacing any way) and then see if you can move it by hand to shift into the big ring. and if not see what is catching or worn.
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sm1thson
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Re: MTB front mech

Postby sm1thson » Sun Nov 11, 2012 13:55 pm

The Beginner wrote:Did you wind the right stop out?

^this.
There is high and low limit screws (labeled H & L), if the H screw is in too far it will stop the derailleur moving all the way up (this is is job, to stop it going too far)


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