34t big ring on 8 speed cassette with an old shimano Lx rear deraileur .Will it work?
01-13-16, 06:20 AM
#1
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34t big ring on 8 speed cassette with an old shimano Lx rear deraileur .Will it work?
Hi all ,
I am looking at putting a 34 t granny gear on an 8 speed touring bike . The rear deraileur on the bike is an old shimano Lx . I have been told I would need a a mega range or long cage deraileur . Will the 1980s shimano Lx deraileur reach ? Cant try before I buy unfortunately . Thanks for any inputs ,
J
I am looking at putting a 34 t granny gear on an 8 speed touring bike . The rear deraileur on the bike is an old shimano Lx . I have been told I would need a a mega range or long cage deraileur . Will the 1980s shimano Lx deraileur reach ? Cant try before I buy unfortunately . Thanks for any inputs ,
J
01-13-16, 06:24 AM
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If you have the derailleur in hand, you can google the part name and number to find the specifications. Both disraeli gears and velobase have a pretty good database for what you are looking for.
You are talking about a cassette with a 34 tooth, right and not a 34 tooth "granny" inner chain ring?
Who told you it wouldn't work? There's more than one model of deore lx but here are the specs for one,
https://velobase.com/ViewComponent.as...ee92c&Enum=108
It can handle 36 teeth on the back but like I said there is more than one model out there.
Here's a photo scan of the specs of another, https://www.disraeligears.co.uk/Site/...1_Page_64.html
Rated at 32 teeth in the rear.
My guess is that the RD can probably handle 34 teeth if this is an MTB long cage derailleur as shimano is pretty conservative in its specs. But impossible to be certain until you try it. Worst case scenario is you end up buying a new derailleur.
You are talking about a cassette with a 34 tooth, right and not a 34 tooth "granny" inner chain ring?
Who told you it wouldn't work? There's more than one model of deore lx but here are the specs for one,
https://velobase.com/ViewComponent.as...ee92c&Enum=108
It can handle 36 teeth on the back but like I said there is more than one model out there.
Here's a photo scan of the specs of another, https://www.disraeligears.co.uk/Site/...1_Page_64.html
Rated at 32 teeth in the rear.
My guess is that the RD can probably handle 34 teeth if this is an MTB long cage derailleur as shimano is pretty conservative in its specs. But impossible to be certain until you try it. Worst case scenario is you end up buying a new derailleur.
Last edited by bikemig; 01-13-16 at 06:30 AM.
01-13-16, 06:33 AM
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If the derailleur almost works but the B-screw adjustment is maxed out you may be able to put in a longer screw or turn the existing one around to get some more adjustment range..
01-13-16, 11:18 PM
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Your LX is almost certainly a "long-cage" derailleur. I've used a couple different "LX" derailleurs over the years and they have all shifted to 34-tooth cogs just fine.
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