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Old 07-26-05, 08:12 PM   #1
gamby
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Upgrade Q's

Hey all--

I postedin the MTB forum, but I want a bit more input.

I am looking to upgrade my old 1993 Supergo Access ALU R/S hardtail.

Currently, it has 7 sp Deore thumbshifters. I'd like to step up to 9 speed (The hub will squeeze in--I've checked) but I'm wondering if newer Deore LX trigger shifters will be compatible w/ my old (93 spec) XT front derailleur and LX rear derailleur.

I've already upgraded to Deore V-Brakes, and new wheels, cassette, chain and chainrings will follow soon along w/ the shifters.

I also haven't eliminated the possibility of going 8-speed and using my existing thumbshifters--since I've heard 7-speed Deore thumbies have an extra click for 8 speed.

Thanks.

(BTW, I know it's pricey--I'd rather put $500 into the bike than spend $1000+ onm a new one)
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Old 07-26-05, 08:23 PM   #2
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Originally Posted by gamby

Currently, it has 7 sp Deore thumbshifters. I'd like to step up to 9 speed (The hub will squeeze in--I've checked) but I'm wondering if newer Deore LX trigger shifters will be compatible w/ my old (93 spec) XT front derailleur and LX rear derailleur.
The front most likely not compatible with the index trigger shifters. The 9 speed front also will have a narrower cage that will work better with the 9 speed cain. The rear is compatible,but may be worn enough that it will shift slopply with closer 9 speed spacing. I'd just figure derailers into the cost to do it right with no issues.
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Old 07-26-05, 08:52 PM   #3
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Those are the answers I was looking for. Thanks.

Any other input is still welcome.

Still haven't ruled out 8 speed w/ thumbies.
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Old 07-26-05, 08:57 PM   #4
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Originally Posted by gamby
Those are the answers I was looking for. Thanks.

Any other input is still welcome.

Still haven't ruled out 8 speed w/ thumbies.
Even if there is an extra 'click', 7 speed cog spacing is 5.0mm,and 8 is 4.8mm. Close enough that it usually works, but not close enough for some.You coould always get crazy, and just use the front thumbie and your choice of rear shifter for whatever speed you choose.
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Old 07-27-05, 07:09 AM   #5
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The .2 mm difference is negligable. Over the entire span of 8 cogs, it totals 1.4 mm. A dime is 1 mm wide. Look at your chain/cog interface and see how much play is in it. .2 mm will not make a difference.
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Old 07-27-05, 08:00 AM   #6
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The .2 mm difference is negligable. Over the entire span of 8 cogs, it totals 1.4 mm. A dime is 1 mm wide. Look at your chain/cog interface and see how much play is in it. .2 mm will not make a difference.
You really gotta understand that sydney's right when he says that it DOES make a difference to some. Just because you're happy with it doesn't mean everyone will be.
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Old 07-27-05, 11:14 AM   #7
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Originally Posted by monogodo
The .2 mm difference is negligable. Over the entire span of 8 cogs, it totals 1.4 mm. A dime is 1 mm wide. Look at your chain/cog interface and see how much play is in it. .2 mm will not make a difference.
I disagree. I've messed with just about every 7/8 speed combination at one time or another and I haven't been satisfied with the performance of any of them. Right now one of my bikes has an 8-speed cassette shifted by 7-speed barcons. I got so tired of clattering and funny shifting and fiddling with cable tension that now I just ride it in friction mode and I'm happy.

The people who say 0.2mm doesn't make a difference are either better tuners than I am or are less picky than I am.
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Old 07-27-05, 04:44 PM   #8
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It's funny. I've read both ends of the argument. There are a whole lotta guys who are happy w/ running an 8-speed thumbie setup, but I guess it's all opinion.

I'm a bike mechanic at a sporting goods store (Decathlon), so I'm going to see for myself what's up w/ that .2 mm. We have a couple of altus/acera bikes that are 8 speed, so I'm jsut going to chuck one of those wheels on and see how it works.

I'm really torn between keeping it old school and updating to current stuff. Having ridden a couple of 9-speed trigger bikes, I must say that the shift action on them is sweet.
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Old 07-29-05, 12:37 PM   #9
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Close enough that it usually works, but not close enough for some.
I'll agree with sydney, as that applies to everything.

I thought about trying this, but I'd rather just spend the time to get a 7-speed shifter and know that I can tune it optimally. But for the record, its only a 1.2 mm difference, since you don't count a .2 mm space on the outside (shifter will put 7th at 28.8, cog is at 30 mm). If you're going to do it, I would adjust the 4th cog to be "right on" making 1st and 7th off by .6mm. You might also vary the optimal cog based on your riding tendencies...
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