Dragon Ride Gearing

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Postby mrP(Boonen)VT » Wed May 16, 2007 12:43 pm

Personally, I would favour a compact, or for lots of mountains a triple, but Adam's not going to change all that Shimano drivetrain, so I suggested the sprocket option.

39*25 is OK for the first 1 or 2 mountains (provided they are not Alpe D'huez :roll: ) then it really hurts. :shock:

I was amazed last year to notice that hardly a single ("foreign" - to me) rider on the Marmotte was using a 39 - ALL compact or triple.
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Postby Robh » Wed May 16, 2007 1:05 pm

[quote="mrpvt"]Personally, I would favour a compact, or for lots of mountains a triple, but Adam's not going to change all that Shimano drivetrain, so I suggested the sprocket option.

39*25 is OK for the first 1 or 2 mountains (provided they are not Alpe D'huez :roll: ) then it really hurts. :shock:

I was amazed last year to notice that hardly a single ("foreign" - to me) rider on the Marmotte was using a 39 - ALL compact or triple.


Not really a surprise as most of those guys don't have the 400-450 watts threshold to ride a 39 tooth small ring all day in the mountains like the pro's.
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Postby Elliot M » Wed May 16, 2007 1:16 pm

or they are used to real mountains in their country!
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Postby -Adam- » Wed May 16, 2007 1:19 pm

So if i get a 12-27... is the same rear derailleur going to cope or do i need to adjust it?
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Postby Jon H » Wed May 16, 2007 1:24 pm

Rear mech will cope OK with a 27 sprocket, no problem.

If you're on 9 speed another possible option would be to fit a MTB casette to give you a 32 sprocket. But then you might start running into problems with the rear mech capacity, and the steps between gear ratios could start getting a bit big too.
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Postby -Adam- » Wed May 16, 2007 3:13 pm

Thanks jon, im gonna stick to the 27, hopefully i wont even use it. Although i bet i do, just because its there!
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Postby Graham O » Wed May 16, 2007 3:21 pm

Adan

Got my 12-27 from Wiggle for £28.50. (This includes £1.50 discount because I have spent so much bleeding money with them). They are actually selling for £30. Delivery is free.

You can also get a 105 10 speed cassete for £23 or so.

PS - Anyone want to buy a 12-25 10 speed ulgetra casette, or swap for a 12-23.

Ta,

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Postby -Adam- » Wed May 16, 2007 5:05 pm

For the sake of a few grams, and given that ill only be using it in France... Does anyone think ill be able to tell the difference between a 105 and an Ultegra cassette!? As ill need to fork out for the tools to get it off and on anyway.

By the way, what is it i need, a chain whip thingy and a whadaya call it to undo the lock nut?

And how do you know how tight to tighten the locknut?
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Postby Dominic » Wed May 16, 2007 6:33 pm

The weight difference is about 2g like for like. Nobody will be able to tell the difference on the bike. I sometimes wonder myself what the difference between the cheaper and the more expensive cassettes are. Mind you if I ever buy an expensive cassette I will be more likely to change the chain more often than wait and change both chain and cassette.

You will need a chain whip and a splined lock ring spanner. I just usually tighten the lockring up to just 'tight' without any pressure.
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Postby mrP(Boonen)VT » Thu May 17, 2007 2:25 pm

[quote]So if i get a 12-27... is the same rear derailleur going to cope


Campag rear mech - no problem, but not sure about Taiwanese imports

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Postby Elliot M » Thu May 17, 2007 2:59 pm

you should be able to find out for sure on shimano's website - i think it states both max difference in teeth on the cassette and max difference in teeth in the system (cassette + chainrings) that the mech can handle

12-27 should be fine but you will need more links in your chain
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Postby Dombo » Thu May 17, 2007 5:41 pm

You might not need more links. I changed a 12-23 to a 12-28 with no problem and ran it on a 105 short cage mech.
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Postby Graham O » Fri May 18, 2007 9:35 am

Got my 12-27 last night and fitted it OK. I need to lengthen the chain by a link or two, and spent ages last night trying to break a link in the chain. Had to give up in the end, cos I wasn't strong enough.

Just a sanity check. Are you supposed to break shimano chains using a link extractor like in the old days, or is there a fancy new method which I know nothing about..
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Postby mrP(Boonen)VT » Fri May 18, 2007 11:20 am

[quote]Are you supposed to break shimano chains using a link extractor like in the old days


Goodness knows what the Japanese are up to these days :?:

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Postby Elliot M » Fri May 18, 2007 1:29 pm

all MTBers i know bin shimano chains because of the difficulty in rejoining - you can break as normal but are supposed to use a special shimano rejoining pin, which needs the end broken off with pliers (or a good whack with whatever's to hand)

Use sram instead, which come with a "powerlink" which can be used to join without tools, but can also be rejoined using the existing pin
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