Disc brake help - upgrading from mech

snowfruit

Ok I have a Saracen Scarab whihc I bought recently. Good frame and nice Marzochi fork, but only dic brake front and vbrake rear. Good thikng however, buth hubs and wheels are ready for discs.
So Chain Reaction seem to have a good deal on Shimano XT Disc Brake M765 at the moment, or on Juicy 3's (but the later only in rear format so I would have to stick with the mechanical front). Which setup would be prefered?
And what do I need to look out for fitting wise? Chain Reaction give all sorts of mount adapters from 74mm post mount to various IS sizes.... do i need any of these?
Also, what size rotors would you reccomend for mostly all mountain riding, with some mild downhill?

*edit*
Oh, before I forget, they also have some Shimano Deore Disc Brake Dual Control M535 on sale. Now I'm a bit of a brand snob, so I would instinctively prefer the XTs or Juicys but is there really a lot of difference? And I'm not too sure about the dual controls... not seen or used these before?

supersonic

Dual control is like marmite - you must test first!

Brackets you require depends on what mount is on your fork, the brake, and what size rotor you plan to use. So a few combos depending on what you want!

Are your shifters seperate from your existing brake levers? If not, will need new shifters.

snowfruit

Yeah my shifters are separate so ok on that front.
I was thinking 160mm rear rotor and 180mm front.
I have since spotted the deore shifters in he package are out of stock so they're a no go.
And the juicy 3's only have 203mm rotors in stock for the rears, so they're out too.
That makes my mind about what I'm getting - Shimano XT's.
So, I have a Marzochi fork (I forget what model ) which has a mechanical disc mounted to it, and the same hub and mounting style on the rear although its running vbrakes on the back.

From that do you reckon i need any of the adapters Shimano are offering? Its giving me the following options for the front:
* Shimano Mount Adaptor Front No Mount Required For 74mm Post Mount 160mm (Default choice, but i want 180mm so i guess not this option ??)
* Shimano Mount Adaptor Front Post to IS 180mm74mm Post to IS 180mm
* Shimano Mount Adaptor Front Post to Post 180mm 74mm Post to 74mm Post 180mm

And for the rear:
* Shimano Mount Adaptor Rear Post to IS 160mm 74mm Post to IS 160mm

supersonic

So the fork is the IS 51mm standard?



Check what mounts the brakes come with.

snowfruit

defo the 51mm IS

supersonic

Most shimano brakes come with the required mounts. If not, then:

http://www.chainreactioncycles.com/Mode ... elID=17390

Do you have a link to the brakes you have seen?

snowfruit

Rear http://www.chainreactioncycles.com/Kits.aspx?ModelID=23483
Front http://www.chainreactioncycles.com/Kits.aspx?ModelID=23482

supersonic

Right I see how you are doing it. Pretty self explainatory it seems! Pick the adaptor that matches the size of the rotor you are buying.

So the 160 mount option for the 160 rotor at the rear, the 180 mount option for the 180 rotor front.

snowfruit

Yeah after seeing the pic you posted its started to sink in Thanks for the help. I'm just gong to doubl check my mountings and hubs when #i get home, but I reckon I'm sold on these now

thanks again for the great help.

supersonic

Lol, no probs, got there in the end!

synchronicity

supersonic wrote:

Dual control is like marmite - you must test first!

That's the best I've heard yet regarding dual control.
I wouldn't recommend it if you have more than one bike. too confusing. Same with the inverted rear mech shimano had out last year or the year before...