# Which rotor size?



## Brandane (24 Dec 2011)

I am thinking about a Christmas present to myself, and upgrading my Trek 6500 MTB (2007 model with V brakes) to hydraulic discs. The bike comes disc conversion ready with mounts on the frame/forks/hubs.

Having looked at various brake systems, the best VFM I can find is the Shimano SLX M666 system, with Shimano XT rotors. But what size rotors do I need? There is a choice of 160, 180 or 203 mm. Would I be correct in thinking 180mm on the front, and 160mm on the rear? Cannot find anything to tell me for sure!


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## Cubist (25 Dec 2011)

That combination is spot on for general riding. Bags of power with SLX brakes (at least as much as you're going to need unless you weigh over 20 stone and favour downhill stuff.......) and if you move onto 203mm front you have to start buggering about with adpators and checking fork warranties and so on. Check that those shimano rotors are compatible with your wheels, ie six-bolt or Shimano Centrelock

Good choice by the way.... I have some upgrade money burning a hole in my pocket and would love a set of those.


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## Brandane (27 Dec 2011)

Thanks Cubist. Wheels have 6 bolt fittings. Think I will go ahead and order them.

Edit: As a cost/quality compromise, I ended up ordering Shimano Deore hydraulic disc brakes, and a pair of Tektro rotors.


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## Brandane (31 Dec 2011)

Brakes and rotors arrived this morning. Didn't realise I would need an adaptor plate to get the rear brake to fit to the frame mounting lugs , so have now ordered that. Also the brake lines are way too long, so going to have to shorten them and probably re-bleed them. So no MTB for another week or so.....

Some hours of fun later ...... Now got the hoses to the correct length, and the brakes bled so that they have a firmer feel than as supplied out the box! So just waiting for the bracket to arrive and a 5 minute job to fit the rear caliper. Unfortunately it could take a day or two longer due to New Year post. They are only a few ££ so might see if one of the Glasgow bike shops is open on Jan 2nd and has one in stock.


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## rusty bearing (2 Jan 2012)

Obvious I know but shorten them at the front and use new inserts and olives. Most times you wont need to bleed as you wont have lost any fluid.


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