How can i upgrade my disc brakes on my bike to 203mm discs rather than the 160mm std disc that i have?

Question

Hi! on my bike at the moment i have 160mm front disc brake with a standard I.S mount caliper. Is there a way i can upgrade the disc size to 203mm using my existing caliper? is there an adaptor available? and does any1 know where i can get one! or am i chatting rubbish!!! haha
thanks for the help

Answer 1

203mm is huge up front - ONLY go this route if you are doing long downhill runs!!! Hayes, among other brands, does NOT recommend 203 up front with the use of a ANY STANDARD quick release axle - this rotor is BEST used with a 20mm thru-axle.

I personally run a 185 up front, with a 160 in the rear on my Remedy66 with organic pads.

I would encourage you to try a different pad compound as well, a LOT can be acheived by a simple brake pad replacement.

Furthermore, and MOST IMPORTANTLY... Make sure you get the bracket adapter that is the SAME BRAND as your rotor. Different brands vary slightly in size and you will have a hard time indexing the brake caliper to get the pad wear correct if you vary the brands of rotor and bracket.

I ran 203's on my Rocky Mountain Flow 3.0 and it was WAY too much... Your case may be different

BEst wishes on that one !

P.S. Notice in the web-ad of the above poster(CRC), the bracket of for hope and is labeled 165, not 160 and 205 not, 203 - this is EXACTLY what I"m talking about with the bracket!

Answer 2

Well.... you must first check if your fork can take rotors that size. I had a Fox Talas and a RS Revelation, and both can take 203mm rotors (I've had them on my bikes).

Are they the best? It depends on you and your riding style. If you're doing long downhill segments, a larger rotor helps on brake fading (it's easier to cool). In my case, I'm a clyde at 230 lbs plus gear, so the larger rotors do help. If you're less than 200 you can probably go with 180mm rotors. The front is more important that the back (my backs are 160mm).

I run Shimano XT with a Hayes adapter, so you don't need to have the same brand, but it helps. Actually, Hayes has 2 different adapters for 203 mm rotors (one is just wider than the other one), and the first one I had was too wide, I just went and got the slimmer one.

Answer 3

all you need is an adapter to space out caliper far enough to work with the bigger rotor. finding an adapter for an IS caplier is tough though. it so hard that when i upgraded to a 203mm, i just bought a post mount caliper along with it. if you get a post mount caliper, you can easily find an IS to 6" post adapter easily. any good bike shop will order one for you. it costs around $15.

Answer 4

Yeh, the best and cheapest shop online in the UK is 'CRC', they do free next day delivery within the UK.

This is what you need:
http://www.chainreactioncycles.com/Models.aspx?ModelID=778

A +40mm adapter will take your existing caliper from 160/165 to 203/205 mm rotor size

(In reference to some other answerers frequent mentioning of Hayes - I listed the Hope bracket as Hope and Magura are the only mainstream companies that use IS standard caliper mountings, therefore, Hayes e.t.c. do not make the required bracket type as it is not necessary for their product range. I Expect Magura also make their own +40mm I.S.-I.S. front adapter as well if you are using Maguras and not Hopes.)

Answer 5

The extra strain could screw up your forks fella. The warranty on the forks certainly wont be valid if you fit discs that big. Try a 180 rotor instead, it's a big difference and won't damage your forks(or wallet).
Wooly Hat Shop on EBay sells adaptors to suit.
http://cgi.ebay.co.uk/A2Z-Mountain-Bike-Disc-Brake-Caliper-Adaptor-20mmAD486_W0QQitemZ300070954707QQihZ020QQcategoryZ58082QQrdZ1QQcmdZViewItem

Answer 6

Give the guys at Merlin Bikes a call http://www.merlinbike.com/ they'll sort you out.