Buying new brakes - Post / IS - Confused!

rapid_donkey

Hi all, new to biking and after some advice.
Im going to buy a new set of disc brakes for my 2012 Carrera Vulcan and eyeing these up http://www.merlincycles.co.uk/Sale+Sect ... LIXIR3.htm
Can anyone explain in simpleton terms, what is post mount and IS mount exactly?
I dont know whether to go for the 180/160 set or 160/160 set because one says post, and one says IS& post.
On my vulcan, the front caliper bolts directly into the forks (bolts going from back to forward) and on the rear caliper the mounting bolts go in from the top. Both calipers are mounted onto black brackets, I presume to keep a distance to match the disc size.

nicklouse

Have a look in the tech FAQs there is pictures as well as words.

Just incase you are not aware of the area. viewtopic.php?f=40073&t=1590919

IBISMojoHDamon

Post mount is what you have by your description as the caliper mounts from the back of the fork leg or the top of the tube on the seatstay of the bike.

I.S. Mount is when the brake mounts from the side of the fork or the side of the frame.

IMHO, Post mount is less fiddly to set up.

Adaptors typically come in 20mm increments but if yours bolt straight to the frame, they will typically be 160mm so with a 20mm adaptor you can fit a 180mm rotor, which is as big as you should need.

If buying an adaptor, make sure you select post to post rather than I.S. to post or post to I.S.

The Rookie

rapid_donkey wrote:

On my vulcan, the front caliper bolts directly into the forks (bolts going from back to forward) and on the rear caliper the mounting bolts go in from the top.

That means both callipers are post mount (PM) how do the adaptors bolt to frame/fork?

Simon

chez_m356

rapid_donkey wrote:

I dont know whether to go for the 180/160 set or 160/160 set because one says post, and one says IS& post.

you need to find out what size your discs are mate, it should say on them some where, looking at a pic of the bike on halfords site, the front disc looks bigger than the back, and as its on a post mounted adaptor it may already be a 180 you have on the front, thats if your planning on changing the discs, the callipers should work on the discs you have on now anyway, so i don't suppose it matters that much

rapid_donkey

Thanks for the quick replies, you guys are always helpful on here.
On the front fork, the adaptor bolts to the fork with the bolts going back to front (exactly like the caliper) and on the rear, the adaptor actually bolts to the frame from the side (outboard to in). Does that mean its an IS to post adapter?
Ive had the bike out to fit new tyres and my free mbuk chainguard, and I think its a 180mm front disc and 160mm rear.
When ordering new brakes, do you go by how the caliper bolts to the adapter? And then if buying new size adapters, go by how they bolt to the fork/frame?
I went to Scartree trail red route last week, and the front brake was just scary. Superstar dont do M4 sintered pads, just kevlar and organic, so Im just replacing the whole lot I think. Should have bought the Fury!!!

chez_m356

rapid_donkey wrote:

Thanks for the quick replies, you guys are always helpful on here.
On the front fork, the adaptor bolts to the fork with the bolts going back to front (exactly like the caliper) and on the rear, the adaptor actually bolts to the frame from the side (outboard to in). Does that mean its an IS to post adapter?
Ive had the bike out to fit new tyres and my free mbuk chainguard, and I think its a 180mm front disc and 160mm rear.
When ordering new brakes, do you go by how the caliper bolts to the adapter? And then if buying new size adapters, go by how they bolt to the fork/frame?
I went to Scartree trail red route last week, and the front brake was just scary. Superstar dont do M4 sintered pads, just kevlar and organic, so Im just replacing the whole lot I think. Should have bought the Fury!!!

yes rear is IS to post, callipers bolt to both adaptors the same way, you may not even need new adaptors, the callipers may fit what you already have, you really want to change just because of the pads, have you tried ebay ?

IBISMojoHDamon

EBC do good (cheapish) brake pads.... and one place that I wouldn't want to scrimp too much on!.... I know this sounds strange, but good brakes make you go faster!... ;0)

chez_m356

if there the SX brakes described on halfords site, you want these http://www.ebay.co.uk/itm/Sintered-Magu ... 547wt_1077