IS-Post mount adapter sizing

Sorting out your thrunge brackets, fettling your inter-rositers and even stuff about bike parts.
User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

IS-Post mount adapter sizing

Postby bobcheese » Tue Jan 01, 2013 20:03 pm

Hi Guys, need some advice. I have changed the frame on my hardtail (from GT Aggressor to Genesis Abyss) i have used the majority of the parts from the GT. When I have come to refit the rear calliper I have found that even though the frame requires IS - post mount adapter (same as GT) when I mount the calliper I have to put all the spacers on the underneath of the calliper to 'pack it out' so that it fits the disk. I haven't changed the rotor, its still 160mm but is it possible I need to buy a bigger adapter? Is confusing as the adapters are marketed for larger rotor sizes not different frames.

Any help appreciated

User avatar
nicklouse
Lives Here
Posts: 80713
Joined: Thu Mar 20, 2003 12:14 pm

Re: IS-Post mount adapter sizing

Postby nicklouse » Tue Jan 01, 2013 20:28 pm

Read the topic in the FAQs?

Re you using a front or a rear adaptor?

And what caliper?
"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown

User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Tue Jan 01, 2013 21:00 pm

Hi NIck, read the FaQ but didnt get anything for my situation as the topic mainly refers to fork mounting but my issue is rear. Also the calliper & adapter were originally on the back so not covered by the section about moving from one to t'other.
Avid Elixir r calliper.

Cheers

User avatar
The Rookie
Posts: 23062
Joined: Thu Apr 30, 2009 09:29 am

Re: IS-Post mount adapter sizing

Postby The Rookie » Tue Jan 01, 2013 21:47 pm

For a 160mm disc you should only need one set of the CPS washers below the caliper on the right adaptor.

User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Tue Jan 01, 2013 21:58 pm

Hi, using the rear 160mm adapter and 1 set of CPS washers isnt enough. If I use both sets below the calliper its about right but I dont want it like this (and im sure its not meant to be).


User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Tue Jan 01, 2013 22:07 pm

yeah that was my next move. However, then im thinking 'well, if its the case they are in different positions and then that means I do need a larger adapter the how can this be a standard and the adapters advertised based on rotor size when the whole thing is mount location dependant'?

User avatar
nicklouse
Lives Here
Posts: 80713
Joined: Thu Mar 20, 2003 12:14 pm

Re: IS-Post mount adapter sizing

Postby nicklouse » Tue Jan 01, 2013 22:59 pm

bobcheese wrote:Hi, using the rear 160mm adapter and 1 set of CPS washers isnt enough. If I use both sets below the calliper its about right but I dont want it like this (and im sure its not meant to be).

Are you sure it is a rear? And it is mounted correctly?

Pictures.
"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."

Parktools :?:SheldonBrown

User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Tue Jan 01, 2013 23:46 pm

it says 'rear' on it. Haven't tried swapping it round just yet but if it was the wrong way round my calliper wouldn't fit over the disk when the wheel is attached would it? Will sort pics tomorrow

User avatar
nicklouse
Lives Here
Posts: 80713
Joined: Thu Mar 20, 2003 12:14 pm

Re: IS-Post mount adapter sizing

Postby nicklouse » Tue Jan 01, 2013 23:53 pm

bobcheese wrote:it says 'rear' on it. Haven't tried swapping it round just yet but if it was the wrong way round my calliper wouldn't fit over the disk when the wheel is attached would it? Will sort pics tomorrow

Yes it can. But the rotor size would seem to be wrong.
"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."

Parktools :?:SheldonBrown

User avatar
The Rookie
Posts: 23062
Joined: Thu Apr 30, 2009 09:29 am

Re: IS-Post mount adapter sizing

Postby The Rookie » Wed Jan 02, 2013 04:34 am

It's not mounted facing rearwards instead of forwards is it? Photo required.......

User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Thu Jan 03, 2013 21:46 pm

Hey guys, OK all sorted. So i turned round the adapter and hey presto fits perfectly. :oops:

However, in my defence I want to share the pic of how the adapter was installed then hopefully you will see im not a complete dunce:

Image

As you can see. It would be easy to assume this was mounted the correct way.

Lesson learned


User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Fri Jan 04, 2013 09:11 am

@ The beginner - this is what I am on about. This is a pic of the adapter BEFORE i swapped it around. That is what got me. I assumed the way in the pic was how it should be installed. Turns out not.

User avatar
The Rookie
Posts: 23062
Joined: Thu Apr 30, 2009 09:29 am

Re: IS-Post mount adapter sizing

Postby The Rookie » Fri Jan 04, 2013 11:27 am

I knew that is before it was corrected which is why the arrow is pointing THE WRONG WAY.....when facing the right way the arrow is the other side as you don't need to see it to tell you you got it wrong!

User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Fri Jan 04, 2013 16:23 pm

OK.....the thing that got me with it then is the 'r' for rear and the arrow I saw this as 'fit so the arrow points to the rear'.


User avatar
bobcheese
Posts: 306
Joined: Sun Oct 18, 2009 20:18 pm

Re: IS-Post mount adapter sizing

Postby bobcheese » Fri Jan 04, 2013 16:54 pm

lesson learned

02GF74
Posts: 484
Joined: Tue Oct 19, 2010 20:12 pm

Re: IS-Post mount adapter sizing

Postby 02GF74 » Sat Jan 05, 2013 18:54 pm

adapter mounted upside down - arrow points upwards.
there should be one pair of CPS each side of the adapter, not all on one side as fitted.

the CPS between the adapter and calliper are not necessary - I run my Elixirs without them to save a few grammes in weight.

User avatar
The Rookie
Posts: 23062
Joined: Thu Apr 30, 2009 09:29 am

Re: IS-Post mount adapter sizing

Postby The Rookie » Sat Jan 05, 2013 19:06 pm

Erm, you need the washers or the caliper will foul the disc unless you use (as an example) you use a 185mm adaptor with a 180mm disc.

Also helps if you read the thread!


Return to “MTB Workshop & Tech”

Who is online

Users browsing this forum: No registered users and 0 guests