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Technical & Reference Section => Tech and Restoration => Topic started by: jasbadboy on April 25, 2011, 01:52 PM

Title: Spongy front brake
Post by: jasbadboy on April 25, 2011, 01:52 PM
Has anybody any tips on getting a good response from a front brake. My brakes are dia compe 901's via a hollow stem bolt and it just seems really spongy and slow to respond. It is also difficult to get the calipers to pull in equally on both pads.
Is this just due to the routing of the cable? Does it reduce performance when you cut the cable length?
Title: Re: Spongy front brake
Post by: ED209 on April 25, 2011, 02:22 PM
Has anybody any tips on getting a good response from a front brake. My brakes are dia compe 901's via a hollow stem bolt and it just seems really spongy and slow to respond. It is also difficult to get the calipers to pull in equally on both pads.
Is this just due to the routing of the cable? Does it reduce performance when you cut the cable length?


if your cable loop coming out of the bottom of the fork crown area into the brake is too tight then it reduces performance...try and get as big a loop as you can without it looking dumb...

(http://www.radbmx.co.uk/archive/albums/i63/209ed/BMX/25042011.jpg)

personally I never use a cable guide on the forks ... just use a cable tie and leave it as loose as possible.

(http://www.radbmx.co.uk/archive/albums/i63/209ed/BMX/25042011_001.jpg)

take the cable out squirt some WD40 down it and see if its any better... always works for me.
Title: Re: Spongy front brake
Post by: Robbo on April 25, 2011, 02:33 PM
Ed sort it out, running your cable through that purpose designed cable guide is hardly going to reduce the stopping power you may already have!?!?!  ::)
Title: Re: Spongy front brake
Post by: ED209 on April 25, 2011, 02:39 PM
Ed sort it out, running your cable through that purpose designed cable guide is hardly going to reduce the stopping power you may already have!?!?!  ::)

Well Rob... in my opinion ( IMO ) it does help so I posted up what works for me.

Its a much tighter line through the cable guide...it a bitch to get in ( and out ) and fooks up the cable. The way I have it is a better curve for the cable and is easy to do... especially when you are setting up a new bike and might need to take it on/off a few times...and the brake works perfectly.

so  :P

 :D
Title: Re: Spongy front brake
Post by: MartyC on April 25, 2011, 02:46 PM
901's were never designed to be used on a Potts Mod conversion, DC introduced the 880 for that purpose.  You'd probably be better off trying to get an 880 or maybe one of the later DC Nippon / Bulldog brakes.

880:

(http://www.radbmx.co.uk/archive/albums/w194/ChevyMuscle454ss/dia-compFS880-1.jpg)

Nippon:

(http://www.porkchopbmx.com/images/Brakes-883Front-BLUE1.jpg)

Title: Re: Spongy front brake
Post by: Robbo on April 25, 2011, 03:22 PM
Ed sort it out, running your cable through that purpose designed cable guide is hardly going to reduce the stopping power you may already have!?!?!  ::)

Well Rob... in my opinion ( IMO ) it does help so I posted up what works for me.

Its a much tighter line through the cable guide...it a bitch to get in ( and out ) and fooks up the cable. The way I have it is a better curve for the cable and is easy to do... especially when you are setting up a new bike and might need to take it on/off a few times...and the brake works perfectly.

so  :P

 :D

You are the king of odd brake cable routage but I still love you x  :smitten:
Title: Re: Spongy front brake
Post by: ED209 on April 25, 2011, 03:30 PM
Ed sort it out, running your cable through that purpose designed cable guide is hardly going to reduce the stopping power you may already have!?!?!  ::)

Well Rob... in my opinion ( IMO ) it does help so I posted up what works for me.

Its a much tighter line through the cable guide...it a bitch to get in ( and out ) and fooks up the cable. The way I have it is a better curve for the cable and is easy to do... especially when you are setting up a new bike and might need to take it on/off a few times...and the brake works perfectly.

so  :P

 :D

You are the king of odd brake cable routage but I still love you x  :smitten:

and me you.

I'm setting off now.

Usual layby.

8.30.

 :smitten:
Title: Re: Spongy front brake
Post by: Robbo on April 25, 2011, 03:31 PM
Ed sort it out, running your cable through that purpose designed cable guide is hardly going to reduce the stopping power you may already have!?!?!  ::)

Well Rob... in my opinion ( IMO ) it does help so I posted up what works for me.

Its a much tighter line through the cable guide...it a bitch to get in ( and out ) and fooks up the cable. The way I have it is a better curve for the cable and is easy to do... especially when you are setting up a new bike and might need to take it on/off a few times...and the brake works perfectly.

so  :P

 :D

You are the king of odd brake cable routage but I still love you x  :smitten:

and me you.

I'm setting off now.

Usual layby.

8.30.

 :smitten:

Awesome, brush your teeth this time though.  ;) :daumenhoch:
Title: Re: Spongy front brake
Post by: jasbadboy on April 25, 2011, 10:07 PM
 Sorry you are right I do have the 880. I guess the lube should help and I think you are right on the size of the loop at the forks. Mine is an 85 master and I have just used 1 of the guides on the forks.
I am sure the outer sleeves of the brake cables used to have a metal end cap on both ends of the cable. The cable I have has no cap on the caliper end.
Any experience with different brake blocks? On my skyways I am using generic White blocks and not the genuine item. Maybe that would help stopping power.
Title: Re: Spongy front brake
Post by: ED209 on April 25, 2011, 11:26 PM
Sorry you are right I do have the 880. I guess the lube should help and I think you are right on the size of the loop at the forks. Mine is an 85 master and I have just used 1 of the guides on the forks.
I am sure the outer sleeves of the brake cables used to have a metal end cap on both ends of the cable. The cable I have has no cap on the caliper end.
Any experience with different brake blocks? On my skyways I am using generic White blocks and not the genuine item. Maybe that would help stopping power.

you will be shocked as to how much some WD40 will help... Glen told me to do mine and I thought... ok when I get a mo... but once I did it...  :smitten: they worked a treat... really helps get the snap back... ALWAYS listen to Glen  :D

BTW the lock nut on the front of your brake isn't too tightly done up is it?

To centre it your brakes you just need to give the spring little taps with a hammer & punch/screwdriver  :daumenhoch:

Brake blocks wise you could try the newer longer Skyway pads.... or take yours off and give them a rub on some sand paper first.
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