KR1S Front Brakes

headcoats · Post by **headcoats** » Fri Oct 02, 2009 3:38 pm

After riding the Hybrid with KR1S front end for a few months now i feel the front brakes aren't as powerful as i'd like

If i have to REALLY brake ,i have to use all my fingers to haul the bugger up

I'm used to 2 finger braking but with these brakes i have to apply alot more pressure.
Is this normal or are my brakes playing up ?

Charles · Post by **Charles** » Fri Oct 02, 2009 4:51 pm

headcoats wrote: If i have to REALLY brake ,i have to use all my fingers to haul the bugger up
I'm used to 2 finger braking but with these brakes i have to apply alot more pressure.
Is this normal or are my brakes playing up ?

I'd say this isn't normal, the brakes are very powerful, on my bike 2 fingers are enough. But your hybrid will be somewhat heavier too

headcoats · Post by **headcoats** » Fri Oct 02, 2009 5:27 pm

I thought so as they fit these brakes to 750's

Could it be something simple as crap pads perhaps ?
I did have alot of trouble bleeding them when i first built them but holding the lever in overnight did the trick.

What size bore is the front mastercylinder as i had mine off evilbay and maybe the wrong size

Charles · Post by **Charles** » Fri Oct 02, 2009 5:51 pm

headcoats wrote:What size bore is the front mastercylinder as i had mine off evilbay and maybe the wrong size

5/8"

headcoats · Post by **headcoats** » Fri Oct 02, 2009 6:10 pm

I must have asked this in a previous thread so i think it is the 5/8 fitted

headcoats · Post by **headcoats** » Thu Oct 08, 2009 12:19 pm

Yep checked the mastercylinder and it is a 5/8 bore

They just haven't got the pull i was expecting,i don't really know what to check next though

SHimmer45 · Post by **SHimmer45** » Thu Oct 08, 2009 1:25 pm

possible leaking seals?.

on a small bike like a KR the 4 pots should stop you like hitting a skip in the dark

headcoats · Post by **headcoats** » Thu Oct 08, 2009 1:39 pm

I rebuilt the calipers with genuine seals
i did notice a light brown coating on the discs which i removed but didn't
change the braking performance.
Like i said they pull up nice when i use all my fingers but with two it's a bit touch and go

Because i used secondhand discs and new pads i thought it was a matter of time as the new pads bedded into the old discs but it didn't happen

JanBros · Post by **JanBros** » Fri Oct 09, 2009 6:52 am

do you have a modern bike to ?

if so, sounds to me like your brakes are ok, but compared to modern stuff, you do need to use more force for hard braking.

headcoats · Post by **headcoats** » Fri Oct 09, 2009 7:55 am

I have a Buell with a dustbin lid sized single front disc and a 6 pot front caliper

but a really heavy bike

Woulld changing the mastercylinder give me anymore feel,maybe a rdial type ?

Howie · Post by **Howie** » Fri Oct 09, 2009 10:20 am

Are you using sintered pads? I changed from sintered to standard on my ZX6 & noticed a huge difference, specially in the wet.

What about brake lines? Rubber or braided?

I would also look at a master cylinder rebuild if you've had trouble bleeding the calipers? I always bleed mine till I get good pressure on the lever using the standard method of bleed hose in a bottle of oil then 24hrs later just loosen the bleed nipple (have a rag wrapped round the caliper) & you may get a few small bubbles of air out, quickly re-tighten the nipple, do the other side, check the fluid level & then see if there is any difference in braking performance.

Howie

headcoats · Post by **headcoats** » Sun Oct 11, 2009 9:04 am

I'm not sure about the pad material,i will check them
The lines are braided type and i did have trouble bleeding them but when i held the brake lever in over night ,it seemed to do the trick.

Would a radial front master cylinder give me more feel ?
What size would i need and what bike could i get one off ???

spannerman · Post by **spannerman** » Sun Oct 11, 2009 9:18 am

my kr is standard pads braided lines origional master cylinder it stops ok three fingers lever feels very on /off
however my sons zxr h has the same calipers sintered pads braided lines but a 05 radial r6 master cylinder the lever feels very long and soft to the hand but brakes are very good
ade

headcoats · Post by **headcoats** » Sun Oct 11, 2009 10:26 am

So would an R6 05 mastercylinder fit my bike then ?
Are there other radial mastercylinders that would fit ?

mgtkr1 · Post by **mgtkr1** » Sun Oct 11, 2009 12:14 pm

yes, a radial master cyl will transform the feel/braking performance hugely. sinterted pads are a must though really. brembo, AP, magura ect do top notch ones but for a fraction of the cost get one off the modern bikes. just as good tbh. my calipers arte far from been tip top but with sintered pads, brembo master cyl, braided lines i was amazed at the stopping power and didnt get out braked by anyone at cadwell earlier this year. your m/cyl could be a bit tired?

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