Problem with GSXR front brakes.

[hopper650]

Hi all,

I have a serious problem. I have just completed a GSXR front end conversion on my SV k4n. I have got GSXR k6 forks, bottom yoke and spindle with GSXR 1000 k6 callipers and a GSXR 1000 k5 radial master cylinder. For the front wheel I have a SV1000 wheel and disks. Evrything bolt up ok. Put after fitting the wheel and callipers and blending them up I got a heavily binding front wheel. I stripped and cleaned the calipers and greased the pistons and rebuilt. The binding has improved but when I test rode the bike after 1 mile the pressure on the lever increased to the put where the front brake locked on and I coulden even move the lever. After allowing to cool for 10 mins I was able to ride the bike again but the rubbing is so bad it causes the disks to get so hot.

Has any body experienced this problem before? Or am I using incompatable parts? I am really stumped with this one and and help will be appreciated. Has anyone done the conversion with the same parts I have used?

Please help guys as I really need my bike sorted :(

Cheers

[andrewsmith]

It sound like the calipers need a rebuild with new seals.
Is the brake lever a pattern or genuine one?

[davepreston]

try testing another master cylnder to rule that out

[hopper650]

I'm using a pattern brake lever. It's one of the short spazzo type that are on eBay. I have rebuilt and copper greased the calipers the seals where all ok, no dirt or grit. The only other master cylinder I have is the standard naked sv one non radial is it worth trying that?

I think I read something on sv rider about wheel compatabilty and am wondering if the 06+ forks only take the wheel and disks from the same years??


Did you get my message Dave?

[maviczap]

Check the brake lever, some have been known to cause this problem I seem to recall

[andrewsmith]

Check the brake lever, some have been known to cause this problem I seem to recall

Yes few racers have had brakes lock on and spit them off.
Typically whats happens is what your suffering

[hopper650]

So put the standard brake lever back on? Worth a shot.

Can anyone confirm or deny for definite my thoughts about the wheel?

[andrewsmith]

I think the SV1000 wheel is compatable
Others will confirm this

[flymo]

assuming there is some play at the lever (it shouldnt be pressing against the master cylinder plunger when the lever is in its normal position). Check the caliper positions laterally, do the discs look to be roughly in the center of the caliper gap or miles out? If all looks well then I would agree with Andrew, the pistons may be binding and not returning properly in to their bores when you release the lever.

If so, then strip and service the calipers.

[hopper650]

The disks don't look to be central, the outside pistons seem to be tighter against the disk than the inside. I have allready striped and serviced the callipers, and copper greased the pistons. The calliper seals where very clean so didn't replace just removed, cleaned and replaced

[Bibio]

so you copper greased the calliper seals?

[flymo]

can you post up a pic?

[flymo]

...copper greased the pistons...

Not a great idea to do that as the grease may attack the rubber of the seals. I doubt that this is the cause of your problems though although its possible that the seals have swollen.

Really should use a rubber friendly grease, red rubber grease is a favourite.

[hopper650]

Yea I copper greased the pistons and seals, should I strip clean and re try with rubber grease? I will try and get a pic up tomorrow.

Any thoughts yet on my wheel concerns? To me it seems like the Disk mounting surfaces are too wide so the outside disk face rubs on the outside pads??

I'm clutching at straws though lol

[andrewsmith]

You need new seals TBH
Copper grease ain't the best for rubber

[Bibio]

depends on how long the copper grease has been on them. copper grease will swell the seals.

wait a minuet i think i see your problem...

k6 forks
k6 yokes
k6 callipers
SV 1000 wheel with SV1000 discs

SV1000 discs are 320mm and k6 gsxr are 310mm so discs will be rubbing on top of the gap on gsxr callipers.

[hopper650]

Bollox wish I remembered red rubber grease yesterday, got to do the job again :(

Still this doesn't explain the par rubbing and lock up as it did that before I stripped the calipers?

Will definatly change the seals now though and use rubber grease

[hopper650]

Bibio do I need k6 gsxr disks then?

[Bibio]

yes or look for calliper spacers for radial callipers.

[hopper650]

Ok how much do I need to space the calipers? Is it 5mm, does the 5mm spacer replace the little collar that is in the fork legs or do you put it in as well as that standard collar.

Or will k6 gsxr disks fit on my sv1000 wheel? That handy guide that was posted on sv rider about all the componants seems to have dissapered.

[flymo]

best thing to do, before filling the brake system is have all the components in place and check for smooth rotation of the wheel. Nothing should bind. If it does you should be able to see where.

Check that the calipers are roughly central to the disc they are surrounding. The pistons should find there own relative position when brake pressure is applied, it doesn't matter than one side extends out of the caliper more than the other (within reason). Also check that the pads are lined up so that they contact the disc in the correct place.

If all that checks out then you likely have a problem up at the handlebar, my guess though is that the pistons aren't returning into the calipers properly due to swollen seals or some other problem.

[hopper650]

Ok guess i will have to take a trip to my suzuki dealer and get some seals and stripping down the calipers again today, and rebuilding with rubber grease this time lol.

I need some more information on the calliper spacers as well anybody got any ideas?

[flymo]

I need some more information on the calliper spacers as well anybody got any ideas?

Just pop it all together and measure the gaps.

[hopper650]

Just pop it all together and measure the gaps.


Which gaps? There are no gaps between the calipers and fork legs if that's where you mean

[Bibio]

its a simple case of maths to work out the size you need.

320-310/2=5mm

[hopper650]

its a simple case of maths to work out the size you need.

320-310/2=5mm


Ok so a 5mm spacer between the calipers and the fork legs. Is that as well as the locating collar that is between them at the moment?

[Bibio]

you have to replace the collar's with another that is 5mm bigger to give you the extra 5mm required to lift the callipers clear of the disc. this 5mm will end up what looks like a washer between the calliper and the calliper mounting on the fork lower bracket.

like these
http://customspacers.co.uk/products-page/motorcycle-parts/radial-caliper-spacers-shoulders-10mm1/

no they are not the ones you want but you could try phoning them to see if they will make a set for you.

[flymo]

where are these dimensions coming from?

[Bibio]

where are these dimensions coming from?
he has 320mm sv1000 discs and gsxr k6 callipers that are designed for 310 discs so you have to raise the callipers to fit the 320 discs or go and buy 310 discs. the cheaper option is to spacer them out.

[flymo]

he has 320mm sv1000 discs and gsxr k6 callipers that are designed for 310 discs so you have to raise the callipers to fit the 320 discs or go and buy 310 discs. the cheaper option is to spacer them out.

yep, was just out of interest wondering if all these dimensions were available for reference somewhere.

On the spacers though, I wouldnt have thought necessary assuming everything runs freely and the pads line up with the braking surface well enough. The link you provided shows spacers that would move the calipers laterally rather than reposition them further away from the front axle center line?

edit..... aha....I'm with you. The calipers are radially mounted rather than side on as with stock SV items right?

[Bibio]

yup, penny dropped :-)

i personally use k4/5 600/750 forks as they have taller mountings with k6 callipers and 320 discs and it fits like a glove. the reason for this is that the 320 discs are readily available cheaply from blackshadow.

[hopper650]

Ok so I spent some time on the lathe and have turned up some spacers. The front wheel does seem to spin more freely than before now so hopefully problem solved.

Just about to test ride so I will let evryone know the result.

I was under the impression that the sv1000 discs where 310mm but mabye I was wrong lol

[yorkie_chris]

SV1000 are 310mm.

Clean the copper slip out. Use red rubber grease.
You should be able to push pistons back by hand, if you can then seals are OK for now.


Personally I think master cyl is problem.

Test it, then crack nipple off and retest. If it is master cyl cause then that will free it off.

[hopper650]

Well the spacers seem to have worked so hopefully that's case closed. I made a spacer out of some stainless on the lathe.

Thanks for all you help guys will post some pics soon.

[Bibio]

double check the pads on the discs to make sure that they are landing on the disc face properly.

and yc is correct the sv discs are 310. my mistake. but i suspect that you have actually got a gsxr 1000 k1-2 front wheel or similar. is there any way you could actually measure the discs?

[yorkie_chris]

Well the spacers seem to have worked so hopefully that's case closed. I made a spacer out of some stainless on the lathe.

Thanks for all you help guys will post some pics soon.

Aye but are your pads overhanging the disc now? You don't want this.

[hopper650]

The pads look like they are on the disk face ok, I suppose the real test is to look at pad wear in a few hundred miles.

I got the wheel of davepreston who said it was a sv1k wheel, but arnt the k1-k2 gsxr wheels the same as the sv1k?

[hopper650]

is there any way you could actually measure the discs?

I suppose this will tell me what the wheel actually is. I can mesure them on Monday

[andrewsmith]

The Wheels are from a K1/K2 GSXR1000 to my knowledge
But maybe wrong on this

[Bibio]

don't matter about the wheels as all the diamond spokes fit radial forks up to k8 (cant remember the exact cut off) with different spindles but if preston sent him a front wheel from a 1000 k1-2 with discs to match then the discs will be 320mm.

[flymo]

rather than measure them, can't you just check them visually?

[Bibio]

suppose you could.

gsxr 1000 k1-2 are solid type spokes on carrier can be gold/silver/black

sv1000/gsxr k4> are lattice type spokes on carrier and are black

[hopper650]

rather than measure them, can't you just check them visually?

How do I do that?

[andrewsmith]

SV1000 discs are 310 and GSXR1000 are 320's
And Biblo's technique should be best

[flymo]

How do I do that?

Assuming the wheel is rotating just fine to start with, fit the calipers with no pads. All still rotating properly? Yes - Fit the pads and check position, No - position the calipers properly with spacers if possible, fit the pads and check position.

If the bottom end all fits together nicely then you have a problem elsewhere.

[hopper650]

http://img.tapatalk.com/1f5652b3-146a-59a2.jpg


Not the best pic but hopefully someone can recognise which ones these are lol

[Bibio]

sv1000

[yorkie_chris]

If the discs came from preston then I'm relatively sure they came off a SV1000 hence 310mm.

[andrewsmith]

If the discs came from preston then I'm relatively sure they came off a SV1000 hence 310mm.

It was the 650 that had a Gixxer front?

How recently did you get the wheel of Preston?

[Bibio]

those are 310mm discs as the 320's are completely different.

[flymo]

yep, exactly the same as mine - 310 mm discs. Also, the wheel has the code J17M/CXMT 3.50 DOT cast into the spoke.

[Bibio]

take the spacers out...

[hopper650]

It was the 650 that had a Gixxer front?

How recently did you get the wheel of Preston?

About 3weeks ago he sent it to me.

[hopper650]

take the spacers out...

But it seems to be do much better now they are in. They work well and don't hear up to the point they lock up.

Mabye I have different year forks to what I was told on eBay??

Is there a way to tell?

[andrewsmith]

Thats a SV1000 wheel, I can confirm that

But it seems to be do much better now they are in. They work well and don't hear up to the point they lock up.

Mabye I have different year forks to what I was told on eBay??

Is there a way to tell?

If my memory serves me right the black coating on the sliders was only one generation of the GSXR's but I can't think which generation

[Bibio]

your going to have to look at the top of the callipers threw the slot to make sure that the pads are indeed landing on the discs properly. any overhang on the pads will cause heaps of trouble.

[hopper650]

Ok I will have a look.

Would other years of GSXR forks require spacers or do all radial forks use 310mm discs?

I do have another problem with my speedo to. I have mounted a hall effect sensor from a GSXR to a bracket on the left fork leg, and I have installed 4 equally spaced magnets in the disc rivets.

The speedo seems to be over reading and it never settles down.

For example when I doing a constant 30 mph it will read jump from 24, 30, 28, 36, 32 etc...

Do I need more magnets on the disc? I read somewhere that some models require 8 instead of 4 is there a way to tell?

[hopper650]

http://img.tapatalk.com/d5cde1ac-2547-f4dd.jpg

http://img.tapatalk.com/d5cde1ac-2629-6696.jpg

http://img.tapatalk.com/d5cde1ac-265a-8369.jpg

http://img.tapatalk.com/d5cde1ac-26ea-0bbb.jpg


Here are some pictures of what the callipers look like after the spacer install. There is a slight gap between the discs and pads at the front of the calliper but at the back the pads and disc align nicely. All of the pad does seem to be on the disc but what are your opinions?

I have also included a pic if the forks themselves hopefully some one can recognise what year they are from?

Cheers guys

[davepreston]

to answer the question about the wheel its a sv1000 sz (k5) front wheel with the same disc's
and my 650 i sold to irksy had the sv1000 front on it from the sz ,hence why i have a 650 with thou forks and no front wheel in my garage atm till i put an orginal 650 front back on, and why that barsteward irksy is now merrily ragging my thou around while im walking to work, argggggggggghhhhhhh. but should be sorted by tuesday woooooohooooooooo

:)




also for your info the sv1000 front wheel was never changed in any dimention from k3 the first to k7 the last to be made

[hopper650]

Still not 100% sure what's caused the problem. But it's defiantly better with the spacers in the callipers.

Just waiting for someone to add the 10 pence about the pics I have posted.

Bet you can't wait to get my forks in lol

[davepreston]

just a bit lol