Mate needs some advice....

Laughingboy · Post by **Laughingboy** » Mon Mar 31, 2003 2:08 pm

Hi guys,

I just had my mate on the phone wanting to know if its ok to mix tyres on a bike.

Hes got a Dunlop 207 on the front and want to replace the 207 on the back....but Silletts no longer do 207's, only these new 208's

Anyhow, he asked me if he could mix 207's with 208's and my answer was
"Not a clue buddy!"

So do you think this is a good idea or should he hold out and try and find someone with a 207??

Backs 400 · Post by **Backs 400** » Mon Mar 31, 2003 2:20 pm

He can mix them.

Dunlop say that the 207 and 208 are totally compatible (and so does Rob at Silletts). However..you are something like Ã‚Â£98 for a rear, and Ã‚Â£78 for a front, but you can get a pair for Ã‚Â£150 fitted (i have just got..lovely tyres..very sure footed)..sooo..if the front is needing replacing soon(ish)..it might be woth doing the pair now and saving some cash.

Commander_Flash · Post by **Commander_Flash** » Mon Mar 31, 2003 4:20 pm

Are you sure he's not just out of stock as i got a set of 207s today and he told me that was the last pair, I asked if he meant forever, he replied he would be getting more in but they would probably be none left next year.

I also agree with backs , might as well get a set for that price..

Laughingboy · Post by **Laughingboy** » Mon Mar 31, 2003 5:18 pm

Thanks guys,

I think he'll go for just the back! His front was replaced by shirlaws when he bought the bike last year, its barely done a few hundred miles and is still nearly new!

That said, I'm going for a set for the bandit as Ã‚Â£150 is a flipping bargin! And if you lot reakon they're fine, thats good enough for me!

Anyhow, next problem now!

I rung him back to tell him its ok to mix them and he informs me that his front disks are loose!

Right, you know the gold bell bit and the disk are attached to each other by those round 'O' things (yep, my bike knowledge is unsuppasable!). Well apparently these can be moved a couple of mm either way!

Now I'm guessing this is bad! Any idea how to sort this? As there doesn't seem to be any way to tighten them at all.

Cheers for the help.

Commander_Flash · Post by **Commander_Flash** » Mon Mar 31, 2003 5:21 pm

The bobbings should allow the disk to move on the carrier not sure by how much though but I doubt it would be a problem unless the bike is very old/high milage etc?

I'm sure any nice bike mechanic would look at it for free.

Post by al » Mon Mar 31, 2003 5:25 pm

They are "floating" disks but there shouldn't be that ammount of movement if I remember correctly

If an OEM replacement is too expensive then I can recommend the EBC prolite disks with matching HH pads. ( ....... cue all the shizzle about corrosion etc ..... )

Commander_Flash · Post by **Commander_Flash** » Mon Mar 31, 2003 5:29 pm

Must be winter corrosion from sitting iin the garage all winter

Laughingboy · Post by **Laughingboy** » Mon Mar 31, 2003 6:10 pm

Cheers guys,

Apparently, according to the guys at shirlaws this is a common SV650 problem and the bike may need the front disks replaced at a whopping Ã‚Â£100 ish per disk (if my memory is correct!)

Also, the sponginess he was complaining about could be shizzle trap in the caliper. He was told that the calipers would need to be stripped off and cleaned.

You think two enthusiastic mechanics could manage this ourselves?

Oh, and how much are those EBC prolite disks you mentioned Big Kneed Al (master of the emergency stop & "stand up" comedian)? and where would be the best place to get them?

Commander_Flash · Post by **Commander_Flash** » Mon Mar 31, 2003 6:30 pm

EBCs can be had from M&P 140 quid per disk + 23 quid for the pads, sure you can probably get them cheaper elsewhere, cleaning the disks is easy enough and also replacing the disks, should be a DIY jobby...(IN my opinion) save on the labour cost , just remember to use threadlock on the disks and a torque calibrated wrench...

missile · Post by **missile** » Mon Mar 31, 2003 6:50 pm

For a competent DIY mechanic it is straight forward job, but brakes are important and IMHO opinion if you need to ask if it is a difficult job then don't even try

Big Kneed Al (master of the emergency stop & "stand up" comedian) (the self appointed expert) knows all about brakes! After all he done all his own maintenance on many bikes for at least three weeks

Commander_Flash · Post by **Commander_Flash** » Mon Mar 31, 2003 6:58 pm

I agree bob, I'd rather do my own brakes as I find it hard to trust people

that way when i go over the handlebars I've only myself to blame...

Laughingboy · Post by **Laughingboy** » Mon Mar 31, 2003 7:31 pm

Just to clarify...

I can do brakes no problem....Done them for yeras on the car and I have just recently done the ones on the Bandit.

What I was needing to know was this...Shirlaws said the calipers needed to come off, have the piston taken out and have everything cleaned. Well I did this to the calipers on my MKII Cavy a few years back but and didn't find it all that hard

The folks at shirlaws were saying it was a real pain so I just wanted to check if any of you lot have stripped calipers before and is it really that hard on a bike?

Post by al » Mon Mar 31, 2003 8:51 pm

Laughingboy wrote:Just to clarify...

I can do brakes no problem....Done them for yeras on the car and I have just recently done the ones on the Bandit.

What I was needing to know was this...Shirlaws said the calipers needed to come off, have the piston taken out and have everything cleaned. Well I did this to the calipers on my MKII Cavy a few years back but and didn't find it all that hard

The folks at shirlaws were saying it was a real pain so I just wanted to check if any of you lot have stripped calipers before and is it really that hard on a bike?

Spongy brakes usually means hohed hosed or sticky pistons. I'd try cleaning the pistons first by whipping out the pads on one dise at a time and extending the pistins a bit and clean them up with cotton buds abd spare brake fluid till they can move smoothly. Once both sides are donbe you should notice a difference.

Commander_Flash · Post by **Commander_Flash** » Mon Mar 31, 2003 9:25 pm

You dont usually have to take the pistons right out, a good old clean with break fluid should do the job.Saves bleeding the system etc etc

Post by al » Mon Mar 31, 2003 9:35 pm

Commander_Flash wrote:You dont usually have to take the pistons right out, a good old clean with break fluid should do the job.Saves bleeding the system etc etc

Is there an echo in here?? :I can't believe it's not butter!

Laughingboy · Post by **Laughingboy** » Mon Mar 31, 2003 10:12 pm

Cheers guys, I'll give that a try.

I spoke to Gavin (SV650 owner and non Aberdeenbikers Forum convert!)

He's taking the bike done to Sillets to get his new rear tyre and he's going to swing by mine on the way home.

So, I can feel a bout of Sunday post pub spannering coming on!! :I can't believe it's not butter!

Expect to see an ad soon for a dirt cheap SV650 in need of a new front braking system!

And don't worry...he'll be converted soon!

Backs 400 · Post by **Backs 400** » Tue Apr 01, 2003 9:44 am

Floating discs should not have noticable movement if you give them a wiggle by hand.

See how much standard Suzuki SV discs will cost from Shirlaws. Sometimes the OE ones are infact cheaper than the EBC ones. Remember to use thread loc and TORQUE THE BOLTS PROPERLY!

As for spongey brakes, these are caused by the following...

Old fluid. (this will be yellowish in colour). Simply bleed the brakes whilst topping up the reservoir with fresh fluid. When the fluid at the calipers starts to come out clear, the job is done.

Old rubber hoses. If you look at the service book, you will see hoses are ment to be replaced every 2 years. Basically the spongy feeling is caused by the hoses "buldging" when the brakes are applied, and thus taking up some of the power being transferred to the pistons. Drain the system, replace the hoses, using new copper crush washers, and re-fill/bleed the system. Braided hoses will give a more positive feel, but can make the brakes feel wooden.

A leak in the system. If this is the case, you would notice fluid somewhere along the system. It would be pretty obvious normally, and the brakes would get worse and worse each time they were applied as fluid escapes and air gets sucked in. Sometimes a heavily scrathed piston can weep fluid, this is harder to spot without a complete strip down.

Air in the system...replace fluid, check all connections are tight and them bleed.

As for cleaning the calipers etc..there are two ways to do it.

Easiest is to remove the calipers and place a thing piece of wood between the pistons, and very carefully pump the pistons out slightly. Get a good brake cleaning solvent and spray around the pistons, wiping away any crap. Check the dust seal (if any are fitted) are intact. Get some "caliper grease" or Copperslip and lightly lubricate the pistons before pushing them back in. Add more grease or "anti-squeel" paste onto the reverse of the pads and stick it all back together.

Hardest, but most thourgh way is to strip down the calipers. You will need compressed air to pump out the pistons, although if you are really careful, this can be done using fluid. Once the pistons have popped out, give them a good wipe, checking for any surface scratches, as this will allow fluid to leak past the seal. Check the fluid seal and dust seal and replace if need be. WARNING..these are stupidly expensive...over Ã‚Â£80 for my ZXR 400! Once everything has been checked/replaced, lightly smear brake fluid over the pistons and "pop" them back into position. Make sure they go back in there original holes. Once more, use copperslip or anti-squeel past on the back of the pads when putting stuff back together.

One last tip, when left over night, wrap something around the brake lever to keep the brake applied over night. This should help expell any trapped air in the upper half of the system....you may even see bubbles in the reservoir.

Big breath....hope this helps.

Post by al » Tue Apr 01, 2003 10:14 am

Backs 400 wrote:
Backs 400 wrote:Old rubber hoses. If you look at the service book, you will see hoses are ment to be replaced every 2 years. Basically the spongy feeling is caused by the hoses "buldging" when the brakes are applied, and thus taking up some of the power being transferred to the pistons. Drain the system, replace the hoses, using new copper crush washers, and re-fill/bleed the system. Braided hoses will give a more positive feel, but can make the brakes feel wooden.
If i'm not mistaken the figure is usually about 4-5 years for replacing the hoses and the fluid 1-2 years.

Backs 400 wrote:A leak in the system. If this is the case, you would notice fluid somewhere along the system. It would be pretty obvious normally, and the brakes would get worse and worse each time they were applied as fluid escapes and air gets sucked in. Sometimes a heavily scrathed piston can weep fluid, this is harder to spot without a complete strip down.

Air in the system...replace fluid, check all connections are tight and them bleed.
If the above two were present then the problem, as you say, would be getting progressivly worse to the point you couldn't stop.

Backs 400 wrote:As for cleaning the calipers etc..there are two ways to do it.

Your first way is a bit much.

First thing to do is to pump out the pistons on one calliper slightly then clean them up with brake fluid as described in my earlier post. This is usually all they require as long as the dirt has not worked it's way into the calliper so try it first.

If that doesn't work then what you want to do is bleed your brakes and whip out your pistons, dust seal and fluid seal. Give the pistons and the inside of the callipers a good clean with some old brake fluid and make sure you clean out the groove that the fluid seal/o-ring sits in thouroughly as the dirt usually works it's way in there and causes the o-rings to "pinch" on the calliper body.

At this stage I would say that if you are going to the effore of stripping down your callipers then fit new dust seals and fluid seals while your at it. The SV onlt has 2-pots so you should be looking at no more than Ã‚Â£20 per calliper.

Do NOT use coppa slip to grase your pistons!! Only use brake fluid or silicon brake calliper grease. Lightly lubriacate the sealing o-ring and the calliper body before re-inserting, re assemble on the bike. Do the other side. Put in new brake fluid and bleed as usuall.

Big Kneed Al (master of the emergency stop & "stand up" comedian).

Backs 400 · Post by **Backs 400** » Tue Apr 01, 2003 10:30 am

Big Kneed Al (master of the emergency stop & "stand up" comedian) (Bandito boy) wrote: If i'm not mistaken the figure is usually about 4-5 years for replacing the hoses and the fluid 1-2 years.)

Just quoting my suzuki service book infront of me

Naturally it may differ for different bikes/makes.

Big Kneed Al (master of the emergency stop & "stand up" comedian) (Bandito boy) wrote:Do NOT use coppa slip to grase your pistons!!

This is a contentious one. Anti-squeel paste is infact a copper based grease OR silicone grease. If you read the Copperslip tupe, it clearly states it can be used for pistons/calipers. It is also recommended by many mechanics (especially for kawasakis as they are prone to sticky pistons) that you should remove the dust seal and pack the gap with copperslip to prevent dust being drawn into the gap. I did this at first on the ZXR, but when I completely re-built the calipers, I went back to proper dust seals.

The Haynes manual for the CB500 recommends "a copper based Grease", but shows a tube of Copperslip

http://www.molyslip.co.uk/antiseize.html (Molyslip is the proper name for it)

At the end of the day, silicone or copper based grease seems to be recommended depending on where you go/what you read.

Backs 400 · Post by **Backs 400** » Tue Apr 01, 2003 10:35 am

Laughingboy, I just found this link...very useful I think

http://www.sv650.org/sv_restorer.htm

How to restore an SV, including the brakes :)

Post by al » Tue Apr 01, 2003 10:53 am

This is the stuff you want - http://www.biketrade.co.uk/gp-products_ ... rease.html

Don't see any mention of putting copper grease on the piston sides / fluid seal. I don't claim to be a mechanical or chemical engineer so I can only speak from my own limited experience but I've seen the problems caused when an o-ring of a certain compound is exposed to the wrong type of grease.

You have obviously had to do your callipers a few time so I can only assume that you know what you are doing. But let's just say I wouldn't use it on my pistons.

Backs 400 · Post by **Backs 400** » Tue Apr 01, 2003 11:17 am

Big Kneed Al (master of the emergency stop & "stand up" comedian), like I said, it all depends on who you speak to

If you do a quick search on Brake Overhaul, some say copperslip, some say silicone grease...I just like the colour..so thats why I use it!

Post by al » Tue Apr 01, 2003 11:22 am

I once used the wrong type of grease on an o-ring when assembling an MWD tool. Not a mistake I would care to make again as it was a nightmare to dis-assemble even though the tool hadn't gone down hole. The o-ring had swollen enough to clamp the two sections of the tool together.

I don't fancy taking a risk on that happening with my brakes no matter what other people say. For the sake of Ã‚Â£5 it's not worth risking you life using copper slip just cause you have some at the time.

If a jobs worth doing it's worth doing properly.

Backs 400 · Post by **Backs 400** » Tue Apr 01, 2003 12:02 pm

Indeed..sooooo...looks like Shirlaws will be doing it then

Commander_Flash · Post by **Commander_Flash** » Tue Apr 01, 2003 12:10 pm

Coppersliip, its like HP sauce it can go and will do on anything