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Discussion Starter #1 (Edited)
Hello guys.

I just bought myself a RC51. I got it as a project bike and first bike.

I'll give you some details about the bike. it is an 01 red silver. It cam with a power commander pc3 and an aftermarket exhaust (brand name started with a y i believe). it has 16000 KM (about 10 000mi) and runs really well.

The things that needed attention were some missing bolts for the fairings, he dropped the bike in the garage so there is some fairing damage and the left handle is a bit damaged (he included a new clip on).

Brakes are the next issue. He "upgraded" to the 01+ brakes (they are thicker) and then put on new pads. This caused the brakes to be tight up front. The battle plan for that is to but the stockers back on (which were included) and then wear the pads down a bit and then put the 01+ ones back ons they were apparently less prone to warping. however that may not get done since it is my first bike and i would not be heat the brakes up to the point of warping the brake rotors (correct me if i am wrong).

The seller also included SS brake lines, a steering dampener, the power commander pc3, flush mount tail lights, and the flapper valve has been removed, and lastly of course the exhaust. the bike also has new tires(literally never used), and brand new pads I bought the bike for 5800. the bike has been sitting for about a year


Now i have a couple of questions. The rear brake reservoir is bone dry and the brake is causing some resistance on the rear wheel. the bike is difficult to move around. we are going to try and fill it to see if we can get the brake to work...but i think there is something else wrong (unless brakes are designed to do this). he has new pads on the rear. My question is...With new pads is the bike supposed to be like that? would running the caliper dry like that? should i be simply replacing something because it has been dry? there is water in the reservoir as well, should i flush something through to get rid of that? and what?

Next question is about the front brakes. With the thicker rotors on, is there a way to make them work on the 01's? they are brand new rotors and i would like to use them if possible (as this would mean not taking the front wheel off). i'll do some poking around on here on the topic but if anyone could answer me that would be great.

Last but not least, is there anything else i should be doing while the bike is somewhat apart (i am currently going through it to make sure everything is in the condition i want it to be in)? I am having all the fluid replaced and getting a new chain. I am also going though the harnesses.

Thanks for the help and I hope to hear back.
 

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Welcome to the site!!

First off, it sounds like your rear caliper will need to be rebuilt or replaced.
The piston is sticking in the bore causing the brake drag you mentioned.
If the caliper piston bore is too badly corroded, it will probably be best to replace the rear caliper. If the bore isn't too badly corroded, then rebuilding the caliper may suffice.

If the rear is that bad, you may need to closely check the fronts as well.
If the brake fluid is cloudy, then it's got water moisture and should be purged completely.

Buy a tube of dielectric grease and put a healthy dab on all your electrical connectors.
It's great for water proofing and prevents corrosion of the contacts. Also makes the connect/disconnect easier as well.

Besides changing out all your fluids for fresh, check all your radiator hose clamps to ensure they're tight. Might also need to have your valve clearances checked if the last interval is unknown. Replace the air filters as well.

In other words, a complete service plus close visual inspection.
 

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According to the service manual, the '00-'01 brake rotor thickness is 4.5mm while the '02-'06 rotor thickness is 5mm. That's only a .5mm difference, which is almost negligible.

I'm not sure if the rotor offset is different as I have an SP2 and haven't closely compared to an SP1. But they should be about the same (comments from SP1 owners?).

The drag or "tightness" you mention may be similar to the issue with your rear brake.
It could be your front caliper pistons are either dirty or corroded in the bores and not retracting properly.
Since your rear brake had water contamination, I'd seriously check the fronts closely.
If your brake fluid is very cloudy (contaminated), you should purge your lines with fresh fluid.

Also remove your calipers and pads, but don't retract the pistons.
Grab some brake cleaner and a tooth brush and scrub the brake dust and dirt from around the pistons. That could be one of the problems as well.
 

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Discussion Starter #5 (Edited)
I was out working on the bike today.

I have a new theory about the brakes.

i am going to bleed the brakes...clean the callipers and see what happens.
The front brake fluid is clean with no water contamination. the level is at the top so im not to worried there. the rear brake let up a bit after taking it off and moving it. so i am going to just drive it and see what happens. i'll get a rear caliper ordered and

You could still move the bike around, it just took a bit of effort.

i think i am still going to switch to the thinner rotors and put the ss brake lines on. i am currently tracking down a front stand for the my bike.

i am hoping to have it roadworthy tomorrow. i want to get everything to its operating temp and i think that will help get all the parts moving like they should again. once i give it a good spin i will reassess what needs to be replaced. i have it booked in for a new chain and inspection.
 

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Don't take stuck pistons or dragging brakes lightly.
The heat from the pads can cause them to expand and grip the rotor even more and get into a vicious cycle. I know from first hand experience.
I had some sticking pistons on a six-pot Nissin caliper start this process.
The first indication was suddenly slowing from 90 Mph to 55 Mph in a matter of seconds.
Also that much friction can glaze the rotor and pads, requiring replacement.
 

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Discussion Starter #8
i have decided to simply replace the rotors with aftermarket ones (one of the stockers is bent) and i am simply going to book the bike in to the shop. I figure since i don't know enough about this issue, nor do i want to tamper with the brakes and have them fail...i will get a professional opinion on it. I will be replacing the chain and getting an inspection done as well.

the cool thing is after using them for a bit, they loosened up and the bike rolls freely now. i bled the rear brake and it works as it should. I just have to get the fronts up to par. Any ideas for a good pair of front rotors? apparently Galfer is the bee's knees next to brembo. i am thinking a waved pattern.

Thanks for the help guys.
 

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I currently have Galfer wave rotors installed, but I was originally going with Braketech Axis Cobra's in stainless. Although I have no complaints with the Galfer's.

I liked the Braketech design, but at the time (last year) they were back-ordered due to manufacturing issues. They're only $10 more than the Galfer's.

There are several other brands out their that you may want in wave or petal design.
 

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Welcome to the forums! BTW, agree with all: listen to SubSailor - def' the go-to for SP/RC stuff!
 

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Discussion Starter #11
Hey guys. Just an update.

I decided to hold out on the aftermarket front rotors and use the sp2 ones i had. After riding it around a bit the brakes have loosed up and it rolls freely now. However i think i am going to use aftermarket ones before the season ends.

The bike has a jardine slip on however i think those might get replaced as well. it sounds good but looks really funny. could be that since the bike was dropped on is further out than the other...but it just looks all wrong. i am thinking an undertail exhaust however i love the look of the pipes sitting out on the side.

I guess at that though, i am finally weeding out the main issues and getting to the little issues. It is a somewhat slow process however its finially looking like a winning battle.

Yesterday i took it for a cruise and it handled beautifully, you couldn't ask for more. took it up to top speed and it handled as it should. no weird vibarations or weird sounds. ran like a champ.
 

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when i got my rc51 the slip ons were not symetrical. i inspected and quickly found the problem. the prvious owner made a common mistake. he mounted the boss on the elbow outside the footpeg mount. i took them off and installed them with the elbow mount boss on the inside of the peg mount. all is well now.
 
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