Derbi—The Red Power

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On Holloween I went around for a ride. I hadn't yet gotten the rear brake working, and I noticed that the front brake started to lose pressure. I didn't like having a front going soft, especially since I didn't have a back up.

Today I went forward with working on these today. The rear brake had a bad res, and I couldn't seem to make it happy. The adjustment didn't seem to help. That's a 9 mm in case you want to know.

So I swapped out the res. The one I had was contaminated too. Check it out--did you ever see shit like this? It crystalized.

The bleeding. This setup worked well on the rear. But It's still a job that's a whole lot easier to do with two people. The rear bleed screw is a 7mm, and the front is a 10mm.

Turns out it was leaking at the master where the seals are located. The leak appears to be due to corrosion.

I cleaned it all out, put it back together, and tested it. Still leaking. So I swapped out the entire front brake with another one, then flushed and bled that one too. I'll see what I can do to repair original one. It's an AJP, and I think I should be able to get seals for it, but the cylinder could be bad too. If I had the bucks I'd just install a brembo.

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Had to run some errands today, so it was a good opportunity to test out the brakes. The rear was working great. So nice to have one again. The front took quite a while before it started acting properly, and it seems to be doing better now. Since I swapped out the entire hydrolic part of the front brake from master to caliper including the line I had hoped to avoid any issues. It took quite a while for the pads to bed properly. They still seem to bite less than the ones that were in the bike's caliper, so I may just swap them out.

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Tora,

Bad deal on the Brakes...What you have there is someone mixing incompatible Brake Fluids. I have seen this countless times, it's a lot easier to correct on a bike than when this condition is presented on a car.

Regular Brake Fluids are hydroscopic and typically as moisture makes it's way into the system it gets evenly dispersed throughout the system with no real adverse effects except lowering the boiling point, with the exception of large amounts of water the Reg. Brake Fluids still has fairly good corrosion resistance. Which is why we are encouraged to periodically bleed out our brakes.

With Silicone Brake Fluids we have an entirely different set of problems. Silicone fluid does not absorb the moisture and now you have tiny little blobs of water floating around throughout the system.

These little blobs like to find each other and form bigger blobs and find nice little areas to hangout, this is when things start getting bad. If the Moisture Gang lays claim in the Master Cylinder area you will typically see corrosion / rust forming on the surrounding metals and eventually leaking seals or poor brake pressures. If said Gang sets up shop in a nice neighborhood like behind a Caliper Piston, well this is when shit gets really bad...Water boils at a relatively low temperature and I don't think I need to describe what would happen when water boils off behind a Caliper Piston.

Speaking of Gangs, Moisture Gangs aren't the only ones that are competing for space in Silicone Brake Fluids. The others are more loners, but still worth noting...Suspended throughout the Silicone Fluid is tiny, tiny, tiny little bubbles of air, these little fuckers don't settle out like they do in Reg. Brake Fluids.

As we all know, air is compressible and these little bubbles do compress when the brakes are applied.
This is what is responsible for the Bad-Rap you might hear folks give for Silicone Fluids having a vague feel.

Oh, and when these two gangs start mingling, well you got yourself a nice picture of that already ...
Silicone Brake Fluid is for Trailer Queens that only need to use their brakes when they are being pushed on and off a trailer.

Now, the worse is when some jack-ass mixes Regular and Silicone Fluids. Slimy, stringy, goopy, mess !!!

Hey, you have a nice picture of that too...The only real way to undo this disaster is to completely disassemble and flush and flush and flush...Time consuming pain in the ass !!!

Best of luck, but I would suggest a regular regimen of brake bleeding to make sure you have purged the evil.

Thanks for the post Xero! I personally have only used the synthetic stuff in clutches. The RSV used it. For my brakes I try to run at least decent stuff. Currently I'm running the Motul 5.1 that they sell over at Treats. It's only $11 for a half liter, and well that's more than I can usually use before I should toss the bottle anyway.

The Silver Bike didn't have the crystals--it was the stock 11 year old factory fluid. But the reservoir that I used to replace the broken one did--so the flushing I did, after I cleaned it all out with paper towels, hopefully got all the H2O gangs out of the system.

I've found caliper piston/seals, and such for the AJP brakes that are employed on the Derbi bikes at both Easy Parts, and Maxi Scoot. But I've not found repair kits for the masters.

For the RCS on the Black Bike though I have been thinking about switching to the Motul RBF 600 that Matt mentions. But since I don't own a trailer I'll have to give it some serious thought.

I have ran the Motul 5.1 in other bikes and currently have it in my RS as well. No real complaints other than they should sell this stuff in smaller bottles, hate tossing 1/2+ bottle every time.

I have no experience with the RBF 600, so it would be improper to comment on it without doing some research. I will note that Treat's product description for the stuff is either meant to be funny or someone doesn't get wet/dry boiling points of Brake Fluids.

Unless you are actually using your brakes hard enough to need ultra high temp fluids I wouldn't waste the extra scratch on the stuff. Personally, I have a bigger problem with warping solid mount rotors than with brake fade when using the Motul 5.1, so the stuff works good enough. As far as a hydraulic clutch is concerned, heat is not a problem like it is in brake systems so using an ultra high temp fluid is way over kill.

I do not recommend using Silicone Brake Fluids.

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Sometimes being a wrench means helping your friends with their bikes. Today was help my friend with her Aprilia Scarabeo. Mostly this mean putting on some new Shinko tires we sourced from Treats yesterday.

Something was leaking. I think it was at the valve cover. Tightened it up a bit so we'll see.

Got to try out the bead breaker that Greg gave me. Works so much better than jumping on it with my feet!

Had a bugger of a time getting the rear axel nut to break free. Repeated lubricant, removing the extension from the wrench, and having my friend sit on the back of the bike with the brakes pulled tight. It finally broke free. Don't worry that torque wrench isn't a torque wrench. It use to belong to a friend's roommate. It failed as a torque wrench so now it's a fancy breaker bar!

The axle seems to be a bit loose. I need to check into this one.

Fresh tires on the Scarabeo.

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I went hunting for some bits today. The local hardware store didn't have what I needed so I headed off to the Home Depot. Hay, as you can see, it was a good time.

I found some parts, but one of the things I needed was a rod, but how to carry it home on the bike?

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Greg has been taunting me with photos of his bikes in all these cool places one would ride. So recently I've been taking snaps of the Silver Bike as a response. These have been showing up in this thread—of course! Today GL and I rode out to Bolt Labs, with a quick visit to the Local Taco Bell. Can you say seven layer burrito? Sure, thought you could. I've been feeling like the Silver Bike moves out rather quickly for a stock bike. But today riding with GL, and getting totally dusted I was with no uncertainty made aware of the true slowness of a stock bike. Have to suck it up until the Wicked GPR comes back online.

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Over on MA someone challenged my Derbi knowledge. They should know better. Below is the post, since this info is relevant here too. The Gila reed block mount, as near as I've been able to deduce is the same as the AM6—but here I gladly admit I don't know that for sure.

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I currently have 2 senda 50 phbg intakes on 2 lomats with gila reeds. No slotting or elongating stud holes.

Who doesn't love a good challenge? I'm a bit surprised though that you cat's haven't learned that when it comes to the GPR stuff it's really difficult to trip me up. I think Bobby might know more about these bikes than I do, but it would be a really good competition. ;D

Okay lets open up a brand new Gila kit from Treats, and grab the reed block.

Lets compare this to the Derbi EBE075. Upon first inspection we can see the holes are not going to line up.

But knowing this is MA I'll even put in a couple of the mounting bolts to let you see that all four are not going to line up.

Next lets check out the Derbi EBE050. Again all four holes do not line up.

Now we will inspect the Derbi SENDA engine. As we see these holes don't line up either.

Last we can check the Derbi EBS050. And again the holes don't line up.

How about we compare the Malossi reed block with the Gila. As we can see there is over lap due to the oval design of the Malossi mounting holes. This is one of the features I really like about the Malossi. You can run it on your Gila, you GPR, your RS50--it's just a great versatile design.

As far as I know that's a pretty complete sampling of the Derbi engines that came to North America. I don't have any of the Derbi DB Euro3 engines, but their intakes are supposedly the same as the EB Euro2 engines.

Why do you have a "Gila" reed block that matches up to a "Derbi" intake manifold? My guess would be that you either don't have a real Gila reed block, or you don't have a real Derbi manifold. Or maybe your Gila reed block isn't from the Gila kit for a Puch—which is what most people consider a Gila reed block origin.

Got some more info. The guy had a Chinese rip off of the Derbi engine, and a reed block from an Athena kit. So he had neither Derbi nor Gila parts from whence he deduced his position.

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