Economical front brake upgrade

OK; so after a couple of pants-pooper freeway ALL STOP from 80mph situations wherein my front brake on the '81 faded nearly AWAY I decided to try to improve it a bit without going the stainless lines and floating rotor route.

I found this guy: http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0336844645 on eBay and decided to give it a try.

WARNING: Grinding brake rotors is NOT recommended. They need to be ground from both sides simultaneously to ensure that they will not warp under high-heat conditions. This guy's process doesn't do that, but he uses a Blanchard grinder and is aware of the need for a slow cold grind. He races cars and does rotors for racecar people too and hasn't had problems.

That being said, I've had no issues so far. I waited until the pads were bedded and I had a few hundred miles (and a few hard stops) under their belt before posting this. YOUR RESULTS MAY VARY.

I did send him a 7K-mile rotor with almost no wear; he only took .04mm-.06mm TOTAL off the thickness. That may be part of why it worked ok in this case.

I used a new set of OEM Yamaha pads from chacal, and the braking is greatly improved. I'd say at least about a 20% increase in overall stopping power (stock rubber lines 2-3 years old) and the fading issue is nearly gone.

The increased stopping power may very well be attributable to the newer technology Yamaha pads, but I honestly think the venting (drilling) helped with the fading.

The EBC floating rotor and stainless steel lines on my '83 are an obvious upgrade; this one not so much:

 

nice looks pretty too. maybe a winter project for the maxim. that and a master since the sight glass seeps a little some times.

 

I still can't believe the difference that the stainless steel lines made on my 550. Best upgrade I've ever made on the bike!

 

Ranger; I wholeheartedly agree. I've got them on my '83 and at some point will probably install them on the '81 as well.

 

The braided stainless lines and the bar mounted master cylinder improved my braking power so much I am almost doing stopies.

 

speedlinez.com cheap and a great line.

 

ebay@lines-pro.com 4 line set for 81.00 + shipping, tell them what lengths you need from end to end and what ends you need on each line and they ship fast. if you are getting lines for the Seca 750 the lines to the anti dive should be 8" with 15 degree fittings or 7" with a 15 degree on one end and a 45 degree on the other.

 

Just out of curiosity, can someone explain to me why the US got a single disc up front on the XJ,s,while the rest of the world it seems,including us here in Australia, got 2 I,ve always wondered why. Cheers ,Murray

 

Apparently they didn't think we ride fast here.

 

Nice 'n shiny.
Do have Issues with your ahem... Drillings though . Those holes are Countersunk/chamfered, are they not?? (internet photos are hard for my old eyesight)
IF so ..then that has made them even more useless . (Drilling does not aid cooling unless the holes are of smaller diameter than the disc thickness.. sadly true and proven)
Drilling is a looong discredited practice. Slots have superceded these..and even when drilled/slotted the hole edges MUST be left sharp as it's the sharp cutting edges wiping off used pad material that creates the perf increase.
But Hey! this is not news .. or at least it should not be :roll:
Spend a a few minutes with your friendly Google and see for yourself.

 

Like I said, I'm evaluating this guy's work...

Holes are almost the SAME size as disc is thick. I'm aware of the fact that slots are more efficient yet.

I know about the "scraping the pads clean" concept; my primary goal was to help with the fading issue and it seems to have. Maybe THAT'S attributable to the new Yamaha pads also, I don't know.

 

Fade is caused by the pad outgassing when hot. Gas gets trapped between the pad and rotor and keeps the pad from having good contact with the rotor.

Holes (of any size) give the gas a place to escape and let the pads maintain contact with the rotor.

 

It seems to work; nearly fade-free now; at least enough so that it doesn't fade completely away before I get the bike whoa'ed up.

I haven't had the opportunity to fully test it yet; once the pads are broken in a little more I'm gonna pull two or three tire-squealers from 75mph and see what happens. Out in the boonies, not in I-94 rush hour traffic.

 

Fitz that drilled rotor looks good. I would like to have that done to my Maxim. I not too impressed with it's braking abilities. I have had fellow riders ask why I keep my distance while riding tail end of the group.

 

make sure its in the boonies...

i dont want to be the one to run you over when you come to a complete stop in front of me at the gratiot exit in the wrong lane...

oh wait, that was the IGNORANT cager on the phone that did that 35 minutes ago!

 

I've BEEN taking I-75 up to 696 and cutting across to Van Dyke since it's shorter...

But did you see what happened to the 9-mile Rd. bridge over I-75 last night? IT'S MELTED. I75 closed 8mile to 696 indefinitely.

I guess I'm gonna be back on 94 in about 15 minutes.

 

UPDATE

Went ahead and invested in Stainless Steel lines (including a shortened upper for the low bars) and THAT IS the biggest improvement yet.

The rotor drilling got rid of 95% of the fading; PLUS the brake now works much better in the wet, especially when you first use it.

SS lines give you "grabbing a rock" feel with none of the traditional Yamaha sponginess.

Now that the new rear is broken in, this bike STOPS.

 

Good post for sure, love learning about how the gas gets built up between the rotor and the holes are for releasing it. I always thought it was for cooling, excellent!
My bike unfortunately will need all new lines rotor and caliper and master cylinder, so hearing this has solidified my choices, I will use Chacal on my full front break overhaul!
Man I love this site, bike knowledge all right in front of you to get your bike running and the vendor to get most parts for that project!

 

Fitz,
i had gone to 4 shops asking for somone to do this a few months back and couldnt get anyone to do it. machine shops are scared of the liabilities... one place told me if i bought a new rotor and had it shipped dierct to them that they might do it for $100 ..... i am curious to know what this guy charges

 

Hey fitz, I was curious, while looking at chacals catalog i noticed some of the dissadvantages of ss lines. Notably that if the rotor is on the wobbly side the lack of spongyness will make the pads bounce on and off. (Ya this is a bad description, ive been at work a while but i hope you get the idea)

Anyway did you notice any of this, or have any issues. My bike was pretty beaten by the PO and im worried about "grabbing the rock" of what might be some slightly warped brakes.

 

I'm a bit of a bike newb but if your front rotor was a bit on the 'wobbly' side... I'd say that was a very bad thing and to replace/turn that rotor ASAP...

 

well not that it IS wobbly. it is just that apparently you wont feel slight wobble with rubber brake hoses. and with ss you feel everything

Im just wondering if anyone has felt brake wobble with ss that was hidden with rubber

 

midnightblu: It was $70 including shipping.

maxhog650: No signs of warpage; however: The rotor I sent the guy was off a bike with less than 8000 miles on it. It took VERY LITTLE grinding to make it perfect; the total (both sides) taken off was only like .04-.06mm. It now has about 600 miles on it; the pads (new Yamaha) are fully broken in, and I just fitted the stainless lines, only 120 miles since they went on.

It may still warp (one of the possible consequences of not grinding both sides simultaneously) and we shall find out. I had one OMG pulldown from 75mph to crawling on the freeway yesterday, and although I could smell the pads, there was no fade and the rotor isn't warped (yet.)

Stay tuned.

 

Do you guys all have the remote master cylinder with a cable from the brake lever to the master cylinder on your bikes?


Are there any know issues with this system? Good alternative upgrades etc??

 

No, mine (the 550s anyway) have a conventional bar-mounted master cylinder. I THINK the remote M/C was unique to the Seca 750.

 

I've heard that the hot set-up is diagonal, ball milled grooves ( not slots) that don't go all the way thru. They vent to atmosphere, they scrape, they add surface area, and they don't take away strength, (much).

Holes would vent one pad over to the other pad, unless you had vented rotors. The gas would be trapped inside the hole in the rotor??

Sure looks good tho, Fitz. You could probablly get a European wrecker to mail you a fork leg and caliper. . . .

 

I really don't think the bike is heavy enough to merit all the extra unsprung weight of the second disc and caliper. Once improvements are in place, the single disc has plenty of stopping power.