Hobo's hot nail mod

Has anyone tried Hobot's hot nail suggestion for the master cylinder valve? What were the results?

Thanks all.

A hot nail will not change the law of physics.

There is NO RISK as No Resleeved master cylinder have ANY resistriction offrice/valve. The few brave souls who've done it enjoy distinct better sonic physics of tire patch and grippy surfaces. It don't change the leverage hydroualic ratio just distincly less pilot effort to control and make tire grip noises better but adds more fear- skill not to lock up in panics. If ya don't like it and survive a horriable hobot mod, just put new rubber brake reaction restrictor back in. It does not improve the distain some have for retaining all Norton brakes of course. I'd remove the whole rubber booty thing but its part of the spacing factor for return spring travel.

I did this a few years back and was pleased with the result, I figured in my head that to push the caliper pistons x amount you would need to move x amount of fluid from the master cylinder, and applying the physics to say two tubes of toothpaste one with standard end and the other say an inch wide aperture and you stood on each in turn it's obvious which one will empty easiest. My problem was that my brakes were good but very stiff and on/off like at the lever, doing hobot's mod eased the lever and a more progressive feel. Don't knock him till ya tried it!! Give it a whirl, there only pennies!

I submitted this before.
This is from a personal email reply I sent hobot about his Norton front brake master cylinder brake upgrade (hot nail through the rubber piece). He asked that I post it public, I included his reply at the bottom.

Me:
Sorry I did not reply back sooner. I wanted to do your upgrade and get some riding time on it for evulation of the difference. Plus I am not known here so I get no private messages and don't even think to look here for them.
Well I did do your upgrade, but only partially evualted the difference. I haven't gotten in very many rides on it since then (lots of different reasons) but at least enough for an initial aprisal. However I cannot make a true direct comparison as there were other factors also. This is what I did.
My Norton (1974 850) had a master cylinder leak since I got it (2 years ago). It did not leak too bad, but every once in a while the front brake lever would go all the way to the grip with no resistanse (scarry sensation). The next pull or two would restablish fluid pressure and it would hold good pressure. So it was ridable as long as space was left in case the first pull failed. But the cylinder did need fixing, so that was done along with your upgrade. The cylinder was cleaned then honed out with fine sandpaper (it had some rust and lots of crud but mostly in the area not swept by the piston). It looked good after I was finished. The piston was pretty rough and rusty (about 1/2 of it) but it also cleaned up ok. I cleaned everything up real good. I got a brake kit from Old Brits and replaced the rubber parts. I then did your upgrade on the old black rubber part with the hot 6 penny nail and put it all back together. I also took the front wheel brake disk off and used a "scott brit" pad on my drill to deglase the disk on both sides. I am no expert on doing that so I hope I did it right. I haven't noticed any puslating so it is probably ok.
So the master cylinder was brought back to normal and the disk deglased along with your upgrade.

My initial finding from the short rides I have done are positive, but not as rosy as your postings. I have found that now it does indeed stop better. I can now even lock up the front wheel if I pull very very very hard. Before that was not possible at all, you could get maybe 1/2 as much stoppage as that, plus it felt totally wooden as they say. It does stop much more evenly now too. Before it seemed to stop somewhat ok at first but then less well as it slowed down (like the same pressure was not slowing it down any further), requiring even harder pulling to get it to stop fully. The stopping distance is now a good bit less, somewhere between 1/3 and 1/2, depending on how hard I pull. It does take less pull to stop, but is by no means an easy pull. The lever still has to be pulled hard, very hard for fast stops. Before it had to be pulled very hard to stop at all. But compared to my 2007 Bonneville, you have to pull more than twice as hard on the Norton. Plus the modulation is way better on the Bonneville, meaning I can lightly change how much pressure and immedeatly feel the difference. The Norton still can't match that, you have to pull hard and pulling harder doesen't have as much effect. It is still more of a on/off brake than a modern. I know I didn't explain that part very well. There is definate improvement. I can't say how much came from any one part of what I did. It is now much much better than it was and is far safer to ride. Before I had to leave lots of room to stop, now I can ride with normal traffic spacing confidently. Thank you for sharing your upgrade with me. The only thing I am dissapointed with is still having to pull so hard. From your posts I was expecting 2 finger operation like my Bonneville. I have a good grip so it is no problem to pull hard, just was looking forward to more, plus I worry that someday I will forget which one I am on and pull the Bonnie's lever at Norton strength and crash. Anyway I do thank your for your help, it has made a big difference. I may still get a sleeved master cylinder later, but for now I will stick with this upgrade and see how it feels as I get more used to it.

hobot:
Alrighty David you got about as much as one can expect form the factory hydraulic ratio do appreciate hearing how much just a bigger hole makes for actually having a lockable brake. Its somewhat a safety feature it takes so much effort to squeal at good speed but guarantee if a panic need arises it wont hardly noticed. I got a decent grip so not much a bother to me to squeal at will. Next thing to improve the ease is get something like the RGM race lever and SS hose. Do not mistake ease of squeaze with actual stopping distance once a loud squeal or lock up can be had then that's all there is from two fingers or ham fisted grab. Once pistons or pucks get rusty they are more prone to re-rust and mess with bore pitting. Your email would be fun to read on forum with a title like hobot brake mod let down : )

Does anyone have a picture of exactly which part gets the piercing? Just did the rear m/c and will probably have to do the front also.

It is number 11 in the picture, sorry it is a link not the picture itself. Second one is the associated description page.
http://www.oldbritts.com/1973_g22.html
http://www.oldbritts.com/nor_comm_73_22.html

One fella in Texas posted me complaining it still took about as much squeeze pressure and only gave him about 1/3 less decision time and braking distance instead of halving it. I sense more immediate predicable action. Mostly it made my fear factor shift from getting enough squeeze on lever to getting enough tire traction. Just need to get orifice at least as open flow as rest of the passages. I believe Norton did this to mimick drum brake habits but don't have any evidence for that but how it feels hot Nailed. Add RGM race lever and it'd be close to two finger ease of sleeved m/c's. Most proving on Trixie I did was seeing if she could even hang with super expensive exotic squads out for 120's mph fast fun so had to stay on speed into turn braking seriously not to hit their tail lights before I let go to lean and turn almost same speed as they would, many times in a row on 20-30 mile runs. Prior the braking took too long so could not stay in sight of the hot shots after one real slowing down event. I only let Trixie get 112ish upper 6000's in the opens so squad would walk away few 100 yds in long opens so I had to stay fast longer than they did which means meaner brake dependence than hp. Not a great improvement but does allow me good fun with slightly pissed off moderns. All brakes are too powerful for off road.

You'll not change caliper pressure one iota by punching anything with a hot nail. There may be a placebo effect, though.

Come on guys, get the dam master cyl resleeved to 12mm. That's the only decent fix there is. It works like a dream, and not hard at all to pull the brake on.
I made up my own kit. Made a 12mm sleeve which was relieved on the outside where the bleed holes go through the side. this enable the thing to work without having to correctly line the holes up if necessary. I then loctited it in the cylinder and then drilled the main relief hole going to the reservoir. I obtained 2 x 12mm cups and a spring from a brake supplier, then made up a piston to fit the to cups [ the type with holes in them ]. A removable end cap for the piston was made in which I could fit shims, reassembled the whole thing and worked out the amount of shims to line the front or primary cup to just be clear of the relief hole. [ needed to enable more fluid to enter the cylinder as the pads wear ].
works really well.
Dereck

A hobot hole is only a nice cheap down/dirty improvement in how it improves tire reponse on same strong squeezxe. BUT any and every other mod away from a factory Norton will give stronger sharper easier caliper power, duh. BUTT I Dare ya to jump on/off 3 cycles, 1. plain. 2. holed 3. 12 mm, to see what change is felt more in control of tire, less restriction or higher ratio, as both operating on resleeves but who else has put a restrictor in a resleeve or taken out the Norton one to sense the significance w/o confusion.

JimC please Stop Putting Words in My text or annoying chastising on claims I Did Not Make. SQURREECEEECH... ah.

"
JimC please Stop Putting Words in My text or annoying chastising on claims I Did Not Make. SQURREECEEECH... ah."

Hobot, just where did where did I put words in your text? As for your claims, I will indeed continue to chastise your claims that are contrary to the laws of physics. Personally, I think you are the biggest fool on this forum. 17,000 plus posts would certainly make you the most prolific of the forum members. Some of your "information" could be downright misleading to the uninitiated Commando owner. Your J-B Weld, hot nail and ridiculous top speed claims , to name a few, pretty well confirm you are a bit "off".

Thanks for all the information...I am going the resleeve route.

nberg said:

Thanks for all the information...I am going the resleeve route.

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You are correctly addressing one of the inadequacies of the Norton front disk brake. That being, the master cylinder piston is way too large for the stock caliper. According to Vintage Brake a 5/8" master (stock Norton master cylinder) would be about the size you would want for four 41mm caliper pistons. Of course, there are other options that will produce an even better performing front brake. Forum member Madass, as well as CNW, provide some excellent options. Years ago, I put together a 12" floating rotor, Grimeca 2 piston, IIRC 42mm, caliper and a 11mm Grimeca master cylinder, with matching clutch lever, for around $700. Probably the best money I ever spent on my Norton. Just remember, it's the size that counts, not the brand. A Grand Prix Brembo brake systems that is not properly sized won't stop worth a damn.

hehe ya 'nailed' me good JimC and still left much out of my dirt laundry list. If I'd not experienced the sigfinicant improvement I'd feel the same recoil you do on my claims. If you've got enough fluid dynamics background I'm all ears to understand why Norton put in such a tiny oriffice calling it a valve. Like Teflon and LSD, properties were discovered by accident trial/error not reasoned planned knowlege, same with hobot hole. What occured in my case was going all out removing-changing everything really ole Norton in Peel that over rev'd so accquired Trixie in interum I swore I'd only use numbered parts to keep Trixie pure Combat. Prior Ms Peel brake was resleeve'd to 12mm d/t bore pitting, RGM race lever, SS hose and 1.6 lb lighter Heinz rotor for best brake I've experienced in motorcycles as gave good control, not so sensivitive as moderns in panics at hi speed or slick surfaces yet able to lock up over the ton and feather ABS like down to a short stop. I had trouble keepping butt planted not to fly over Peels bars. My SV650 and Ninja stoppied too easy to pull down that hard which surprised and pleased me no end - So I had Peels normal/standard/rouine/proven upgraded brake on hand when I found Trixies brake scaring me as couldn't squeeze lever hard enough to over come tire traction. Trixies factory mastercylinder and caliper, rubber hose and rotor surface had been renewed but still drum like weak power even with panic adrenalin squeezing. Got to thinking about Australian fella Chris that made a stock size new piston [14 yr ago] that left out the rubber valve hole and his pleased reports so hot nailed Trixie's hole open - after finding drills are useless - to get such good control almost similar to Peel's sleeeved brake I now think the main thing that makes sleeved m/c's so popluar is no restriction to flow rather than increased hydrualic ratio. I have tested this and one other I know of who reports same improvement while you are claiming its impossible w/o testing yourself or hearing it form a respected expert. hobot hole so effective in Trixie I'm pissed I listened to experts on 100 tire instead of 110 to point I gave Peel brand new 100 Roadrider to Wes as too little tire for Trixies holey factory brake. When tire is limiting factor not brake power then its just a weak grip fella that needs more ratio help but ain't gonna slow any better than tire/surface allows.

Timely topic JimC. I have a stock 850 Commano sitting in the garage. It leaks its fluid content from the master cylinder even after a rebuild so it is about time for a sleeve repair/modification.

Dance's I dare ya to try hobot hole on your leaker before resleeving to see why I think removing restriction is more beneficial than just ratio change. Of course don't tell anyone here but pm me if ya do on which factor pleases the most, ease to lock up or ease of tire control howling to a stop. Will be getting a G meter bar mounted gizmo to pass around for some objective to find pecking order if ya game. Everyone always removes this restriction when resleeving so always assume its only easier ratio that improved control. I've tested it so rest of ya just guessing.

hobot said:

Dance's I dare ya to try ......

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Yawn. :lol:

I only consider double dog dares. Besides this, you will shoot your eye out.

I am not saying your hot nail trick does something nor am I saying your hot nail trick does not do something. I am not going to waste my time as I have a leaking stock master cylinder and I want to maintain the stock look and I understand the principles at play here.

I already know the benefits of increasing the hydraulic ratio on a Commando race bike using a Magura master cylinder.

I already know the benefits of further increasing the hydraulic ratio by using a Lockheed AP racing caliper, Magura master cylinder and Norvil larger diameter brake together.

I have the 14" floating disc, ap racing caliper and braided hose etc and the brakes were very good but the feel at the lever was hard, it was hard to tell just how close you were to locking up until you found out the hard way. The rgm racing lever gives a greater mechanical advantage to sledgehammer the fluid through the tiny 40 thou hole but opening the hole to 160 thou gives the same affect using the standard lever. I don't think anyone is claiming that pressure at the pistons is increased, pressure will only rise once the fluid has finished flowing and altering the size of this hole alters the feel at the lever as the fluid shifts. Two identical systems one with and one without Hobots trick couldn't possibly have the same feel at the lever. It won't make a shit system any better but it does make a good system feel different at the lever, think of it like the 1,2,3 adjuster on modern sports bikes.