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Scared of locking up your front brakes?

Discussion in 'Technical and Troubleshooting Torque' started by Loz, Jul 14, 2008.

  1. I've got a device I really should test for the mag, but I have no real desire to fit it to my bike. I've put it off for too long and thought I might see if anyone's interested.

    It's one of these: http://www.tcbbrakesystems.com/

    Effectively according to the manufacturer it provides a bit of flex at the limits of braking to allow the pads to slip over surface irregularities on the discs instead of gripping and locking the wheel. The effect is supposed to be that you can brake harder without skidding the front wheel.

    Why don't I want it? Well, I practice hard braking all the time, and I use such sticky tyres that I don't think I can remember a single time when I've lost the front under braking. The bike stoppies well before it feels like slipping. I'd get very little benefit from this device if it works like it says it does.

    So here's the offer; I'd like to test the unit on a bike that DOES slide the front under hard braking - I'd imagine this would include most cruisers, 250cc bikes with long-wearing tyres, that kind of thing. Cruisers would probably be preferable, their rearward weight distribution gives the front tyre a hard time under heavy braking 'cause there's no way the rear will come up. I believe it has to be a japanese bike because of the thread size of the unit I've been given.

    If anyone's willing to be a guinea pig for this gear test, and let me test the braking of your bike before and after fitting, take some photos etc - then you're welcome to keep the TCB unit afterwards, they sell for a hundred bucks or so IIRC. We'll fit and test it at a spanner night, and if you don't like the effect I'll take it off and put your bike back to stock.

    My expectation is that the brake lever will feel a bit more progressive, rather than the quick bite and grab that sportsbikes tend to aim for, and that you'll be able to grab the brake harder with a bit more confidence, particularly if you feel your front brakes are a bit full-on. If it feels at all dangerous to me when I test the thing, we'll yank it off and piff it ceremonially into the bin before it has a chance to cause you any danger.

    I've had this thing since January and I really should write it up with a full and honest review using it on the type of bike it's designed to help. We'll bleed your brakes before both tests so we can be sure we're testing your brakes at their best.

    Anyone interested? Feel free to ask any questions.
  2. Hmmmm tempting, kinda think i'd make a good guinea pig too.

    2001 FZ1, recently lowered 20mm, front adjusted, feels like totally different bike. Much appreciation to Hi Octane Motorcycles Thomastown for the work.

    Recent massive change in riding style due to badly injured right leg, now much more reliant on front brake operation, now much more nervous over front brake operation. Did a slow run down the spur a cuppla weekends ago and was not confident with the front on several of the tighter corners.

    Waddya reckon, fit your bill for a test ?
  3. Interesting concept. I've actually seen an amateur variation on this where an oversensitive and overenthusiastic rear brake on a special was tamed by introducing a minute quantity of air through the bleed nipple, using a small syringe. It was surprisingly effective, so this might actually work.

    Can't help with the testing though (although the Ural, as a machine where locking the front can be tested in complete safety, has a certain appeal).
  4. Interesting. I'd say the best way to improve your trust in a bike like that would be to fit a sticky front tyre. Does the front brake feel too grabby? Could it be that your forks are too sloppy instead?

    At the moment the front-runner is probably Envy-t with a Bandit 250 that's had a few front wheel slides under brakes, unless somebody's got a cruiser. But I'd be happy to check your FZ1 out and see if I can find any brake issues if you can get it down to a spanner night.
  5. Hmm yeah the issue with air is that it tends to contain moisture, which can then be heated to boiling point under sustained hard braking, at which point it all goes haywire. This jigger adds a bit of flex but without the air in the fluid.

    This sort of system is apparently used on aircraft landing gear, where the wheels are pretty much solely used for super-hard braking. Still sounds like "spongy brakes" to me but I'm interested in testing it. And yeah, a trike would be perfect. Pity!
  6. They're very effective units. This sort of device was very popular in cars in the 70's/80's.
    It works by softening the pressure spike you get in an hydraulic braking system when the wheel locks up.
    You won't get spongy brakes, teh pressure diaphragm is set to move at something like 700-900 psi, so they only work at close to teh limits of the hydraulic system.
    Early ones designed for cars were adjustable to a degree on teh pressure point at which the diaphragm would start moving.

    Regards, Andrew.
  7. Would the unit work on hard packed dirt roads? May be as an idea? I'd be more then happy to test a unit, however with a single disc and a grippy front, I rarely lock up the front on biatch-u-men unless I'm meaning too. Too much respect/too scared of the damage bill. (Dirt roads are another story :wink:)
  8. We tested the system last night... Sorry, should have updated this thread...

    Envy-t's still got the thing on his Bandito 250, and can't tell any difference from stock either. I didn't feel like I could stop it harder with the jigger on. Photos (hopefully) and a full bikergene review to follow in the next week or so.