Topic: i thought you couldn't lock up the front brakes on an SOHC...

[paulages]

last night i was taking my 550 around the block as a comparison ride from the 450 i've been restoring. i was two blocks from my garage, and had gunned it for the short block i was on. the roads were wet from a recent rain, so i took it easy around the corner. approaching the stop sign, i braked...and the front end locked up (going at least 40MPH). next thing i know, i'm skidding across the pavement with no leather and no gloves, and my bike is grinding through the intersection on its left side. i jump up and run to check on the bike (first thought of course).

pulled it upright and rode it back to the shop. left bar-end mirror sheared right off, stator cover demolished but not leaking, and the left turn signal is smashed. none of these are really  a big deal, but the left clip-on contacted the tank and left a little dent. 

moral of the story: dual disk brakes on wet surface will lock up.

[paulages]

What happens when a disc brake is engaged, is it uses the friction of the rubber and the pavement to reduce lock up.  Wet surface decreases that friction, therefore all brakes will lock up easier on wet surfaces.

Always gear up when riding in poor weather, it increases your chances of an accident occurring.  Also, don't brake in your corners, brake before them.  Braking in corners only increases the chance of front end or back end squirreling out.

Glad you're okay!  Bikes can be fixed!

yeah, thanks WT. i know how they work, i just think you'll find that most people around here couldn't make these old brakes lock up no matter how hard they tried. it was obviously the wet surface. thanks for sharing your advice though--i do know how to corner pretty well. i wasn't cornering when i laid it down. i was going dead straight when it locked up. my mistake was just grabbing too much brake on a wet surface.

[scondon]

 Sorry to hear about your tank, Paul. Glad you're ok

  As soon as the wet season hits, the intersections and on ramps become a scary place for gunning or braking. Cars sit at intersections and then gun it and on on ramps they go from slow to fast in short order. A bit more oil is deposited in these areas than most other places on the roads. And watch out for the wet crosswalks and direction arrows

  Not direct advice to you,Paul, just a general reminder that it's that time of year again

[paulages]

Sorry to hear about your tank, Paul. Glad you're ok

  As soon as the wet season hits, the intersections and on ramps become a scary place for gunning or braking. Cars sit at intersections and then gun it and on on ramps they go from slow to fast in short order. A bit more oil is deposited in these areas than most other places on the roads. And watch out for the wet crosswalks and direction arrows

  Not direct advice to you,Paul, just a general reminder that it's that time of year again

yeah, the frustrating thing is that i had just done a really fun and windy ride the day before (bull run for you portland people), and with all the leaves and wet patches had taken it pretty easy. it's always when you don't think you need to be worrying that something happens, which is a good reminder that there is never a time when riding to let your guard and level of perception down.

[andy750]

Good advice on keeping your guard up when least expect and especially now with the wet roads/leaves/gas puddles everywhere 

recent example here in Mass....last Sunday 3 of us were riding sharp twisty backroads in Rhode Island and gunning it round the corners (dry, sunny, cold day so no wet leaves )...Im in the middle of the 3 and we take a sharp blind corner only to see about 10 meters of sandy, unsurfaced pavement on the other side. Scott (S-dog) in front brakes hard, I brake and aim for the center and cruise through, hear squealing of brakes and Ben (Azuredesign) behind me locks up the rear and runs off the road. No one went down and no bikes damaged but could have been a lot worse.

Keep alert!
cheers
Andy

[mlinder]

Your hands ok, Paul?
No gloves? Ow.
Everything ok?

[scondon]

Sorry to hear about your tank, Paul. Glad you're ok

  As soon as the wet season hits, the intersections and on ramps become a scary place for gunning or braking. Cars sit at intersections and then gun it and on on ramps they go from slow to fast in short order. A bit more oil is deposited in these areas than most other places on the roads. And watch out for the wet crosswalks and direction arrows

  Not direct advice to you,Paul, just a general reminder that it's that time of year again

yeah, the frustrating thing is that i had just done a really fun and windy ride the day before (bull run for you portland people), and with all the leaves and wet patches had taken it pretty easy. it's always when you don't think you need to be worrying that something happens, which is a good reminder that there is never a time when riding to let your guard and level of perception down.

   Yes, the backroads are beginning to look that way around here too. Simple to remember to take it easy when the road is covered with pine needles, acorns, leaves, branches, and disturbed bits of hillside, but it's my daily commute that brings up the most trouble. Those four wheel things can recover from loss of traction better than my two wheels so I have to change my habits this time of year and just back waaaay off of everything. Hard to do when the bike pulls so well

   I was reading your list of damage to your bike and thought the same thing....Smashed mirrors, no sweat. Wasted turn signals, no problem. Busted stator cover, I can deal. Dented tank.............Nooooooooooooooooo!!!!!!!  Hope there's a good replacement or fix in your near future

[bill3749]

Oh, I know if you are really stupid you can lock the front on a 78 K8 cause I almost dumped myself in my own drive right after I rebuilt the front caliper, new EBC pads, and new braided stainless line. Decided to try'em out so did the hit it in first gear and jerk the lever. Managed to catch it cause I was only going about 15mph but had one of those fleeting moments of terror. Finally figured the jerk was on the bike.

[Short Round]

I've locked up my single front on dry pavement.  Scared the crap out of me.....Chris

[754]

I didnt have any trouble getting mine chirping and hopping at at 50mph.. Stock, drilled discs, -3 lines ..same as on my red chopper..

 Now wet.. be really easy..

[FunJimmy]

Glad to hear that you're in one piece Paul.
Sounds like a reason to pour a Blitzkrieg Hop!
Pretty much everything sounds like a good reason for a brew though.

Cheers

[paulages]

Glad to hear that you're in one piece Paul.
Sounds like a reason to pour a Blitzkrieg Hop!
Pretty much everything sounds like a good reason for a brew though.

Cheers

funny you mention the blitzkreig hop... i'm carbonating my latest batch and trying it for the first time here in a few hours! good reason not for a brew: going riding.



fall comes a little later here in the pacific NW, so we're just getting our major leaf drop now. i'm generally scared of wet roads, so regardless i scale back my riding when this weather sets in. we actually get plenty of mid-winter riding days here, but i try and plan that time period to do my major projects. i think this was the excuse i needed to go on and pull my 550 for the road and prepare it for the hotrod engine. lot to do there...

[Soos]

last night i was taking my 550 around the block as a comparison ride from the 450 i've been restoring. i was two blocks from my garage, and had gunned it for the short block i was on. the roads were wet from a recent rain, so i took it easy around the corner. approaching the stop sign, i braked...and the front end locked up (going at least 40MPH). next thing i know, i'm skidding across the pavement with no leather and no gloves, and my bike is grinding through the intersection on its left side. i jump up and run to check on the bike (first thought of course).

pulled it upright and rode it back to the shop. left bar-end mirror sheared right off, stator cover demolished but not leaking, and the left turn signal is smashed. none of these are really  a big deal, but the left clip-on contacted the tank and left a little dent. 

moral of the story: dual disk brakes on wet surface will lock up.

I dunno about you other dual disk riders, but I have only once locked up my front tire.
But i'm using '79cb750 DOHC calipers, and a MC from a KZ1000.
Even on dry ground i can lock mine up(with a mighty grab mind you).

Not something i would suggest though.
I was lucky and didn't loose it, although i did end up with my front tire about 12 inches off the bumper of a truck that blew a tire and hit the curb ahead of me.


Glad to hear you are ok.....

l8r

[azuredesign]

dual disk brakes on wet surface will lock up.

Hey Man,
I'm glad to hear you're alright as well! While I don't mean to minimize the most traumatic,( glad it wasn't too traumatic) part of your post, your misfortune brought to mind an interesting thought: can dual front discs be a detriment rather than an improvement on the SOHC bike?

Wet weather and front brakes into a turn are tough no matter what, but I wonder if sensitivity of front brake metering suffers with duals. It kind of makes sense to me that duals increase front wheel weight and front suspension needs to be stiffer to compensate for increased dive effect. Is it harder to " feel" where front brake lock up is with a dual brake set up on our bikes?

[754]

Where did you get the idea that they could NOT lock up??
Riding any bike even with single disc with that thought is asking for it.

[paulages]

Where did you get the idea that they could NOT lock up??
Riding any bike even with single disc with that thought is asking for it.

i'm exaggerating when i said "couldn't" lock up. i read somewhere (one of those "cb750" books  i think?) that they intentionally made the cb750 disk mushy, so that people coming from drum brakes wouldn't be sending themselves over the handlebars left and right. in any case, no matter how good your stock system is set up, it doesn't brake anything like a modern multi-pot caliper does. on dry pavement, i know exactly where the threshhold of my braking system is, and correspondingly how late i can brake before a curve. when i ride with friends on modern bikes (my friend garrett's cbr F4-I for example), this threshold becomes really obvious in really tight twisties. usually i can grab a pretty decent handful of brake and give no thought to locking up, and my brakes stop WAY faster that all of my other bikes with stock setups.

[turboguzzi]

grab your front brake real quick, there will be no time for transfer of weight to the front wheel and you can almost lock it at will. Touching the rear a bit before applying the front will transfer more weight to the front wheel and is a good way to avoid locking. At least that's what they say at the advanced riding course I took.

TG

[azuredesign]

Touching the rear a bit before applying the front will transfer more weight to the front wheel and is a good way to avoid locking. At least that's what they say at the advanced riding course I took.
TG

That's interesting to hear, as I've been doing it by instinct as long as I can remember without knowing why. I've locked up the rear plenty of times, but never the front. I have had the front end slide out on me a couple of times, and certain bikes like my old GS 1100 seemed to want to understeer, both not great feelings IMHO!

[MoTo-BunnY]

Glad to hear that you're in one piece Paul.
Sounds like a reason to pour a Blitzkrieg Hop!
Pretty much everything sounds like a good reason for a brew though.

Cheers

funny you mention the blitzkreig hop... i'm carbonating my latest batch and trying it for the first time here in a few hours! good reason not for a brew: going riding.



fall comes a little later here in the pacific NW, so we're just getting our major leaf drop now. i'm generally scared of wet roads, so regardless i scale back my riding when this weather sets in. we actually get plenty of mid-winter riding days here, but i try and plan that time period to do my major projects. i think this was the excuse i needed to go on and pull my 550 for the road and prepare it for the hotrod engine. lot to do there...

'blitzkreig hop' is a GREAT name for a brew. . .lol. .. .especially if you 'wanna be sedated' 

I was able to ride year round last year, save for a few weeks when it was cold and wet enough to have black ice potential.. .yikes! Also, wet leaves in the corners, along with gravel, are the worst. . .

 .. .I have a full gore-tex rain suit that really helps with riding in NW winter. The biggest thing though, are these neoprene diver gloves I got off of feeBay - without those my hands just go numb in cold weather - NO other glove combination works like the diver gloves under my leather gloves.

Sucks to ride when its cold and wet but my CB is my daily driver, along with my mountain bike. . ..  . . lol

[754]

I call them daily rider.. but then I never knew how to drive a car till I was 21..

where in the PNW.. I am in the PNNW and I rode a few winters and Nov/Dec..

[paulages]

i'm in portland (think she is too). what is the "PNNW?"

[754]

AHh the part North of the 49th!!..

 actually not really on the Pacific..a little island got in the way

[MoTo-BunnY]

yup yup  . . .  Stumptown here too  (Portland, ORYGUN)..  .. scaring the locals since Sept., 2001  (moved from Michigan on Sept. 11 yeah, THAT Sep 11 - what a day to move out of my apartment to go across country)

I lived in Olympia WA in the early '90s being a riOt grrl in a couple bands and what not, hung out at Evergreen State - used to come down here a lot and ended up liking it way better than Oly so I (eventually) moved here after a hiatus back in Michigan to get my degree.

I wuvs it here. . .very kewl, funky, weird town - suits me well.   

[Quail "Owner of the comfortable k8"]

Yea we joke that the K8 is to fat and heavy to slide the front wheel but when it locks you feel the fool.  The worst habit I have is to over use the front thinking it won't lock.

[paulages]

I lived in Olympia WA in the early '90s being a riOt grrl in a couple bands and what not, hung out at Evergreen State - used to come down here a lot and ended up liking it way better than Oly so I (eventually) moved here after a hiatus back in Michigan to get my degree.

what bands? who knows, i might have played with you...