Topic: Long trips on the mini-multis: 350 and 400 four

[TwoTired]

In reading contemporary road tests of the 400, the testers talk about not being able to lock the front wheel.  I think it's a matter of it being a "ok" brake, but not a great one. 

True, it's not a great brake.  But, I used to have a CB400F and rebuilt the front brake with the SS lines.  Huge difference in brake feel and effectiveness.  Nearly dumped the bike when the front tire locked during testing.
My fault, really.  The 400 is a lighter bike than the Cb550 that I was used to riding. It takes a lot less pressure to lock the front tire on the 400 than on the heavier 550.

When you bleed the brakes try to visualize the hydraulic system high points.  That is where air bubbles will naturally rise to.  Position the bike so that these high points have an escape route to an exit.  Such as the master cylinder.  Given time for the tiny bubbles to meander, the brake will self bleed.
Cheers,

[Bob Wessner]

Just curious. I've seen a number of references to wheel lock-up as though it's a good thing. Since max braking efficiency is lost once a wheel locks, why would one want to? 

[csendker]

why would one want to?

True, you don't want to lock them up.  I think it's more a case of being able to lock up the brakes rather than actually doing it. Then you know you're getting the most out of them, rather than leaving some braking capability on the table from crappy lines or incomplete bleed.

[Bob Wessner]

OK, that sounds like a reasonable explanation. 

[cb650]

Lock up would depend on tire too.



            Terry

[martini]

I've done a few 400 kilometer plus trips on my 350 Twin. She cruises along quite nicely but passing can be a bit of a strategic exercise. I'd recommend a full face helmet - having learned a paiful lesson passing an open gravel truck! Have a great trip.

[GroovieGhoulie]

I'm getting a full-face this week.  My only concern is my "underpowered" front brake.  I'll be sticking to rural highways mostly, and there will be very few interstate legs.

One question:  why would running with large throttle openings cause the engine to heat up?  I'm not planning to tear ass, but I don't want any seals or gaskets to let go from heat.

[heffay]

i did nearly 300 miles in one day on my 350f a couple of years ago. (mind you, my cafe seat only has 1/2 inch of foam so it seemed like i rode all day!)  you're right, try to stay off the interstates... 80 miles per hour is not something that 350's and 400's want to do for extended periods. 

have you tried the ever simple brake cleaner? 

they way i like to figure if she's good for the "long haul"... how much riding do you do normally.  as my 350 hasn't been out from under the cover in months... i can't use it as an example.  so, the 7r is ridden almost daily, weekly riding accumulates about 100-400 miles, so when i want to ride to baja and back for spring break for a total 3-4000 miles that breaks down to 10-40 weeks of riding... let's average that at 20 weeks of riding packed into 10 days.  so, 20 weeks?
bike seems like it will run for the next 20 weeks... take it for the long haul.
bike doesn't seem like it will run for the next 20 weeks... better opt out.

[GroovieGhoulie]

That's an interesting perspective Heffay.

I figure I do about 100 or so miles a week (normally).  So 350 miles each way is 700 miles which is nearly two months of riding.  Hmm...Might think about it.

[cbjunkie]

IMHO a 350 is not a safe vehicle to ride on any interstate, anytime, anywhere. but... maybe i'm just a wuss...i got mine up on the local interstate here in st. louis one time and got swallowed up by the traffic, and it was night and it was my first time on the interstate - not smart move? i know! after about 10 miles i exited and rode home in peace on back roads.

i think it's the intimidation factor for me - the 350 was just too small and underpowered compared with even the wimpiest car on the road. and there is something nerve-wracking about having your bike wound out all the way all the time - hm...maybe i was just tired.

on the 750? totally different story. short of a driver being a deliberate idiot or asshat, the 750 is better than anything else on the road - i did 400+ miles the first time i ever sat on the ole girl - never broke a sweat and rode all day long.

junkie out.

[GroovieGhoulie]

My route would be a "scenic route" with rural highways and back roads.  There would be minimal interstates right when I got near my house.

The problem is the weak (to me) front brake.  Not as much of an issue when running around town at 30 or 40 MPH, but at 65+, it becomes a bigger issue.

I'm still considering it, but not as much.

[Uncle Ernie]

... yeah, the 350 is a tad underpowered.  A 400 would go all day no problems.  As far as braking goes- who brakes at 65mph?  If you have to brake that hard to make your exit, you'll stuff it on anybike or get whacked from behind.  Take the next exit.

[GroovieGhoulie]

... yeah, the 350 is a tad underpowered.  A 400 would go all day no problems.  As far as braking goes- who brakes at 65mph?  If you have to brake that hard to make your exit, you'll stuff it on anybike or get whacked from behind.  Take the next exit.

I meant more like panic stop.  I know to swerve, but sometimes you just gotta stop.

When I pull the lever as hard as I can, it gets rock hard about 1/2" away from the grip and the front tire will not lock, but sometimes chirps, like I'm getting 9/10ths or even 10/10ths braking and it won't lock.  I guess that's ideal, but I'm really amazed at the lack of stopping power.  Though with the back brake in action, it does stop with authority.

Of course I'm used to seeing my neighbor on his new CBR600 stop from 100 MPH in like, 12 feet.

[Mopar_Tony_SF]

One question:  why would running with large throttle openings cause the engine to heat up?  I'm not planning to tear ass, but I don't want any seals or gaskets to let go from heat.

Becasue you are making more power when you open the throttle more which puts more stress on the parts.  More power means quite literally more heat.  Also, when engine revs are increased, there is more crankcase pressure which stresses seals.

My 3K mile 400F has rock hard factory brakes and from expereince they are working 100%.  However, they seem to be way undersized in emergencies.  My 750 Kaw H2 runs about the same rotor diameter and similar clamping forces as my little 400F and on the H2 its real, real scary with the added weight, bigger tire and double the HP.  I do not know if anybody makes higher coefficient brake pucks for the 400F but this could help a little.  Increasing lever length is not going to do much as the piston area of caliper is unchanged.  Menaigful solution is dual discs or a much larger rotor and a more powerful caliper.

One thing to keep in mind, if you are running larger diameter tires your brake power goes down.  Smaller diameter brake power goes up.  I do not think this can be significantly changed on a bike with stock fenders.

[GroovieGhoulie]

But for a given RPM, throttle position shouldn't matter, right?

6500 RPM at half throttle versus 6500 RPM at 7/8 throttle shouldn't make a difference, I would think.

I'm not a small guy at 5'11" and 190lbs (losing it, getting down to 170), and I've got to be on 3/4 or better throttle in top gear for anything over 65.

[cb650]

What work have you done to your brakes?   I think they are mostly the same as my little twin and on it if I was more daring I think I could do a stoppie.  Its all stock just rebuilt.  Your bike might be a little heavier but not too much.  




                            Terry

[GroovieGhoulie]

What work have you done to your brakes?   I think they are mostly the same as my little twin and on it if I was more daring I think I could do a stoppie.  Its all stock just rebuilt.  Your bike might be a little heavier but not too much.   




                            Terry

Fresh fluid and pads and bleed.

The rotor needs to be turned as there are some grooves in it, but I don't know where to get that done (places around here only do cars).  Might just find a new rotor.

[cb650]

If the groves ar deep and many they cut down the braking surface.  Try a rotor.  Most bike rotors wherent meant to be turned.



          Terry

[heffay]

ok... heffay goes on rant... riiight... here.      brakesem smakesem!  i've never ridden my 400f (it's a really long project!) and I HOPE I NEVER HAVE TO HIT THE BRAKES!

does that help?... let's put it another way.  go on your ride!  your bike was built to be ridden.

 let's look at it another way shall we?...  1 mile per cubic centimeter?  hmmm... that's an odd comparison.  anyone make sense outa that one?

[supersport_CB400F]

The front brake was always crap, I done the journey on the map (the blue line) in 22.5hrs on my 400 mostly French Motorway, the guy with us on the K7 took 2.5 days 

[GroovieGhoulie]

ok... heffay goes on rant... riiight... here.      brakesem smakesem!  i've never ridden my 400f (it's a really long project!) and I HOPE I NEVER HAVE TO HIT THE BRAKES!

does that help?... let's put it another way.  go on your ride!  your bike was built to be ridden.

 let's look at it another way shall we?...  1 mile per cubic centimeter?  hmmm... that's an odd comparison.  anyone make sense outa that one?

I agree it's meant to be ridden and I'm gonna do it, I just am a little excited/nervous before my first cross-country ride and I want everything to be as perfect as I can make it.  I don't want something to fail because I cut a corner somewhere or I didn't work hard enough to maximize a system.

[ofreen]

6500 RPM at half throttle versus 6500 RPM at 7/8 throttle shouldn't make a difference, I would think.

Oh yes it does.

[GroovieGhoulie]

Well the pads must have bedded because on a test run tonight I grabbed a handful of brake at about 40 MPH and nearly threw myself over the handlebars.

I think it's ok.  It's just I gotta GRAB it to get it to do that, it won't do it when I gently caress the lever, which is kinda what I was expecting.  THough this is better as it allows easier modulation.

Combine with the back brake and it's gonna be fine.

[cbjunkie]

sh*t yourself?   

[GroovieGhoulie]

sh*t yourself?   

Nearly.

I was shocked actually.  Part of it was my test technique.  I squeezed the lever progressively every other time.  This time I just grabbed it as hard as I possibly could (like I would in a panic stop).......and then promptly let go 1/10th of a second later, a few shades whiter.

I take back everything I said about the 400's brakes.  They will work, you just gotta REALLY call on 'em.  Which is good, like I said, becasue it means normally you have an easy-modulating brake that is progressive and predictable, but when you grab the crap out of it, it'll show up.

I'm still gonna re-do the lines with SS however.

However, after a few stops it developed the "SOHC squeak".