BSA B50 -500 APG Build

[wobblywalrus]

Tom, in reference to that rear brake problem you had, an article about fabricating a rear brake is in the current issue (August 2015) of "The Horse Backstreet Choppers."  According to the author "The last piece of engineering is very important and almost always missing on home made controls - the return spring.  The master cylinder has its own tiny inner return spring that helps push the brake pedal back, but it is not strong enough to keep the pedal from building a slight amount of pressure on the brake system.  Again, I take calls from customers who are having problems with their caliper locking up and 99.9 percent of the time it is because there is no return spring on the brake lever."

[Koncretekid]

Tom, in reference to that rear brake problem you had, an article about fabricating a rear brake is in the current issue (August 2015) of "The Horse Backstreet Choppers."  According to the author "The last piece of engineering is very important and almost always missing on home made controls - the return spring.  The master cylinder has its own tiny inner return spring that helps push the brake pedal back, but it is not strong enough to keep the pedal from building a slight amount of pressure on the brake system.  Again, I take calls from customers who are having problems with their caliper locking up and 99.9 percent of the time it is because there is no return spring on the brake lever."

Bo,
That return spring makes a lot of sense on a foot operated rear brake master, because the pedal is typically relatively long and heavy and gravity would cause it to fall.  I am using a front brake master which is an aftermarket copy of a GSXR master.  Gravity in this case does not adversely affect the handle and it seems to return quickly.

These are my 2 cents about slight drag on calipers. There are 2 tricks I use. One being that I back off the mounting bolts 1 full turn then safety wire both bolts. the other is on dual caliper style, I use springs on the pad mounting poles. This will reduce drag as well. However I do this on my Dragbike for 1/4 mile sprints, but works well.

Marty,
Good tips and thank you.  I was going to try to fit some springs or probably small pieces of rubber on the pins between the pads, but the design of the late model Kawasaki caliper would not make that easy.  I had the rotor turned and there is not much drag.  If I back off the pads manually, I can reduce the drag to zero, but I then have to pump the handle three times to get my brakes to grab, which is not something I was comfortable with at Loring from 150 mph.  Now at Bonneville, I'll use this trick, as I have 2 miles (usually!) to slow down.

Tom

Tom

[Old Scrambler]

Tom...........we are both getting older and smarter.............but will have to wait another 12-months to let the world know about it

[Koncretekid]

After a 3 month hiatus from the Bonneville Bike, now just, "Landspeed Bike", I have returned to Nova Scotia and unloaded the bike from the trailer where it was loaded up, ready to go, when I went to Colorado in August.  After watching the Colorado Mile event, I decided I might want some front brakes if the Salt doesn't heal quickly.  I don't need front brakes in Loring until I reach 175 mph, so that is not an issue.

  The forks on my bike are from an early disc braked GS Suzuki while the wheel is off a later XJ650 Yamaha.  While in Colorado, I picked up the correct disc and caliper from an XJ and a left handed remote reservoir brake/clutch handle off eBay. Obviously, the caliper would not bolt directly to the GS forks so I spent one day measuring and drafting up a bracket and another day milling it on my manual Rong Fu mill drill.



Today I fit it all together and it seems likely to work (brake line not hooked up) but there are problems.  The first is that the wheel will not slide into the caliper with the caliper in place.  I don't know if this is due to narrower forks or possibly I narrowed up the front wheel at the disc mount (can't remember!) when I fitted that wheel.  So the wheel must be installed and then the caliper.  but then I can't install the front fender which not only must bulge out about 3/4" to clear the caliper, but does not allow the caliper to be installed after the fender is in place.  The only way I can see to do it is to cut most of the back of the left side of the fender away to be able to install the caliper.


View from inside the fender with the caliper in place, but the wheel won't slot into the caliper.



Outside view showing no access to caliper bolts with the fender in place.

Another issue is that of fitting both a clutch handle and the brake handle on the same handlebar and be able to operate each separately and be able to turn the bars without contacting the fairing.  And then there's the issue of routing the brake cable thru the front of my fairing which is now completely closed off.
 


So if I can manage to get both those controls to work separately, or possibly revert to a rear foot operated rear caliper to free up the right handlebar for the front brake, I can probably make some runs without the front fender or purchase another fender and cut the heck out of it.

Here's hoping the Salt will heal SOON!

Tom

[Frank06]

Tom, have you considered swapping fork tubes side-to-side so the caliper would be on the front?  I've done this (in reverse) with my old triples.

[Koncretekid]

Tom, have you considered swapping fork tubes side-to-side so the caliper would be on the front?  I've done this (in reverse) with my old triples.

Good idea.  I don't see why I can't do that and it might give me enough extra fender clearance although looking at my first  and third photo, the caliper would still be under the fender.

[Old Scrambler]

Tom...........could you 'hang' the caliper at 5-o'clock?

[wobblywalrus]

The double leading shoe brake from an old Honda 450 or 350 might work nice if you cannot get the disc setup to fit. 

[sofadriver]

Now that we'll probably need to run a front brake, I'm facing the same problem with levers.

My rear disc is rule compliant but so small that it's pretty much useless.  The front is a 12" floating disc.  My master cyl. is from a Suzuki  GSXR 750 so it's got more than enough volume and power to work both discs at once so I'm going to tee the brake line and operate both discs with it.  With the pads backed off the discs it might take a lot of pumping to get any stopping power but we'll see.  That GXSR master can move a lot of fluid.

Besides, REAL men don't use brakes. 

[Koncretekid]

The double leading shoe brake from an old Honda 450 or 350 might work nice if you cannot get the disc setup to fit. 

I could do that Bo, but after converting to cast wheels for their better quality, I hate to revert back.  I actually have both a Honda 350 spare complete wheel, and a real nice Honda 450 brake laced to an Excel rim on a Bridgestone race bike I built.

Tom...........could you 'hang' the caliper at 5-o'clock?

Dennis,
 Heck I just spent two days making that bracket and I don't feel like doing anything else at 5:00 except opening up a cold bottle of suds!

Now that we'll probably need to run a front brake, I'm facing the same problem with levers.

My rear disc is rule compliant but so small that it's pretty much useless.  The front is a 12" floating disc.  My master cyl. is from a Suzuki  GSXR 750 so it's got more than enough volume and power to work both discs at once so I'm going to tee the brake line and operate both discs with it.  With the pads backed off the discs it might take a lot of pumping to get any stopping power but we'll see.  That GXSR master can move a lot of fluid.

Besides, REAL men don't use brakes. 

I am using a Chinese copy of a GSXR to power my rear brake and if I back off the pads a bit, it takes two pumps to get the brakes back.  Using it to power both brakes might work, but at Loring they have made a new rule that for bikes over a certain speed, two master cylinders are required (rule change after Bill Warner's catastrophe.)  That doesn't affect me, but I don't know if any of the mile events have this rule or not.

"Besides, REAL men don't use brakes."  I tried that at Bonneville one year when I changed sprockets and forgot to adjust the brake.  Of course I didn't realize this until I had drifted about 100 yards past the 5 mile and they had to come get me because my right foot got stuck behind the shifter trying desperately to downshift!

Tom

[Koncretekid]

For those of you who haven't seen this under the Loring posting, I modified my transmission last week.  The work begins in ernest this weekend, if the parts come in.
Tom

[Calkins]

Oh Sh!t!!!


Are you planning on go to Speed Week?  We will be there.

[Koncretekid]

Oh Sh!t!!!


Are you planning on go to Speed Week?  We will be there.

No, Loring and BMST only, due to my schedule.  Good luck with yours.

[Rex Schimmer]

Tom,
I do have to say, Tom, that your tranny mod is unique and the removal of the side "cover" is interesting but I do see a challenge to its replacement.

How fast were you going when you decided to do the "modification"?

Rex

[Koncretekid]

Tom,
I do have to say, Tom, that your tranny mod is unique and the removal of the side "cover" is interesting but I do see a challenge to its replacement.

How fast were you going when you decided to do the "modification"?

Rex

That's not just the side cover, Rex, it's the main engine cases, as this motor is the later "unit motor" with the transmission in the cases.  I wasn't moving.  I had just started it on the roller starter and reached over to pull the transmission back into neutral but I pulled too hard and it caught 1st gear (without pulling in the clutch). Odd though that it took out a tooth on the layshaft as well as two teeth on the mainshaft without taking out the shifting dogs (constant mesh gears.)  Those broken teeth jammed between the two shafts forcing the layshaft down which broke the cases. 

Replacement requires new cases (now getting rare $$) as well as sleeve gear and layshaft.  Expensive mistake on my part.

Tom