Author Topic: CB400F bars and rear-sets on my CB500. A "how-to", of sorts.... (Read 13305 times)

dave500 · « **Reply #25 on:** May 14, 2011, 03:20:08 AM »

thats a very nice bike,i wonder what was the idea of that wire guard on the rear brake pedal?i would cut it off.

Scott S · « **Reply #26 on:** May 14, 2011, 03:40:39 AM »

Quote from: apex_seeking on May 13, 2011, 08:24:02 PM

What did you use to heat up and bend the brake lever?

A fellow forum member.

He used an oxy-acetylene torch. Your local welding shop should be able to do it for you.

Scott S · « **Reply #27 on:** May 14, 2011, 03:41:46 AM »

Quote from: dave500 on May 14, 2011, 03:20:08 AM

thats a very nice bike,i wonder what was the idea of that wire guard on the rear brake pedal?i would cut it off.

Yeah, like I said, the bend looks a little hokie to me. Maybe I'll take it off one day, remove the guard and dress up the welds.

Scott S · « **Reply #28 on:** May 16, 2011, 07:41:51 PM »

I took Kevin400F's suggestion and re-did the linkage so that the heim joints are on the same side. We had it welded back on.

Scott S · « **Reply #29 on:** May 16, 2011, 07:43:05 PM »

Quote from: Kevin400F on May 12, 2011, 04:40:42 PM

Scott, to re-gain the proper power and feel for the rear brake, drill a new hole in the brake actuating arm, closer to the pivot point, where the brake rod connects.

See picture below of the conversion I did on my '76 CB550K. (Pardon the grunge, its a rider, not a show queen.)

This one's still got me scratching my head, though....
I'm no engineer, but wouldn't the lower hole reduce leverage? I've been pondering this one for a couple of days now, LOL!

Kevin400F · « **Reply #30 on:** May 16, 2011, 08:51:57 PM »

Hi Scott, actually I am an engineer (but don't hold that against me). See the rudimentary diagram below. Dimensions are made up for sake of illustration and understanding

Suppose you have a 10 inch long brake pedal and you apply 10 pounds of pressure with your toe. If the brake rod attachment point is 2 inches from the pivot, you get 50 pounds of pull in the rod.

If you shorten your brake pedal to 5 inches and your brake rod is still 2 inches from the pivot, your 10 pounds of pedal pressure only gets you 25 pounds of force in the rod.

To get back to 50 pounds of rod force with the shorter pedal, you need to move the brake rod attachment point down to 1 inch from the pivot.

Scott S · « **Reply #31 on:** May 17, 2011, 05:24:07 AM »

Kevin, you may have just unwittingly helped me on another project. You have an email.

haill · « **Reply #32 on:** May 19, 2011, 05:21:43 AM »

does moving the brake arm rod postion down 1" in this diagram increase the travel distance of the brake peddle to apply the brakes?

Kevin400F · « **Reply #33 on:** May 19, 2011, 03:40:10 PM »

Yep, in the same way that the toe pad on the "twice as long" OEM pedal moved further than the toe pad on the shorty 400F pedal. Longer travel = more leverage.

Kevin

haill · « **Reply #34 on:** May 19, 2011, 04:27:35 PM »

thanks for getting back with the answer. have modified my rear brake arm when made some rearsets but have a limited amount of brake arm travel due to my exhaust being close. The rear brakes work, but if the brake arm travel is increased don't think it will work in my case.
regards keith

apex_seeking · « **Reply #35 on:** May 24, 2011, 08:29:03 AM »

Quote from: haill on May 19, 2011, 04:27:35 PM

thanks for getting back with the answer. have modified my rear brake arm when made some rearsets but have a limited amount of brake arm travel due to my exhaust being close. The rear brakes work, but if the brake arm travel is increased don't think it will work in my case.
regards keith

What is that kicker? It looks like it has an extra bend in it. Is that an from F?

haill · « **Reply #36 on:** May 24, 2011, 09:49:51 AM »

no it's a cb500 kicker just has been kerf cut then bent and rewelded to clear.

Scott S · « **Reply #37 on:** June 09, 2015, 05:04:33 PM »

Bumping this for my own reference.

straat-toe · « **Reply #38 on:** June 11, 2015, 02:07:29 AM »

Pretty cool thread.
Just found it now. I just happen to have 400 rearsets that need restoring just laying in a cupboard being useless and a 76 550K. mmmmm. Is it crucial to use the 550F kicker. Mine's a K. Doesnt the 400 footpeg flip up? 550F kickers are as rare as hens Teeth around these parts. I have looked for my other 550F.

Scott S · « **Reply #39 on:** June 11, 2015, 03:14:43 AM »

Yes, you have to use the 550F kicker to clear.

seanbarney41 · « **Reply #40 on:** June 11, 2015, 05:18:09 PM »

I think that the cb400f rearsets will work semi-easily on some other sohc4's...I will post my findings here

cosmicvision · « **Reply #41 on:** July 04, 2017, 09:03:44 AM »

Super cool thread, thanks for the tipoff Scott. Bump for great information. Planning to attempt this as soon as I source parts and can let the bike sit still for more than a few hours! Looks like a little more work than meets the eye but very worth it. A true Gentleman's Express mod!!

Cheers,
Josh

jamesk · « **Reply #42 on:** June 14, 2019, 10:03:21 AM »

Bringing this thread back from the dead to say thanks for the excellent idea! I picked up a set of front pegs from a 75 400f and am going to try this out on my 77 550f. I'll post a new thread with the results once I track down a shifter and linkage. Cool stuff!

Scott S · « **Reply #43 on:** June 14, 2019, 05:40:53 PM »

Quote from: Kevin400F on May 12, 2011, 04:40:42 PM

Scott, to re-gain the proper power and feel for the rear brake, drill a new hole in the brake actuating arm, closer to the pivot point, where the brake rod connects.

See picture below of the conversion I did on my '76 CB550K. (Pardon the grunge, its a rider, not a show queen.)

As a follow up, I tried this on the latest bike with 400F pegs and was NOT happy with the rear brake feel or performance. I feel like it works better and gets better leverage in the stock hole.

Scott S · « **Reply #44 on:** June 14, 2019, 05:42:25 PM »

Quote from: Kevin400F on May 12, 2011, 04:48:21 PM

Another thing you may want to consider is disassembling the Heim joint from the shift lever and moving it around to the outside. This gives the rod a more efficient, straighter push on the transmission shift rod link.

Substituting a slightly longer threaded rod lets you keep everything parallel for better efficiency and good range of adjustment.

And this, on the other hand, is definitely worth doing. I've never had to add a longer rod.

Don R · « **Reply #45 on:** June 14, 2019, 08:44:28 PM »

I like your process and result. did the JDM style headlight switch and parking lamp in the headlight on my 400F.

News:

Author Topic: CB400F bars and rear-sets on my CB500. A "how-to", of sorts.... (Read 13305 times)