Author Topic: Braking news for 77-78 750F  (Read 3198 times)

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Offline scondon

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Braking news for 77-78 750F
« on: October 05, 2005, 08:09:34 PM »
    Or maybe not, but it was certainly news to me. I put the dual piston front brake calipers from a '79 DOHC 750 on my '78 750F last week. Had to swap the mounting brackets as well. A straight bolt on affair with no mods needed and they work with the '78 brake discs. The '79 brake pads don't contact all of the disc, about 1/2" closest to the hub does not get used due to the smaller pads, but this has not been a problem.

    The "new" 836 motor with a hot cam was giving me the willies coming up on the turns until I made this swap.

     YeeeeeHaaaaww :) :) :)
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eldar

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Re: Braking news for 77-78 750F
« Reply #1 on: October 05, 2005, 08:50:50 PM »
can you write up some kind of instruction for this? Sounds easier than a dual disk.

Offline mick750F

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Re: Braking news for 77-78 750F
« Reply #2 on: October 05, 2005, 09:01:09 PM »
    Or maybe not, but it was certainly news to me. I put the dual piston front brake calipers from a '79 DOHC 750 on my '78 750F last week. Had to swap the mounting brackets as well. A straight bolt on affair with no mods needed and they work with the '78 brake discs. The '79 brake pads don't contact all of the disc, about 1/2" closest to the hub does not get used due to the smaller pads, but this has not been a problem.

    The "new" 836 motor with a hot cam was giving me the willies coming up on the turns until I made this swap.

     YeeeeeHaaaaww :) :) :)

  Hmmm...So you're noticing a significant difference in braking eh? Wish I knew that before I rebuilt my front brakes. I know the rotors from '78 to '79 are the same diameter and that they are the same distance/height from the hub. But your pads don't fully contact the rotors at the inside? Are the pads beyond the rotor at the outside edge or are they making full contact and just not covering the entire rotor? Inquiring minds would like to know... :D

Mike
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Offline mick750F

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Re: Braking news for 77-78 750F
« Reply #3 on: October 05, 2005, 09:04:38 PM »
can you write up some kind of instruction for this? Sounds easier than a dual disk.

Yo eldar...It's a dual disk to begin with being an "F" model. Sorry, you don't get off that easy. ;D

Mike
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eldar

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Re: Braking news for 77-78 750F
« Reply #4 on: October 06, 2005, 07:42:39 AM »
But it would not HAVE to be a dual disk huh huh. Only one side would need to moded. So there! :D

Offline mick750F

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Re: Braking news for 77-78 750F
« Reply #5 on: October 06, 2005, 08:30:40 AM »
But it would not HAVE to be a dual disk huh huh. Only one side would need to moded. So there! :D

Okay you weaseled out of that one. ::)

Mike
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Offline scondon

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Re: Braking news for 77-78 750F
« Reply #6 on: October 06, 2005, 08:45:27 AM »
Are the pads beyond the rotor at the outside edge or are they making full contact and just not covering the entire rotor? Inquiring minds would like to know... :D
Mike

   The pads do not go beyond the rotor edge. They contact the same distance from the outer edge as the stock calipers.

    My brakes were never very good for some reason. New pads, new-ish rotors, rebuilt MC, steel braided lines, nothing seemed to improve them. Until this.

can you write up some kind of instruction for this? Sounds easier than a dual disk.

   Remove brake line from caliper. Unfasten the two bolts holding caliper/bracket to fork. Remove and replace caliper/bracket. Re-attach brake line. Bleed brakes, RIDE! :) :) :) :) :) :) :)  Truly a bolt-on affair.

  Sadly, I'm not sure that it would work on a K or early F 750 without some tricky modification. The 77-78 750F calipers mount BEHIND the fork. Not sure of any differences in spacing for the mounting bracket so it may be possible.
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Offline MRieck

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Re: Braking news for 77-78 750F
« Reply #7 on: October 06, 2005, 10:14:02 AM »
How's that engine running Sean? It should be breaking in about now.
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Offline scondon

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Re: Braking news for 77-78 750F
« Reply #8 on: October 06, 2005, 10:52:23 AM »
How's that engine running Sean? It should be breaking in about now.

     Engine's running great, Mike :) I've been fiddling about with the jetting and air intake, doing just about everything BUT dismantling the carbs to change the needle clip position. I've gone down to what I believe are 114 mains( odd size I know, but that's what's stamped on'em ). I could probably go down to 112.5 or even 110 without running lean. The engine really starts pulling around 6500rpm, but I'm still running a bit rich between 4000-6000. I only notice it when going up an incline in 4th and 5th gear. I put the airbox on to see if it might smooth out the midrange (K&N filter inside) but it ran hopelessly rich even with the 114 mains.

     I asked at the shop where I got the Kerker and they couldn't get competition baffles for it(they weren't in the catalogue). Where can I get one and will it affect my jetting choice?

    I've put 500 miles on the engine and this weekend I'm putting in a new clutch and changing the oil. I plan to see just how fast this thing can go :)
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Offline MRieck

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Re: Braking news for 77-78 750F
« Reply #9 on: October 06, 2005, 04:45:56 PM »
I'll check on the baffle. The med comp will reallly help. the large comp is even better! ;)
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Offline Terry in Australia

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Re: Braking news for 77-78 750F
« Reply #10 on: October 07, 2005, 05:18:14 AM »
Those Honda twin "side by side" piston calipers are good for our old bikes because it's hard (but not necessarily impossible) to mount decent modern 2 or 4 (or even 6) piston opposed piston calipers due to the narrower clearances between forks/discs/wheel etc, these modern brakes of course are "state of the art" compared to the ol' single puck calipers that came with our bikes. Also, being a "bolt on" conversion, it's good for guys with no access to machine shops etc, and affordable too, as they're not really sought after items as such.

Having said all that, a well set up pair of F2 calipers feel like heaven on a stick compared to all the other horrible SOHC-4 brakes. My Suzy GS1000S has the same OEM calipers (Tokico supplied all the jap bike manufacturers) as my F2 and I've hauled it down from 145+ Mph speeds with confidance, and that's with the spongy old rubber brake lines. It's one of those things that has always felt so good, I just have never bothered changing them, they work, so they stay.

Well done Sean for bringing it to our attention mate, and good to see you're getting out on your "beast", too! It's supposed to rain here tomorrow, but if I can sneak out I'll try to get some miles under at least one of "the fleet", ha ha! Cheers, Terry. ;D   
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Offline mick750F

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Re: Braking news for 77-78 750F
« Reply #11 on: October 07, 2005, 06:00:37 AM »
   Does anybody know if we're limited to just the '79 DOHC calipers for the bolt-on application? I know Honda changed some things after '79 but my knowledge of the DOHCs is pretty limited. It would widen the search if the '80-'82s worked as well. 

Mike
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Offline Terry in Australia

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Re: Braking news for 77-78 750F
« Reply #12 on: October 07, 2005, 06:13:58 AM »
   Does anybody know if we're limited to just the '79 DOHC calipers for the bolt-on application? I know Honda changed some things after '79 but my knowledge of the DOHCs is pretty limited. It would widen the search if the '80-'82s worked as well. 
Mike

Yeah Mike, they will, that style of caliper was the standard for honda thru the '80's, even the first CBR1000 used a similar caliper. Cheers, Terry. ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline mick750F

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Re: Braking news for 77-78 750F
« Reply #13 on: October 07, 2005, 07:04:47 AM »
   Does anybody know if we're limited to just the '79 DOHC calipers for the bolt-on application? I know Honda changed some things after '79 but my knowledge of the DOHCs is pretty limited. It would widen the search if the '80-'82s worked as well. 
Mike

Yeah Mike, they will, that style of caliper was the standard for honda thru the '80's, even the first CBR1000 used a similar caliper. Cheers, Terry. ;D

Thanks Terry...you da man! ;D

Mike
'
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