gregforesi wrote:Sorry 5speed, but I missed your question.
Any front master with a 14mm piston will cure that "wooden" feel. I'm not sure on this, but I think the goldwing was the first high production machine with dual front discs, and maybe Honda was worried about too much brake in the front. I believe the stock 75 to 79 front masters were all 17mm. The "wooden" feel was partially addressed in 79 when the wheel caliper pistons got bigger. The 79 also had a rectangular front master reservoir (still a plastic reservoir) but I'm not real sure about the piston size on that one.
So if delinking an 1100 Interstate to have standard brakes then you're suggesting a 14mm bore on the master cylinder?
I cannot find a single answer to this question. 14mm, 16mm (5/8) to stop a naked GL1100 and get rid of the linked brake setup?
CYBORG wrote:14mm is the right answer for delinked brakes
And if we want to keep the linked brakes, but improve the feel of the hand brake, is 14mm still good, or something else? Already replaced the rubber brake lines with SS type, and new pads.
Many of us have un-linked our brakes because we feel safer being able to control the front & rear separately. Its less of an issue now because sidecar outfits rarely fall over but when my 'Wing was a solo I was thankful that I could apply the rear alone every time I left work to find that the road had been graded.
BTW: if you are going to un-link them I highly recommend finding a pair of calipers from something else that both have the same size pistons. When I first did mine the pads on the side with the smaller pistons always wore out faster.
I have a 1200 front end on one of my 1000's. and use a 14mm brake master, and it works great. And, of course, they are de-linked. Stops very well, and the lever is rock solid. Can't address the wear issue, but you are probably right
1978 custom GL1000
1977 custom with 1200 engine
1985 gl1200
Sidecar Bob wrote:I think a 12mm would be better for a single disc.
BTW: if you are going to un-link them I highly recommend finding a pair of calipers from something else that both have the same size pistons. When I first did mine the pads on the side with the smaller pistons always wore out faster.
Hmm, based on the shop manual both sides of the front wheel calipers should be 30mm diameter pistons. But I will keep it as is (linked) for the time being. So will be looking to see if a master cylinder with a 1/2 inch piston is available.
My '83 came with smaller pistons on the side that was linked to the rear than on the other side of the front or the rear. I believe that the so-called "proportioning valve" was merely a splitter and the piston sizes were the main means of making the front brake grab harder than the rear.
Sidecar Bob wrote:snip.................... I believe that the so-called "proportioning valve" was merely a splitter .
Correct
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1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
Mine is a 1983i model standard. I've just looked at the shop manual and it only lists 30.1mm as caliper piston OD. Doesn't specify which side.
It was recommended by Vintage Brake folks that a 11mm MC would do the trick (improve the feel/modulation). Although finding a 11mm MC is not that easy.
Yeah, the FSM (or at least the PDF version I have) does only list one size piston (30.148 - 30.198mm) for all of the calipers.
And the parts book calls for 43107-MA7-006 for both fronts and 45107-MB9-781 for the rear.
BUT when you look at the fiche in your favourite dealer's website it calls for:
Front
PISTON (LEFT SIDE) 43107-MA7-006
PISTON (25.4MM) (RIGHT SIDE) 45107-MB9-781
Rear
PISTON 43107-MA7-006
Iv bought and fitted a 14mm master cylinder to stop my gl1100 interstate. I have de-linked the brakes and fitted stainless lines and fully bled the system...but my lever is travelling all the way to the handlebars with virtually no resistance.
If you're getting no significant pressure, then you've got air in the lines somewhere, or the master cylinder isn't working properly. Did you 'pre-bleed' the master cylinder before installing the lines? Also, you may have had air work it's way up into the master cylinder even after bleeding. Check your fluid level... Sometimes it's the simplest stuff...
"I have no special talent. I am only passionately curious." - Albert Einstein
"He that is good with a hammer tends to think everything is a nail" - Abraham Maslow
"If you can't take the time to do it right the first time, how are you ever going to find the time to do it over?" -Unknown
In The Shed:
'81 gl1100I barn find aka "Josie, the farmer's daughter." (almost comatose build)
'77 gl1000, roller parts bike.
'82 gl1100I, 'Old Crusty' titled roller parts bike (free!)
'82 gl1100I, My first 'Wing, and an expensive lesson! New2U Bike? Read Me.
I thought I read on Randakks site that you should never use DOT 5 in these bikes regardless of whether you have a completely clean system and lines etc.
Maybe I am imagining that, yet there was something about how the original seals/parts are not designed to operate with silicone brake fluids?
Current Bikes:
1966 CL77 - Honda 305cc - Dual purpose - "Gentleman's Scrambler" was a period moniker.
1967 CL175K0 - Low production number with #802 engine serial- winter 2019/2020 full restoration.
1972 CB350F - Baby Four with low mileage - Cosmetic refresh to the next level 2021/2022.
1978 CB550K - Very original bike with only 7499 Km. from new - light cleanup and refresh done.
1983 CB1100F - Canadian model - DOHC Supersport in pristine low kilometre condition from new.
1984 GL1200 - Standard model in showroom condition - two owner bike from new.
1984 CX650E - Restored summer 2017 - a rare Eurosport model - excellent one owner bike.
flyin900 wrote:I thought I read on Randakks site that you should never use DOT 5 in these bikes regardless of whether you have a completely clean system and lines etc.
Maybe I am imagining that, yet there was something about how the original seals/parts are not designed to operate with silicone brake fluids?
I've had DOT5 in mine for 10 years.
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1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder