Brake modification

[02GF74]

I cannot say I have found the standard brakes (4 pot) lacking in anyway but the mod monkey won't stop jabbering and is making work for idle hands.....

So I have accumulated and cleaned up a pair of Sumitomo 6 pot callipers and R1 blue spot callipers (actually silver spot).

I also find the Vmax clutch lever is further out than I would like (and I don't have small hands!!) so have a set of after market adjustable levers and a set XJR1300 brake and clutch master cylinders which have 5 position lever adjustment. The brakes have a smaller bore to match the R1 blue spot callipers.

So there are quite a few combinations to fit, in order of preference

1. XJR1300 master with 6 pot callipers; the brake lever travel will increase (31mm to 35mm) - not sure that is going to be a problem
2. Vmax masters with after market levers, assuming they fit? and 6 pot callipers
3. XJR1300 masters with R1 callipers (100% compatability)

I would be fitting braided hoses so the position of the outlets on the masters and inlet on callipers may need longer than stnadard hoses.

Opinions and comments?

 

[desert_max]

Have you obtained or are you prepared to fabricate adapters for the calipers selected?

 

[Parminio]

The easiest way to go about doing all of that is @one2dmax. He puts together a kit with the Hyabusa calipers front and back with the adapters you need included.

 

[Fire-medic]

Plenty of already logged discussions on alternative Yamaha masters. The stock 5/8" bore works for R1 & R6 calipers. It will work w/the Sumitomos. On the prior threads is info on what years XJR's have what size masters. They differ.

I have 6 piston Sumitomos and R1's and currently am using the stock VMax 4 piston (dual opposed) w/SS braided brake lines and HH pads in front. They ride fine.

 

[MaxMidnight]

Initially I ran the R1's with the OE m/c and found it very wooden. Once the XJR's were installed I was very happy with the set up. Note that the banjo mounting on the R1's is 90 to the OE calipers so bear this in mind when getting the replacements.

 

[desert_max]

The easiest way to go about doing all of that is @one2dmax. He puts together a kit with the Hyabusa calipers front and back with the adapters you need included.

Exactly! I installed that kit on my ‘86 and I am very, very happy with it.

 

[02GF74]

thanks for comments - i did ask for it LOL ... but I was hoping they would be regarding the items I already have - not planning to spend any more, other than new pads/hoses plus buying from US is going to add around 30% for shipping and taxes etc.

 

[Screwloose]

I cannot say I have found the standard brakes (4 pot) lacking in anyway but the mod monkey won't stop jabbering and is making work for idle hands.....

So I have accumulated and cleaned up a pair of Sumitomo 6 pot callipers and R1 blue spot callipers (actually silver spot).

I also find the Vmax clutch lever is further out than I would like (and I don't have small hands!!) so have a set of after market adjustable levers

Can I ask you where you got the adjustable levers, I could not find any in the UK, and ended up heating and bending mine to better suit my hands. But i’m always wary of doing that and would prefer an adjustable set.

Appreciated if you had any info in the above.

 

[Fire-medic]

One of the well-documented things with aftermarket levers, whether adjustable or fixed, is that the hole for the rod inserting into the brake lever may not be drilled sufficiently, causing issues with proper brake activation. You can search for that. Just check out the free-play once you install the lever. If you have none, check out what needs modification, either grinding-down the rod, or drilling the lever hole for it, deeper. Ensure that you don't weaken the lever!

If Mr. Midnight would be so-kind as to gaze-upon the master cylinder, and read-off the bore dimension which normally is cast-into the body, then you will have additional information. However, he's apparently using R1 calipers, and you wish to use your three opposed pairs Sumitomos.

A prior thread on the issue will show a link to a chart which gives you ratio information based upon piston size & number of pistons, and that will help you to make an informed decision.

 

[desert_max]

Have you obtained or are you prepared to fabricate adapters for the calipers selected?

 

[02GF74]

Can I ask you where you got the adjustable levers, I could not find any in the UK.

Appreciated if you had any info in the above.

I noticed today that the brake lever has reach adjustment by means of a bolt a locknut, not as elegant as rotating dial but will do the job.

There is no adjustment for the clutch.

Right, getting back to your question.

The adjustable levers are chines ebay specials said to fit vmax but I believe that when I see it, for the time being they have gone AWOL - I was wanting to compare them to the XJR1300 ones as I was cleaning the masters.

I'll post back when they turn up. I will then have an idea as to what mods are required to fit the Vmax masters, removing metal = easy, adding it, not so.

 

[Fire-medic]

an idea as to what mods are required to fit the Vmax masters, removing metal = easy, adding it, not so.

Pics of changing the contour on a SOHC Honda 750 brake lever, to reduce what I perceived to be excess freeplay. Now, it's minimalized, and the front disc begins to bite sooner. Pic after adding weld bead, and before final contouring.

Pics:

setting up brake lever for adding bead
adding bead
contour template
removing stuck caliper piston of a SOHC 750 Honda hydraulically when an air hose won't
40 year-old mung removed from the caliper
bolloxed brake caliper mounting screw drilled out with a 'pillar drill' for removal (the English term)
fabricated tool to remove SOHC Honda brake master cyl piston
disassembled master cyl after piston removal tool use
cleaning brake master cyl bore w/a cordless drill and 220 grade sandpaper on a 3/8" ratchet extension

 

[user 16790]

I have silver spot callipers with early XJR master cylinder, works good enough for me even on my smaller early model discs,
I have aftermarket adjustable levers for the XJR masters which are ok but the original levers were more comfortable in use,
I had some after market adjustable levers for the standard Vmax masters but the clutch lever was further out on its 'closest' setting than the original lever, it was quite easy to modify to bring it closer in though, just carefully file away at the adjuster contact point

 

[MaxMidnight]

One of the well-documented things with aftermarket levers, whether adjustable or fixed, is that the hole for the rod inserting into the brake lever may not be drilled sufficiently, causing issues with proper brake activation. You can search for that. Just check out the free-play once you install the lever. If you have none, check out what needs modification, either grinding-down the rod, or drilling the lever hole for it, deeper. Ensure that you don't weaken the lever!

If Mr. Midnight would be so-kind as to gaze-upon the master cylinder, and read-off the bore dimension which normally is cast-into the body, then you will have additional information. However, he's apparently using R1 calipers, and you wish to use your three opposed pairs Sumitomos.

Mr Midnight has moved on and is using ISR m/c and six pot callipers. The XJR's have found a new home.
From what I can ascertain the V Max and XJR1200/R ('94-'97) and XJR1300 ('98-'99) m/c have the same bore size (15.9mm). The XJR 1300SP ('99) EU has a 14mm bore which is the sam as bikes that use blue spot style callipers so is the ones to use with this set-up.

For those who want to improve the feel or remove slop at the clutch lever the PDF shows the process involved. It may also work for the brake?

 

[Screwloose]

I noticed today that the brake lever has reach adjustment by means of a bolt a locknut, not as elegant as rotating dial but will do the job.

There is no adjustment for the clutch.

Right, getting back to your question.

The adjustable levers are chines ebay specials said to fit vmax but I believe that when I see it, for the time being they have gone AWOL - I was wanting to compare them to the XJR1300 ones as I was cleaning the masters.

I'll post back when they turn up. I will then have an idea as to what mods are required to fit the Vmax masters, removing metal = easy, adding it, not so.

I had a set of XJR levers and they were so far out of spec for my VMax I would have needed to do some welding, chopping and machining. I’ll have a look on ebay as mentioned and see if anything has changed since the last time I was looking.

 

[Fire-medic]

I had a set of XJR levers and they were so far out of spec for my VMax I would have needed to do some welding, chopping and machining. I’ll have a look on ebay as mentioned and see if anything has changed since the last time I was looking.

Screwloose, if I were you, I'd be looking for a 7/8" handlebar, 5/8" bore adjustable lever master cylinder. Maybe a L & R pair so they would be alike in appearance. My friend with a Hyabusa engined GSXR 1000 just bought some from China, and they appear to be fine in function, the adjustable levers offer a lot of range. The reservoir is on the small side, about the only thing I'd wonder about. Delivery was a few weeks.

 

[MaxMidnight]

Screwloose, if I were you, I'd be looking for a 7/8" handlebar, 5/8" bore adjustable lever master cylinder. Maybe a L & R pair so they would be alike in appearance.

Not if he is using the R1's as the lever ratio will be wrong.
The advantage of using the SP' s is that they look similar and retain the mirror mounts. The only difference is the micro swirches.
This is easily remidied by the use of banjo bolt switches.

 

[Screwloose]

Not if he is using the R1's as the lever ratio will be wrong.
The advantage of using the SP' s is that they look similar and retain the mirror mounts. The only difference is the micro swirches.
This is easily remidied by the use of banjo bolt switches.

Thats interesting, thanks allot. I can see allot of experience coming out on this topic that I had no idea about .

 

[Fire-medic]

The correct ratio often mentioned is equal to 16 mm where the Gen. 1 VMax is 5/8 or 15.875 mm, so I doubt that .007% of a difference (16 mm vs. 5/8") is going to be noticeably by anyone under any circumstances.

Mr. Midnight has in the past referenced using a 14 mm master cyl diameter, with the R1 non-radial brakes (1998-2003) and he said it made a significant difference. (27) R1 front calipers upgrade | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net) post #15

Trying to find info for specific master cyl diameters for bikes can be difficult. Here is a cornucopia of brake info: (26) Master cyl bore sizes of Japanese bikes and calculation chart for proper sizing | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net) This would be a good one to bookmark, as it contains lots of info for determining what works, and what doesn't work well.

 

[MaxMidnight]

Here is the information I have