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Big-Arse Brakes Mod

Started by The Prophet of Doom, July 25, 2013, 07:51:59 AM

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Rikugun

Quote from: QBS on July 29, 2013, 01:27:55 PM
Could two '82 brake sytems be installed on an '82?
The short answer is no...  :) Adding to roro and specifically fret nut's comments - if you used the (left) '83 lower leg and caliper on the left side, you'd have to use the smaller diameter '83 rotor on that side as well.  :( So rather than having "two '82 brake systems" you'd have a system consisting of half '82 and half '83 parts.  :D
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

The Prophet of Doom

The plate will end up being 7mm at its narrowest point.  Will that be strong enough? I've never done this before so Feedback welcome!!!

I got some 10mm 6061 T6 Plate ($40) from my favourite metal place.
I didn't use acrylic for a template as this is as expensive as aluminium, but I used an acrylic document folder I had lying around and trimmed well enough as a cutting template.  It's just rough - till I get the holes right, and then I'll radius the corners with a belt sander.

The template is transferred to the plate which I'll cut out next week on a bandsaw.  The plan is to get the templates cut out and then make a transfer punch out of a sharpened 12mm bolt to place marks for the holes.  I'll do one at a time so there should be no mistaking where they go.

The caliper is spaced out with a piece of 1.5mm TIG rod duct taped to the rotor

When the whole thing is cut out, I'll mill down the fork leg edge about 3mm to make the caliper align with the rotor - I have some spacing issues I still need to address before I do that.





Rikugun

Quote from: roro on August 05, 2013, 07:20:35 AM
The plate will end up being 7mm at its narrowest point.  Will that be strong enough? I've never done this before so Feedback welcome!!!  The carrier bracket on the Tokico caliper I used is only 6mm thick although it is steel. If the edges of your pads start to wear you'll know the torsional forces are overwhelming the thin material!  :o  :)

I didn't use acrylic for a template as this is as expensive as aluminium, but I used an acrylic document folder I had lying around and trimmed well enough as a cutting template.  I happened to have some laying around from another project so put it to use. I think treedragon used cardboard so what ever works!  ;)

When the whole thing is cut out, I'll mill down the fork leg edge about 3mm to make the caliper align with the rotor - I have some spacing issues I still need to address before I do that.  Is the milling in lieu of using washers to space it as questioned in an earlier post? What other spacing issues ar you having? Did you figure out the wheel centering?
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

The Prophet of Doom

6061 T6 has supposedly better strength and yield than mild steel, though I'm sure there's more to it than that.  I know ali is prone to stress fracturing.

Yes, milling is easy enough at the local high school, so why not, the offset is about 3mm - I think.  I think it will look more pro.  I only get 2 hours a week max on the machines including setup - so I have to plan carefully.  I also have 4 projects on the go at once as machines are shared. 

No I didn't sort the alignment issues out, the fork brace removal/ jiggling made no difference.  It's only a few mm so I'm wondering  if there's some leeway in tolerances that don't matter with floating calipers and so never get noticed.  Plan B is to strip the forks and check the runout of the inners.  My lathe's not big enough so yet another project for my high school shop class.  If I need new inners, I'll get some with an extra 2 inches which will make clip-ons a possibility again.  MikesSX seem to have them at a good price, though some nice Gold Tarozzi inners might be the shit at only EUR250 each.

Rikugun

I considered bent stanchions too but didn't want to say it out loud   :(  Maybe it is offset as fret nut mentioned so the left and right adapters will have to be slightly different. If it comes to it, here's another fork tube vendor:
http://www.frankmain.qpg.com/

Quote6061 T6 has supposedly better strength and yield than mild steel
Stronger by weight or volume of material? If weight, the identical sized steel part would be stronger, right?
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

sunburnedaz

What year R1 did the rotors come off of?
1982 Yamaha XZ550 - Almost bone stock
2005 Honda F4i - Nothing stock
98 ZX-6R Track Bike
1998 Chevy truck - AKA recovery truck

Rikugun

I think they are '03 or earlier 6 bolt design.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

The Prophet of Doom

'98-02 NZ models all had the 6 bolt pattern - then they moved to 5 bolt

The Prophet of Doom

Seems there is a bit of interest in this - so I'll be fairly detailed.  Skip to the pretty pictures if you like...

So the fork alignment seems to be due to the lower triple.  It's a mm wider than I think it ought to be which translates to 3mm at the bottom.  Because the Vision fork is only really bolted on the left side (the right is floating till the pinch bolt is done up) everything is slightly out of whack.  Not an issue if using floating calipers, but a bit of a deal with the Brembos - I don't want any lateral stresses on the rotors.  I've decided to mill only 2.5mm on each adapter and take up the rest of the space with shims (washers) which will allow the slight off-centredness to be compensated for, but still work if I replace the lower triple down track.

BTW a good way to check for bent stanchions is to lay them together and try to drop a fine feeler gauge between them at the centre, then each end, turn one 1/4 turn and repeat till you have measured each 1/4 with each 1/4.  Any gaps a feeler gauge can enter indicate bendedness (or perhaps lumpy corrosion).

I positioned the rough cut adapter on the fork, and used a sharpened 10mm bolt as a transfer punch to locate the centre of each hole, then drilled out to 3mm, 6mm, 9mm and finally 10mm.  Then I lay the two adapters on top of one another and used the transfer punch to identically match the holes on to the opposite side. (PIC 1)  I then marked where the fork mounts go and milled 2.5mm off to space the caliper inwards.  I just did a straight line - no fancy wobbles. (PIC 2)  Notice that the fork mounts are not evenly spaced out from the fork.  I positioned so that the adapter matches the line of the fork.

There was no way a transfer punch was going to fit into the caliper without hitting the rotor so I cut the 10mm bolt and cut in a screwdriver slot (PIC 3).  Screwed this into the caliper so it was proud, then slid it up to position along the 1.5mm TIG rod taped to the rotor for correct spacing and hit the adapter with a BFH rubber mallet.  You can see the line scribed on the way in and the hole centre (PIC 4)

Drilled out the caliper holes in the same fashion as above and now just have some edges to dress, and radius the corners on the belt sander.

They seem functional enough, though not exactly pretty.  Any opinions on whether I should polish them or powder them black? I'm thinking satin black.


Hellgate

Here's the set up I did on my '82 XV920R. I used FJ600 wheels, EBC rotors and pads, Galfer brakes lines, and FZ1 calipers and MC. My buddy machined the adaptors.

The difference is night and day.



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Pete
Past Yamahas: '73 TX500 - '76 RD400E - '82 Vision - '85 RZ350 - '07 FZ6 Current Yamahas: '05 R6 Track Bike - '06 FZ1

The Prophet of Doom

Hellgate, very nice.  Are they Alloy? How thick? Have they ever been through a safety inspection?
There's a lot more air in those adapters than I would have felt comfortable with, but you have encouraged me to at least think about some speed holes

Hellgate

I don't recall the thickness off the top of my head. I'll measure them tomorrow.

As far as a safety inspection there is no such thing in Oklahoma, even if there was no one would know the difference on a bike that old.

If you consider the direction of the braking forces the cut outs are not an issue.

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Pete
Past Yamahas: '73 TX500 - '76 RD400E - '82 Vision - '85 RZ350 - '07 FZ6 Current Yamahas: '05 R6 Track Bike - '06 FZ1

Hellgate

15.5mm thickness.



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Pete
Past Yamahas: '73 TX500 - '76 RD400E - '82 Vision - '85 RZ350 - '07 FZ6 Current Yamahas: '05 R6 Track Bike - '06 FZ1

charlie h.

The braking thread is piquing my interest, as I have 2 1982 XZ550RJ Visions, also a 1981 XV920RH, and a Vintage roadrace bike, 1975 RD350 with a 1982 XZ550RJ Vision front fork and front wheel, mounted in an XS650 tripletree modded to fit the shorter steering neck of the RD350. I have been checking brake rotor sizes lately, the RJ Vision rotor is 298mm OD, which is the same size as the 98-02 R1 rotors, but the r1's are drilled for better braking. I am interested in fitting either an R1 or R6 single rotor of the same size (298mm) to the front forks/wheel  of the racebike, and then see if i need a better caliper. I am using an FJ1300 Master cylinder with the rd350 and the Vision stock caliper and rotor, so I have plenty of Master cyl. and at Beaver Run (PITT) I has an SV650 about crawl up my butt on the braking into the last hairpin curve. He mentioned the surprise that the RD350 could brake that well. So I am going to find an R1 (98-02) rotor and replace the non drilled stock Vision rotor, and check out the difference. Oh, by the way, I used a XS400 Seca rear wheel on the RD350 to match the Vision front wheel, as it is chain drive, and also have a XS650 swingarm which adds 3" to the wheelbase. All bolts right on, except for the steering stem which I cut down the top bearing step about 5/8" to seat the tapered roller bearings into the top race. What do ya think??

fret not

Drilled discs provide better braking in wet conditions than undrilled ones as they wipe the brake pads clean, and they are a bit lighter which is better for keeping the tire in contact with the road surface.  For significantly better braking get cast iron discs, like Ducati and MotoGuzzi use.  They will rust if allowed but have much better friction characteristics.  Custom brake discs are avaiable for about $100 per made to fit your specs.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

Rikugun

Prophet - very nice post and love he detail and pics too. Nice creative work-arounds with center punches etc. Can I ask why so many steps when drilling the 10 mm holes? Wouldn't a pilot and then final sizing suffice?

Very odd about the fork/triple clamp alignment issue. I wonder if shimming the stanchions in the top triple would help. I've used strips cut from a soda can for things like this. Maybe a strip placed on the inside section of the top triple to move the centerline of the top of the stanchion out a smidge to match the lower triple clamp width? Just a thought... 

Regarding the color I like the idea of black. Are your sliders black too?


Hellgate - very, very nice and tastefully modified 920 you got there!  :) 
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

Hellgate

Thanks very much. She's in the process of getting an 1100cc transplant with JE pistons,  Web cams, and porting.  She's also being painted R1 blue.

I tried to use only Yamaha parts and keep a clean OEM look.

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Pete
Past Yamahas: '73 TX500 - '76 RD400E - '82 Vision - '85 RZ350 - '07 FZ6 Current Yamahas: '05 R6 Track Bike - '06 FZ1

The Prophet of Doom

#37
Quote from: Rikugun on September 18, 2013, 08:41:29 PM
Prophet - very nice post and love he detail and pics too. Nice creative work-arounds with center punches etc. Can I ask why so many steps when drilling the 10 mm holes? Wouldn't a pilot and then final sizing suffice?

Very odd about the fork/triple clamp alignment issue. I wonder if shimming the stanchions in the top triple would help. I've used strips cut from a soda can for things like this. Maybe a strip placed on the inside section of the top triple to move the centerline of the top of the stanchion out a smidge to match the lower triple clamp width? Just a thought... 

Regarding the color I like the idea of black. Are your sliders black too?


Hellgate - very, very nice and tastefully modified 920 you got there!  :)
I guess as long as the previous hole is larger than the next drill's chisel tip you should be generally OK, though I think the more material you take off at a time, the higher the chance of drilling an oversized or out of round hole.  Really they should be drilled then reamed, but I haven't got a set of reamers. 

Yes sliders are black,  but painted and I'm contemplating stripping and powdering.

I'll have to give shimming some thought

The Prophet of Doom

#38
I removed my forks from the triples to do some shimming and found a tiny (1mm) lump of hard gunk that was throwing the alignment out.  A quick dremmel and everything is in line now.  I re-milled the adapters to take off a final 0.4mm. 

I wanted to use stainless bolts, but finding the right stainless grade for calipers is tricky.   I ended up using M10 grade 12.9 black steel socket cap (all the other bolts on the bike are socket cap, though mostly stainless 316) hacksawed to the right length as it's a strange size and there's no room for overhang.

The calipers sit with about 0.2mm gap either side.  That will change when they are bled, but as they sit they are perfectly centred on the rotor with no rubbing when the wheel is rotated.   It's all getting disassembled when the new over-length fork tubes arrive, so I'll powder these then.

[EDIT] I should add that the standard 3 piece brake lines will not fit.  The 2 line kits look like they will fit for length, but not for orientation of the ends.  I'll try again when it's warmer in the shed than 4 degrees.

Rikugun

Very nice work Roro. Looks clean and professionally done. :) Can't wait to see the powder coated finish. Great news about the alignment, glad you got that sorted.  :D  :D
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan