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I think that'll work great then! I didn't know that the master cylinder matched the slave. That puts you at between 3.73 and 4.02mm of pressure plate movement. If you can dial down the stroke with the lever, then you'll have a good range to work with and get it perfect!
That would be great! Once you pull the information together, if it makes more sense, you could add it to that existing thread if you want. Either way
So far, I have a Kawapriliaha, but I'm not done yet...
Right now I have a mix between a Yamaha, Ural, Husqvarna, Honda, and Aprilia. I had Kawasaki and BSA parts on there at one time or another too. I just can't make up my mind I guess!
osteoderm
out of the box
Not a big week on the bike so far; been too busy working to pay for it! Did manage to drop in on the machinist...
...just to introduce the swingarm to the Bridgeport milling machine.
While the new gussets are being welded, I'll be piecing together a mount to hold the swingarm in position on the machine bed. Hopefully I'll be able to get enough shots of the "Big Drill" in action so you can see why...
...just to introduce the swingarm to the Bridgeport milling machine.
While the new gussets are being welded, I'll be piecing together a mount to hold the swingarm in position on the machine bed. Hopefully I'll be able to get enough shots of the "Big Drill" in action so you can see why...
osteoderm
out of the box
Excellent progress today! First, I rounded up the materials for the milling fixture, then dropped in at 7 Star to have it tacked together...
Teak started off with a couple tacks, but just couldn't help himself... so now I have a fully TIG'd single-use jig.
Here I'm laying out the holes to bolt the fixture to the bed of the Bridgeport...
...while across the shop, Teak is getting set to complete the welding of the new gusset pieces. I left him to it, and a few hours later got the call to pick it up. We had discussed "stacks of tacks" and just stitching it with a handful of 1" welds. Well, turns out everything came together A-1 with no heat/warping issues, so he just kept going until the dang thing was fully seam-welded.
Beautiful TIG welds, so much nicer than the short stitches I had been imagining.
The swingarm legs sprang in approx. 1/8" with the heat, but everything stayed nicely centered. Acceptable tire clearance, yes!
Stock XS650 on the left, modified TX750 on the right. It's a compromise design, no doubt, but as serious as I could make it while keeping decent clearances.
I had had some concern about the final sprocket clearance, but it looks great so far.
Here's the swingarm mocked-up in the milling fixture. The next set of swingarm pics will show it better than I can explain, but basically, the whole works will be clamped onto the Bridgeport table, leveled, squared, and braced so we can cut the bore for the monoshock linkage pivot shells. Yeah, uh, just read that to myself, and it doesn't really explain much, does it?
This 5/8" nut and setscrew should let us align the swingarm left-right for level. Front-back level will be set by diagonal braces tacked back to the rear crossbar.
So far, the only particularly bad aspect of this new welding is how it makes the factory welds next to it look so... not as nice. But overall, I'm mega stoked! All the fiddly math, measuring, and prep is paying off.
Teak started off with a couple tacks, but just couldn't help himself... so now I have a fully TIG'd single-use jig.
Here I'm laying out the holes to bolt the fixture to the bed of the Bridgeport...
...while across the shop, Teak is getting set to complete the welding of the new gusset pieces. I left him to it, and a few hours later got the call to pick it up. We had discussed "stacks of tacks" and just stitching it with a handful of 1" welds. Well, turns out everything came together A-1 with no heat/warping issues, so he just kept going until the dang thing was fully seam-welded.
Beautiful TIG welds, so much nicer than the short stitches I had been imagining.
The swingarm legs sprang in approx. 1/8" with the heat, but everything stayed nicely centered. Acceptable tire clearance, yes!
Stock XS650 on the left, modified TX750 on the right. It's a compromise design, no doubt, but as serious as I could make it while keeping decent clearances.
I had had some concern about the final sprocket clearance, but it looks great so far.
Here's the swingarm mocked-up in the milling fixture. The next set of swingarm pics will show it better than I can explain, but basically, the whole works will be clamped onto the Bridgeport table, leveled, squared, and braced so we can cut the bore for the monoshock linkage pivot shells. Yeah, uh, just read that to myself, and it doesn't really explain much, does it?
This 5/8" nut and setscrew should let us align the swingarm left-right for level. Front-back level will be set by diagonal braces tacked back to the rear crossbar.
So far, the only particularly bad aspect of this new welding is how it makes the factory welds next to it look so... not as nice. But overall, I'm mega stoked! All the fiddly math, measuring, and prep is paying off.
pregrid
XS650 Guru
Nice work, a LOT of it, but nice!
1974jh5
Curmudgeon.
Nice work! That guy is an ace welder, beautiful seams.
Yeah, if using needle bearings if the linkage bits are not all in the same planes uggy things will happen. For that reason I have been considering using spherical bearings with what I'm skulling out. I discovered during my last project that the the Yamaha R1-R6 shock needle bearings are slightly barrel shaped to allow for a small amount of misalignment.
Yeah, if using needle bearings if the linkage bits are not all in the same planes uggy things will happen. For that reason I have been considering using spherical bearings with what I'm skulling out. I discovered during my last project that the the Yamaha R1-R6 shock needle bearings are slightly barrel shaped to allow for a small amount of misalignment.
What you did with the channel is what I was thinking about doing to strengthen a stock XS650 SA. It will still look pretty much stock but be stiffer.
Leo
Leo
osteoderm
out of the box
Nice work! That guy is an ace welder, beautiful seams.
Yeah, the precision I'm aiming for is on account of all the needle bearings. In some ways I too wish for spherical bearings or poly bushings to make things a little more reasonable! Still, i think it will be worth it (at least that's what I try to convince myself!)
osteoderm
out of the box
Trying to "still look pretty much stock" is one of my goals, at least as far as the outboard profile of the swingarm is concerned. I'm going to avoid additional under/over bracing if I can. For a stock (ie., non-monoshock) application, I think the TX750 swingarm alone is worth finding; a significant increase in both strength and stiffness with very little installation/fabrication hassle.
osteoderm
out of the box
Because I didn't have enough side-projects already I've been working on the brakes too. Part of my build plan has always been dual discs up front. I've read most (if not all) of the threads, and am inclined to agree that an upgraded single disc is probably a better way to go (lighter, less parts/hassle), but I haven't been able to shake off how much I like the looks of the twin discs.
I've also been trying very hard (in the face of much temptation) to keep a vintage feel to this build. For me, that means stock early calipers and discs. I've been collecting the parts for awhile now, but am just now getting into this area.
Early disc off eBay. Minor scoring and ugly fasteners, but not warped and with plenty of meat left.
Finally have the rotor apart, and started a quick clean with a wire brush and patience. The aluminium disc carrier is lighter than I imagined... not sure if the early discs are lighter than the later ones overall, as I don't have one to compare it to. Personally, I like the early two-piece look anyways.
I'm fairly convinced that I'll never find new lock-tabs for the nuts, so those little nubs are going away! Have ordered Class 10.9 6mm buttonheads and stover locknuts for the reassembly.
Of course i want to drill the rotors; who doesn't? Well, I covered both sides of this rotor with all sorts of layout lines and mock-ups, trying to figure out what looks best to me, but wouldn't be a ridiculous amount of work. Unfortunately, I kept coming back to a simple pattern with tons of holes. Was seriously not looking forward to drilling 80 +/- holes in each disc, until my machinist friend pointed out that he knows an excellent local waterjetter with reasonable rates...
Generally speaking, CNC work is easier if you can supply your own full-scale CAD files. This layout is still subject to change, but (for this build) I like the direct simple look, without elaborate swept arcs, swirls, etc. Here, the holes are 8mm, staggered 8mm, set back 2mm from the edges of the braking surface. Works out to 96 holes per disc; tempted to squeeze in at least 4 more for that even 100.
I've been working on the brakes too. Part of my build plan has always been dual discs up front. I've read most (if not all) of the threads, and am inclined to agree that an upgraded single disc is probably a better way to go (lighter, less parts/hassle), but I haven't been able to shake off how much I like the looks of the twin discs.I've also been trying very hard (in the face of much temptation) to keep a vintage feel to this build. For me, that means stock early calipers and discs. I've been collecting the parts for awhile now, but am just now getting into this area.
Early disc off eBay. Minor scoring and ugly fasteners, but not warped and with plenty of meat left.
Finally have the rotor apart, and started a quick clean with a wire brush and patience. The aluminium disc carrier is lighter than I imagined... not sure if the early discs are lighter than the later ones overall, as I don't have one to compare it to. Personally, I like the early two-piece look anyways.
I'm fairly convinced that I'll never find new lock-tabs for the nuts, so those little nubs are going away! Have ordered Class 10.9 6mm buttonheads and stover locknuts for the reassembly.
Of course i want to drill the rotors; who doesn't? Well, I covered both sides of this rotor with all sorts of layout lines and mock-ups, trying to figure out what looks best to me, but wouldn't be a ridiculous amount of work. Unfortunately, I kept coming back to a simple pattern with tons of holes. Was seriously not looking forward to drilling 80 +/- holes in each disc, until my machinist friend pointed out that he knows an excellent local waterjetter with reasonable rates...
Generally speaking, CNC work is easier if you can supply your own full-scale CAD files. This layout is still subject to change, but (for this build) I like the direct simple look, without elaborate swept arcs, swirls, etc. Here, the holes are 8mm, staggered 8mm, set back 2mm from the edges of the braking surface. Works out to 96 holes per disc; tempted to squeeze in at least 4 more for that even 100.
osteoderm
out of the box
The rest of the YZF-R1 rear brake parts showed up in the email yesterday...
Mocked the caliper and caliper bracket into place on the old swingarm. I had some hope for this brake, but I'm not sure about the looks.
The caliper bracket very neatly clears everywhere it counts, with the torque tab in a good place for a retainer to be welded to the swingarm. Assuming a stock front hub/rear axle/custom spacer scenario, this is all good: plenty of spoke clearance, disc in a useful position, brake line lead right in line with swingarm... mechanically good enough, but just ugly. What I'm really trying to find is a way to have a small(er)-diameter rear disc, close in size to the sprocket on the opposite side, with a minimal caliper. Bonus points for any caliper bracket that can somehow be used without a torque-arm.
The search goes on... Suggestions?
Mocked the caliper and caliper bracket into place on the old swingarm. I had some hope for this brake, but I'm not sure about the looks.
The caliper bracket very neatly clears everywhere it counts, with the torque tab in a good place for a retainer to be welded to the swingarm. Assuming a stock front hub/rear axle/custom spacer scenario, this is all good: plenty of spoke clearance, disc in a useful position, brake line lead right in line with swingarm... mechanically good enough, but just ugly. What I'm really trying to find is a way to have a small(er)-diameter rear disc, close in size to the sprocket on the opposite side, with a minimal caliper. Bonus points for any caliper bracket that can somehow be used without a torque-arm.
The search goes on... Suggestions?
osteoderm
out of the box
Another late night with the CAD software has me at this drilling pattern:
That's 160 8mm holes per disc, something I wouldn't even dream of attempting without a waterjet. Can't tell if it's all too much, or if "too much" is just enough
The bare discs cleaned-up nicely:
I used the "spun on a slow-turning drill-press, dressed with a random-orbit sander" procedure I'd read about somewhere on this site. Thanks again to whoever's idea that was! I'm satisfied enough with the surface that I'm no longer trying to find a brake lathe for them.
McMaster-Carr to the rescue again... 100 grade 10.9 6x16mm buttonheads with locknuts, for 1/4 the price of any local store. Still not sure how I want to finish the disc carriers (polished? painted? anodized? blued?), but the black buttonheads are a keeper.
That's 160 8mm holes per disc, something I wouldn't even dream of attempting without a waterjet. Can't tell if it's all too much, or if "too much" is just enough
The bare discs cleaned-up nicely:
I used the "spun on a slow-turning drill-press, dressed with a random-orbit sander" procedure I'd read about somewhere on this site. Thanks again to whoever's idea that was! I'm satisfied enough with the surface that I'm no longer trying to find a brake lathe for them.
McMaster-Carr to the rescue again... 100 grade 10.9 6x16mm buttonheads with locknuts, for 1/4 the price of any local store. Still not sure how I want to finish the disc carriers (polished? painted? anodized? blued?), but the black buttonheads are a keeper.
pregrid
XS650 Guru
Looks like WAY too many holes in that disc to me. Depends on what you're aiming for. are you looking for maximum cooling or looks? I've just never seen a disc drilled with that many holes.
osteoderm
out of the box
These are the exact same questions I've been asking myself
. I've never ridden hard enough to feel concerned by brake-fade due to rotor heat, so cooling wasn't foremost in my mind.It's looks and weight. (And yes, I completely agree that there are probably better ways to shave the weight!) I Haven't seen a motorcycle disc with that many holes per se, but the Galfer "wave rotors" have more "missing area" than my layout.
I suppose the two worrying factors are swept area and strength. The 160-hole layout I have only reduces the swept braking area by 20.7%. Of course, with two discs, I will have a net increase in swept area. (Two drilled discs having 158.5% the swept area of a single solid disc). So I think I'm okay there.
As far as strength goes... I've set the outermost holes 2.5mm in from the edge of the rotor (greater than the distance the mounting holes are from the inside edge). No hole is closer than 5mm to any other hole. Since the rotors are ~7mm thick, there's actually still a lot of material left. I certainly wouldn't think of trying this with a thin(ner) modern rotor! I agree that it looks like there's hardly any disc left, but the numbers say otherwise.
I'm not dead-set on this scheme. If there's something I'm not thinking of, I'd like to know it!
pregrid
XS650 Guru
i'm no expert by any stretch of the imagination, just thinking out loud.
Tack427
XS650 Addict
I'll add something to think about. If you ever get stuck out in the rain and you heat the disc up and cool them, they may crack.
I had one drilled rotor on my car crack and I was guessing it was from getting off the highway and hitting some puddles. Maybe, maybe not. it could have just been defective.
I had one drilled rotor on my car crack and I was guessing it was from getting off the highway and hitting some puddles. Maybe, maybe not. it could have just been defective.
osteoderm
out of the box
No worries. I value your input and commentary!
The holes have several purposes, one is colling but there are more important ones.
When you use your brakes, as the pads heat up they create gases. These gases can lift the pad from the rotor. Decreasing braking action. The holes are to let this gas escape.
As the pads wear the rotor metal from the rotor imbeds in the pads. Decreasing braking action. The sharp edge of the holes clean these metal bits off the pads.
So after drilling just clean up the holes to remove burrs, don't bevel the edges of the holes.
Leo
When you use your brakes, as the pads heat up they create gases. These gases can lift the pad from the rotor. Decreasing braking action. The holes are to let this gas escape.
As the pads wear the rotor metal from the rotor imbeds in the pads. Decreasing braking action. The sharp edge of the holes clean these metal bits off the pads.
So after drilling just clean up the holes to remove burrs, don't bevel the edges of the holes.
Leo
osteoderm
out of the box
Good points. In this application, I'm sure a lesser amount of holes would still effectively combat outgassing. The holes won't have any burrs to clean (the waterjet cuts wicked precise and clean), but my preference would be to just barely touch a bevel to the holes; cracks like to propagate where fine edges are subject to thermal cycling.
As for the number of holes, well, I'm reading every kind of opinion online, but not hearing from anyone who has had a first-hand problem with cracking these heavy stainless rotors. Frankly, I'm totally expecting (almost wanting!) someone to chime in with a horror story to bring me back to a less ambitious plan...
yamaman
xs650 addict
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hi, if you go to the old 650rider site, go to page 2 of the vault, there is some top info on drilling discs. Sorry I just couldnt post a link 
I think I read somewhere, the hole diameter should be = to disc thickness. Pretty sure Gorans 90 hole pattern sweeps the entire disc. Leo, I believe pad outgassing is a thing of the past, modern pads dont behave like they did 30 years ago, though be good to see some evidence either way.
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I think I read somewhere, the hole diameter should be = to disc thickness. Pretty sure Gorans 90 hole pattern sweeps the entire disc. Leo, I believe pad outgassing is a thing of the past, modern pads dont behave like they did 30 years ago, though be good to see some evidence either way. Posted via Mobile
