[dsn_klr650] what causes tire cupping? nklr

[R. Kaub]

What did help, however, was the addition of the Happy Trails fork brace. the Highway to Fred's shop was milled and grooved. Tim wanted me to try his fork brace out, so I bolted one up at Fred's shop. Then I had to hustle into town to run errands. Looked down at my speedo, 75mph and the front end was about as calm as it has ever been. Too early to tell if the fork brace may be the answer to running an aggressive knobbie in front and not having to take out a life insurance policy when riding on pavement, but it seems that way now. <<<<>>>> Gino: I've been kinda looking for any feedback/comments on Tim's fork brace. While I'd call myself one of the more sedate riders on the list, I'm for any upgrades which make the bike less likely to spit me off. Riding in muddy ruts is about my most not fun way to get somewhere and I was wondering if fork braces would do anything to stabilize the bike a bit as the front tire bounces from side to side in the rut. I've learned to "get loose" and not overcontrol and to look way ahead and not down but the pucker factor takes some of the fun out of it for me. Do you think fork braces would make any meaningful difference for me? Thanks. Bob Kaub

[k650dsn@aol.com]

In a message dated Tue, 13 Jun 2000 9:36:46 AM Eastern Daylight Time, "R. Kaub" writes: >>

[k650dsn@aol.com]

In a message dated Tue, 13 Jun 2000 12:52:20 PM Eastern Daylight Time, "Walter Lesnowich" writes: >>

[Kurt Simpson]

> The price sounds reasonable. I studied the picture of it > and since I used to work in a speed and machine shop > I can appreciate the amount of time it must take to produce. > Time is money after all. The only way I can see it costing > much less would be for Tim to produce a run of at least > 10,000 of them on a CNC machine but there is hardly the > demand for that.

Tim told me that start-up for tooling on each fork brace is $10,000 that is gone forever. He's promising me one for the DR650. Kurt

[Jeff Walker]

----- Original Message ----- From: Kurt Simpson To: Walter Lesnowich ; dsn_klr650@egroups.com> Sent: Tuesday, June 13, 2000 11:00 AM Subject: RE: [DSN_klr650] Squirmy tires (was Moab Reflections) NKLR > > The price sounds reasonable. I studied the picture of it > > and since I used to work in a speed and machine shop > > I can appreciate the amount of time it must take to produce. > > Time is money after all. The only way I can see it costing > > much less would be for Tim to produce a run of at least > > 10,000 of them on a CNC machine but there is hardly the > > demand for that. > > Tim told me that start-up for tooling on each fork brace is $10,000 that is > gone forever. He's promising me one for the DR650. > > Kurt > > Tooling costs are so outrageously expensive you wouldn't believe it. A couple of months ago I inspected a die for plastic injection molding that was made using Electrostatic Discharge Machining, and cost well over $80000 to make, so this company can produce a plastic part that is probably worth about $0.80 cents worth of plastic. Jeff

[Dash Weeks]

> >Tooling costs are so outrageously expensive you wouldn't believe it. A >couple of months ago I inspected a die for plastic injection molding that >was made using Electrostatic Discharge Machining, and cost well over $80000 >to make, so this company can produce a plastic part that is probably worth >about $0.80 cents worth of plastic. > >Jeff

Aye, tooling is expensive but product design and efficient process selection can drastically reduce tooling costs. For these fork braces there are three processes that can make them more efficiently than one CNC milling process out of billet. First is to extrude the shapes in long bars, that's where product design comes in. Next you have to slice the parts out of the bars. Because of the extrusion shape and the compound curves you can't band saw them, well the clamp parts can be sawed but the bridge can't. So my choice would be to wire or water jet them, laser is nice but much more expensive. So now we have the shape and we have the size, now cut holes, threads, and counters, toss them all into a tumbler and get your final finish, anodize them and boom your done. The set up for doing holes, threads and counters is much easier and faster and less tooling intensive than doing it all from billet. Extrusion tooling is pricey ($5K each) but the advantage is that it can sit on a shelf until you are ready for the next batch. Most milling machine tooling would be set up for each run and I guarantee it will never, ever be the same twice, within tolerance, but not the same. You don't need a huge indexing mill to do it efficiently either so a cheaper job shop with CNC can do it. 7000 series is easily extruded as is 6000 series, then again the same tooling techniques and costs will be involved to extrude titanium, only material costs will go up there. So for the fork brace we are talking about two extrusion dies and subsequent milling set-up. A bit greater than the $10K that was mentioned, but much faster, less material wasted to chips, and some really trick parts since the extrusion dies can produce complex shapes cheaper per material cost than the billet route. We are looking at a one piece bridge instead of the flat bridge with spacers. So who's up for taking this design to production? I'll do all the design and FEA work, I'll provide the prints and I get 5-10% royalty, hell I'll even middle man with the shops I normally work with. Not interested in patents, but I am putting this all down on paper and will mail it to myself, certified mail so don't think about borrowing my ideas without a whooopin. LaterZ Dash

[Jeff Walker]

> First is to extrude the shapes in long bars, that's where product design > comes in. Next you have to slice the parts out of the bars. Because of > the extrusion shape and the compound curves you can't band saw them, well > the clamp parts can be sawed but the bridge can't. So my choice would be > to wire or water jet them, laser is nice but much more expensive. So now > we have the shape and we have the size, now cut holes, threads, and > counters, toss them all into a tumbler and get your final finish, anodize > them and boom your done. The set up for doing holes, threads and counters > is much easier and faster and less tooling intensive than doing it all

from

> billet. Extrusion tooling is pricey ($5K each) but the advantage is that > it can sit on a shelf until you are ready for the next batch. Most

milling

> machine tooling would be set up for each run and I guarantee it will

never,

> ever be the same twice, within tolerance, but not the same. You don't

need

> a huge indexing mill to do it efficiently either so a cheaper job shop

with

> CNC can do it. >

Wire EDM cutting? Water Jet Cutting? These are spendy in comparison to milling, but they are great processes. (WJC sure is messy though!) Hmm. I toured Richland Specialty Extrusion this year, and they had some pretty loose tolerances on their tubes, compared to Sandvik Special metals, which uses pilgering for its seamless tubing. As far as the milling operation, that has a lot to do with what kind of mill you are using, and the state of tool wear, and who the operator is. I machined a precision gyroscope last term, and I can garuntee you it is within a .0005" tolerance, which is far closer than you would ever need for most any other project.

> 7000 series is easily extruded as is 6000 series, then again the same > tooling techniques and costs will be involved to extrude titanium, only > material costs will go up there. >

Titanium and Zirconimum are generally unsuitable for extrusion due to their crystal structure (hexagonal close packed, it cracks under the residual stresses imposed during the extrusion. Pilger rolling is the preferred process). The government found this out the hard way. They built the worlds largest extrusion press to extrude zircoloid tubing to use as nuclear fuel rod cladding, and discovered that the process was seriously flawed after conducting a couple of runs. They now lease that facility to Richland Specialty Extrusion, a division of Kaiser Aluminum. I've seen it in operation, its great. They take these aluminum billets that are about a foot in diameter and two feet long, then press that out into a 40 foot long tube, which then gets shipped off to Easton Sports who draws that into softball bats.

> So who's up for taking this design to production? I'll do all the design > and FEA work, I'll provide the prints and I get 5-10% royalty, hell I'll > even middle man with the shops I normally work with. Not interested in > patents, but I am putting this all down on paper and will mail it to > myself, certified mail so don't think about borrowing my ideas without a > whooopin. >

Are you a P.E.? Don't you have an intellectual property contract with your company? I'm sure they will take a piece of that too, even if you did think it up on your own time at home. You know, the problem with patents is that once you apply for one, your design is out there for everybody to see, and unless you have lots of money for a good legal team, your idea can get stolen. I did some work for a associate professor who owns his own company. They are designing and producing power converters to use with fuel cells, and he is afraid of applying for a patent for that very reason. Jeff

[Jeff Walker]

> My first job at Boeing was very similar to this "problem", except it > involved tires loaded to max weight at max speed (270mph). When the > tread flexed, it built up so much heat the tires flew apart > (=problem). I was given a stack of equations which described a > standing wave in a spinning tire. The task was to mathematically > model this "multi-degree-of-freedom system". > > I called one of the large aircraft tire manufacturers, and whipped > out my math. I still remember it clearly. He said "well, you're > talking about a problem that a full-time staff of perhaps 20 to 30 > brilliant PhDs has been working on, specifically, for 20 to 30 years. > Frankly I don't think you're going to figure it out." I found out > that my math was rather puny in the real world. > > Tom

He He, yeah......I tell you, I often wonder why I am pursuing a minor in applied math. These days the big trend is to just do a finite element analysis on the computer and call that good enough. If computers had been invented first, calculus would have never been invented. Jeff