Wilsons Sandbox

On Mon, 24 Nov 2008 02:14:55 -0000 "revmaaatin" writes:

> Hello list- > > Does anybody have some motorcycle articles that I could read that > talk about fork-brace dynamics, when, and when not to use a fork > brace? List wisdom has varied on this topic; fork brace for > highway, > but not off road; fork brace for off road, but not on the highway. > > Then I notice, there are a number of road bikes with fork braces, > and > the vintage mx bikes still run fork braces....

SNIP

> But back to the fork brace. > Where I have a question is this-- > > Does someone here have some substantiation for believing the fork > brace contributes to the failure of the fork seals?

SNIP

> revmaaatin.

*********************** *********************** Martin, First I don't have anything for you to read unless you show up out here again. : ) Then you can take a look at my Tony Foale book Motorcycle Handling and Chassis Design the art and science. It's not a book most folks will want to pick up I'm thinking as the price tag is something like $135 or so. But it is the gospel according to handling and chassis design. I took a look through it briefly, it's not an easy read... : ) and found in the Front Suspension chapter on page 7-3 a brief reference mentioning the fork brace. I'll quote it here so you get what it says but know that it's much more complicated than what's in this short quote concerning telescopic forks. "These features add up to a fork that is relatively flexible in most directions, and as we have mentioned earlier, lateral flexibility can impair stability. However, this aspect have been vastly improved over the past decade. The upside-down (USD) fork in particular has improved stiffness in all directions, larger wheel spindles have become more common, often hollow to save weight. Pre-USD forks often had a mudguard bracket or fork brace above the wheel which added overall stiffness to the assembly, but the USD fork only has the axle to hold the two legs in alignment. Thus the size of the axle is more important in this case. High quality USD forks perform very well but can be quite expensive. For fashion reasons some cheaper motorcycles are fitted with USD forks of dubious quality with small diameter axles, often resulting in greater flexibility than other older types. Confirmation of this is easily obtained by holding the front wheel between your knees and twisting the handlebars." So although this is really talking mostly about USD forks it also implies how important reducing flexibility is for good fork performance. Our KLR forks are well known as being flexible. I also looked through a few other references and could only find one other mention of a fork brace and that was a definition. It said pretty much what you'd think it would say. That book was published in the early 1970s when I was first getting into motorcycles. You pretty much know my take on the fork brace on the KLR based on our conversations in my shop and while riding together. In the last year I had a talk at the riding club with a group of riders that are experienced, skilled and knowledgeable. Most of us thought that suspension upgrades were a waste of money for the majority of riders. Of course most of us don't want to be lumped into this group but the fact is most of us aren't as proficient as we'd like to believe we are. We also agreed riding a bike that is well set up is more pleasant than riding one that has issues. One person suggested that for someone to be a good enough rider to benefit from suspension upgrades they should be capable of riding the same line 5 times in a row. As you know, Nemo Road is not far from my house and I like to think the first 10 miles of it are a good test area to try for consistent lines. I was, and still am, a believer that I'm one of the guys that still won't benefit from suspension upgrades. : ) Yup, me and more than 95 plus percent of the rest of the riders in the world. Now having said that... you know I've recently mentioned to you I'm thinking about up grading the suspension on my KLR this winter. : ) I think it's time for steering head bearing replacement, servicing the forks including replacing the stock springs which I think are now sagged out after 27,000 plus smiles and maybe installing cartridge emulators. But a fork brace isn't on the list for my type of riding. Now Tony's talk about USD forks above with small diameter axles probably relates quite well to the stock KLR forks with small diameter fork tubes. We all know you can flex the front end like he talks about doing. And what we hear from folks with fork braces is how they stiffen the front end noticeably and improve "feel". But like you've experienced and we've talked about... a fork brace in mud can have a negative impact on handling and front wheel rotation. For me that's the number one reason I won't put one on my bike. If a guy is only planning on riding on pavement or maybe light duty dirt they might work fine. But I don't think they are the answer to everyone's KLR stability questions. I think riding within the limits of the bike are a better solution. As to your question about the fork brace contributing to fork seal failure. I've got nothing. : ) But I suppose if it is installed too tightly or clamped unevenly it could put pressure on the slider causing the fork seal to distort. Since the purpose of the fork brace is to hold the sliders in the same plane and I suppose to help keep the sliders from twisting when hard cornering I'm guessing you don't need a lot of clamping force. Maybe 14-18 foot pounds of torque on the clamping bolts would be plenty or more than plenty. So my guess is the fork brace may help some folks get a better "feel" for what their bike is doing and that's a good thing. In many situations I ride in it could be helpful but I'm in enough situations where that "feel" isn't going to make a difference to make it worth installing. Feel is important for good control of a motorcycle. How each of us interprets what we feel and then how we respond to that interpretation is gonna be different. And that interpretation and response is why most of us can't ride the same line 5 times in a row. : ) If we each ask ourselves how good we really are as a rider, and then answer honestly I suppose most folks will realize a fork brace could be nice but isn't a necessity. Improving our skills as riders will go much further than installing a fork brace alone. I'd rather ride a slow bike fast than a fast bike slow. Best, Jeff Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650, 79 R100RT ____________________________________________________________ Visa, MasterCard, AMEX & Discover. Compare Offers & Apply Online. Click here! http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw2Oq4FAd42HZfKyhSBCiRHGiyeRgPvClPIx059KNwTv3E8lO/

--- In DSN_KLR650@yahoogroups.com, "revmaaatin" wrote:

> > Hello list- > > Does anybody have some motorcycle articles that I could read that > talk about fork-brace dynamics, when, and when not to use a fork > brace? List wisdom has varied on this topic; fork brace for highway, > but not off road; fork brace for off road, but not on the highway. > Then I notice, there are a number of road bikes with fork braces, and > the vintage mx bikes still run fork braces.... > > Sitting on my bench is an uninstalled Studebaker fork brace. Anybody > have the installation instructions, specifically torque values? I am > contemplating its re-installation.... > > Earlier last month I reported a couple of oddities that occurred > during my Great Divide Ride--one of which were blown fork seals, and > the other discovering that fork braces of the present low-profile ilk > don't work well, cough, at all if you get in gumbo mud...the tires > lack the ability to self cleanse at slow speed, and the sticky mud > results in a packed tire to fork brace interface--followed shortly by > face to mud impact. Yes Virgina, face to mud impact validated more > than once--to invalidate the chance of it being a fluke occurrence. I > liked the validation process so well, I was able to validate the > occurrence more than once, on more than one KLR, in less than an hour- > - while 'trapped' in the Great Basin of Wyoming....please, no > comments about being a slow learner. grin. > > It was suggested that the fork brace might have contributed to the > fork seal failure--which I have yet to figure out exactly how that > could be.... > > The fork seals were a 'premium' after-market variety that showed > weepage at less than 1500 miles after installation (installed by PO > on the new to me, highly frakelized 98KLR). Upon replacement, the > aftermarket variety set side by side to the OEM--and found wanting; > as the aftermarket was not nearly as visually robust (=tall, it > required an additional washer on top to make up the proper height), > not as robust as the OEM that went back into the bike. > > List wisdom has suggested for some time, the BEST fork seal for the > KLR is the OEM--which is not an issue for me, at least. Based on a > side by side comparison, there is easily 25% more surface area on the > OEM seals than there were on the premium aftermarket seals. > > In conversation with the local KAWI dealer (Pierre, SD), men known > for their historical experience in motocross, trials, and drag bikes, > they were in heated agreement when I suggested that the OEM fork > seals were far superior to the aftermarket one. They went on to say > (in their opinion) that there is yet to be a seal that is as good as > an OEM seal, regardless of the brand.) > > But back to the fork brace. > Where I have a question is this-- > > Does someone here have some substantiation for believing the fork > brace contributes to the failure of the fork seals? > > The only, ONLY, thing I remember that made any sense to me, was that > because the fork gaiters are displaced, it MIGHT contribute to less > coverage, thus leakage of grit past the gaiter. I am reluctant to > think that is the case as the gaiter had a good snug fit against the > fork receiver during the tear down process. I am reluctant to think > that the gaiter was the problem, but might be convinced by > stories/experience to suggest otherwise. > > Presently the fork brace remains on the bench--awaiting list > wisdom.... > > 40F, sloppy gravel roads, and chilly smiles are in this weeks > forecast... > > revmaaatin. >

You could do an advanced search at the following and see what comes up. http://www.sae.org/servlets/index Alan

Rev, I'm top posting to keep it easy to find. Two things about the forks leaking. Aftermarket seals often leak MUCH faster than OEM in my experience. The "LeakProof" brand often has meant (to me) leaking soon on a bike near you. I'd suggest using genuine Kaw seals, every time. I've never had one leak that I know of, having done somewhere around a dozen rebuilds. It's a good thing, whether you have a fork brace or not, to lift up the rubber boots and remove buildup around the top of the fork leg. This can cause the seals to fail more quickly. Do a little p.m. every 6 mo's to a year. Some people like braces, some don't. I prefer one on my bike - but I make them. all the best, Mike

--- In DSN_KLR650@yahoogroups.com, "revmaaatin" wrote: > > Hello list- > > Does anybody have some motorcycle articles that I could read that > talk about fork-brace dynamics, when, and when not to use a fork > brace? List wisdom has varied on this topic; fork brace for highway, > but not off road; fork brace for off road, but not on the highway. > Then I notice, there are a number of road bikes with fork braces, and > the vintage mx bikes still run fork braces.... > > Sitting on my bench is an uninstalled Studebaker fork brace. Anybody > have the installation instructions, specifically torque values? I am > contemplating its re-installation.... > > Earlier last month I reported a couple of oddities that occurred > during my Great Divide Ride--one of which were blown fork seals, and > the other discovering that fork braces of the present low-profile ilk > don't work well, cough, at all if you get in gumbo mud...the tires > lack the ability to self cleanse at slow speed, and the sticky mud > results in a packed tire to fork brace interface--followed shortly by > face to mud impact. Yes Virgina, face to mud impact validated more > than once--to invalidate the chance of it being a fluke occurrence. I > liked the validation process so well, I was able to validate the > occurrence more than once, on more than one KLR, in less than an hour- > - while 'trapped' in the Great Basin of Wyoming....please, no > comments about being a slow learner. grin. > > It was suggested that the fork brace might have contributed to the > fork seal failure--which I have yet to figure out exactly how that > could be.... > > The fork seals were a 'premium' after-market variety that showed > weepage at less than 1500 miles after installation (installed by PO > on the new to me, highly frakelized 98KLR). Upon replacement, the > aftermarket variety set side by side to the OEM--and found wanting; > as the aftermarket was not nearly as visually robust (=tall, it > required an additional washer on top to make up the proper height), > not as robust as the OEM that went back into the bike. > > List wisdom has suggested for some time, the BEST fork seal for the > KLR is the OEM--which is not an issue for me, at least. Based on a > side by side comparison, there is easily 25% more surface area on the > OEM seals than there were on the premium aftermarket seals. > > In conversation with the local KAWI dealer (Pierre, SD), men known > for their historical experience in motocross, trials, and drag bikes, > they were in heated agreement when I suggested that the OEM fork > seals were far superior to the aftermarket one. They went on to say > (in their opinion) that there is yet to be a seal that is as good as > an OEM seal, regardless of the brand.) > > But back to the fork brace. > Where I have a question is this-- > > Does someone here have some substantiation for believing the fork > brace contributes to the failure of the fork seals? > > The only, ONLY, thing I remember that made any sense to me, was that > because the fork gaiters are displaced, it MIGHT contribute to less > coverage, thus leakage of grit past the gaiter. I am reluctant to > think that is the case as the gaiter had a good snug fit against the > fork receiver during the tear down process. I am reluctant to think > that the gaiter was the problem, but might be convinced by > stories/experience to suggest otherwise. > > Presently the fork brace remains on the bench--awaiting list > wisdom.... > > 40F, sloppy gravel roads, and chilly smiles are in this weeks > forecast... > > revmaaatin. >

That's a dead horse you can't beat enough. I added riding pants to my standard highway riding configuration earlier this year when a riding buddy got taken down at 70mph by a flying chunk of tire tread. He was wearing ATG except for pants. His nylon wallet literally saved his ass, taking the brunt of the skid and leaving him with a small raspberry as a souvenir of a very long slide next to the median. his Dainese textile jacket was toast, but didn't wear through to his skin. Still loving my bright orange Olympia Motosports jacket! All the best to your friend for a full and speedy recovery. __Arden --- In DSN_KLR650@yahoogroups.com, "fasteddiecopeman" wrote:

> > Guys, > > I'm going to "beat on a dead horse": > > Went for a ride with a good buddy yesterday - I was ATGATT, he had

on jeans, combat

> boots, heavy black leather jacket (NO armor), work gloves, and a

good full face helmet,

> blue. > > He was about 200 yards behind me, about 60 - 65 MPH right at

sundown heading north.

> Car coming towards us must've done SOMETHING to get my attention,

because as he

> passed on my left I looked into my mirrors to see him swerve into

my lane then apparently

> fishtail a bit then into the ditch on my left (his right), and I

could no longer see my buddy's

> headlight, so I stopped and turned back when I had 'cleared' the

road. I had NOT seen car

> #2 following the first in the other lane, as I was looking into my

mirrors.

> > I rode back several hundred yards in mounting horror as, by then, 2

to 4 cars were already

> stopped with 4-way flashers going, and I saw bits of motorcycle

scattered all over the road

> and my friend on his back in the middle of the road, a car in the

ditch about 25 yards past

> him (the first one that had been headed south...). I ran to him and

kept him still till the

> paramedics arrived. His bike was 20 yards off the road, and looked

as if it had been hit in

> the vicinity of the left fork and front wheel. > > He's in the hospital, and will be for quite a while. His injuries -

road rash up his spine

> where his jacket had ridden up (including pebbles under his skin),

as well as on his butt

> and legs where the jeans had NOT protected him, TWO broken legs,

TWO broken ankles

> (car #2 drove over at least one leg as he lay there BLENDING INTO

THE DARK PAVEMENT!),

> a smashed knee cap (probably when car #1 side swiped him with its

rear quarter), broken

> ribs and other internal injuries. His helmet took some pretty good

scraping as it protected

> his head, and his combat boots were scuffed pretty badly, but

didn't wear thru.

> > GUYS, FOR THE LOVE OF GOD WEAR YOUR GEAR!!! > > Ed :

Revmaaatin The front suspension on the KLR650 is inadequate for any serious off road riding because of the long 39mm forks that squirm around when introduces to riding forces. One improvement that can be made is to install a fork brace that will help the forks from twisting while riding. The only disadvantage of the fork brace is the mud clogging issue. I've had a fork brace on my 02 KLR for several years and wouldn't think of taking it off. I've never had a problem with mud clogging that would affect my ride. One thing that could help is to spray silicone on the fork brace prior to riding in mud. When riding off road you want to be able to put the front end where you want it to be and not have the forks twisting. It gives you better control to be precise. The same thing can be said for riding on the road. The biggest improvement that can be made to the KLR is to improve the suspension and the front brake. Any improvement that you make to the suspension will make the bike easier to ride. If you're just going to put put around then maybe suspension improvements are a waste of time and money but if you ride then suspension upgrades are worthwhile. I've never had an OEM seal leak on my KLR due to the fork brace or any other reason. In fact the bike still has the original fork seals. I do have boots on the forks to help keep the dust and mud from the seal area. just my $.02 Doug in NC At 01:18 PM 11/24/2008, you wrote:

>fork brace, fork seals on the KLR > Posted by: "revmaaatin" mjearl@... revmaaatin > Date: Sun Nov 23, 2008 6:14 pm ((PST)) > >Hello list- > >Does anybody have some motorcycle articles that I could read that >talk about fork-brace dynamics, when, and when not to use a fork >brace? List wisdom has varied on this topic; fork brace for >highway, but not off road; fork brace for off road, but not on the >highway. Then I notice, there are a number of road bikes with fork >braces, and the vintage mx bikes still run fork braces.... > >Sitting on my bench is an uninstalled Studebaker fork >brace. Anybody have the installation instructions, specifically >torque values? I am contemplating its re-installation....

---------- Doug Pippin 828-684-8488 d_pippin_89@... ---------- [Non-text portions of this message have been removed]