[QUOTE=Tweety;209305]BrakeTech has (or had) a good article about this on their website. they claim that warped rotors are actually rare. Uneven buildup of brake pad material causes eneven heating of the rotors. Their idea is that stopping with hot brakes and holding the brakes on causes a buildup where the pad sits still and bakes to the hot rotor.


In terms of fork tubes, the stiffness of a tube of a given wall thickness and material increases with the diameter squared. So doubling the diameter results in 4 times the stiffenss. Inverted forks put the large diameter in the triple clamp where the bending moment (leverage) is highest, resulting in a much higher stiffness, even though it is thin walled aluminum in the outer tubes. VTR forks have 41mm stanchions, CBR F4i, etc. forks have 43mm stanchions, CBR900RR forks are 45mm. This is why the VTR forks (and other older forks) in particular benefit so much from using a fork brace.

 

I'm in!

 

[quote=RCVTR;209308]Heh... you did the techie bit and I did the fluff part...

I have only seen warped rotors on one bike that wasn't caused by stupidly forgetting the disc lock... And that was the result of one pad having the channels blocked and overheating, leaving the disc a nice swirly colors blue...

 

[QUOTE=Tweety;209305]you may have something here tweety. several years ago i changed organic pads and replaced them with ceramic pads on my van within a short time the brakes began to shudder. Maybe it's a good idea to resurface/sand the rotor when changing pad types. I'll try it and see what happens.

thanks, nathan

 

I mentioned earlier about running this thru FEA to verify design intentions. I played around a little today at work to see what a brace would do in a mock environment.

The brace does work depending on the load direction being applied.

I ran my setup thru a frequency test to see the displacement values on the assembly with and without a brace added. As you can se in the right panel, it does help with displacement. These tests could of been conducted in a force application rather than frequency to get a better idea of the effects. But using a frequency I'm able to get a off the cuff idea of it it does anything or not. In short it helps in rigidity but to what extent...I wouldn't know without know all the parameters of the assembly (dimensions, materials, load values, etc). In this test the brace helps by roughly 9 inches of displacement given the conditions I applied to this FEA test. Obviously these results are exagerated as I do not know the dimensions and everything but it does show it helps with rigidity. To get a good idea of actual performance of the brace it would need to be run under multiple FEA runs and under various loads and directions.

See attachments...

 

The brace actually goes closer to the middle, atop the lower sliders, where its effect would be even more significant.

 

well Im having the part drawn up. Also getting a test piece cut on the water jet to ensure the bores will be precise enough.

 

Fixed

Also I forgot to mention these results vary in range from 400Hz-485Hz.

 

noticeably better I'd say.....

 

dam! you'd think that this much deflection would be be cracking the fender, wouldn't ya?

 

that position would be a rough ride, lol!


"Hey! Where'd my compliance go?!"

 

You'd be removing fillings in your teeth for sure . I think the scale of those is also around 1/400 . 1:1 would blow them apart.

 

might even losen those bugs in your teeth, huh?

 

I was wondering if we could get a general idea of the timescale involved. while I'd love to use this fork brace, I want to get one before I do any trackdays this year. but if they'll be a while in coming, I might just buy a coerce FB. I know these things take time, and its not an impatience issue. just trying to plan my season. holler back

 

Im having a blank cut out in the next few days to make sure the measurements are right.

Once everything checks out Ill have them cut out. Ill say 3 weeks untill I start shipping.

 

swordfish, you might be better off doin your trackdays w/o the fork brace if it's not ready and then you'll be able to eval the effects for yourself. I believe others who say that it is an improvement, and I will get one myself. But the reality is that the rider is the primary variable here, and the forkbrace is a superficial tweak comparatively. I've got plenty of experience at full lean with the hawk under all road conditions during the last 8 or 9 years, and the brace never crossed my mind til I read about it here.

nathan

 

The configuration he has with his cutouts would not cause the brace to be significantly weaker than if it were a solid chunk. Think of each bar or rib as a pin constraint.

 

it always messes me up looking at your posts cause you throw in the "nathan" at the end, and my name is nathan, so I always have that double-take moment. anyway, thats good advise, but I've done 2 trackdays at this track before with the hawk "as is". so I'll be able to make a decent comparison. and having any additional direction change ability will be obvious cause this track is all about the corners. anyway, 3 weeks is no prob. I just hope I have the bike out of storage in 3 weeks. friggin winter won't give up.

 

Ha!, Ditto..

What with all the Gregs and Nathans on this site.. Something odd with names and VTRs is going on.

 

Definately interested.

 

when you see nathan, do you sometimes wonder if you are reading your own post and don't understand why you would ever write such things? LOL. Should I sign, " another nathan" so there is no confusion.

Yeah, if you've been knee draggin you should be able to feel the diff, especially if the track surface is irregular on turns and if there are quick transitions; although it might be optimal to run the track a few times and then slap the brace on and run a few more. Do you have a steering stabilizer? or suspension mods.....i don't remember seeing anything on your signature.

thanks, another nathan

 

truck,

you need to concentrate on parts that aren't available ! design up a cool chain adjuster ( would be cool to incorporate spools ) & i'll be first in line.


tim

 

I see the name and its like someone spoke it. and I'm compelled to go "what?". anyway, I've got a 01' gsxr 750 front end that will be installed at some point but I'm still hunting for parts. so as a compromise for this season since I probably won't get the new front end on till the end of this season or the beginning of next, I'm gonna do some cheap improvements to tide me over till the big swap is ready to go. those improvements include a set of all ***** roller bearings and the fork brace.