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What am I trying to correct?

80 posts Started 1 Feb 2011 Last recovered post 26 Jan 2014 Wayback Machine snapshot 16 Jan 2022
#1 CornerCarver Thread starter

Ok. I have read every thread on this board related to USD fork conversions and the myriad ways to correct the steering geometry.

These [image: gallery_7288_2662_13186.jpg]

ZX14.jpg

are on the way and questions remain.

If i go with 929 lower and 954 upper triples, how has the geometry changed? Is my rake increased? Is my trail lengthened?

If I stay with the 929 lower, can a custom upper return the geometry to stock rake and trail?

For reference, as we discuss what needs to be corrected, I have included another image...

[image: gallery_7288_2662_12560.gif]

Rake and Trail.gif

#2 VIFFER93

Lots more variables involved,

- Length and Height of forks (I am not familure with zx-14 specifications)

- Length and height of rear suspension ( I raised the rear suspension 10mm ,some have left it stock)

- Offset of 929/954 triples compared to OEM

- Tire profiles will also affect your suspension settings.

Personally, I think a lot of it is taking the time to work out all the measurements because everyone has thier own combination of components. I do not think there is a defined formula.

#3 Veefer800Canuck
cornercarver

If i go with 929 lower and 954 upper triples, how has the geometry changed? Is my rake increased? Is my trail lengthened?

If I stay with the 929 lower, can a custom upper return the geometry to stock rake and trail?

- Trail will be lengthened.

- Both triples must have identical specs (hole spacing) or the fork tubes will not slide through them. Cannot have different upper and lower triples unless they HAPPEN to have exactly the same hole spacing (RC51 and CBR 929/954 share common hole spacing)

To combat the increased trail, you can raise the rear ride height. Your front will robably already be lowered from the shorter forks, though I'm not sure what ZX-14 fork length is.

#4 CornerCarver Thread starter

OK, the rear shock was purchased on the Elka group buy about 4 years ago and was built with 15mm increased ride height.

I have also rebuilt my 5th gen forks with Race tech gold valves and F3 internals and lowered the triples on the forks to drop them 18mm below stock height. the bike currently handles amazingly well for it's heft (and my heft).

Canuck, you are stating that the trail will be increase with the triple clamps that I mentioned. Is this because the offset between fork and steering stem is greater, thereby pushing the front wheel farther out in front of the axle centerline?

#5 Veefer800Canuck
cornercarver

OK, the rear shock was purchased on the Elka group buy about 4 years ago and was built with 15mm increased ride height.

Good, that should help.

Canuck, you are stating that the trail will be increase with the triple clamps that I mentioned. Is this because the offset between fork and steering stem is greater, thereby pushing the front wheel farther out in front of the axle centerline?

Because the distance between the fork holes and the steering stem is LESS, you have greater trail.

Look at your diagram above. Mentally move the forks "southwest" in the diagram.

See the "vertical axle line"? It just moved slightly to the left, correct? That makes the trail longer.

#6 CornerCarver Thread starter

Ok, just when I thought I was getting a grasp...I agree that the forks will move SW as you stated but in reducing the distance from axle centerline (and tire contact patch) to the point where a straight line down the steering stem would put the axle, I though you were reducing trail and making the bike less stable (lower trail-sometimes less stable at high speeds but easier to turn).

what am i missing? (besides the obvious- timmys Charm, Bailyrocks good looks, Sebs fabrications skills, etc...)

#7 SEBSPEED

keith - get the forks in hand, measure them, and we'll go from there.

#8 VIFFER93
cornercarver

Ok, just when I thought I was getting a grasp...I agree that the forks will move SW as you stated but in reducing the distance from axle centerline (and tire contact patch) to the point where a straight line down the steering stem would put the axle, I though you were reducing trail and making the bike less stable (lower trail-sometimes less stable at high speeds but easier to turn).

what am i missing? (besides the obvious- timmys Charm, Bailyrocks good looks, Sebs fabrications skills, etc...)

Your "Suspension Tube" line is moving SouthWest which moves the "vertical Axle" line back (to the left) but your "neck line" is remaining contant.

If you increase your suspension height in the rear, drop your forks further in the stem you will increase the angle of the "neck line" which shortens the "Trail"

Edited February 1, 2011 by VIFFER93
#9 VIFFER93
SEBSPEED

keith - get the forks in hand, measure them, and we'll go from there.

+1 on that.

#10 CornerCarver Thread starter

OK, Fedex says they arrive this Friday...I am just trying to get some triple clamps on the way as soon as possible.

#11 SEBSPEED
cornercarver

OK, Fedex says they arrive this Friday...I am just trying to get some triple clamps on the way as soon as possible.

I think you need to have a pizza party for your cnc guys. :wink:

#12 CornerCarver Thread starter
VIFFER93
cornercarver

Ok, just when I thought I was getting a grasp...I agree that the forks will move SW as you stated but in reducing the distance from axle centerline (and tire contact patch) to the point where a straight line down the steering stem would put the axle, I though you were reducing trail and making the bike less stable (lower trail-sometimes less stable at high speeds but easier to turn).

what am i missing? (besides the obvious- timmys Charm, Bailyrocks good looks, Sebs fabrications skills, etc...)

Your "Suspension Tube" line is moving SouthWest which moves the "vertical Axle" line back (to the left) but your "neck line" is remaining contant.

If you increase your suspension height in the rear, drop your forks further in the stem you will increase the angle of the "neck line" which shortens the "Trail"

AAAAAAAAAAAAHHHHHHHHHHHHHHHHHHH, that makes sense now..kinda.

Thanks

#13 VFR4Lee

Don't forget to adjust the "neckline" for maximum "cleavage". :beer:

#14 SAFE-T

The dreaded Paralysis of Analysis.

Just get a CBR929/954 or RC51 SP-1 lower and a CBR929/954 upper and forget about it.

#15 KevCarver
SAFE-T

The dreaded Paralysis of Analysis.

Just get a CBR929/954 or RC51 SP-1 lower and a CBR929/954 upper and forget about it.

Do you know the clamp diameters on the ZX forks? Honda seems fairly standardized at 54 lower and 50 upper, but as I posted earlier my old 636 USD were 52/50.

Again, need to have them in hand before going forward, I think..

#16 KevCarver

Maybe Concours triples would be more relaxed, more VFR like?

By the way, I have SP1 triples and a 954 upper in hand if you want to take a look at them. (and bent up 636 triple)

#17 CornerCarver Thread starter

Yes, I know I am over-analyzing it but my bike finally handles like I had hoped it would from the factory, and I definately don't to slow it down or lose much ground clearance...the fork tube diameters match up with Honda standard 50/54...

since I took my center stand off for track days I can't quite get consistent measurements of angles and dimensions I am going to pop for a rear stand or front chock and start taking better measurements this weekend.

These forks were measured (by the guy selling them so take that with a grain of salt) at 755mm in length so they are a bit shorter than my 5th gen forks but right in line with the RC-51 (sp-1) forks that I passed on so that I could have radial brakes...

Kevin, I may take you up on the offer to test fit with your triples before I splash to have some made or see what other options are out there...

#18 KevCarver

Hey, I got a pair of stands you can borrow if you want.

#19 Rice
cornercarver

OK, the rear shock was purchased on the Elka group buy about 4 years ago and was built with 15mm increased ride height.

I have also rebuilt my 5th gen forks with Race tech gold valves and F3 internals and lowered the triples on the forks to drop them 18mm below stock height. the bike currently handles amazingly well for it's heft (and my heft).

In my most humble of opinions, you have the bike sorted out pretty well as is.

If I can ever make the same statement, I ain't touching anything.

I wonder if any of the USD conversions done by others in the past have really yielded acceptable ROI.

Improved brakes, probably, although I wonder by how much really.

Same with the forks. I understand the improved stiffness and more knobs to turn, etc... BUT if you already have the thing sorted out. Why go through this and then face a chance of not being able to say that the bike handles even more amazingly well.

I guess to me, this suspension thing is more of a dark magic than a science and personally I'd be afraid of losing the 'magic'.

And yes, I do understand the desire to improve and change things. I'm the same way really.:comp13:

Good luck with it. :fing02:

#20 CornerCarver Thread starter

Good points Rice, and that is one reason it has taken me three years to pull the trigger on the USD conversion. But these forks are as I'm running now only have the tubes and brakes as they came from the factory.

Part of it is being committed to a Duc or Tiumph single-nut rear wheel and the requirement to de-link the brakes to pull that off and the other part is to see if I can make the bike handle as well as it is maxed out right now.

I wish Honda would hurry up and call back with the job offer, I bet them a years wages that I could make a VFR from their parts bin that would sell well enough to return a profit. :goofy:

Kevin, you busy Saturday...you are welcome to come over and pick up the Staintune... :fing02:

#21 Rice

Alright then.

But none of your mods will improve the top end of that bike.

I recommend replacing the old duct tape with new. You know, for looks and improved aredynamics :laughing6-hehe:

#22 CornerCarver Thread starter

IF i decide to keep the 5th gen bodywork, I have 3 brand new still in the wrappers Puig screens on the shelf, 1 each in clear, smoke and dark...If I go with something else they will be posted up on VFRd for sale.

You should read my winter mods list on Sebs thread winter mod thread....I actually mention going with new duct tape for the 2011 season. :laughing6-hehe:

#23 KevCarver

It took me riding a well sorted SP1 to commit to the swap, myself. I have been dissatisfied with the stock brakes for years, so that's why I didn't go with just an internal change. Thought I wanted radials, but when it came down to it I was just interested in the look of it. Love my stock RC51 brakes with stainless lines. They are fantastic!

Keith, have you seen the new Marvic Duc wheel? I think it's pretty bad ass! I'll try to find a pic in a little bit. (Linky)

Should be free on Sat.

#24 SAFE-T
cornercarver

Yes, I know I am over-analyzing it but my bike finally handles like I had hoped it would from the factory, and I definately don't to slow it down or lose much ground clearance...

Get Tony Foale's suspension analysis program (BLS has one...) and plug in your numbers, then. You will probably have to raise the rear ride height a bit to adjust for the increased trail. You will end up with slightly steeper rake than stock.

cassandtim made his own triples.

#25 CornerCarver Thread starter

Kevin, I will give you call around lunch tomorrow to check your saturday schedule, if you have time to come over, i would love to borrow your stands and test fit the forks with your triples...or we could meet somewhere in ATL. I saw that thread on the wheels but really like the look of these.

[image: gallery_7288_2662_213042.png]

OZ Forged.png

a little spendy but...pretty light

Safe-T thanks for the tip on Tony Foales program. I will pm Larry and see if he has time to plug in my numbers after I gather them this weekend. I saw TimandCass write up am trying to have some triples built as well but running into $$$$ issues. approximately $4,ooo is the quote from three sources...still the way that I would prefer to go. got a lead with Ben (Talldrinkofwater) here and he may have some good news soon, fingers crossed.

#26 V4 Rosso

[image: View Post]cornercarver, on 23 February 2011 - 06:15 PM, said:

Exchanging emails with Patrick about the CB600F triples and stem....looks like I have found my stock geometry triples for roughly half of what I was minutes away from droppng on the Gilles units!!!!!!!!!!!!
Are you sure the CB600F Hornet triples are a match for your forks? The Hornet has 41mm USD fork and your's is a 43mm.
#27 SEBSPEED

[image: View Post]V4 Rosso, on 24 February 2011 - 04:12 AM, said:

[image: View Post]cornercarver, on 23 February 2011 - 06:15 PM, said:

Exchanging emails with Patrick about the CB600F triples and stem....looks like I have found my stock geometry triples for roughly half of what I was minutes away from droppng on the Gilles units!!!!!!!!!!!!
Are you sure the CB600F Hornet triples are a match for your forks? The Hornet has 41mm USD fork and your's is a 43mm.

As far as clamping the USD forks in the triples, it doesn't matter what the tube size is. What matters for fit in the trees is the outside diameter of the sliders(the fixed upper part).
#28 SEBSPEED

[image: View Post]cornercarver, on 23 February 2011 - 09:44 PM, said:

[image: View Post]SEBSPEED, on 23 February 2011 - 06:26 PM, said:

[image: View Post]cornercarver, on 23 February 2011 - 06:15 PM, said:

Exchanging emails with Patrick about the CB600F triples and stem....looks like I have found my stock geometry triples for roughly half of what I was minutes away from droppng on the Gilles units!!!!!!!!!!!!

These are not as nice as the Gilles units but that saves me $700 to put towards the 848 wheels and rear axle... :fing02:

Gilles wants $1400 for that triple set?

Even worse, Honda wants $700 for a set of Hornet triples??   :comp13:

Gilles US distributor wouldn't work with me on pricing, their current price for the RC51 adjustable upper and lower triples with the steering stem was quoted at $1,383 USD.  I was drafting my ok to order email when I clicked on the link Finn36 had psoted and contacted that group.  They are cutting the triples with 40 mm of offset and 50/54mm diameter so it is not quite stock CB600F but they are working through the details with me.  I should be able to order when I get home from Chicago on Friday and then it is about 4 business days to delivery.

I can hardly wait.  I was agonizing over the issue of running non-stock geometry and now I will not have to do that.   :bliss:

I may even pop for the Carrozerria wheels now.   :fing02:

What made you change your mind about getting some made? To outsource those files I sent you would have cost $600-700 for one set, nevermind that it would have been lower for the minimum of three that we could have made? Guess I'm on my own once again with that.
#29 CornerCarver Thread starter
You are correct.  The CB600F is a smaller diameter USD clamping area than the forks I am using.  Patrick at I.M.A. can bore the clamp diameter to the 50/54mm specs needed with no issues.  He has even found a set of tapered bearings to suplly instead of the ball bearings that they provide as an option.

The stem diameter upper and lower is 26 mm and 30 mm respectively.  Will my VFR all balls tapered bearings work for this?

pics and dimensions next week for the forks...
#30 FinnRC36

[image: View Post]cornercarver, on 24 February 2011 - 06:51 AM, said:

You are correct.  The CB600F is a smaller diameter USD clamping area than the forks I am using.  Patrick at I.M.A. can bore the clamp diameter to the 50/54mm specs needed with no issues.  He has even found a set of tapered bearings to suplly instead of the ball bearings that they provide as an option.

The stem diameter upper and lower is 26 mm and 30 mm respectively.  Will my VFR all balls tapered bearings work for this?

pics and dimensions next week for the forks...

Your bearings will work as those are the exact dimensions of the VFR stem and I also checked that the CB600F has the same stem bearings as VFR.
#31 CornerCarver Thread starter
:cheerleader:   WOOO HOOOO !!!!!!!!!!!!
#32 Vee-Ef-Ar
Double woo hooo's
Somebodys excited.

Don't blame ya   :cheerleader:
#33 V4 Rosso

[image: View Post]SEBSPEED, on 24 February 2011 - 06:42 AM, said:

As far as clamping the USD forks in the triples, it doesn't matter what the tube size is. What matters for fit in the trees is the outside diameter of the sliders(the fixed upper part).
I know, but expect them to be closely related with the (wall) thicknes of the slider bushing and outer tubes being equal.

I looked at both the cb600f and cb1000r triples today and they look very similar. The cb1000r does have the bigger 43mm fork tubes. Both 600 and 1000 have the same rake and trail figures.

[image: Posted Image]  [image: Posted Image]

The cb1000r has a beefier lower triple. Maybe the stem length is a bit longer than that of the VFR. The length of the neck is about 205mm.
#34 CornerCarver Thread starter
[/quote]

What made you change your mind about getting some made? To outsource those files I sent you would have cost $600-700 for one set, nevermind that it would have been lower for the minimum of three that we could have made? Guess I'm on my own once again with that.
[/quote]

Sebastian, I missed this post ealier today before work.

Co$t made me change my mind.  

Of the 5 places I contacted to bid the upper and lower machine work, 3 replied.  One could only do the upper ($800)  and the other two wanted either "about $2600 deoending on how much programming time" to $3600 for the CNC programming and a sample set of parts.

Patrick at IMA has been a pleasure to communicate with and since I don't need the CB600F risers my final qoute due tomorrow should come in right at $600 including tpaered bearing, steering stem and shipping. :biggrin:

If these prove out then we have found a ready source of USD triples with proper geometry at a reasonable cost, and a qty discount may be available if some enterprising VFRD memebers decides that USD fork kits is a niche to be filled   :fing02:
#35 CornerCarver Thread starter
Got an email from Patrick at IMA this morning.  Said they shipped my upper and lower triples, steering stem and that he had sourced a tapered bearing for the lower since I passed on his ball bearing standard.  He asked me to let him know when I received them and what my thoughts were.  

I replied that I am leaving for Vegas soon and although I could let him know when they arrived I wouldn't be home to see them or mock up the mounting until next Friday.

37 minutes later the doorbell rings...FedEx...


pics to follow.   :cheerleader:
#36 SEBSPEED

[image: View Post]cornercarver, on 03 March 2011 - 10:48 AM, said:

pics to follow.   :cheerleader:

You've had 26 minutes... where's the pics?!? :goofy:
#37 KPerham
Keith, shoot me your email. PM or email: kperham986 at hotmail
#38 CornerCarver Thread starter
Well, here we go, no turning back now.

The package left Italy on Tuesday of this week...

[image: Posted Image]
2011-03-03_10-19-48_51.jpg

and arrived at my door Thursday before 1030 AM.

I was a little anxious.

[image: Posted Image]
2011-03-03_10-20-36_472.jpg

everything looked good inside.

[image: Posted Image]
2011-03-03_10-20-49_772.jpg


Stock VFR geometry in a 50/54 USD fork set of triples...

[image: Posted Image]
2011-03-03_10-20-58_930.jpg

A little packaging gave it's life to protect the contents, nothing scatched or marked on the triples.

[image: Posted Image]
2011-03-03_10-22-37_530.jpg

Patrick even included the tapered bearing and seal for the lower...I have to decide whether to re-use my all balls upper or source another just for the upper.

[image: Posted Image]
2011-03-03_10-22-52_19.jpg

The lower with the styo-beads from the packaging still clinging to it, one last chance at relevance before I grab the airhose and blast the beads into obscurity.   :biggrin:

[image: Posted Image]
2011-03-03_10-23-09_875.jpg


I know the issue was raised earlier about whether the CB600F triples (with a non-standard bore of 50/54 mm) would be sturdy enough for the heavy VFR800...I think the above pic answers that question.

I will also post up some pix of themock up later this weekend when i get a minute and before I drop my forks at Traxxion Dynamics for the gold valves and re-spring...

:cheerleader:    :cheerleader:    :cheerleader:

Three Cheers for IMA and Patrick and for Finn36 who suggested I take a look at what they had to offer....
#39 SEBSPEED
Cool! They sure do look beefy!

How's the stem attach, I assume it's bolted in vs press fit?

I see they left the holes for the bar risers in the upper, did you have the option to have them omitted?
#40 CornerCarver Thread starter
Real beefy, the bottom has 4 bolts for clamping.  I told Patrick that I didn't need the bar risers and he deducted them from the cost.

The stem I am still undecided on.  It appears to be solid.  There is no hole in the top or bottom and it must have been pressed in. No place for a powerlet outlet in the stem now.

I just mounted my ignition to the top triple and set one of these in place...

[image: Posted Image]
ZX14.jpg

Looks great.  So much to do still...I can have the forks mocked up this weekend but without a front wheel to fit nothing more so I think I am dropping my forks in Woodstock tomorrow to leave with those guys...
#41 V4 Rosso
Looks good :fing02: I hope the install is a breeze.
#42 Vee-Ef-Ar
Nice CC... all systems go mate.
#43 KPerham
Have you had any chance to do anything more? If you go ahead with your tail idea, give me first crack at your Sargent?
#44 V4 Rosso

[image: View Post]KPerham, on 10 March 2011 - 03:37 PM, said:

Have you had any chance to do anything more?
:+1:
How long is the steering stem of the CB600F as IIRC the neck of the CB is quite a bit longer than that of my VFR. I can't find my notes right now but thought the CB is somewhere near 205mm and my 3rd gen VFR 170mm.

In the picture it looks like it is rather long:
[image: Posted Image]

Is the neck of the later gen VFRs (5th & 6th) that much longer than the earlier versions?
#45 CornerCarver Thread starter
OK, just got back from Vegas tonight...mocked up the front end.  i really need a front wheel to work out my axle, bearing, spacer and brake rotor offset spacing/dimensions...

OK, what happened to the picture posting link???? I just figured out to post a pic last year   :blush:   and now the thing I used to click is gone...
#46 V4 Rosso

[image: View Post]cornercarver, on 10 March 2011 - 11:26 PM, said:

i really need a front wheel to work out my axle, bearing, spacer and brake rotor offset spacing/dimensions...

I am getting a SP1 wheel (with 954 wheel bearings) as that looks very similar to my stock front wheel (6 spoke). Also the mating surfaces for the rotors are spaced 117mm apart so it seems stock SP1 rotors will work but are 320mm. 310mm Fireblade or CBR600RR rotors have the same bolt spacing and offset so are also an option if you do not want to use caliper spacers.

I also looked at what fender to use on the ZX fork and think the R6/R1 fender looks best and comes closest to the rear mounting bracket (yellow dot). It doesn't look too difficutl to fabricate the front mounting bracket.
[image: Posted Image]
#47 CornerCarver Thread starter
My forks are up Traxxion in Woodstock...should be back by next weekend...

My triples are at a local machine shop for some work.   :blush:

When I mocked the front end up I did not yet have the lower bearing on and couldn't tell that the area where the stem goes is not the same from the VFR to the CB600F.

I have spoken to Patrick about it and he has made this change before but does not think it worth the cost to return ship to Italy and back to me.  He recommended removeing "some" of the material that interfers on the lower triple and spacing the bearing upward, as the Cb600F has a longer steering stem than the 5th gen.

I didn't steering stems were still growing in length.  I knew that that was one are of progress from the mid 80's to the late 90's as the triples being further apart provides more front end rigidity in the clamping of the fork tubes.

When I dropped the forks off at traxxion we found that one of them was bent and about 15 thousandths out, they will also straighten both forks (the other was out 3-5 thousandths - the tech said this is caused by overtightening the triple clamp on the fork tube.)

Here are a few pics to explain what I am seeing.

Once I have the details worked out I may make 5-10 kits for sale if there are enough guys interested.  PM now if you want and i will keep you up to date with additional info.

[image: Posted Image]

space above the triple for top mounted clip ons...

[image: Posted Image]


Not too bad but the ZX14R clip ons have to go...look kinda weird with the bolt holes.

[image: Posted Image]


A little tight so I will work out the wheel and brake selection option when I get the forks back....prolly going with a set of wheels from OZ.
#48 V4 Rosso

[image: View Post]cornercarver, on 22 March 2011 - 05:03 PM, said:

space above the triple for top mounted clip ons...
You had to raise the forks 1" through the triples to get stock geometry?
#49 CornerCarver Thread starter

[image: View Post]V4 Rosso, on 25 March 2011 - 10:08 AM, said:

[image: View Post]cornercarver, on 22 March 2011 - 05:03 PM, said:

space above the triple for top mounted clip ons...
You had to raise the forks 1" through the triples to get stock geometry?

No, the ZX14R forks are pretty long.  I will get the exact dimensions on them when they come back from Traxxion next week but I matched the distance of the front axle from the steering stem bearing and had plenty of room above the top triple for the bars to mount.

much to do still but Friday I saw the steering stem and it has been pressed out and cut down to the correct lenght.  The bottom triple goes into the lathe (or vise) this week...getting tight on time to source wheels for this conversion....
#50 CornerCarver Thread starter
OK, I have the forks and triples back in my hands finally.

I pressed the bearing on and mounted the triples, slide the forks into place and put the axle in.

Started to repeat my measurements taken prior to disassembly, and found that I couldn't find my notes from a month ago.... :mellow:

So, can anyone compare these numbers for me?

With approximately 25.4mm of fork tube showing above the top clamp I have:

524mm from the bottom of the steering neck to the center of the axle.

I have 162mm between the inside surface of each axle.

It apprears that the fork tubes are centered 203mm apart and that I have 133 mm between the brake caliper centers.

I think that the fork spacing should have been 205mm and the process of boring the CBR600F triples to the proper fork diameter has changed the fork tube spacing.

Can anyone tell me what their distance is from the bottom of the steering neck to the center of their axle with stock geometry?

Also, anyone with prior Frankenviffer experience know of wheel/brake options with similar measurements that may only require spacers to be fabbed?

Lastly, anyone in the Atlanta area have a front wheel with a 25mm axle that I can use to mock before laying out the cash for a wheel and brakes that "Might" fit?

Thanks,

keith
#51 Switchblade
Cant help but nice write up. I think everyone RIDING    !!!!!!!!!!!!!!!!!!
#52 FinnRC36
The '10 CBR1000RR has rotor outer surface to outer surface distance of 138mm measured by me. That works out to 133mm center to center with 5mm rotor thickness. This should be the same for '08 onwards and the axle is �25mm and rotors are �320mm. Hope this helps   :fing02:


[image: View Post]cornercarver, on 08 April 2011 - 06:43 PM, said:

OK, I have the forks and triples back in my hands finally.

I pressed the bearing on and mounted the triples, slide the forks into place and put the axle in.

Started to repeat my measurements taken prior to disassembly, and found that I couldn't find my notes from a month ago.... :mellow:

So, can anyone compare these numbers for me?

With approximately 25.4mm of fork tube showing above the top clamp I have:

524mm from the bottom of the steering neck to the center of the axle.

I have 162mm between the inside surface of each axle.

It apprears that the fork tubes are centered 203mm apart and that I have 133 mm between the brake caliper centers.

I think that the fork spacing should have been 205mm and the process of boring the CBR600F triples to the proper fork diameter has changed the fork tube spacing.

Can anyone tell me what their distance is from the bottom of the steering neck to the center of their axle with stock geometry?

Also, anyone with prior Frankenviffer experience know of wheel/brake options with similar measurements that may only require spacers to be fabbed?

Lastly, anyone in the Atlanta area have a front wheel with a 25mm axle that I can use to mock before laying out the cash for a wheel and brakes that "Might" fit?

Thanks,

keith

#53 KPerham

[image: View Post]FinnRC36, on 10 May 2011 - 02:06 AM, said:

The '10 CBR1000RR has rotor outer surface to outer surface distance of 138mm measured by me. That works out to 133mm center to center with 5mm rotor thickness. This should be the same for '08 onwards and the axle is �25mm and rotors are �320mm. Hope this helps   :fing02:


For what it's worth, I measured the RC51 from the outside edges of the rotors and got 141-142ish.
#54 CornerCarver Thread starter
Well, with this [image: Posted Image]
2011 05 02 16 19 52 851
and the recovery from it I was not able to complete the conversion before TxMac.

So I bought Earthshakes 5th gen. :cheerleader:

For the past 3-4 years, every time I saw him and his bike I called "dibs" on it whenever he was ready to sell.

I am sure that you have probably read that he bought a Ducati Multistrada last month so...he made me an offer Ii could not refuse on his VFR.

I rode it home from Greenville this past Saturday (collar bone was still a little tender two weeks after the surgery) but I need to set the sag, change the front brake pads (incuded by Bill - what a guy!) and get ready for the ride...I will pick this project back up as time allows.  At least I have a bike VFR to ride while I am working on this conversion...also was able to pick up an 848 front rim to test the fit.

more to come, maybe in June-July.

Finn, thanks for the heads up on the CBR rotor spacing...It's good to have friends and options on parts. :fing02:
#55 V4 Rosso
That's a lot of hardware they've put into your collar bone   :mellow:

btw, if you increase contrast of the x-ray by a fair amount you'll notice there is an alien hiding in there   :blink:
[image: Posted Image]
:laugh:

Contrats on the addition to the stable :fing02:
#56 YoshiHNS

Wow. Someone really wanted those forks on that bike. And I'm a little bit confused on what's going on with the top stem nut, er..bolt?

#58 Rush2112

Boy, those have got a lot of meat on them... I guess they are going for the industrial look :huh:

#59 SEBSPEED
Rush2112

Boy, those have got a lot of meat on them... I guess they are going for the industrial look :huh:

It's not that they have a lot of meat... well, it is,... but that's because they've skipped a lot of the dress-up features which drive up the labor and therefore the cost.

I do the same with my custom sets.

I made these for a guy who wanted to adapt Hayabusa forks to a GS1000-

[image: 8951136f.jpg]

[image: 70f02bbf.jpg]

This is one of the more fancy parts I've made. Still basic, but has a nice shape. Counterboring the stem pinch bolt was slightly challenging.

[image: 4D6B5C16-F230-44C8-9AFF-C4BB7C1A7761-288]

[image: 6E6BB10E-6144-48E5-A360-56F4154E3177-288]

[image: B66EF175-ECA7-4287-A0FA-EF5BFC4BFAE4-288]

#60 Rush2112
SEBSPEED
Rush2112

Boy, those have got a lot of meat on them... I guess they are going for the industrial look :huh:

It's not that they have a lot of meat... well, it is,... but that's because they've skipped a lot of the dress-up features which drive up the labor and therefore the cost.

I do the same with my custom sets.

...This is one of the more fancy parts I've made. Still basic, but has a nice shape. Counterboring the stem pinch bolt was slightly challenging.

I guess that is more accurate... the other shape was blocky, less work put into the aesthetics.

Your work looks outstanding with nice shape, form, and function. :beer:

#61 Rush2112

Does anyone have a CAD drawing or similar format for 54/50 triples with VFR geometry to loan or sell that will allow me to provide to a machine shop for a quote?

#62 Switchblade

Does this mean I get my $250 deposit back ?

#63 Rush2112
Switchblade

Does this mean I get my $250 deposit back ?

??? Was there a custom triple group buy that I'm unaware of?

#65 Rush2112

Anybody have VFR800, RC51, 929/954 steering stem available for measuring? What is the length of the steering stem?

Someone posted earlier a link to a fork conversion table for All Balls Racing and I'm trying to see if there are other options... the unknown is the steering stem length.

#66 SEBSPEED

Just go buy a used Honda triple for as little $$ as possible, and take the stem out. In an accident, 9 times out of 10 the stem is fine and the triple gets tweaked. So finding a cheap tweaked triple with a good stem should be easy.

Then you can press that into your new custom lower triple.

#67 YoshiHNS

The all balls site has the fork conversion. You look up your bike and it gives the steering head bearing ID, OD, and heights, and those of other bikes that are or are close to the same. It's up to you to figure out which bearings you need to use and decide if it is really going to work.

#68 SEBSPEED
YoshiHNS

The all balls site has the fork conversion. You look up your bike and it gives the steering head bearing ID, OD, and heights, and those of other bikes that are or are close to the same. It's up to you to figure out which bearings you need to use and decide if it is really going to work.

It gives you bearing stack heights, not stem lengths.

#69 YoshiHNS
SEBSPEED
YoshiHNS

The all balls site has the fork conversion. You look up your bike and it gives the steering head bearing ID, OD, and heights, and those of other bikes that are or are close to the same. It's up to you to figure out which bearings you need to use and decide if it is really going to work.

It gives you bearing stack heights, not stem lengths.

Right, just bearing dimensions. So it will give you an idea if a different stem even has a chance to fit. Still need to get the stem lengths and compare.

#70 V4 Rosso

CBR929/954: from base of the lower triple to the top 8"7/8. Bearing surfaces on the steering stem are spaced 7" apart (outer dimension).

#71 Rush2112
V4 Rosso

CBR929/954: from base of the lower triple to the top 8"7/8. Bearing surfaces on the steering stem are spaced 7" apart (outer dimension).

Thanks Man!

Anybody know if the RC51 is the same?

SEBSPEED

Just go buy a used Honda triple for as little $$ as possible, and take the stem out. In an accident, 9 times out of 10 the stem is fine and the triple gets tweaked. So finding a cheap tweaked triple with a good stem should be easy.

Then you can press that into your new custom lower triple.

Will the VFR (or RC51 or 929/954) stem be long enough if the custom triples are... let's say, an 1" thick aluminum alloy?

#72 SEBSPEED

It doesn't matter how thick the triple is really. You'll just size the hole and then press the stem to the depth required to achieve the height above the top surface of the triple.

#73 Switchblade

In this day of customizing everything it is hard to believe nobody what produce a generic blank (Honda or Kawasaki or whatever) triple that can be bored to the bottom that you wanted to use ....

#74 Rush2112
V4 Rosso

CBR929/954: from base of the lower triple to the top 8"7/8. Bearing surfaces on the steering stem are spaced 7" apart (outer dimension).

When using the CBR929/954 for a fork swap are there any threads exposed above the top nut? If yes, how far does it extend past the nut? If it doesn't extend beyond the nut is there complete engagement of all the nut threads with the steering stem?

#75 Dutchy

Would a complete '01 CBR954 front end (forks, triples, wheel, rotors) be a pretty much straight bolt on for a 4th Gen?

#77 JamieDaugherty
Switchblade

In this day of customizing everything it is hard to believe nobody what produce a generic blank (Honda or Kawasaki or whatever) triple that can be bored to the bottom that you wanted to use ....

I wish it was that easy! In the end I've found that I can make custom triples to the precise dimensions I want for about the same price. It pays to have suppliers that you've developed a good relationship with!

#78 Switchblade
JamieDaugherty
Switchblade

In this day of customizing everything it is hard to believe nobody what produce a generic blank (Honda or Kawasaki or whatever) triple that can be bored to the bottom that you wanted to use ....

I wish it was that easy! In the end I've found that I can make custom triples to the precise dimensions I want for about the same price. It pays to have suppliers that you've developed a good relationship with!

:wheel:

#79 Rush2112

I've spent hours researching offsets and trail numbers and reading Race Tech's Motorcycle Suspension Bible. The data shows most of the best handling bikes have around a 30mm offset with high 90s to low 100s trail values (CBRs, GSXRs, R1s... early R1s and RC51s are exceptions) and rakes of 23* to 24*; this was also confirmed by a reliable suspension expert.

The stock 5th gen VFR chassis geometry doesn't cut it for this application... and it wasn't designed too. No fault, no grandiose claims that I can engineer better than Honda. Just me attacking a challenge to take something I love and adapt it to a new, more specific application.

Based on this, and some more expert input, I'm going to shoot for an initial set-up of 30mm offset, around 102mm trail, and ~24* rake on my 5th gen track bike. My '09 ZX14 50/54 USD forks are scheduled for delivery tomorrow... so I can start the measuring and wrenching and stop the jabbering!!! Build thread to follow...

#80 KevCarver

My unscientific and nearly accidental settings are CBR/RC51 offset, combined with the front as low as the clutch master cylinder allows (due to hitting the fork) and the rear end shimmed 5mm on the shock mount bolt. It's stock length, and that's where I ran out of threads. Turns out it works. At least for me.

End of thread · 80 posts recovered Wayback Machine snapshot 16 Jan 2022