Fork Swap - Steering stem?

[SEBSPEED]

I'm glad the spreadsheet is finding some use and being built upon. If anyone is curious about the reliability of any of the numbers or sources listed, I can give an idea about which ones I think are 100% correct and which ones may be less than perfect.

Lacy

Lacy, I'm glad you started it, thank you! To be honest, I've been giving you credit the few times I've posted it - only reason I didn't today is because I wasn't sure anymore if you did start it. :blush: In the latest copy I have here, I've added rows for individual wheel weights, and assembled fork weights, just for the heck of it.

I added the other VFR gens and CBR models to hopefully build on going forward - the lengths listed there now are merely best guesses based on internet info - it is only worth what you're paying for it!! I hope to build on & correct the dimensions as parts pass through my shop. :fing02:

[taglicious]

you guys are yet again making this dream happen for the rest of us late comers.

thanks to all whom made the configurations and did the leg work for this to happen. WOOHAA

I wish I'd have kept all the forks I've seen listed here since they've all made a trip through the shop at one time or another... DAMN IT

Edited November 18, 2010 by taglicious

[mrmatt]

Thanks for checking SEB, appreciate it.

Any idea how that compares to the 05 R1 forks you're bolting up?

I prefer to use parts I know going in will work, but cheaper options are always welcome :)

I'll let you know about the R1 forks when they get here on Friday. :wink:

A quick run to the garage with a tape measure (Seb can check my work)

04-06 R1

Top of cap to top of axle: 714mm

Axle: 22mm

Top of cap to center of axle = 725mm

[SEBSPEED]

thanks to all whom made the configurations and did the leg work for this to happen. WOOHAA

Pun intended? :biggrin:

A quick run to the garage with a tape measure (Seb can check my work)

04-06 R1

Top of cap to top of axle: 714mm

Axle: 22mm

Top of cap to center of axle = 725mm

Thanks Matt. Did you measure the leg bare? Out of triple, on its side, fully extended, etc?

[V4 Rosso]

Lacy, thanks for starting the list. I thought it was JZH that had to be credited for it, my bad.

I would take those Internet sources as a rough guide, and trust "primary sources" such as Seb's measurements of the CBR forks as the most accurate:

I agree. Unfortunately this kind of info is not available through manufacturer service manuals. For fork length you always took the length between the top of the fork leg and the centre of the axle?

I'll add SEB's data too, thanks SEB :fing02: I'd also like to add data like brake disc size and offset and I see SEB has allready added some of that to his spreadsheet.

I'm glad the spreadsheet is finding some use and being built upon. If anyone is curious about the reliability of any of the numbers or sources listed, I can give an idea about which ones I think are 100% correct and which ones may be less than perfect.

Please do. And if anyone else can contribute please do too. Currently the spreadsheet can be edited directly by anyone. I realise that this may lead to unreliable data being added, have to look in how to minimise that risk.

[SEBSPEED]

For fork length you always took the length between the top of the fork leg and the centre of the axle?

Good point!

We need to establish some consistency if this is going to be worth anything.

If we make drawings of some of the parts showing where/how to measure the forks & triples, and add that to another sheet within the xls that should help - it'll be down to the person's measuring tool and knowledge of its use.

[luigi]

Post is below

[YoshiHNS]

Here's the pictures about the extracted stem:

My link

My link

My link

Ciao, Luigi.

Have to be a member of the board. Can you upload them to VFRD or something? This was the route I was thinking about going, possibly.

[SEBSPEED]

Have to be a member of the board. Can you upload them to VFRD or something? This was the route I was thinking about going, possibly.

Yosh, I can show you details when you stop by Saturday. I have done this and have stems & parts laying about you can study.

[luigi]

is what steering stem is used on the conversions. I saw that the SP1 stem works, but is that the only option? Are there any others that can be considered from others'...

Hello.

I can tell you that many Honda stems are the same which VFR uses, perfectly the same.

On my "track use VFR" that now fits a GSX-R 1100 conventional forks i have used a stem coming from a 1987 CBR 600 (in USA called Hurricane) inserted in the Suzuki lower clamp.

The only modification required is welding a "lip" in the lower edge of the stem to lock the two parts once everything in assembled.

Like the VFR this stem are in one-block with the lower clamp too , but it's enough remove the welding joint with a lathe to have a stem that can be used on great number of lower clamp.

Here' the pictures:

1987 CBR 600 Stock clamp - Bottom Welding.jpg

This is the bottom of the 1987 CBR 600 lower clamp. Pencil shows the welding.

1987 CBR 600 Stock Clamp - Welding Removed.jpg

This is the stem after the welding removed. To extract it i've used a common workshop hydraulic press.

CBR 600 - VFR 800 Stem comparison.jpg

The CBR stem compared with a 5th gen VFR 800 lower clamp. Absolutely the same.

Note at the CBR lower edge the "lip" welded to assure the complete fixing once the stem are inserted in Suzuki lower clamp that i've used.

11th March 2009

Here the GSXR 1100 front fork installed.

Ciao, Luigi.

[SEBSPEED]

I believe 04-07 CBR1000RR forks are the same, length was quoted serveral times at 725mm, stock. Be good if you could confirm Seb (always had me doubts).

I was tempted to buy them, not only are they plentiful, but they're cheapish compared to RC kit.

The 08-09 are listed shorter at 700mm.

I would love radial calipers, but I also wanted to increase the ride height overall.

I just wasn't exactly sure if there was enough space to mount bars above the triple, even with the gullwing design.

If I was living in the US, I'd have forks running out me ears.

Stock 98-01 VFR forks came in at 800mm.

I just finished measuring both fork sets.

I took one leg from each set, bare but ready to install, and laid each on my workbench. Measured each leg twice with my 62cm Starret vernier caliper. Then measured again with a regular standard tape measure and converted to mm to compare.

Obviously the vernier calipers are not long enough to measure in one step(only 620mm available), so I set them to 600mm and measured from the top of the cap down, made a felt pen mark at 600. Then took an inside measurement from the very bottom of the axle hole to the mark. Added the two dimensions, and subtracted the radius of the axle hole to get the overall length. (I measured the leg with the larger hole in each case, FYI)

Here are the results:

04-05 CBR1000RR fork

length = 710mm

axle dia = 32mm

Fork cap to axle center length = 694mm

06-07 CBR1000RR fork

length = 720mm

axle diameter = 32mm

Fork cap to axle center length = 704mm

The 04-05 fork(s) are freshly rebuilt with stock internals. The 06-07 forks are used, internals unknown.

I am looking into modifying the internal top out spring in my 04-05 forks to allow for more extension.

Kept forgetting to post this up... left to right:

00 R1 - 05 R1 - 06/07 1000RR - 04/05 1000RR

All have stock internals(as far as I know)

[JZH]

Lacy, thanks for starting the list. I thought it was JZH that had to be credited for it, my bad.

Yes, I was going to point that out... My spreadsheet was Honda-only. The main reason why I ditched it was due to my naiive inclusion of second-hand data that I had thought reliable. As soon as I realised it wasn't (e.g., the "common knowledge" regarding the 929/954/SP1 fork offset circulating on the RC30 Yahoo Group turns out to have been WRONG) I realised that my data had been irretrievably polluted. End of, as far as I was concerned--until I'm able to start over using 100% my own measurements, which is unlikely to happen any time soon.

Why not CBR1000RR forks? Yes, they're trick, in that they have radial brake calipers, but they're quite short and the quality deficit compared to the RC51/SP1-2 forks is fairly obvious once you have both in your hands. The RC51 forks are the right size and are very well built. If quality matters to you, get RC51 forks, not CBR forks.

Ciao,

[SEBSPEED]

If quality matters to you, get RC51 forks, not CBR forks.

Ciao,

Say what now? :blink:

What are these differences you speak of? (as I haven't noticed them?)

[Vee-Ef-Ar]

Here are the results:

04-05 CBR1000RR fork

length = 710mm

axle dia = 32mm

Fork cap to axle center length = 694mm

06-07 CBR1000RR fork

length = 720mm

axle diameter = 32mm

Fork cap to axle center length = 704mm

Seb, did you take the measurements from those pictured forks?

I ask, cause I was under the belief the gold forks were only on Repsol blades, or 600RRs.

I could be forking confused however.

[SEBSPEED]

Sorry for the forking confusion, but I have to say I'm glad I fooled you - those are my "NOHLINS" forks. I painted a set of 1kRR forks to look like Ohlins: http://www.vfrdiscussion.com/forum/index.php/topic/63614-fake-ohlins-forks/

[Vee-Ef-Ar]

Haha, the thought had entered my mind.

Then, after searching a few blade forums, ebay pictures, and old emails...

it completely vanished and I hit the "add reply" button.

Honest!!! :biggrin:

Came up trumps mate.

Now, those RC51 forks you have... :goofy:

[kgsmotorcycles]

I ask for input from those lucky to run sp1/2 forks?

What yokes are being used? Are they risen through the yokes a lot?

i only ask as running 929/954 yokes with their relative off set means the 929/954 forks want dropping thru the yokes about 19mm to stop the VFR from running very wide on every bend.

Therefore, longer sp1/2 forks will want dropping even more as they are longer running the 929/954 yokes to get a similar performance. The only advantages might include to add the handle bars on top of yokes comfortably rather than under, handy for keeping standard VFR bodywork and the SP1/2 are race bread items. :fing02:

From practice, i have found the 45mm CBR 98/99 forks, running custom yokes with only a 3-5mm drop was spot on. The custom yokes i guess were CBR custom race replacements being the 45mm.

The guy i got them from said they were made for the VFR, but as a one off i find that hard to believe. But as we know, Fireblade CBR parts being interchangeable its all neither here nor there.

I simply reused my VFR steering stem pressed into them 45mm yokes. Most important here is the offset felt like it was similar to the standard VFR. Unlike the 929/954 and on CBR yokes with their gull wing shape and further offset. Handling was spot on with the 98/99 set up right from the off, unlike my 929/954 set up, which is still in need of minor tuning.

CBR900 98/99 forks, race yokes, similar steering feel as standard VFR750

Above, No drop through yokes needed (maybe 3-5mm max) as i am sure there is no similar offset to the CBR929/954 gull wing yokes as below.

CBR 929/954 forks with yokes.

note 19mm fork drop needed to get bike round corners.

Visually the shots here in comparison the 45mm items on top look as tho they might be further forward than the 929/954 yokes. I dont have them to hand anymore so cannot measure for sure. The gull wing design might also be deceiving?

My ideal wish list would be 50mm custom yokes without the 929/954 yoke offset to run sp1/2 forks. Although these imaginary yokes might well make the newer blade forks too short to run comfortably..

[JZH]

If quality matters to you, get RC51 forks, not CBR forks.

Say what now? :blink:

What are these differences you speak of? (as I haven't noticed them?)

Have you had both forks apart at the same time and compared their components? The only nicer thing about the RR forks is the radial caliper mounts; everything else screams "built to a price" to me.

Ciao,

[SEBSPEED]

Negative, they are the same. I have successfully mix & matched 929/954 & 1000RR triples. Bottoms with tops and tops with bottoms.

My apologies to MrMatt - I found out today that what I stated above is INCORRECT. The offset for the 1000RR is significantly LESS than on the 929/954 - the triples can NOT be mixed!

Very sorry for any confusion!! :blush:

[KevCarver]

Was messing around in the garage today and decided to stick my forks together for a comparison:

SP1/'03-'04 636/5th Gen

On the Kawi forks, the bottom clamp diameter is 52mm and the top is 50mm. SP1 is 54mm and 50mm.

As you can see, the Kawi and SP1 forks are essentially the same length.

The stem on the 636 is too big to fit any bearings into the VFR head, but the stem is pressed into both of the bottom clamps, and both are 35mm. In theory the SP1 stem could be fit into the 636 bottom clamp.

I tired putting the 636 forks in the 636 bottom clamp, and fitting the SP1 top clamp to see if they would go together, but my Kawasaki bits are far too bent up to go together anymore. (That's why they are still sitting around in the garage!) Was close, and I think they may work. I don't have a top clamp from the 636, but I think the center hole is slightly larger.

If I recall correctly, the '05-'06 636 forks had similar measurements, but the stem was shorter and fatter than the earlier. I don't recall if the later Big Piston Forks have the same clamping measurements as the earlier 636 models. Could be worth lurking on a Ninja forum to find out.

All 636 and newer are radial calipers.

[SEBSPEED]

If the RC51 SP 1 stem will go in, that means that a stock VFR stem will go in as well. Larger ID stem hole in the top triple can be easily solved with a custom bushing.

I'd like to know what the offset of the Kawi triples is. (centerline of stem to centerline of fork bores)

[KevCarver]

If the RC51 SP 1 stem will go in, that means that a stock VFR stem will go in as well. Larger ID stem hole in the top triple can be easily solved with a custom bushing.

I'd like to know what the offset of the Kawi triples is. (centerline of stem to centerline of fork bores)

Oh, right. I forget about the stock stem cause it is welded in. But seeing Luigi's post, I guess it isn't so tough to seperate.

I stuck the SP1 top clamp on the bottom 636 (stem removed) and the fork holes didn't quite line up. Then I remembered the different diameters. It really looked like, if my stuff wasn't so bent up, they would fit together.