4Th Gen Fork Options

[Trevor]

surely the Ohlin's is adjustable length?

[rhubarb]

 No, the Ohlins for the 4th gen is not adjustable for length. I was able to find a supplier for linkage plates to lower or raise the 4th gen, as well as a few people who have made their own. The inability to lower the top mount when I installed my Ohlins was a surprise to me, hence me asking how it was done.

 

 

[Mohawk]

Go for a Nitron, equal quality & available in a range of option, including length, hi/low speed compression, remote/integral reservoir etc.

[rhubarb]

38 minutes ago, Mohawk said:

Go for a Nitron, equal quality & available in a range of option, including length, hi/low speed compression, remote/integral reservoir etc.

 

I'm happy with Ohlins. As for adjustable length shocks, based on my install, a longer shock won't even fit.

[2stroke]

I'm in need for a lot of help with a Front upgrade on a VFR750  RC36-II  ( 1994 - 1997 )
 

I have read through this tread and if I have understand things right the easiest way to do an complete Front upgrade
is to use the complete front end from a CBR600 F4i 
Or ?

Can someone explain in detail what parts I need for a change?
Will the bike's geometry be changed afterwards?

 

 I have found this facts about the F4i front end:
 Quote:

 Honda CBR600 F4i  ( 2001-2006 )
 Differences compared to its predecessor Honda CBR600 F4 ( 1999-2000 ) 

300 grams weight reduction of the Front wheel.
 The wheel bearings have been moved outward, closer to the fork tubes,
 and the rotor carriers moved out closer to the brake calipers to reduce weight and to improve rigidity.
 Each caliper carrier also lost 100 grams.
 There is additional bracing on the steering head for more response, better feedback and feel from the front end.

Rake:  24.0°
Trail:   96.00 mm 

VFR750     4'Th generation:
Rake: 26.0°
Trail:  100 mm

[2stroke]

On 2015-12-18 at 1:17 AM, dogman said:

Most sportbike triples have less offset than the VFR750 (30mm as opposed to 40mm) which increases the trail and slows down turn in
so you need to drop the front and raise the back to compensate.
Obviously the front brake is much much better than the 4th gen front stocker.
 

There are issues you need to work through regarding clearances and steering stops etc, so it is not straightforward but not too much of a problem either.

The advantage of staying with Honda parts is that the steering head bearings all seem to be the same, FWIW

 

Its a shame the VFR's dont have a just slightly steeper rake.

 

On 2015-12-18 at 6:27 AM, kirbster said:

Yeah but trail is only one factor.
Changing your offset definitely does not produce the same thing as moving your forks down through your triples,
even though both changes produce the same outcome (in terms of altering the trail distance).
 

Reduced offset = reduced stability as well.
So you've effectively lessened your stability factors twice by bolting on reduced offset triples and then reducing your trail by dropping the forks.
First time you hit a decent bump mid corner might be a bit exciting...

The VFR is pretty neutral handling in stock form because it doesn't load the front as much as hard core sport bikes.
So it probably won't headshake... much... But just be careful. Change one thing at a time.

What will happen about the total geometry of the bike if I use a CBR600 F4i front end on a VFR750 4'th generation ?

[Trevor]

pretty much nothing if you use vtec triples like i am as they are the same offset

[2stroke]

10 hours ago, Trevor said:

pretty much nothing if you use vtec triples like i am as they are the same offset

What bike in detail ?

[Trevor]

um maybe read the whole thread? I priced out all the parts only one page back, but anyhow, as per the thread title it's a fourth gen, parts being used as follows.

 

2005 VTEC Triples

CBR600f4i forks

fifth gen wheel and axle

CBR600F4i calipers and master cylinder.

 

No alteration in offset so the only worry is the forks are a bit shorter.

[JZH]

On 08/06/2016 at 6:26 AM, rhubarb said:

 No, the Ohlins for the 4th gen is not adjustable for length. I was able to find a supplier for linkage plates to lower or raise the 4th gen, as well as a few people who have made their own. The inability to lower the top mount when I installed my Ohlins was a surprise to me, hence me asking how it was done.

 

 

 

Another option (on the 3rd and 4th gens only) would be to "flip the eccentric" bearing carrier, which adds 30-40mm in rear ride height.

 

Ciao,

[2stroke]

On ‎2016‎-‎06‎-‎14 at 10:58 AM, Trevor said:

* Upper ond Lower Triples --> from 6'th Generation ( 2002 -2013 ) VFR800 VTEC 

* Forks --> from CBR600 F4i ( 2001-2006 )

* Wheel  --> from 5'th Generation ( 1998-2001 ) VFR800Fi
* Wheel axle  --> from CBR600 F4i ( 2001-2006 )

* Calipers and master cylinder --> from CBR600 F4i ( 2001-2006 ) 

 

No alteration in offset so the only worry is the forks are a bit shorter.

I'm a newbie at Honda bikes so please confirm the above.

How much shorter ?
and what does this mean in practice ?

Is it the total length that is different or is it the effective suspension travel
length different ?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

I want to do a full front end upgrade on a VFR750 ( 1994-1997 ) with as little hassle as possible.
I do not want to use a USD fork.
I do not want to change the geometry on the bike.
Which route to go ?

[Trevor]

That looks right to me for years, what I am doing is pretty much your only option if you do not want to alter geometry, I do not know exactly how much shorter the F4i forks are, maybe someone here does.

 

My triples arrived today, annoyingly the bottom right side is out of round, I was still able to fit the fork by hand while levering it open with a screw driver, so hopefully it might tap out with a hammer or something.

 

Also the 5thgen axle is too short, so looks like I need to order an F4i one I guess.

[Mohawk]

Almost all Honda RWU forks are Showa. They use a common thread in the fork top & common clearances throughout. The simplest way to upgrade your forks & not worry about length would be to buy VFR800 Vtec triple Tees & upper fork stanchions which are 43mm, then either a set of CBR600F4 or F4i forks. Strip & reassemble with the VFR uppers & CBR lowers. Thus giving you fully adjustable 43mm RWU forks with hangers for proper 4 pot calipers, of which the CBR Nissin ones are some of the best every made.

 

The only caveat, is you may need an extension piece for the damper rod, depends on how much extra travel the rod has. Cartridges are generally made to one size fits all so shorter forks just use les of the cartridges travel.

[Trevor]

Interesting, I had never considered using the VTEC uppers, as I have been led to believe that a suspension center should be able to increase the length up to 10mm anyhow. I wonder if there are specs for the difference in length anywhere?

 

Also the clipons I am using will let me push the forks down a bit, which should help.

 

I have the F4i master and 4pot calipers ready to go on as well.

[zRoYz]

Trev if lower triple is out of round be very careful as they could dent fork tubes, they may have just been clamped without a fork tube inserted so carefully open them you will prob need to use a large screw driver as a wedge & tape a few times. The F4i axle is from memory about 10mm longer than the vfr axle your trying to use. Fork length with F4i just works again from memory think you want min 500mm from bottom of frame steering head bearing location to center axle.

[Trevor]

Yeah maybe I need to buy another lower, will get Rick to have a look at it and see what he thinks. Have now ordered the F4i axle.

[2stroke]

21 hours ago, Mohawk said:

Almost all Honda RWU forks are Showa.
They use a common thread in the fork top & common clearances throughout.
The simplest way to upgrade your forks & not worry about length would be:
To use a set of CBR600 F4i forks.
to buy VFR800 Vtec triple Tees & upper fork stanchions which are 43mm, 

Strip & reassemble with the VFR uppers & CBR ( What CBR bike and year ? ) lowers.
Thus giving you fully adjustable 43mm RWU forks with hangers for proper 4 pot calipers, of which the CBR ( What CBR bike and year ? ) Nissin ones are some of the best every made.

 

The only caveat, is you may need an extension piece for the damper rod,
depends on how much extra travel the rod has.
Cartridges are generally made to one size fits all so shorter forks just use less of the cartridges travel.

Have patience with me.
Given that English is not my spoken language, I have some difficulty understanding some of your expressions, abbreviations and all your slang expression.

Please explain in detail the highlighted in black areas.
preferably with Pictures.

[Trevor]

I'm not convinced you need the vtec uppers, wait and see how mine turns out. ;-)

[JZH]

7 hours ago, 2stroke said:

Have patience with me.
Given that English is not my spoken language, I have some difficulty understanding some of your expressions, abbreviations and all your slang expression.

Please explain in detail the highlighted in black areas.
preferably with pictures




 

 

 

 

 

 

 

 

"Stanchions" are the chromed steel tubes.  Basically, he's saying to take the CBR600F4i forks apart, and replace the CBR stanchions with your VFR stanchions.  Then re-assemble the forks.  You will then have adjustable forks that are the correct length for the VFR.

 

"Hangers" means the brake caliper mounts on the lower fork tubes.  You cannot use 4-piston NISSIN calipers on the VFR forks because those caliper mounts only work with the linked brakes.  Then you will have adjustable forks that are the correct length for the VFR--and stronger 4-piston calipers.  (Be sure to use the matching CBR600F4i brake master cylinder for the new calipers--the VFR one will be too small.)

 

The caveat is that the CBR600F4i fork cartridges may be too short for the VFR stanchions, and if that is the case the CBR's damper rods (the rods that screw into the fork top cap) would need to be extended slightly.  I did this once on some VTR1000F forks:

 

 

 

 

 

Ciao,

[VFROZ]

But how did you get the rebound adjuster screw to still reach the rebound piston for it to still be effective?

[Trevor]

The method I'm using, as in complete F4i forks is both tried and tested, that bike is prob still in RDM's garage I think, and zRoYz could most certainly post some photos given he built it. There should be no need to muck about with VTEC uppers.

[2stroke]

8 hours ago, JZH said:

1. "Stanchions" are the chromed steel tubes. 
Basically, he's saying to take the CBR600F4i forks apart, and replace the CBR stanchions with your VFR stanchions. 
Then re-assemble the forks. 
You will then have adjustable forks that are the correct length for the VFR.

 

2. "Hangers" means the brake caliper mounts on the lower fork tubes. 
You cannot use 4-piston NISSIN calipers on the VFR forks because those caliper mounts only work with the linked brakes. 
Then you will have adjustable forks that are the correct length for the VFR--and stronger 4-piston calipers. 
(Be sure to use the matching CBR600F4i brake master cylinder for the new calipers--the VFR one will be too small.)

 

3. The caveat is that the CBR600F4i fork cartridges may be too short for the VFR stanchions,
and if that is the case the CBR's damper rods (the rods that screw into the fork top cap) would need to be extended slightly. 
I did this once on some VTR1000F forks.

1. Is the only difference the length ?    ....what about the diameter ?

2. What brakes will fit and from what bike ?

3. Are the pictures from that fork rebuilding ?

[2stroke]

 

6 hours ago, Trevor said:

I'm not convinced you need the ( 2002-2013 ) VFR800 VTEC uppers    ( wait and see how mine turns out )  ;-)

The method I'm using, as in complete F4i forks is both tried and tested,
that bike is prob still in RDM's garage I think,
and zRoYz could most certainly post some photos given he built it.
There should be no need to muck about with ( 2002-2013 ) VFR800 VTEC uppers.

Post pictures with explanations of your modification.

[Trevor]

I have about six times in this thread, once more for luck I guess.

 

Vtec triples (same offset, but 43mm vs 41mm on our bikes)

F4i Forks (43mm less flex and fully adjustable)

5th gen front wheel + F4i Axle.

F4i Calipers and Master Cylinder (4 pistons vs 2 on ours).

[2stroke]

2 hours ago, Trevor said:

* Upper ond Lower Triples -->  ( 2002 -2013 ) VFR800 VTEC   (same offset, but 43mm vs 41mm on our bikes)

* Forks -->  ( 2001-2006 ) CBR600 F4i  (43mm less flex and fully adjustable)

* Wheel  -->  ( 1998-2001 ) VFR800Fi
* Wheel axle  -->  ( 2001-2006 ) CBR600 F4i

* Calipers and master cylinder -->  ( 2001-2006 ) CBR600 F4i  (4 pistons vs 2 on ours)

 

No alteration in offset so the only worry is the forks are a bit shorter.

OK, the above is apparently a working recipe.
With the above recipe will it change the bike's geometry in any way ?

What about the fork as it is shorter ?

What about the total lenght of the VFR750 complete forklegs compared to total length of the CBR600F4i complete forklegs ? 
What about the ground clearance / riding height if I choose this recipie ?

( 1994 - 1997 ) VFR750
Fork suspension travel:  140 mm
Rake: 26.0°
Trail:  100 mm

( 2001 - 2006 ) CBR600 F4i
Fork suspension travel:  120 mm
Rake:  24.0°
Trail:   96.00 mm