86 TIRE installation in 02 FRONT FORKS

[gavicool]

Hello,I was thinking the replacement of the 40mm front fork(with upgrades springs on it) for one 43 mm(standard),what do you think? I´m getting a good price for the "full 02 front end"(tire,disc´s,axel and clanps).
I would like to keep the "spoke tire" ,and I think I will probably need to do some upgrade with the calipers,although I have "Brembo" calipers/disc already installed...
My warry is that I can install the "86 tire" on the new fork without any problem...or at least without "headache"...thank you very much in advance!!!!

 

[Fire-medic]

I would not buy them sight-unseen without inspecting them first for any flaking chrome or pits. If there's any deterioration on where the fork seals 'ride,' then 'just say, no!'

Do it, no issues. I believe the later model at some point went to a bit shorter axle in the rear, but I'm pretty sure the front is the same. You need the newer calipers and rotors too (see below), unless you're using some type of bracket for mounting the calipers now. I believe the 1985-'89 calipers are (I believe) 82 mm o.c. and the 1990-'07 are 100 mm o.c. Check your rotors, are they 298 mm diameter? That's what the 1990-'07 OEM rotors are. I don't know what your Brembos are for caliper mounting distance, or the rotor diameter. Do they mount directly to your 1986 sliders, with no mounting brackets?

You mention "full 02 front end" (tire,disc´s,axel and clanps [sic-clamps]) but no mention of fork downtubes or sliders, I assume that's just not mentioned, and they are part of the package, along with the fender mount/fork brace. You will get greater stiffness in the front end from the greater diameter. I'm not a mechanical engineer but I believe the greater stiffness is more-than the simple increase in diameter would seem to provide (43 mm being 7-1/2% greater than 40 mm).

Look at some aftermarket springs if the front end doesn't have already come with them, who knows, you may luck-out and they're already installed. Be sure to change the oil. If you choose to replace the fork seals while things are apart, OEM seals provide great service life.

Since things are going to be apart, check the front end steering head bearings for sufficient grease, any brinelling (notchiness of the bearings from loose bearings and/or too-many high-impact wheelies). Follow the proper factory manual sequence for tightening the front end axle, triple tree pinch bolts, steering stem acorn nut and double castellated nuts, and the fork brace/fender mount.

VMX12- Service-Manual.pdf (vmoa.net)

 

[gavicool]

Hello Firemedic..thanks for your support!!
Yeap,I have the brembos with rotors and disc(mounting brackets included).I will probably remove the brembo rotors and installed in the 43’s
Yes,the forks come with the down tubes,fender and fork brace.you are right about the “pitting” in the tubes(specially in the seal’s tubes working area,)
I have installed already an aftermarket springs in my 40 mm forks…Could I installed them in the 43’s?
Cheers

 

[Fire-medic]

The answer is, I don't know for sure, but I suspect the early model 40 mm fork springs are different from the 43 mm fork springs. Checking Progressive Suspension fork springs for a 1986 (1985-1989), I see part # 11-1129. Progressive Suspension Fork Springs - 35/50 Spring Rate (lbs/in) - 11-1129 Motorcycle - Dennis Kirk

For Progressive Suspension fork springs for the 1990-2007 I see part # 11-1144. Progressive Suspension Fork Springs - 40/65 Spring Rate (lbs/in) - 11-1144 Motorcycle - Dennis Kirk

Suspension for your 2007 Yamaha VMX1200 V-Max - Dennis Kirk

While they (your 'old' springs) may slip in there, I'd use the proper component.

 

[one2dmax]

Potentially you "could" put them in there but you would have too much side to side deflection causing them to be less effective. Springs are relatively cheap so get a new pair.

The rotors are different size so unless your brembo's are 298mm then you'll need new there too.

OR, instead of getting larger forks you can spend less money on one of our 6 piston hayabusa brake upgrades. You would notice that far more then you'll notice a reduced amount of flex from the fork change.

Sean

 

[gavicool]

The answer is, I don't know for sure, but I suspect the early model 40 mm fork springs are different from the 43 mm fork springs. Checking Progressive Suspension fork springs for a 1986 (1985-1989), I see part # 11-1129. Progressive Suspension Fork Springs - 35/50 Spring Rate (lbs/in) - 11-1129 Motorcycle - Dennis Kirk

For Progressive Suspension fork springs for the 1990-2007 I see part # 11-1144. Progressive Suspension Fork Springs - 40/65 Spring Rate (lbs/in) - 11-1144 Motorcycle - Dennis Kirk

Suspension for your 2007 Yamaha VMX1200 V-Max - Dennis Kirk

While they (your 'old' springs) may slip in there, I'd use the proper component.

Yes,you are right....the safety way is to use the proper component...thank you

 

[gavicool]

Potentially you "could" put them in there but you would have too much side to side deflection causing them to be less effective. Springs are relatively cheap so get a new pair.

The rotors are different size so unless your brembo's are 298mm then you'll need new there too.

OR, instead of getting larger forks you can spend less money on one of our 6 piston hayabusa brake upgrades. You would notice that far more then you'll notice a reduced amount of flex from the fork change.

Sean

Hello Sean..
I agree totally with you and the sugestions of Fire-medic about the "springs".
The brembos are 298 with calipers(in this moment with adapters installed in the 40mm),I think I can swap them...
My worry is about the space between the down tubes for the tire/axel...I do not know if there is the same distance between down tubes.Lets say,if I can use my 86´axel or 02´axel in order to a proper fitting,and in case that I have to use the 02´ axel,do I need a aditional spacer or anything to compensate the "extra width"....? thank you for your support once again...


Cheers.

 

[Parminio]

My two cents: there's an awful lot of "might, maybe and could" in your idea.

I would keep what you have and upgrade the springs and brakes. The difference between 40 and 43mm forks is so negligible that I could let you ride 6 bikes without telling you which is which and you'd have a 50/50 chance of guessing.

It's the brakes and springs / fluid in the forks that are going to be the big deal maker. Not a few mm of diameter in the forks alone.

 

[Woody]

The wheel should fit.same width hubs , if I remember correctly.

 

[one2dmax]

Axles are the same. Wheels are the same (or interchangeable). Brake rotors were larger 298mm in 93-07 vs 280mm in 85-92. Length of forks in the same. Steering Stem is the same. Head bearings are the same. Triples are different. Fork Brake is different. Fenders are the same. All headlight, riser and crown parts are the same. Brake lines and splitter are the same. Calipers and bolt spacing are different (2 piston vs 4 piston). Axle spacers and speedo drive parts are the same.

 

[DreamV4]

Yesterday (junk yard):
-Are you converting Civic drum brakes to rotors because you really need more brake power or you are doing it for fun?
-Just for fun

Have fun!!!

 

[gavicool]

Axles are the same. Wheels are the same (or interchangeable). Brake rotors were larger 298mm in 93-07 vs 280mm in 85-92. Length of forks in the same. Steering Stem is the same. Head bearings are the same. Triples are different. Fork Brake is different. Fenders are the same. All headlight, riser and crown parts are the same. Brake lines and splitter are the same. Calipers and bolt spacing are different (2 piston vs 4 piston). Axle spacers and speedo drive parts are the same.

Gr
eat and precise information...thank you.. very.. very much!!!

 

[gavicool]

Yesterday (junk yard):
-Are you converting Civic drum brakes to rotors because you really need more brake power or you are doing it for fun?
-Just for fun

Have fun!!!

Well...Yamaha impove the front end VMAX in the 90´s....50/50%..I´m getting a good deal for the "kit" and I think is an oportunity....just that.

 

[WC Hart]

i just got a complete 94 front end from Kyle for my 86. Kyle seem to know his stuff and says my 86 front wheel will fit the 94 front end no problem. I ordered new parts to rebuild the calipers and i'm going to repaint them and the lower tubes original silver before i do the swap.

 

[Parminio]

Kyle seem to know his stuff

Seems to?

I sense a disturbance in the force...

 

[WC Hart]

Absolutely not. Have never met Kyle or even talked to him beyond email. That said in the process of buying the front end from him he has been very knowledgeable and helpful. The Force is solid.

 

[CaptainKyle]

Absolutely not. Have never met Kyle or even talked to him beyond email. That said in the process of buying the front end from him he has been very knowledgeable and helpful. The Force is solid.

You should come to the rally this year !

 

[Parminio]

Absolutely not. Have never met Kyle or even talked to him beyond email. That said in the process of buying the front end from him he has been very knowledgeable and helpful. The Force is solid.

My apologies. That was a tongue in cheek joke. Sorry I wasn't more clear. Kyle clearly got it.

He is, in fact, VERY knowledgeable. You can't go wrong dealing with him.

 

[WC Hart]

No sweat my friend, it’s all good. Kyle are you talking about the gathering up north that the organizer jumped ship to HD.

 

[CaptainKyle]

No sweat my friend, it’s all good. Kyle are you talking about the gathering up north that the organizer jumped ship to HD.

No I am talking about my little rally here in Tennessee by the Tail of the Dragon. It is on the events page