Inverted front end

[Poolio]

I am going to be starting my frame off build soon and want to go with a r1 inverted front end. My first question is will the r1 forks be a bolt on like the vmax is for the Sumitomo 6pots? Also will I be able to use my front stock wheel? I’ve seen many aftermarket triple trees for the vmax. Do they all have the same distance between fork tubes? More questions I apologize. How can I maintain the same ride height? I know some year R1’s have the brakes that mount with bolts thru the side and some have the straight on bolts. What years have the side ones. I know I’m dragging on but I won’t just do something without asking. I’ve learned my lesson. Do the forks have to be rebuilt for the added weight of the bike? Thank you for any help. This is one of the triple trees I’ve found

 

[MaxMidnight]

My first question is will the r1 forks be a bolt on like the vmax is for the Sumitomo 6pots?

No, as I think you have already established, you will need custom yokes.

Also will I be able to use my front stock wheel?

Possibly but with some modification. The axle sizes are probably different.
If you are lucky you may be able to overcome this with different bearings.
As there is no provision for the speedo drive you will either have to work out how to accommodate it or change the speedo.
Another consideration will be the rolling radius of the Max v, R1 wheel.
If the Max's larger will it still clear the mudguard?

I’ve seen many aftermarket triple trees for the vmax. Do they all have the same distance between fork tubes?

I can't answer that as they may all be different - you would need to speak to the vendors.

How can I maintain the same ride height? I know some year R1’s have the brakes that mount with bolts thru the side and some have the straight on bolts. What years have the side ones. I know I’m dragging on but I won’t just do something without asking. I’ve learned my lesson. Do the forks have to be rebuilt for the added weight of the bike? Thank you for any help. This is one of the triple trees I’ve found

You will need to either extend the forks with slugs or use stepped yokes.

some year R1’s have the brakes that mount with bolts thru the side and some have the straight on bolts. What years have the side ones.

What year R1 forks are you going to use as they are either 41mm to '03 and 43mm 04 onward. Radial mount brakes were introduced in '07.

Do the forks have to be rebuilt for the added weight of the bike?

Given that the Max is some 70Kg heavier than then R1 yes - this should include springs and possibly revisions to the damping.

I don't know if I heard the sound of your cash register 'chinging' up as you read the above but as you have probably worked out it isn't a straightforward swap and at the end it is questionable how much better it will handle.

You should also consider using the money to uprate the OE front end, rear shocks, solid mounts/ engine bars and lighter wheels.

But as it's your money you are spending and if you go ahead I wish you well.

 

[Poolio]

I have upgraded everything. Rear shocks, front springs with adjustable dampers on top. Fork brace, radial tires. This is for a ground up build. My bike got hit head on by a truck last year who crossed the double yellow in a turn and came into my lane. This will be the last bike I buy for myself. I may buy some to sell or part out. But this will be my last keeper. I’m going big with this one and while I care about money. I’m not going to let it dictate my vision of what I want. I just really want to keep my 6 pots if I go inverted. With purchase price and powder coating and rebuilding and braided lines I’m close to $600 in. And they look sick. This will work. I just need to find the answers. Plenty of guys go inverted and r1 early year calipers bolt directly onto a 93-07 max

 

[sdt354]

Lots to consider Poolie. I believe Sean has everything needed, and worked out for the R1 inverted fork mod. I would use the Thug trees. And a newer radial caliper fork set would be the way I'd roll. Bang for buck, I don;t see it though. Some really good rear shocks, and all the frame mods available give you much for the $$.

 

[Poolio]

It’s more about looking different. This will
Be my last keeper. I’ve been chatting with him about it. When I’m more serious I’ll email him with all my questions. I’m just not losing the stock wheel or the 6 pots

 

[Fire-medic]

The R1 forks are much-shorter than the VMax. Have you checked the R1 axle diameter? I believe the VMax may-be smaller. As-to radial brakes vs. traditional position, the R1 USD forks I've seen used have been the traditional position brakes. I suspect the R1 wheelset is what fits the R1 front end easiest, is going to-be the best choice, assuming that you're doing an USD fork; facing the use of a stock VMax front wheel on an R1 USD fork. As to I’m just not losing the stock wheel or the 6 pots there's no practical way I know of to use three opposed-piston pairs Sumitomo calipers on a radial-mount caliper R1 front end.

I suspect that looking at pics of Gen. 1 VMax'es w/the USD R1 you may find that you can use the VMax front wheel, but other than aesthetics, why would you want-to? The R1 front wheel will allow you to use radial tires, where the width of the wheel is sized for radial tires. I think you're severely-limiting yourself in the advantages of using an USD R1 fork by obstinately staying-with the stock front wheel. You can widen the stock front wheel to 3-1/2" and then you have a choice of either a 17" front wheel or an 18" front wheel. The 17" front wheel gives you more rubber choices. It may cut-down on your cornering clearance though, the way pulling your downtubes up in the triple trees does, and/or using shorter rear shocks than the 13" stock length.

From my work getting VMax wheels enlarged in tire size/diameter and widened for wider rubber, the modified stock VMax front wheel will cost you more-than the Thug triple trees, by a considerable amount. R1 USD fork, R1 front wheel/calipers/rotors makes the most sense to-me. The early R1 'blue-dot' traditional mount calipers are 100 mm o.c. which is what the Gen 1 VMax uses and the traditional mount R1 'gold-dot' are a braking upgrade, which is primarily due to the pistons' metallurgical composition.

Going with a R1 USD front end having radial-mount calipers, the exactrep gullwing triple trees 'OTEC' Stepped CNC Billet Yolks to take R1 Front Forks (1200) and the R1 front wheel and rotors would seem to be the easiest installation, with the newest technology, but then you have to deal with the fork springs for the heavier weight of the VMax, and possibly damping issues too.

There are so-many considerations to fitting USD forks onto a VMax, I think if you really have your heart set on it, just buy a package from Sean Morley, who's done it, who's worked out all these logistical issues, and in the end, you're going to end-up with a safe conversion. Yes, it may cost-more, but you don't want to have the front end fail at-speed.

The exactrep front setup with the gullwing lowered triple trees I think is what I would consider using, as it allows the use of the shorter USD R1 forks at their stock length, without the use of 'slugs' or extensions to the USD forks.

The R1 is much-lighter than the VMax, for the fork to have a chance to work properly, the springs would need to be changed to a stiffer rate to allow the front end to work properly. Otherwise you might end up using up 50% of your fork travel with static sag because of the heavier bike weight. There could be damping considerations too. All the more reason to go with the experience of someone like Sean Morley's kit, complete. Just because you find 'a deal' on a single component, and then try to build a system around that piece, not-knowing if what you're doing is going to be safe, properly-operating, and economical.

Yes, it's cool to have an USD front end on your bike, but there are so-many issues with-which to-contend, and the expense, with the possibility that you end up with an overly-expensive and poorly-executed installation which isn't what you had-hoped. I'd spend the $ on finding some light, wider wheels like the Italian ones Sean was selling (Carozzeria's), which are a direct bolt-on, allowing the use of radial tires and doing upgrades on the OEM VMax Gen 1 fork: Cartridge Emulators or RICOR's, Race Tech or Progressive Suspension fork springs, maybe some of Sean's downtube caps for spring preload adjustment, a good, stiff fork brace (I like the Superbrace), and you already have the six-piston Sumitomo's.

A pair of light wheels like the ones Sean sold, are going to reduce significantly your unsprung weight, allow the use of radial tires, and the improvements in handling from those two things I bet are going to be more-noticeable than a kludged-together USD front end you built because you found a 'deal' on one piece of it.

 

[Poolio]

Thank you for your knowledge

 

[Fire-medic]

I understand the USD 'look,' the appeal that you have something on your bike which is not often-seen. If that's what you've always longed-for, buying a system from Sean for instance, would give you the best chance to have something dialed-in and functioning properly. Sure, you can go it alone, but the cost to end-up with a competent conversion could be more-than you would spend when going to someone who's done it well, before. You may be able to get it done on your own, and once you did, you could offer a complete installation to others. I think an integral part of the performance will be switching to radials, and for that to work the best, that front wheel is gonna need to be wider than stock, how you get there is your choice. Remember that the 1985 VMax has different style wheels, f & r.

Me, I'm cheap, I can't spend $ on something that may be worth more-than the rest of my bike.

 

[Poolio]

Mine is a 02 and I run radials with kyb reservoir rear shocks and progressive springs and six pot sumitumo’s up front. I’ve talked to Sean and I believe that’s the way to go. His system looks thought out and well built

 

[bbadwheels]

Thinking about selling

 

[Fire-medic]

Thinking about selling

There you go, for someone. The sleeve between the top triple tree and the bottom triple tree looks pretty-stout for the sleeve holding the USD fork legs. Is it an R1? I see the three opposed-piston Sumitomo's that Yamaha used at the end of the FZR 1000 models, so I suppose that it could be that, or the YZF 1000, though the YZF 1000 ThunderAce used the four-opposed piston 'blue-dot' calipers which carried over to the R1.

Would the sale include everything forward of the steering head? What is the price?

 

[bbadwheels]

There you go, for someone. The sleeve between the top triple tree and the bottom triple tree looks pretty-stout for the sleeve holding the USD fork legs. Is it an R1? I see the three opposed-piston Sumitomo's that Yamaha used at the end of the FZR 1000 models, so I suppose that it could be that, or the YZF 1000, though the YZF 1000 ThunderAce used the four-opposed piston 'blue-dot' calipers which carried over to the R1.

Would the sale include everything forward of the steering head? What is the price?

Researching eBay this front end looks to be from a 2000-04 Kawasaki ZX12R. It has the factory Tokico 6-pot calipers. The upper ZX12R triple tree has been modified to fit the custom sleeves. Sale would include everything removed off the frame steering head. I'm still trying to figure out a price.

 

[[email protected]]

Thinking about selling

Wow! I've never seen such a thing.

 

[Poolio]

I want to use my stock wheels and upgraded 6 pot Sumitomo’s so Sean’s kit is the best choice for me. He knows what I have and what I’m trying to accomplish. I wanted gold until I saw his black anodized. I’m not out to impress others, I just want to build the bike I dream about. Tell you one thing, I wish I dreamed cheaper lol

 

[Poolio]

Picked up my tubes today. Sean’s going to put the extensions on and rebuild them with some race tech gold stuff. Knowing him they will be awesome