Does anyone make a taller gear for Gen 2?

[1badmax]

After having my VMax(2016) for about 2 months now and making minor mods as the timing permits I find myself curious about this possibility. The Max is everything and more that I had hoped for but since we are shaft driven and do not have sprockets or pulleys for gearing, I was wondering if anyone has tried to go to a taller gear? I assume this would have to be in the differential. This thing is way quick enough even with the rear breaking loose all the time. I would like a bigger top end and also be able to run 70 MPH and not be turning up to 4 grand. Most of you guys probably are wanting to lower gearing especially when on the strip. Would really like to hear pros and cons if there is a way. Especially you guys that have been dragging and going the other way as stated. Really appreciate any input and logical ways this may happen rather than putting a chain on it. Thanks guys!

 

[Itgoes]

No gearing changes available. AVON makes a taller tire that will help a tiny bit.

 

[1badmax]

Bummer man and already have the Avon on.
Thanks Mark!

 

[one2dmax]

It's already even taller then the Gen 1 Vmax Diff gear (by at least 20%). We could potentially help with a custom set of 5th gears but we aren't able to make the helical gears for the rear end.

 

[1badmax]

Dang, I am sure you guys know. Thanks for info Sean! Batting zero so far and thought this maybe the case.

 

[Lunatic]

We need to contact robinson industries about making a 6 speed transmission..

 

[one2dmax]

We need to contact robinson industries about making a 6 speed transmission..

There is not enough room into the case to allow for strong enough gears. Sure a six speed can be made but they would be so narrow that they wont' be strong enough (if you want to run it hard anyway).

 

[Lunatic]

Do you know this as a fact on a (gen2) gear case or just in general. But if this is true wouldn't a stronger gears (billet) get some strength back?

 

[2017VMax]

A 6th gear would be soon nice. I'd buy one.

 

[1badmax]

A 6th gear would be soon nice. I'd buy one.

Me 2 but pretty sure that won't happen

 

[gentsvmax]

I v got a 53 Dodge deuce and a half with a spicer 2spd rear end Ill bet ya could swop-pop and
slap that puppy in there oughta git er done.....

 

[Pighuntingpuppy]

Even my 1982 Virago could have done well with a different set of gears and even done well with a 6th gear. In the end, to get the RPMs down, I had to put a Seca 18" rear rim on. Taller tire got me down 500 overall. Seems like we will forever be chasing those RPMs to suit our needs, right?

 

[1badmax]

Even my 1982 Virago could have done well with a different set of gears and even done well with a 6th gear. In the end, to get the RPMs down, I had to put a Seca 18" rear rim on. Taller tire got me down 500 overall. Seems like we will forever be chasing those RPMs to suit our needs, right?

For sure but think I am tapped out with the taller Avon. I am 5'7" so I cannot go anymore. Did have a few Virago's also, they were some great bikes too. Had an 85 700 and a 94 1100. Best riding bikes I think I have been on as far as hitting bumps and elevation changes in the road.

 

[one2dmax]

Do you know this as a fact on a (gen2) gear case or just in general. But if this is true wouldn't a stronger gears (billet) get some strength back?

I may be one of the rare few with the experience to give an informed answer. If you look at the cavity of the gear case you will see there simply isn't a lot of room in there. I don't have a good pic apparently with it sitting in the case but there is one (of my chaindrive bike). I did have case pics and the gen 1 vs gen 2 comparison too.

The billet gears might buy you more strength but it will still be weaker then the full width gears. If you were not doing any hard driving you might be able to get by but if you get traction you're going to shred it.

We did something similar with our drag Fazer. It had the 6 speed for the 700/750 motor but when we swapped in the 1000 motor we ran with the default 5 speed. So, we thought we would try the 6 speed in it too and that lasted just a few weeks before it took a major shit (wiping out other parts in the process). Back to the 5 speed and no issues after that.

 

[Lunatic]

Well that sucks i am disassembling my motor as we speak but haven't got the cases split yet. I guess i won't worry about going fast anymore. I even raised the rev limiter to 10400 to get a little more speed lol.

 

[1badmax]

I may be one of the rare few with the experience to give an informed answer. If you look at the cavity of the gear case you will see there simply isn't a lot of room in there. I don't have a good pic apparently with it sitting in the case but there is one (of my chaindrive bike). I did have case pics and the gen 1 vs gen 2 comparison too.

The billet gears might buy you more strength but it will still be weaker then the full width gears. If you were not doing any hard driving you might be able to get by but if you get traction you're going to shred it.

We did something similar with our drag Fazer. It had the 6 speed for the 700/750 motor but when we swapped in the 1000 motor we ran with the default 5 speed. So, we thought we would try the 6 speed in it too and that lasted just a few weeks before it took a major shit (wiping out other parts in the process). Back to the 5 speed and no issues after that.

Thanks Sean, with my very limited mechanical knowledge I just thought there may be a way in the drive shaft gearing to go taller. But as you stated earlier you aren't able to make the helical gears which I assume what you are saying is the rear end is what it is and there is no changing it. It's not like changing sprocket or pulley size.

 

[02GF74]

I had a search on the Internet and there are companies that make helical gears. You would need to have two made to mate up, Im not sure if you would get away with just one made.
You would need to know tooth count on the gears you have then see what effect changing the count by one tooth will have.

I have no idea what it wood cost, maybe Investigate other shaft drive bikes and use the parts from them, be simpler to modify.

 

[1badmax]

I have not had my wheel or rear apart but knowing that helicals work in unison and therefore if you are changing teeth and or size of the teeth you would need both gears.

 

[one2dmax]

Sure, they can be made but very very cost prohibitive unless you are making tens of thousands of them. Your choice could be alteration of the middle gear ratios or alteration of the final drive gear (rear diff). Though Yamaha is great for part interchangeability that is simply not one they have other models using. I have a gearing worksheet (file won't load in this group so you'd have to email me if you wanted the active sheet). Screenshot is below.

 

[one2dmax]

What I have to experiment with is an adaption of using a gen 1 diff installed on a gen 2 swingarm. This would be a track limited use only setup with the way it's designed not allowing one of the seals to be able to be used. That would allow as much as a 20% ratio change though. 3.66 (gen 1 Vmax), 3.33 (gen 1 Venture), 2.90 (Gen 2 Vmax).
We have also looked into different chain drive conversions (I do have a converted gen 2 though that was not something I think most would want to do).
Also added pics of the rear diff to show the helical gearing.