Met 660 x 18 x 28 Belt in ZX Trans?

[LMH]

http://m.youtube.com/watch?v=wfQnF2SGcOY

This is MY cvt, as you can see its got nothing to do with a fixed pulley, read the description if you got questions.

[Wheelman-111]

Greetings:

Strapline Axt-ed:

When i measured a 669 belt outside i was wondering why it didnt measure 669mm?

Strapline's website provides the answer:
This is the tension carrying part of the belt; the rest of the belt exists only to carry the forces from the pulley to and from these fibers.
The site goes on to describe a "royally obnoxious" formula to obtain the belt's nominal size, but basically when you run a tape around the belt you're measuring a circle (OK, an OVAL...) that's a little larger than the spot where the fibers live, which is the number belt-makers use to define size.

My goal in this discussion, along with the ZX Trans How-To thread, is to help members improve low-end performance with taller non-stock transmission gears. Swapping in a ZX transmission rear requires a bit of reflection and quite a lot of case-shaving, front Boss length calculation and shim modification, and the cover clearances as well as kickstart and e-start locations need to be addressed. If you don't plan to take the Leap, stop reading here.

Pulley diameter posts are scattered throughout the Forum, but stock Aero/Elite front pulleys are 87mm. Aftermarket sizes including "For Ruckus" variators go up to 97mm - at least that's the biggest I've used. Going bigger is pointless, because the stock Outer sheave - the one with the starter teeth - limits belt travel to about 90mm. The Phongeer aluminum outer sheave may be a bit bigger - if I ever measured it, I've forgotten how much bigger.

I don't recall and cannot measure a stock Elite Rear pulley simply because I no longer own one. According to this, the outer rim measures 118.5mm. It's safe to assume it matches the inner sheave. The ZX rear pulley is at least 10mm bigger than S/SR rear pulleys, and this is the "...trading Speed for Torque" variable to which the author of Strapline's article refers. If the rear belt loop is bigger, take-off torque to the clutch shaft will be greater as the front pulley has to spin more times to get the rear one around once.

But with a bigger rear pulley, a longer belt is necessary to take full advantage of the increased sheave diameter. If the stock front puley is retained, the belt ratio won't "overdrive" as far because when the belt reaches the rim of the front, the rear won't be as close to the bottom. Instead of the 0.8:1 "Overdrive" the belt gets maybe to 1:1. This means a lower top speed, unless a larger front is also installed, ya dig? ("Trading torque for speed" in the article.)

Honda specifies the belt-drive ratio for various models in the Service Manuals at Minimum and at Maximum. We have to do Math or guess how much monkeying with pulley sizes affect those Stock values. Or we can install stuff and see how it feels and record our top speeds. See? Fun!

At about 40 minutes of run time, my 660 x 18 x 28 Met belt seems fine. No sign of unusual wear pattern, no worn sliders, no Trenches and no burnt-rubber smells. Ran up to 54MPH on the Garmin in traffic this morning, without even trying. More to come.

[LMH]

Nice.

[Wheelman-111]

Greetings:

I don't see where I've "told you you're wrong", Strapline. Until that last post I didn't see "your system" anywhere in the thread, so I couldn't say one way or the other. If anything, my responses to your input have been favorable, using the website you provided, for example. In fact, I really haven't addressed any of these posts to you specifically at all. And yet, once again, there's that Pick-a-Fight Pugnacity with no apparent purpose from you. If you do have a question or some input to provide, as you just did, it is welcome.

For everyone else, I'm sharing what I did to overcome sluggish take-offs with 7.58:1 gears by using the ZX transmission setup, properly spaced and shimmed. On the Flash 3 Corsa build, I obtained not-quite-wheelie take-offs and 71.2 MPH. It was so reliable that I didn't touch a thing for almost a year. The stock Honda crank lives on in another Forumista's cases, and the 97mm vario was sold in good usable condition to another. The details were shared for others to try, if they want, or IGNORE if you don't.

[bakaracer]

DONT FEED THE TROLL!!! YOU GUYS KEEP RESPONDING TO THIS TROLL AND HE WILL STICK AROUND. THIS IS HIS WAY OF FISHING FOR TUNING INFO. STRAPLINE AKA IDRANCER AKA TRAINS420 aka........ this guy keeps coming back. you guys get fustrated with his comments and thats what he wants to do. STOP PLAYING HIS GAME AND WASTING YOUR TIME!!!! ENOUGH WITH THIS GUY. HE HAS NO CLUE!

[Wheelman-111]

Greetings:

Easy, big fella. It's just words on a screen. I find it amusing in a Clinical way to try to figure out what they mean. You can ignore if you want.

[Wheelman-111]

Greetings:

About an hour running this 660 x 18 x 20 Metropolitan Kev-U-Lar belt by Gates. So far no scuffing on the outer belt layer that was an issue on the 669 ZX Bandos I've been using. Still no bad smells, and if the 2 degrees of angle difference is an issue, it's not visible to the eye

F6MetBelt1Hour.jpg (119.48 KiB) Viewed 7284 times

nor to the seat-o'-the-pants accelerometer. Speed's come up too, although no time/chance for a real go at the top speed.

The bad news? Checking the belt I noticed how weather-checked my beloved Pirelli SL26 seems to be getting...

[bakaracer]

you. wont have any issues using a 28deg angle cog belt vs a 30. the belt will breakin to the angle if the drive face and pulley face. and any ways most aftermarket pulleys have a steeper face anyways. the gates belts all fray at the edges if thats what your talking about wheel

[Wheelman-111]

Greetings:

Three unprovoked rants without a response, wow!

[Wheelman-111]

Greetings:

Gates 660x18x28 had originally been intended as a gift for my brother to use on his '05 Met. Still needing a gift for him, I stopped at Deepinnaharta Honda to see if they had a Met belt in stock. Turns out Bando makes them.

F6Bando18.14Gates17.75.jpg (143.05 KiB) Viewed 7213 times

At 771mm, it measures a couple mm longer than the Gates. It was wider too; 18.0 to 18.18 mm at different points around compared to 17.73 for the Gates.

"Cheater" installed by squeezing the rear pulleys, removing clutch, and slipping the belt off the front pulley. Width kept it away from center in front, hurting game-off a little. Midrange performance at steady 30MPH dropped RPM to 6500, 299 degrees. Buried speedometer in 1/8th mile. Wish I'd carried Garmin-girl, but whatever the top speed, MHR absolutely rocks!

Sorry for the huge pic. Will fix when I can.

[steffen707]

Greetings:
... by using the ZX transmission setup, properly spaced and shimmed.

EEEK, what do you mean by this? Mine isn't shimmed, though I do recall buying a zx boss I believe. I have no washers or shims and mine runs fine. Hopefully I didn't miss something years ago when i bought my setup.

But I think you might be onto something with the belt lengths, I don't think i'm maxing out my variator, either by belt length, contra spring strength, or roller weight.

EDIT: I went back and re-read the zx-trans how to . You referred to shimming the trans cover by 1/8", because the boss is 1/8" longer on the zx right?

[steffen707]

Greetings:

Gates 660x18x28 had originally been intended as a gift for my brother to use on his '05 Met. Still needing a gift for him, I stopped at Deepinnaharta Honda to see if they had a Met belt in stock. Turns out Bando makes them.

F6Bando18.14Gates17.75.jpg

At 771mm, it measures a couple mm longer than the Gates. It was wider too; 18.0 to 18.18 mm at different points around compared to 17.73 for the Gates.

"Cheater" installed by squeezing the rear pulleys, removing clutch, and slipping the belt off the front pulley. Width kept it away from center in front, hurting game-off a little. Midrange performance at steady 30MPH dropped RPM to 6500, 299 degrees. Buried speedometer in 1/8th mile. Wish I'd carried Garmin-girl, but whatever the top speed, MHR absolutely rocks!

Sorry for the huge pic. Will fix when I can.

So you liked the gates belt better than the bando metro belt?

[steffen707]

Greetings:
... Turns out Bando makes them.

F6Bando18.14Gates17.75.jpg

At 771mm, it measures a couple mm longer than the Gates. ...

you mean 671?

i'm making a table of all the "zx trans" belt options with actual widths, lengths, advertised size, and manufacturer, and then find prices on all of them. Could be fun to swap in and out 6 belts for comparison. Right now I think i'm running a 669 belt, but....don't know if its a bando or gates

[Wheelman-111]

Greetings:

Yeah of course, 671 measured around the belt with a cm. tape. Sorry for the typo. The Met Bando still runs really well, with no slip or abnormal wear at all. Still getting around to making a GPS run, but feels like 70 easy, and almost as quick acceleration as with the 669.

[Red Eft Performance]

Hello Some info to add.
Malossi Kevlar belt for ZX trans
Malossi says
Width 18mm
Length 670mm
Height 9mm
Angle 32 Degrees

Red Eft Performance says
Width 17.98mm
Length 670.5mm
Height 9.18mm
Angle Ill take their word for it haha.