Which variator and belt should I buy?

[techy]

Which variator and belt should I buy?
I just bought an Eton with a 90 cc ported cylinder high compression head and wrh pipe. I need to replace the stock variator and belt due to wear.

I am interested in the Dr Pulley variator or a Koso but am not sure which to go with. Also, is it worth spending the money to get a kevlar belt? I am new to these cvt's so any advice is appreciated! The quad will be used for mx and recreational riding with the ocassional drag race.

Also, I am curious if anyone ever stuffed a larger diameter variator from a 100 cc in a 90 cc motor? According to the specs I found (see below link line 2 and 3 in the chart) the 100 cc variator is 105 mm OD while the stock 90 cc uses a 94 mm OD. If the 105 mm would fit that would translate into higher top end. I am just not sure it the shaft is long enough? It appears that there is clearance for the 105 OD.

http://www.unionmaterial.com/Variat...ooterModels.htm

Thanks for the help!

By the way...Sorry for posting this in two places. I meant to post here as it looks like more folks visit the DRR site as compared to the Eton.

[techy]

I noticed the link was broken...Not sure why. I'll try to post the link again...

The Dimensions of Variators (http://www.unionmaterial.com/VariatorsvsScooterModels.htm)

[SMS]

I use the malossi multi variator and the koso rear adustable clutch. Koso makes several clutches the one that I really like, it has 3 bolt in the side that you use a allen wrench to adjust. It is by far the easiest clutch to adjust. I have some of them out there that have 2 seasons on them, so they do last.

[hotquads1]

Originally posted by techy
Which variator and belt should I buy?
I just bought an Eton with a 90 cc ported cylinder high compression head and wrh pipe. I need to replace the stock variator and belt due to wear.

I am interested in the Dr Pulley variator or a Koso but am not sure which to go with. Also, is it worth spending the money to get a kevlar belt? I am new to these cvt's so any advice is appreciated! The quad will be used for mx and recreational riding with the ocassional drag race.

Also, I am curious if anyone ever stuffed a larger diameter variator from a 100 cc in a 90 cc motor? According to the specs I found (see below link line 2 and 3 in the chart) the 100 cc variator is 105 mm OD while the stock 90 cc uses a 94 mm OD. If the 105 mm would fit that would translate into higher top end. I am just not sure it the shaft is long enough? It appears that there is clearance for the 105 OD.

http://www.unionmaterial.com/Variat...ooterModels.htm

Thanks for the help!

By the way...Sorry for posting this in two places. I meant to post here as it looks like more folks visit the DRR site as compared to the Eton. .

Keep in mind if the variator were larger in Diameter it would make more space for travel but not more travel . the belt is not long enough to travel any further , a longer belt could be used but then it would ride out on the rear pulley so you would need to go to a larger rear pulley also to run the belt, with all of that being said you can by a set-up for this purpose an overange system , by Malossi or Polini, just wanted to start your thinking process , your heading in the right direction but it is going to take more than a variator.
marc

[techy]

Thanks for the help. I went ahead and bought a std diameter Dr. Pulley variator. I got a good deal so I figured it was good enough for now since my daughter is just getting started. I read that some folks are using the malossi 6112742 793/16.8/30 belt. Would this work or should I go with a 787 belt?

Thanks!

[Nichols Atvs]

either one work. Buy both and do some testing IMO

[bulldogfallon]

The 787 is the belt we run in our high rpm motors and don't have any issues.

[SMS]

When using the stock diameter variator and stock rear pulley I go with Garys 787 belt it works really good. I did find the rear over drive to be more than bennifical with the correct belt. The dyno really comes in to play when dailing the clutches in and testing pulleys and belts. Their is a few guys that I have tuned their clutches on the dyno and it seems to make a big difference. Kevin Tait I would say me and him spent the most time trying different setups on his drr 50 and it ripped hard for a 50. Craig Guyers has also spent hundreds of hours here testing different clutch set ups on his 70cc drr they are a couple of good guys to talk to.

[BradLoomis]

A larger front variator diameter has the potential to achieve a greater belt speed than a smaller diameter variator. That bing said... I have found usable roller travel on a flat ramp plane to be the most benficial of everything. The overrange rear pulleys slow down the belt speed because of the lager diameter, think of puting a larger rear sprocket on your gearing, but increases the torque to the output sprocket. By increasing the torque, you can now run a taller gearing ratio for more speed.

I have always found that the skinniest belt, as low as 15 mm, is the best because it can get deeper into the rear clutch sheave to the smallest diameter. The rear sheave has the physical limitation of relaxed state and compressed state and takes ALOT of modifcation to change those 2 dimensions. Belt lengths and widths can be mathmaticaly figured out to achieve the proper tracking needed. Variators and sleeves are easily modified and can be shimmed to get the desired acton.

This all comes down to, do you want to buy something and put it on or do you want that unfair legal advantage that hopefully no one else has, both have their positives and negatives. It is alot of work and I have great respect for those before me and now that are never happy with what is out there and must try to come up with something better.

When looking at belt travel, use the diameters there are tracking at as your ratios. Think of the CVT as a manual transmission and everytime you get the ratios farther apart, you are adding another gear to your manual transmission. 3 speed transmissions was where it started and now you have factory 7 speeds.

Sorry for the rambling:(

[ww228king]

Originally posted by hotquads1
.

Keep in mind if the variator were larger in Diameter it would make more space for travel but not more travel . the belt is not long enough to travel any further , a longer belt could be used but then it would ride out on the rear pulley so you would need to go to a larger rear pulley also to run the belt, with all of that being said you can by a set-up for this purpose an overange system , by Malossi or Polini, just wanted to start your thinking process , your heading in the right direction but it is going to take more than a variator.
marc

His thinking process and what you have posted has got me thinking...lol
how much of a differance is it going to change on the lowend and the topend with this overange kit?
I guess I am asking.... is it worth it for MX?

[hotquads1]

IMO, no it is not worth the money in mx. I have had customers that like it but i have personally used thes in mx and cannot justify the cost over a proper working cvt system , any gains are just too slight most mx tracks do not have enough long straights to use the added overdrive ratio. Try riding a 450 shifter bike arounf the mx track and see how many opurtunities you get to put it in 5th gear , this is the same principle, IMO.
marc

[ww228king]

Originally posted by hotquads1
IMO, no it is not worth the money in mx. I have had customers that like it but i have personally used thes in mx and cannot justify the cost over a proper working cvt system , any gains are just too slight most mx tracks do not have enough long straights to use the added overdrive ratio. Try riding a 450 shifter bike arounf the mx track and see how many opurtunities you get to put it in 5th gear , this is the same principle, IMO.
marc

that is what i was thinkingt too... but i was also wondering, with the rear pully being bigger and the belt is at the top of it on take offs.. will it add more down low for that first 10 to 20 feet... or will it just kick some dirt and all that work and money is wasted in the dust...

[BradLoomis]

Yes it will add more launch torque, but will sacrifice top speed. This is why gearing changes need to be made. The problem I have had with the over range rear sheaves, is that the relaxed and compressed ratio is lower than standard rear sheaves. If you take the relaxed state with the belt in it and measure to OD and then pull the belt in to the compressed state, all the way in until it bottoms reguardless of what belt it is, and measure the OD then divide small OD into the big OD it will give you a ratio. The over ranges have always been less than a standard sheave. So my modifications were always to get as much front variator travel as possible, shimmed according to belt size, to be able to use as much rear sheave travel as possible. Everything comes into play to make this happen, belt length and width, roller weight, rear spring tension, stall speed, operating rpm range, peak rpm, rider weight, quad weight and track type.
Lets just take stall speed for an example. If you have a high stall speed, you are using some of your belt travel just to get the clutch spinning fast enough to fling the shoes out to engage the clutch.
All of the over range rear sheaves I have seen actually slow down the rear bell rpm. They don't add speed, they take it away. I am sure alot of you guys remember the old "granny gear" first gear in the old pickup trucks. It was useless unless you had to move a heavy load or cruize the local strip at 5 mph. But now if you change the differential gear ratio's from say a 4.56 to a 4.11, or mount taller tires, the truck will be faster at top speed with a first gear you could actually use. But since the over range actually has less movement, it would be like taking a gear away from the transmission.
I hope that rambling knda makes sence. In short, I agrre with Marc that I haven't seen an over range that works better than a properly setup standard sized rear sheave.

[Logan #34's Dad]

I disagree.
I'll gladly allow you guys to put your set up in Logan's quad and we'll take timed runs to see which one gets there faster. I think of it like a 15 speed bike. The lower gear in the front and larger in the rear is great for take off BUT as you got moving to go faster we shifted up the the largest gear in the front and the smallest in the rear after we got moving.
I think if you have the right belt and "work" the clutches the overrange is the way to go. IMO
Now, the "regular" set up could be made up by gearing I guess but if you have the best of both then I think it's an advantage.
Once this good ole' Ohio weather breaks I'll switch 'em out and let you know what I've found.
You all got me doubting myself! LOL :eek2:

[BradLoomis]

Originally posted by Logan #34's Dad
I disagree.
I'll gladly allow you guys to put your set up in Logan's quad and we'll take timed runs to see which one gets there faster. I think of it like a 15 speed bike. The lower gear in the front and larger in the rear is great for take off BUT as you got moving to go faster we shifted up the the largest gear in the front and the smallest in the rear after we got moving.
I think if you have the right belt and "work" the clutches the overrange is the way to go. IMO
Now, the "regular" set up could be made up by gearing I guess but if you have the best of both then I think it's an advantage.
Once this good ole' Ohio weather breaks I'll switch 'em out and let you know what I've found.
You all got me doubting myself! LOL :eek2:

You made my point exactly. The larger rear will give great take off, but will rob you on top end. It can final gear ratios can be changed, but you will not get a smaller diameter on a large rear sheave that you will be able to get on a smaller rear sheave. I have my setup at a guys shop in Ohio right now. I wanted to have an independent person run it for themselves after having this same conversation. This is my what I find the most fun in!

[Logan #34's Dad]

Okay, We agree that you will have better take-off (lowend) because the rear pulley is larger even if it is for a couple seconds. Now a belt will only go inside the rear pulley so far before the belt rides on the inside lowest point of the rear pulley. Most rear pulleys have around the same o.d. male part that sides into the female half pulley correct? :devil: perverts! Anyhow, If the front variator is larger and the belt is all the way to the top of that larger variator (which would be a circular objects greatest speed - outer most position) it would be spinning the belt faster for more top end. Like a 15speed with the chain on the largest gear up front and the smallest gear in the back. Win - Win correct?

[BradLoomis]

Yes and no on the rear pulley diameters. The over range pulley is a larger OD than a standard... Yes, so the launch would be quicker on the larger size. But I have yet to see an over range pulley that will allow the belt to get as smaller or deep into it as a standard size. Same width belt into both rear pulleys, the smaller diameter one has always gone the deepest. So without even looking at what the front variator size is, we agree that the smallest back is the faster speed.

Remember over ranges are only larger in the OD, but they only open and close as much, or as I've seen, less than a standard one. So if you start out at larger OD and are only allowed the same or less movement, you can't arrive at the same ending diameter. Think of your fifteen speed back gearing. There are 5 gears and you only have enough derailer travel for 3 gears, the first 3 gears would be quicker ( 1,2,3 ) while the last 3 gears would be faster ( 3,4,5 ). Now you could still get them to run the same top speed, but you would have to change the tire diameter to do that. The quicker style would need to run a larger tire, just like changing the gear ratio.

I used to have all of the math formulations laid out, but I gave most of them away to other racers still running mini's.

[hotquads1]

brad you mentioned a "flat roller ramp" that is an interesting idea , are you suggesting no arch at all?

[Logan #34's Dad]

Oh Brad, I guess we'll have to agree to disagree.

You wrote ---Think of your fifteen speed back gearing. There are 5 gears and you only have enough derailer travel for 3 gears, the first 3 gears would be quicker ( 1,2,3 ) while the last 3 gears would be faster ( 3,4,5 ). Now you could still get them to run the same top speed, but you would have to change the tire diameter to do that. The quicker style would need to run a larger tire, just like changing the gear ratio.---

You say you could get them to run the same top speed? 3,4,5 would go much faster with tires and all being the same. That is the basis behind having gears on the bike or the shifter bike would not have any advantage over a one speed bike.
We all pretty much run the same tires, sprockets and tranny gears so if you add the higher belt speed because the larger variator it would go faster than the standard variator one.
Also, my rear pulley opens up further that a stocker.

[BradLoomis]

Originally posted by hotquads1
brad you mentioned a "flat roller ramp" that is an interesting idea , are you suggesting no arch at all?

No, not nessecarily flat. But definately not a Nike swoosh or freestyle ski jump that's in all of the aftermarket variators I have seen. They have a very aggressive ramp angle especially at the outer edge, where it has more stress on the variator, backing plate and the most belt tension because of the compressed rear spring. I just like a more linear progression to the ramp angles.

[Logan #34's Dad]

Originally posted by hotquads1
brad you mentioned a "flat roller ramp" that is an interesting idea , are you suggesting no arch at all?

Don't you have to have an arch to be able to push the variator halves together. Unless you'd have wedge shaped rollers - and I've never seen them.

[BradLoomis]

Originally posted by Logan #34's Dad

so if you add the higher belt speed because the larger variator it would go faster than the standard variator one.
Also, my rear pulley opens up further that a stocker.

YES, I agree! but I was never talking about a larger varitor diameter except for my very first post. Now if you are saying that you get a higher belt speed out of the same size front variators but with a larger rear sheave tnah with a standard rear sheave... then I will have to disagree.

I'm just trying to make sure we are on the same page.

[Logan #34's Dad]

You wrote: Yes it will add more launch torque, but will sacrifice top speed. This is why gearing changes need to be made.

That is the statement I disagree with. Most scooter racers and riders use the overrange system FOR more top speed.

This post was questioning whether or not he should get the larger variator or standard size. You stated that the overrange(larger front variator and larger rear pulley) or oversized was not as good as the standard size. I argue that both being bigger is better OR even the front only being bigger would be a benefit.

[BradLoomis]

Originally posted by Logan #34's Dad
You wrote: Yes it will add more launch torque, but will sacrifice top speed. This is why gearing changes need to be made.

That is the statement I disagree with. Most scooter racers and riders use the overrange system FOR more top speed.

This post was questioning whether or not he should get the larger variator or standard size. You stated that the overrange(larger front variator and larger rear pulley) or oversized was not as good as the standard size. I argue that both being bigger is better OR even the front only being bigger would be a benefit.

All three different over range " REAR " sheaves/pulleys/whatever I have bought have been larger in diameter than a stock sized rear sheave/pulley/whatever. If you are using a stock sized front variator with a larger diameter rear sheave, it will slow the belt travel down just as it does by puting a larger rear sprocket on the back of a quad without touching the front sprocket. I did say that a larger front variator with a stock rear sheave, will increase belt speed. So yes, I do agree with you just like I stated in my first post.

[Logan #34's Dad]

Great.