Dr. Pulley - Notched Ramps?

loodieboy · Post by **loodieboy** » Sun Jun 14, 2009 12:26 pm

Switching sliding weights yesterday, I thought the 11's I had been running looked a little chewed. Then I noticed that each of the variator ramps has a small and not so smooth fingernail-shaped notch a little past 1/2 up. What the heck are those notches?

Post by **Lostmycage** » Mon Jun 15, 2009 4:04 am

Gremlins! Gremlins grasping at your variator, trying to pull it apart!

Actually, that's a rare occurrence with the variators. I'm guessing that it happens when the engine is running and the variator is in low gear setting. I think it has something to do with the belt being below the width specs (which lets the variator run at that low of a setting) but I'm still trying to gather specifics on there. Have you done anything else to the CVT like a clutch pulley?

loodieboy · Post by **loodieboy** » Mon Jun 15, 2009 10:26 am

I've tried several different configurations, but over the past 1200 miles or so, I have been running with a Gates kevlar belt (PL30707), 1000 rpm clutch springs AND contra spring, a NCY clutch bell, and the aforementioned Dr. Pulley variator with 11 gm sliders. This was my optimum set-up. The variator was fine when I started with this setup.

I guess I should mention that I do ride aggressively in stop-n-go city traffic almost every day. Some WOT runs, but not many. Also, when I pulled the variator and discovered the notches, belt wear was fine and dust was normal. Nothing out of the ordinary, at least to my eye.

Thanks.

Post by **Lostmycage** » Mon Jun 15, 2009 1:48 pm

Is the Gates belt longer than the stock belt? If so, that's the cause. The only way that notching could happen is if the variator is allowed to go to the full open position (lowest gearing setting) where the ramps touch the plate. It then rubs at idle, which causes the notches.

At least, that's the best I've been able to figure...

loodieboy · Post by **loodieboy** » Mon Jun 15, 2009 3:46 pm

Oh no, I think I've miscommunicated. I am talking about the six internal 'ramps' that the sliders themselves, umm, slide up (or out, or along, or whatever). I'll try to post pic's tonight (new puppy permitting).

Post by **Lostmycage** » Mon Jun 15, 2009 4:51 pm

Nope, you've been clear. When you take it apart, look at where the plate contacts the ramps. You'll likely see that the grooves are right there.

The stock belt lets the variator close just a little at idle. The weights push it that distance, which moves the plate off the ramps. If the belt is longer, it lets the variator idle while the plate is still contacting the ramps, which is what's causing the grooves to occur.

Again, this is just my best guess.

They look like this, right?

loodieboy · Post by **loodieboy** » Tue Jun 16, 2009 1:49 am

Yes sir, you are correct! Thanks so much for the dead-on diagnosis, sight unseen.

So I guess it is back to the stock belt. And a big question mark for the Gates kevlar belt. Dang, isn't anyone else running on one?

So, is my Dr. Pulley toast, or will it continue to work okay if I remove the sharp edges on the nicks? Replacing sliders will get real expensive real fast.

Post by **Lostmycage** » Tue Jun 16, 2009 1:56 am

Well, that's the mystery. Have you noticed a hit in performance?

Did you put the Gates next to the stock belt? Is there a size difference?

Cheshire · Post by **Cheshire** » Tue Jun 16, 2009 5:35 am

loodieboy wrote:So I guess it is back to the stock belt. And a big question mark for the Gates kevlar belt. Dang, isn't anyone else running on one?

Djelliot's voodoo spec list on the voodoo buddy site is listing a Gates kevlar belt. Kaos's stats are listing a kevlar belt, but his don't say who's. I didn't see a size, though...but I seem to remember seeing a size spec in some thread...somewhere. I'm too sleepy to search for that tidbit at the moment.

But yeah...at least one other person running a Gates kevlar. I'd like to know if it was a size discrepancy, personally...kevlar belt is one of the upgrades near the top of my list.

loodieboy · Post by **loodieboy** » Tue Jun 16, 2009 1:47 pm

The Gates belt is definitely the right size: PL 30707, but I'll compare it to stock tonight.

The scoot has been running great except for a slight rough idle that I haven't been able to dial away. It's going in the shop tomorrow for an a/f (which I won't touch at my experience level) and idle adjustment, and a few other tweaks, so maybe they'll be troubleshooting this as well.

Anyway, last week I was sporadically getting a slight 'over-rev' (if I am using the correct term in this context). A nice whine on acceleration at about 20 bmph which then dropped off at 25 - 30 bmph, then let off the throttle and wah-wah-wah-whine. So I figured the sliders were sticking, dust maybe, no big thing and an excuse to swap sliders just for fun. That's when I found the notches in the variator ramps. I cleaned things up (there wasn't much dust), pulled the clutch as well and checked the pulley, and all looked good. Well, the clutch pads were glazed but I roughed them up. I slapped it all together 'as-is' (maybe stupid) but I wanted to see where things were headed, and ran it a bit before closing the transmission up. I've taken a few short rides since, and now that I am sensitive to the issue, think I am hearing a slight metallic rattle in the transmission (ramps to plate?)

I'll run it with the cover off tonight to see if that gives me any clue, then I'll swap back to stock. I'll also compare the stock belt to the Gates, but on reflection, I'll be real surprised if they don't match up. Something wrong with the rear pulley, maybe?

Anyway, thanks again for helping me with this!

loodieboy · Post by **loodieboy** » Wed Jun 17, 2009 12:29 am

I matched the Gates belt and stock belt as best I could, and they give every appearance of being the same size. Of course, I had no precise way of measuring.

So, its back to stock for now. Blah.

Post by **Lostmycage** » Wed Jun 17, 2009 1:01 am

Take a flexible tape measure (like for fabric) and use that to get the circumference. If you don't have a metric, you can just use an online converter

If they're the same size, then the belt is not the issue. Of course, that throws my theory right out the window, lol.

loodieboy · Post by **loodieboy** » Wed Jun 17, 2009 1:08 pm

Doh! Could have 'borrowed' one from my wife, but didn't think of that. I'll give it a shot when I get the scoot back.

I just dropped it off at the shop. Unfortunately, they won't / can't help with this issue ("We don't do aftermarket, and anyway, we have never heard of this problem"). Oh well. I'll ask for an opinion next door at Metro Scooters.

Now, the funny thing is the scoot ran like a beast when I took it to the shop with the stock variator and belt (10g/12g sliders - the 11g's are trashed). Don't know about top end, but good pop off the line and ran up to 60 with no problem. Hmmm.

As for the noise, no more wah wah wah when I let off the throttle, but still a decent whine on acceleration. But such things are subjective, I suppose. Particularly because (another Doh!) I first became conscious of the noise last week when I switched back to my tried and true Scorpion EXO 400 (which actually allows you to hear the scoot) from my POS Shark Evoline which generates so much wind noise that I can't hear anything but the hurricane.

bpnwmike · Post by **bpnwmike** » Wed Jun 17, 2009 4:15 pm

Another way to measure the belt length is the lay it down, wrap a piece of string around the outer circumference, and then measure the string length (when straightened of course.)

I've never heard or seen this issue with the notched ramps before. Thank you loodieboy for bringing it up and lostmycage for showing a picture. It's something I'll watch out for in the future.

bikebuda · Post by **bikebuda** » Wed Jun 17, 2009 5:09 pm

i think all of you are missing the point

if the rollers (or sliders ) are the wrong size ( to small ) they let the two ramps contact each other

take one apart and have a good look, in the retracted position rollers/sliders are on the innermost side inside of the variator the ramps are then the closest together if the sliders are to small they allow the ramps to become to close and contact each other

to test this ,remove the variator and hold it in your hand with no rollers or sliders in it notice how the two ramps now can fully run into each other install a set of stock rollers and notice how they cannot contact eachother .

nothing to do "at all" with the belt

loodieboy · Post by **loodieboy** » Wed Jun 17, 2009 7:27 pm

Thanks, bikebudda, I'll check that as soon as I get my scoot back (I left the Dr. Pulley variator and 11g sliders in the pet carrier hoping to get some insight from the shop).

Strange thing is, however, that I am 100% positive 1) that the variator is the correct variator for the Buddy 125 (181401); 2) the sliders, at least as packaged and marked (the size is stamped into the sliders) are the correct size (GY6 18x14), and 3) I installed the sliders with the correct orientation (and yes, the spacers were installed as well).

I can't believe (although I guess it may be possible) that the 11g'ers could wear below spec in only 1200 miles. So if you're right, then I would have to conclude that either the sliders were below spec from the get-go (for whatever reason), or the variator was off spec from the get-go (for whatever reason).

But hey, Lostmycage, did you ever figure out what happened to the notched variator you posted a pic of?