Flash 3.26

[Wheelman-111]

Greetings:

Without much effort, Flash bettered 60 by 10.5%..
Deepinnaharta Freeway traffic prevented a real long run, but blending in and a short WO burst before my exit were recorded for Posterity.

F3.2MPH66.3.jpg (42.29 KiB) Viewed 4322 times

For some time I have noticed a high-sppd noise issue; sort od a soft grinding vibe felt through the floorboards and grips. Amplitude oscillates at 2Hz, like Wom-Wom-Wom. It occurred with 2 other engines, not just the Corsa.
Thinking it might be the 3.50 tire tread rubbing, I swapped for 90/90; same thing. (But quicker take-offs )
Maybe they all do this, but I'd like to know the source. Gears looked fine and they're the helical type.

[bakaracer]

its the trans.could be due to the mix match weights or a warped rear sheave.

[Wheelman-111]

Greetings:

Sheaves are true, but the weights could sure be the culprit. I'm not sure it's goog to have such imbalance on the crenk end. I will balance. Thanks Baka!

[burnt_toast]

not sure if its what you're describing, but I've always felt a pretty noticeable vibration at ~70mph which I accounted as just speed wobble on 10in tiny wheels, usually would occur right anything above 65mph.

NOTE now that I think about it, this affect was much smaller and high speed ride was smoother when running 7:1 primaries hmm..

(8.44:1 secondaries currently)

ps. congrats on netting 66.3mph thus far, fun stuff

[Wheelman-111]

Greetings:

Thanks Toast! It's definitely not not speed-wobble thing. "Sound" can't be heard with 60-MPH wind roar, but the vibration felt through the entire scooter is enough to be disconcerting. It starts at anything much over 55 and gets stronger as speed increases. I checked the rear tire for contact against the cases or centerstand and that's not it.

This leaves the engine itself, the belt drive, and final-drive gears on the Suspect List. The engine seems happy, continued to supply ample torque at stable temp of about 350 since switching down to 118 main/up to 50 Pilot. (It was still accelerating at 66 but I had to exit... AND I was a bit spooked by the "racket".) I took the gear cover off and the expected oil quantity and color soiled my Priceless Persian Rug. Gears and bearings all appeared fine, and no telltale metal flecks anywhere.

I'm thinking the belt is going around at a rate approximately twice that for which it was designed. Is it possible to "balance" a belt? Failing that, next time I have a wrench handy, I'll take a peek at what kind of mish-mosh of rollers I put in there last time to make up the 32 grams I'm using, and see if I can shave a few old heavier weights to balance the load.

[Bear45-70]

Greetings:

Thanks Toast! It's definitely not not speed-wobble thing. "Sound" can't be heard with 60-MPH wind roar, but the vibration felt through the entire scooter is enough to be disconcerting. It starts at anything much over 55 and gets stronger as speed increases. I checked the rear tire for contact against the cases or centerstand and that's not it.

This leaves the engine itself, the belt drive, and final-drive gears on the Suspect List. The engine seems happy, continued to supply ample torque at stable temp of about 350 since switching down to 118 main/up to 50 Pilot. (It was still accelerating at 66 but I had to exit... AND I was a bit spooked by the "racket".) I took the gear cover off and the expected oil quantity and color soiled my Priceless Persian Rug. Gears and bearings all appeared fine, and no telltale metal flecks anywhere.

I'm thinking the belt is going around at a rate approximately twice that for which it was designed. Is it possible to "balance" a belt? Failing that, next time I have a wrench handy, I'll take a peek at what kind of mish-mosh of rollers I put in there last time to make up the 32 grams I'm using, and see if I can shave a few old heavier weights to balance the load.

Anybody ever think to get the wheels and tires balanced?

[Wheelman-111]

Greetings:

Does anyone even do this for 10" Rims??
Anyway, it doesn't feel like a wheel balance issue, but a mechanical grind/whir. Frequency is too high.

[bakaracer]

do you have other variators? what weight is your total roller weights in the pulley?

[Bear45-70]

Do your own.

http://www.harborfreight.com/motorcycle ... 98488.html

or

http://www.harborfreight.com/portable-w ... 39741.html

Weights are available a lot of places.

Mechanical issues don't just appear at high speed, they are there all the time.

[Wheelman-111]

Greetings:

Thanks, Bear! Yeah, it isn't hard and I already have the double-stick lead weights. Just don't have $70 for a balancer...
Hmm, maybe I can just take my tire into the HF store and check it there.

Baka I only have my Giant 97 BrandX with about 32 grams loaded working against the +1000 spring you suggested. If I could balance the Vario on Bear's HF balancer, I'd do it! It's almost big enough.

[bakaracer]

bear that noise that wheel is hearing and somewhat feeling is not the wheel,its the trans. I've experienced this many times over the years. its either the weights or the belt or a pulley either the front or rear that has gone bad.most times its the weights.if you look at the variators for these engines,they are not exactly even where the roller weights are spaced.if all 6 weights are the same weight then at high rpms the engine doesnt make a harmonic hum. but to fine tune the trans you have to mix match rollers to get the right weight amount.Thats why in alot of my post I always say when you mod these engines to this extent,you need to get rollers that are in the odd weights so you can fine tune the trans so all 6 weights are not that far off from each other. so having 5.1,5.2,5.3g..... for example are those odd weights.

[Wheelman-111]

Greetings:

Yeah, I just sort of tossed 'em in last time. I do have a 1/10th gram scale and I'll examine more closely when I reassemble.

[bakaracer]

what weight rollers are you using to make 32grams? check the belt too lumps.

[Wheelman-111]

Greetings:

They're all 5.5s and 5.1 or 5.0. I'll put the belt on Bear's balancer too.

[z50r-ghost]

Mr Wheelman, I too hear the "wom-wom-wom" harmonic sound when riding at high speeds on my Aero. Definitely a transmission sound. I disassembled my Stage 6 clutch and weighed each of the three shoes to make sure they were exactly the same weight. They were spot-on, so my guess is the belt or my mismatched roller weights. I have the pricey Daytona weights which are like new, so maybe the belt? Hmm... Good topic dude...