RPMS at 70 miles/hour

What does your Tachometer read at 70 Miles/Hour?
Thanks,
Disturbed

My rpm's are about 5000-5200 rpm's. I have the Dr Pulley sliders so they reduce the rpm's about 300-500 rpm's at 70 mph. I think before I had the sliders I would be around 5400-5500 rpm's.

Yep, my SW with OEM rollers and 20,000 miles runs about 5500rpm at 70mph. I'm not sure if this bike has it's original CVT belt or not. As soon as my GW gets out of the shop I'll be installing a set of 28 gram Dr Pulley sliders as well as a new belt and I'll try to verify the rpms with the Dr. Pulley sliders and a new belt.

Hello Jeff,
What weight Dr Pulley sliders did you install? Also do you recomend an OEM replacement belt?
Thanks,
Disturbed

I have the 28 gr sliders. When I first bought them I got the 21 gram and they pushed the rpms too much, but gave great acceleration. I then bought the 28 gr and it is a much more relaxed ride. If I were to do it again I would get the 26 gr for a bit more acceleration and good rpm's. They only had the 2 weights when I bought them back then.

How many miles does your belt have? If it is close to 16,000 miles I would go ahead and change the belt since you have everything open already. And then just keep the old belt as a back up belt if one ever breaks. I think the sliders smooth out the swing a bit more and will reduce the rpms some too.

It seems you have had the same scoots as I have had. I started with the Reflex, then the Majesty, and now the SWing (after quite a few m/c's)

I would highly recommend sticking to the OEM belt. It costs you less than $0.01 per mile and you would only save a small fraction of that buying a different one - other things on your bike cost far more per mile (gas for instance costs me about $0.07 per mile). This isn't a fan belt - it is very purpose made and works extremely hard.

If you have high RPMs, it is either stuck/worn rollers (somewhat unlikely) or a worn belt. I suppose it could also be a clutch problem, but you would probably notice that in power loss.

Thanks for the advice. I will order the 26 gram weights and a new OEM belt.

JeffR_ wrote:

I have the 28 gr sliders. When I first bought them I got the 21 gram and they pushed the rpms too much, but gave great acceleration. I then bought the 28 gr and it is a much more relaxed ride. If I were to do it again I would get the 26 gr for a bit more acceleration and good rpm's. They only had the 2 weights when I bought them back then.

How many miles does your belt have? If it is close to 16,000 miles I would go ahead and change the belt since you have everything open already. And then just keep the old belt as a back up belt if one ever breaks. I think the sliders smooth out the swing a bit more and will reduce the rpms some too.

Jeff

You could always mix those 28 & 21 gm sliders to come up with 24.5 gm sliders. Bold acceleration yet mannered RPMs.

Tim

I should've tried but I sold the 21gr after I installed the 28gr. I'm happy with them and have had them a couple of years now. Maybe I will get new pins and re-install my j costa one day just for fun.

I have the 22g sliders and this morning when I checked my engine RMPs when the speedometer read 70 mph my RPMs were right at 5550 rpms. As for my gas mileage, I still average between 50 mpg to 54 mpg. For me, this is a great combination of quick acceleration and fuel economy.

2012 with 900 miles...run 5200 at 70....everything on engine stock.

Rpms aren't stricty related with certain speedo readings.For instance ...for the same speed,rpms may differ up to 500 depending if you are up or downhill

Yes, I have noticd that too. I try to find a flat stretch of road to observe my rpm to speed telationship, but it is difficult here in Colorado - everything seems to be a bit up hill or down hill...

micbusathens wrote:

Rpms aren't stricy related with certain speedo readings.

The rev counter is measuring engine revolutions.
The speedo is measuring wheel revolutions.

Between the two is a variator which is continually altering the gearing ratio to achieve best performance.

Exactly.The word "variator"is the key.There aren't steady ratios ,as on a clutch ,gearbox type engine.Variator always changes ratio according to drivers demands.So a straight windless road should be considered as reference for all those readings with the throttle as steady as possible

I get 5500 RPMs at 70 MPH indicated on straight level road without wind.
2002 SWing, 29.5K miles, stock variator/rollers/belt.

I just ordered the Dr Pulley HiT clutch and 26 gr sliders.

I just got the new belt this afternoon and pulled the cover off this evening so I should have the Dr. Pulley sliders and the new belt on tomorrow. Then I'll see what difference they make. If I wasn't too lazy I'd make a run with the old belt, put on the new belt and compare it then add the Dr Pulley sliders and check things out again. Unfortunately I'm too lazy to make four comparison runs.

Yeah, I thought about that myself, but I decided that since there are descriptions on this forum of what differences each mod makes, and how they feel, I'd go the lazy route and do the clutch kit and sliders at the same time. When I go for the test ride, I should be able to observe the differences independently, since others have told me what to watch out for.

I finished up installing the 28 gram Dr. Pulley sliders today as well as a new belt. I don't know if the old belt was original or not, the bike had 19,638 miles on the odometer when I changed it. The old belt didn't look bad, it's a wee bit narrower, I don't know exactly how much because I didn't have a pair of straight edges handy to measure the width properly. The whole job can be done in less than an hour, the actual job being about 30 minutes. I spent about an hour and a half including cleaning old rubber dust and some dirt from the various parts as well as fifteen minutes to build a holder to prevent the variator from turning while removing the bolt and replacing it later.

The difference in the scooter isn't spectacular but is noticeable. It's quieter which is probably due to the old worn rollers rattling a bit. At 70mph the tach shows right on 5,000 rpm whether uphill or down. I think the variator is at it's narrowest at that rpm since I didn't see any change in tach reading going up or down a 1-2% grade. At 50 mph I saw right on 4000rpm as near as I can read it. Since the ratio of speed/rpm isn't constant it probably means the variator isn't at its narrowest at 4000 rpm and probably will show slightly different tach reading going up or down hill. At 70mph the drive system seems to be in its highest ratio so one could expect to see about 3570rpm at 50mph but the tach actually reads 4000rpm indicating the sliders in the variator aren't at their maximim outward travel. At 90mph I saw very close to 6400 rpm on the tach which is what one would expect if the CVT ratio was the same as it was at 70mph. This tells me that there is no more shifting action in the variator at speeds 70mph or above but there is still some varation in the gearing ratio left at 50mph because the ratio between speed and rpms isn't the same as at 70 and 90 mph.
I should have gotten the same rpm readings before I changed the OEM rollers for the 28 gram sliders but due to lack of time didn't. Nonetheless those speed checks do give a bit of a view into the operation of the CTV system. It looks like the CVT does no more changing of belt ratios around 60mph. In other words somewhere around 60 the system is in top gear. Below that and it's effectively downshifted somewhat.

Cosmic_Jumper wrote:

Jeff
You could always mix those 28 & 21 gm sliders to come up with 24.5 gm sliders. Bold acceleration yet mannered RPMs.
Tim

After buying the 21's from Jeff that is exactly what I did! I have been very pleased with the what the combination has delivered.

On my ride today my RPMs at 70mph were 5000. I'm using 28gm Dr Pulley sliders and standard size rear tire.

When I was using a Sumitomo "Darkside" rear tire the RPMs were less because the larger tire changed the final drive ratio giving the effect of an overdrive.