BEST bang for your BUCK...Dr. Pulley Sliders for your variator

justscootin

Member
When your scooter was running with the original rollers/sliders your engine was running at 5000rpm with the 33 grammar and the fuel economy was 58mpg at 60mph (this is just an example) after replacing with with Dr pulley 28 gram rollers/sliders how much did your rpm's go up and fuel economy go down. As when I replace mine I was also thinking I may go this route as I read that Dr pulley may last 15 times longer (that is a long distance and hard to believe). This job may never have to be done again.

Running at 7 or 8,000 rpm's plus the volume does not impress me.
 
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SteveADV

Active member
The wedge shape of the slider allows the variator to actually open a bit wider at rest, dropping the belt into a smaller circumference between the variator halves, essentially lowering your gearing from a start and helping with off the line acceleration. As they are lighter than stock, your bike is revving higher, closer to it's torque peak and can apply more force through that lower gearing, hence the two-pronged increase in performance.

The same wedge shape also does the converse, at high speed, forcing the variator halves closer together than before, effectively raising your gearing and lowering rpms, even with lighter weights. Brilliant design.

The standard rollers (which actually also slide, not "roll", are fixed diameter, with taller gearing from the start and lower gearing at speed...

So, faster pickup and lower RPMs at 80mph, right? Doesn't there have to be some down side?
 

Eccles

Member
Just got around to doing this myself. So far no downside just better throttle response and performance.
I took some pics of the process and posted here Installing Dr Pulley Sliders in a BMW C600 Sport - Scooter Community, Everything about Scooters, Join the Scooter Community, pretty straight forward really.
Whilst there check out what we get up to downunder in the lengthy COZ we can thread Sydney "Coz We Can" Ride - Scooter Community, Everything about Scooters, Join the Scooter Community (plenty of pics ).
 

Skutorr

Active member
In the pictures the end of the crankshaft seems to have heat marks from the aluminum cover bearing binding-up. Did it turn freely and still retain grease? This is a common problem in almost every larger-displacement CVT system...
 

Eccles

Member
Yes, I did inspect the bearings in the cover and all appeared in order. I did make a mental note though to replace the seals and bearings in the cover next time I pull it down, this perhaps to install a HiT clutch. Bearings etc. are generally cheap.

Took it for on a 800km (500mi) run on the weekend and all was good. I also have a steep climb out of my driveway and the scoot is much happier doing so with the gearing at low speed.

Another thought though, is how well the final chain and sprockets stand up to the extra torque generated from take-off. The sliders must take a second easy off the 0-60 time, and then there is the constant propensity to do so.
 

davidh

Member
Just ordered mine. Looking forward to getting rid of the roller clatter at just 6,000 miles!

BTW, I checked with Buggy Parts NW and they won't have these parts until later this fall. Best to order from the link in the first post.
 

Skutorr

Active member
Buggy Parts does NOT carry the Sliding Pieces (GUIDES) which you should ALSO change-out when installing the Sliders. Tightens-up all the slop in the variator and eliminates ALL rattling. You just need to hand fit them for minimum tolerances with smooth sliding action.

(Oh, that sounds NASTY!!!)
 
P

Pierrel

Guest
Finally got around to get the Dr. Pulley sliders installed by the dealer here in Victoria, BC. They had to wait until they received the required tool from Germany before installing the sliders. Since yesterday was one for the first rainy day of the season so it was very slick on the street and I could not really check how well these performed. But I can say that the difference in acceleration is noticeable. I would not go as far as saying that this is a totally different bike but it does make a difference :)
 
Hi guys,
Pretty old tread but I just replaced the rollers and sliders on my BMW c650gt with 28gr Dr Pulley and I’m not happy with it. There is some lag at start which doesn’t bother me much but the rpm is super high at all times. Around 5-6k rpm, when accelerating and also on high speed around 70-80mph. Is that normal?? Bike is very loud of course because of the high rpm and at low speed from 0-30mph it feels like you ride in 1st gear.
Just wanted to check if all this is normal?
thank you,
Ben
 

Delray

Well-known member
"I just replaced the rollers and sliders on my BMW c650gt with 28gr Dr Pulley and I’m not happy ... There is some lag at start ... the rpm is super high at all times. Is that normal??"

I replaced mine two weeks ago with a new belt (2013 GT with 15,000 miles). I had a similar reaction. The rev's seem high, though it's hard to be precise with BMW's bar system, with each bar spanning 1,000 rpm's.

This was a definite culture shock for me coming off a 2016 Burgman 650 -- Suzuki's SMART transmission has that bike at 3,000 rpm's for 50 mph and 3,500 for 60 mph like clockwork. Amazing transmission. Unfortunately, it has a belt buried so deeply it takes a master mechanic to replace or $4,000 at a dealer. The Burgman also handles like a bathtub on wheels at low speed. I owned three and STILL can't turn around on a two-lane road without putting my feet down. That's never a problem with the BMW.

I noticed the same lag when starting out. Some of that comes from Gen 1.0 models, pre-2016. I owned 2016 and 2017 GT's and takeoff was WAY better. I've been living with the lag on my 2013, thinking it was normal. Maybe the sliders made it worse? I can't tell.

One BIG positive is the bike now ZINGS when I accelerate quickly over 20 mph. If I twist the throttle hard, it's hold on to your hat time. The bike is a rocket, quicker than my '16 and '17 were. It takes off faster than the Burgman's Power button, which basically drops gearing by 1,000 rpm's to work like "Turbo" mode. I really enjoy the enhanced acceleration.

Not sure I'd put the sliders in again. Not sure I want to change them back. Eventually I'll end up with a low mileage '19 or '20 and I'll see how that performs. I have a feeling I'll like it just fine, as-is.
 
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"I just replaced the rollers and sliders on my BMW c650gt with 28gr Dr Pulley and I’m not happy ... There is some lag at start ... the rpm is super high at all times. Is that normal??"

I replaced mine two weeks ago with a new belt (2013 GT with 15,000 miles). I had a similar reaction. The rev's seem high, though it's hard to be precise with BMW's bar system, with each bar spanning 1,000 rpm's.

This was a definite culture shock for me coming off a 2016 Burgman 650 -- Suzuki's SMART transmission has that bike at 3,000 rpm's for 50 mph and 3,500 for 60 mph like clockwork. Amazing transmission. Unfortunately, it has a belt buried so deeply it takes a master mechanic to replace or $4,000 at a dealer. The Burgman also handles like a bathtub on wheels at low speed. I owned three and STILL can't turn around on a two-lane road without putting my feet down. That's never a problem with the BMW.

I noticed the same lag when starting out. Some of that comes from Gen 1.0 models, pre-2016. I owned 2016 and 2017 GT's and takeoff was WAY better. I've been living with the lag on my 2013, thinking it was normal. Maybe the sliders made it worse? I can't tell.

One BIG positive is the bike now ZINGS when I accelerate quickly over 20 mph. If I twist the throttle hard, it's hold on to your hat time. The bike is a rocket, quicker than my '16 and '17 were. It takes off faster than the Burgman's Power button, which basically drops gearing by 1,000 rpm's to work like "Turbo" mode. I really enjoy the enhanced acceleration.

Not sure I'd put the sliders in again. Not sure I want to change them back. Eventually I'll end up with a low mileage '19 or '20 and I'll see how that performs. I have a feeling I'll like it just fine, as-is.
Thanks for your reply.
So it seems normal. I think I’ll go back and replace with the oem ones. New rollers new sliders and again 200$ labor:(
Yes it’s definitely faster now but it’s working hard all the time and the engine sound is different.
I don’t know if there is a way to only adjust the gear ratios…
I really feel like I’m in only one gear right now. If anyone else has a different experience I’d appreciate your input before I throw another 400$.
Thanks
 

Delray

Well-known member
"I think I’ll go back and replace with the oem ones"

If you do, please share your thoughts here. That would be an excellent "before and after" test, although an expensive one for you.

What year is your C650 GT?
 
"I think I’ll go back and replace with the oem ones"

If you do, please share your thoughts here. That would be an excellent "before and after" test, although an expensive one for you.

What year is your C650 GT?
Lol, yes. Hopefully I’ll go back to nice and quiet ride. I thought and as I read here people were saying that acceleration is better but you get lower rpm at higher speeds which is not the situation in my case. And as I did the service at a BMW dealership I don’t think they did something incorrect. Its 2016, I just did the 12k service.
 

Delray

Well-known member
You piqued my curiousity about rpm's and what is normal, so I took a run down I-95 this evening ....

Like most of South Florida, it's a flat road, so it's easy to get a good idea of what's happening with rpm's without factoring in climbing or descending grades.

I rode for several miles at 70 to 80 mph and the bike had a ceiling of 6,000 rpm's, which could have been 5100 or 5500 or 5900, given BMW's maddeningly imprecise tachometer. When I reached 50 mph, the bike went to 5,000 rpm's. At 40 mph it was 4,000 rpm's. At 30 mph it was 3,000 rpm's, and 2,000 rpm's at 20 mph. That tidy correlation stayed the same whether I increased or decreased speed.

That's my version of what is normal for Dr. Pulley 28 gram sliders (and insert pieces -- I've heard they make a difference). For "test" purposes, the rest of the bike is tip-top and up to date ... good tires, new belt, new engine oil and filter, new air filter and CVT filters, new coolant and new spark plugs.

As for loud, it's just kind of a loud, growly BMW bike. I'd suggest foam ear plugs, if you don't wear them already. I never ride this bike without them.
 
You piqued my curiousity about rpm's and what is normal, so I took a run down I-95 this evening ....

Like most of South Florida, it's a flat road, so it's easy to get a good idea of what's happening with rpm's without factoring in climbing or descending grades.

I rode for several miles at 70 to 80 mph and the bike had a ceiling of 6,000 rpm's, which could have been 5100 or 5500 or 5900, given BMW's maddeningly imprecise tachometer. When I reached 50 mph, the bike went to 5,000 rpm's. At 40 mph it was 4,000 rpm's. At 30 mph it was 3,000 rpm's, and 2,000 rpm's at 20 mph. That tidy correlation stayed the same whether I increased or decreased speed.

That's my version of what is normal for Dr. Pulley 28 gram sliders (and insert pieces -- I've heard they make a difference). For "test" purposes, the rest of the bike is tip-top and up to date ... good tires, new belt, new engine oil and filter, new air filter and CVT filters, new coolant and new spark plugs.

As for loud, it's just kind of a loud, growly BMW bike. I'd suggest foam ear plugs, if you don't wear them already. I never ride this bike without them.
Wow, hope you had a nice ride. As I mentioned I did the 12k service today and replaced the belt with Malossi and dr Pulley rollers and sliders. I’ve read all great reviews and when I took the bike I was shocked. I don’t know what could be the problem. When I rev up from 0 it has a little bit of lag and then it goes to 5k rpm and it doesn’t move from there even on 70-80mph. I also notice that it disengage at 15mph when I release which is so bad as in NYC most of the time we ride slow:(.
Thanks for your input. It makes me think that they haven’t installed something right. Maybe it needs to be adjusted.
Ben
 

Delray

Well-known member
"it has a little bit of lag and then goes to 5k rpm and it doesn’t move from there."

Definitely not normal. Something sounds funked up in Variatorville. A CVT by nature is a smooth, progressive up and down band.
 

davidh

Member
One additional note for the slider vs roller argument -- sliders last MUCH longer than rollers. So even if you don't get super-amazing performance, you'll get much longer life out of them. I replaced my rollers (with sliders) at 10k miles and am only on my second set of sliders and currently have just over 66k miles.
 
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