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Doppler variator

Last post 02-24-2014 12:01 AM by INMA. 12 replies.
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  • 08-31-2012 03:22 PM

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Doppler variator

     I've just taken delivery of a Doppler variator which should get me away from the changing rollers to tune the transmission game.  The Dopple variator has wieghts but they work the pulley without the need for sliding rollers.  The idea is better engine speed control which will be handy if it works.

    http://www.sip-scootershop.com/en/main/base/Details.aspx?ProductNumber=DP324327

    I am waiting for a tacho to arrive so I can see where the engine is currently running and get quickly to a similar speed range with the new variator.

    Has anyone else tried one of these variators?

    All advice welcome.

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 09-05-2012 03:43 PM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    Looks like I am the only brave one with a Doppler variator in Australia.
     
    The tacho came yesterday so I installed it and went for a ride to see how the old variator was working.
     
    Cutch engagement was a bit over 4,000 RPM with a bit of flaring to 7,000 RPM as she accelerated to 40 km/hr where the engine settled in a bit below 8,000 RPM till 60 km/hr where it was at 8,500 RPM till the transmission ran out at 9,000 RPM and she accelerated to over 10,000 RPM at about 75 km/hr.  Those numbers varied by about plus or minus 500 RPM variation, some runs were great others a bit slow but all acceptable.
     
    The torque driver operation did not allow proper slowing of the engine at low loads and was sluggish to get the engine revs up at increasing throttle, engine speed changes on the torque driver were less than 1,000 RPM.
     
     
    I put the new Doppler variator in with the weights already fitted.  It came with a new belt that was a few mm longer that gave a bit better gearing (good value).  The variator also came with a complete set of weights for tuning which means the $80 is great value.
     
    Lucky for me the standard weight was good in my transmission.  Clutch engagement was just over 4,000RPM with no flaring and a smooth take-up (the new belt changed the gearing a bit matching belt to clutch speed better than before). She accelerated to 35km/hr settling a bit above 7,000 RPM and held 8,500 RPM or a bit more till the transmission ran out at about 70 km/hr.  Top speed of 75 km/hr occurred at 9000 RPM.  I could have tried for higher top speed but that was not the plan.
     
    The torque driver operation did allow proper slowing of the engine at low loads and was quick to get the engine revs up at increasing throttle, engine speed changes on the torque driver were better  than 2,000 RPM.  The extra response works well in corners.
     
    I could drop the weights a bit and aim for 9,000 RPM on hard acceleration for a bit more acceleration but the current setup is pretty good for my daily commute.
     
    I had a slow take off at the lights when mixing it with cars so I might take the clutch engagement speed up over 4,500 engine RPM if it annoys me.
     
    I have only had the variator on for a day and I already love it. I can't imagine ever going back to the sluggishness of a roller weighted variator.  Big scooters with lots of power don't need the variator response the way small scooters need it.  The little 68cc Zuma is close to perfect for my commute now I have sorted the transmission.
     
    Engine braking through the transmission seems to be smoother which will make turning into corners a bit more relaxing (less rear brake and power up to get the lag out of the transmission).
     
    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 09-12-2012 09:31 AM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

     

    I have used the Doppler variator for a week and still believe its the best variator compared with the traditional roller variators.
     
    It works so well with the standard torque driver and makes control with the limited power of a small engine so much easier.
     
    Anyone buying other variators is making a mistake, the Doppler on a small scooter is so much more responsive under power and when slowing down.  The difference is remarkable.
     
    Any scooter mechanics reading this, buy a Doppler and learn how to set it up, its simple, costs about the same as other brands, works so much better and does not require further maintenance unless you need to change engine speeds.
     
    Owners, if you get a mechanic to put a Doppler in your scooter, make sure the mechanic gives you the spare weights in case you want to change the speed later.
     
    I fitted a $13 Chinese digital tacho to the engine to help me see how the variator was working, it made checking the variator while riding easy.
    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 09-12-2012 10:04 PM In reply to

    Re: Doppler variator

    Yes

    Yuminashi Pcx 164cc can of whopass!
    Ex Takegawa Pcx 170cc
    Ex Today 94cc Kitaco
  • 10-02-2012 10:24 PM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    After about 2000km, the belt self destructed in a most comprehensive manner with nothing left other than a few chnks of rubber, kevlar and cotton wrapped around the pulleys and black rubber dust everywhere.

    The good news is I had a newish belt ready to go.

    The interesting news was I forgot to check whether the new belt that came with the variator was running inside the pulleys.  Evidence was that the belt had run past the top of the front pulley quickly destroying the belt.  I can't blame the Doppler belt or variator, I left a modified outer pulley on the crankshaft which made the belt run higher than planned by Doppler.

    I normally mark the variator pulley to check where the belt is running and space the end pulley in or out to get the belt high on the pulley for top speed.  I was so impressed with the Doppler variator, I forgot to check the belt.  Can't blame the Doppler because I changed the outer pulley position.

    So an old belt was put back in and she rides like she should.

    I took the oportunity to lower tha clutch engagement speed from about 6000 engine RPM to about 4000RPM.  Not sure how this will takeoff at the lights but low speed control when filtering should be a bit smoother.  Its fun adjusting things once you figure out what needs changing and you have the adjustable bits.

    So far the engine has done 5000km without needing to be touched and apart from the belt, the transmission seems good for many thousands of kilometers.  The Variator set speeds and torque driver have been working perfectly.

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 01-05-2013 09:34 PM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    A quick update on the Doppler variator.

    Brilliant, no change and working the same after a few more thousand kilometers. 

    I have no need to touch anything, no weights wearing or sticking, no issues when it gets hot, transmission and engine tune has not changed which is brilliant.

     

     

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 04-04-2013 10:33 PM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    Four months on and 8000km and nothing has changed.

    Engine braking is excellent as the scooter slows a lot better than roller type variators and response into corners is faster.

    I can't fault the variator. I have considered some fine tuning of the clutch to get a bit more slip and revs when starting but the extra noise from the exhaust is an issue near the house and slow speed at work.  I've never had such an stable transmission to set up and make adjustments but I want to leave it untouched to see how it lasts untouched.

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 04-06-2013 09:09 AM In reply to

    Re: Doppler variator

    INMA,

    What are your thoughts on this then?

    ( Source http://www.mopedarmy.com/wiki/Aftermarket_Motobecane_Variators )

     

    • A note on Doppler variators*

    It has been noted that Doppler variators, specifically the ER2 and ER3 have a tendency to wear faster than others. The fact that each individual part is available for replacement from the dealers is both evidence that this is true and a solution to the problem. The cheeks that the belt rides on become grooved in the lowest and uppermost positions over time due to belt slippage in those areas. I’ve read an account of an ER2 worn so badly that it felt like a two speed rather than the progressive change in speed normally associated with variators. If running a Doppler variator, use of the proper belt is essential to the life of the variator. The Doppler belt, or Bidalot 782 is recommended. If the variator collides with the driven pulley (as is a known problem with the ER3) use of a longer belt (such as the aforementioned Bidalot 782) should take care of it. USE OF A STOCK BELT WILL RESULT IN PREMATURE WEAR!!

     

    Kymco Xciting 500Ri ( About to sell )
  • 04-06-2013 11:15 PM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    They are interesting quotes.

    I can't talk about other's experiences and I have not looked at my scooter's front pulleys in over 6000km.

    The Doppler variator cost about $90 when I ordered it from Germany.

    Wear is something that would depend on things like power and the type of riding.

    As power goes up wear is bound to increase.  My power is probably 10hp at about 10,000rpm but I tuned the transmission to work at the lower end of the powerband between 7500RPM and 8900 rpm, clearly I am not pushing the power through the transmission that a watercooled engine with a race crankshaft could produce.

    For the $90 you get a new contra spring, belt and full set of weights.

    If there was signs of belt slip which will increase wear, the tuner should put a heavier contra spring in and increase the weights.

    My guess is the transmissions they are talking about are in extreme use and may not be properly set up if there is high powers involved.

    I spent more than $90 on roller weights and contra springs learning how to tune the transmissions in the early days, all that came in the box with the Doppler variator ready to go, no need to order other bits.

    If there is significant wear when I do inspect it I would just spend the $90 on a replacement, the stability of the transmission is that good I would not go back.

    The comments on the belts is a bit of a wank.  Kevlar belts don't offer advantages over better quality belts like Gates or DAYCO as long as you get the right size and section.

    I must admit I have been thinking of adding some cooling holes to the transmission cover to help keep the temperatures down, that might be wise to reduce wear of the belt and pulleys.

    Also in the quotes there is no information on the state of engine tune, mileage or type of use.  I try to list those sorts of details and let the facts tell the story.

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 04-07-2013 02:10 AM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    I had another look at that page, the variators mentioned are moped, systems significantly different to the systems in the Yamaha.  The ones mentioned have the clutch built into the variator.

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 04-15-2013 08:04 AM In reply to

    Re: Doppler variator

    Thanks INMA, you rock.

    Kymco Xciting 500Ri ( About to sell )
  • 11-26-2013 11:30 PM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    I did not use the scooter for winter and then I was away.  Its back in use and passed 10,000km with no issues.

    I probably should have a look but it works fine so I'll just use it till something changes or the belt fails.

    It is possible the contra spring has relaxed a bit, the cruise RPM might have dropped 200 RPM from 8100 to 7900 but my memory is not that good and it rides better than any other variator I've tuned.  I am happy.

    Anyone spending money on  50cc variator is an idiot if they don't get a Doppler.

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
  • 02-24-2014 12:01 AM In reply to

    • INMA
    • Top 50 Contributor
    • Joined on 03-19-2009
    • Posts 837

    Re: Doppler variator

    I was waiting for something to change in the Doppler variator but after 10,000km, I decided to take the cover off and have a look.  No surprises.

    I had planned to put a better torque driver in but I can't find one that is a straight swap for the original torque driver.

    So I measured the belt and it was 15mm compared with 16.5mm new.  Not bad wear given the increased power of the engine.

    I decided to change the engine speed lowering the variator weights about 15% which increased the speed by about 10% from 8200 RPM to 9000RPM flatout at 60 km/hr.  Cruise at 60 km/hr is 7,900 RPM.

    The transmission still works perfectly, there were no signs of wear where the weights push the half pulley.

    So its back on the road working well and I don't expect any issues for another 10,000km where I will check the belt again.

    The reason I wanted the extra 800RPM was because the engine would bog down when I motored into big headwinds and at least twice I had soft siezes at lower speeds.  My hope is the extra engine speed plus sealing air leaks on the engine coul will keep the engine cooler under heavy loads. So far several trips into heavy winds confirms the increased engine speed helps the scooter avoid bogging down.

    There is some extra performance with the higher revs but I tend not to use it because you can only do about 65 km/hr in the traffic.  It easily does 70-80 km/hr but that is not my normal speeds (I did wind it off the speedo to 9,500 RPM by accident, it does not take a lot to go fast if you don't back the throttle off).

    So I still love the Doppler variator and will never go back to a roller type variator, I have full sets of rollers and springs but its just not worth the effort compared with the Doppler system.

    2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.
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