New Generation Dr Pulley HiT Clutch

I've been using the new generation Dr Pulley V-4 HiT Clutch for about 1500 miles now.

It is an immediate improvement over the original HiT Clutch version. Right out of the box it's great and there's been no need to change the springs in order to sort out the clutch operation.

The clutch starts to grab at about 2300-2600 RPMs while the Push Pins lock up the clutch at about 35 mph. After that it's immediately responsive to the throttle.

The Clutch Kit comes with an assortment of various (tension) size springs for both the initial clutch operation as well as springs to alter the Push Pin operation so that the clutch will lock up at whichever RPM range you choose. Dr Pulley refers to these Push Pin operating springs as Pillow Springs.

You can, if you choose, leave the Pillow Springs out entitrely, if so, the clutch will lock up immediately and you'll be doing wheelies. It's something that I really can't reccommend --unless you're trying to impress those good looking nurses in the Emergency Room.

In a much as the clutch slippage is eliminated at cruising speeds my fuel economy has improved too. Recently when using the OEM Clutch with (White) Malossi springs my fuel economy was averaging in the low to mid 40's. Using the new V-4 HiT Clutch I'm getting in the neighborhood of 50-53 mpg.

The springs are easily changed using using a 'headlight and brake spring hook' tool
to relieve the spring tension and remove it from the mount. While a small 1/4" blade flat screwdriver easily levers the new spring on to the mount.

I'm scheduled to do the Iron Range Scooter Rally later next month. That'll be about a 3000 mile round trip for me. I'll post some more info after that 'test' ride.

You can get more info about the HiT V-4 Clutch Kit by contacting the Dr Pulley folks at UnionMaterial.com

Tim

I'm definitely interested to hear your results Tim from the Iron Range with the new clutch. If you match your preliminary results, that would be awesome. It's hard to improve power and mileage at the same time, but I can see how the reduced slippage would do both. I found a link on youtube that shows some guy assembling a hit clutch. It does look simple. I've still not put my malossi clutch in yet. If the hit turns out to be that much better, I may have to offer someone a good deal on it.

https://www.youtube.com/watch?v=ZGtMsBun4EQ

Hey Ron

I'll post an update as soon as my brain recovers from the gonzo 19.5 hour, 862 mile rain ride from Milwaukee on the second leg of the ride home. I still need to crunch some numbers so that I can post some reasonably accurate info.

Tim

Hey Tim, I can understand that. Glad you made it back safe! I don't know if I could ride that long and keep my sanity. I did 24 hours in a car once from Long Island N.Y. to Tampa, FL and I swore to myself never again. I can only imagine on a bike. I'll be looking forward to your numbers. Take your time.

How do we know if this Dr Pulley HIT clutch ( http://www.buggypartsnw.com/home?page=shop.product_details&flypage=flypage.tpl&product_id=418&category_id=30 ) is the V4 version??

honda_silver wrote:

How do we know if this Dr Pulley HIT clutchis the V4 version??

Phone him?

bigbird wrote:

honda_silver wrote:

How do we know if this Dr Pulley HIT clutchis the V4 version??

Phone him?

Dr Pulley's own website ( http://www.unionmaterial.com/HiTClutchType.pdf ) does not even delineate with a version number to be able to delineate. I do not know if the model number changed. I doubt the brand new distributor which just started carry the HIT Clutch could answer the question.

Cosmic_Jumper had the original HIT Clutch and the new V4 HIT Clutch, so he may be able to help answer or determine how to identify the newer version.

x

bigbird wrote:

You might be surprised. Michael at Buggy Parts Northwest is VERY knowledgable about the Dr. Pulley stuff. If he doesn't know, he WILL find out for you. I have dealt with him before. He has the same professional calibre as Matt at Scootertrap.

High praise indeed.

JC

Hi, finally have also installed the V4 hit clutch in SW-t400 with suggested set of springs (red -20 kg) for clutch and (pink -25 kg) for pin locks.
Have tested them only for short period of time because of chilly weather, around freezing point.

I use it together with pulley 26 gr rollers, my impressions are very positive, the throttle response is subjectively better especially over 60 km/h.
I noticed difference in takeoff, it is far smoother then with stock one, maybe a little bit with higher revs than the stock one. I think it needs more km to make before pads and bell will be "in phase" and start doing their the best.

I am going to check the cluth after 1000 km for any excessive wear or any other problem and let You know.

Sorry for my english, if i wrote sth in funny way

radiolog wrote:

Hi, finally have also installed the V4 hit clutch in SW-t400 with suggested set of springs (red -20 kg) for clutch and (pink -25 kg) for pin locks.

I noticed difference in takeoff, it is far smoother then with stock one, maybe a little bit with higher revs than the stock one.

IMHO The reason that you need higher revs than when the stock clutch is that you need lighter Kg springs for both the clutch and push pins.

That way the clutch will (begin to) engage at lower revs and the push pins will lock-up shortly after the clutch is fully engaged.

The 12.5 Kg clutch springs & 16 Kg push pin (pillow) springs Pico-Thai mentions in his post are much closer to the springs which I'm using.

BTW, After ~8,000-10,000 miles my V4 HiT Clutch is still performing great.

Tim

Cosmic_Jumper wrote:

radiolog wrote:

The 12.5 Kg clutch springs & 16 Kg push pin (pillow) springs Pico-Thai mentions in his post are much closer to the springs which I'm using.

Tim

What are the exact springs You are using, and what are the revs during fast accelaration?
Another doubt is that with very light springs using so called "friction zone" that is very helpful in slow u-turns is gone because clutch engage fully at low rev -am I correct?
I wonder if 400 cc that runs higher revs than 600 cc should have the same or harder springs?
Higher revs mean stronger centrifugal force

I understand your comment & concern about the "friction zone" and it's use in slow speed maneuverings, but I've never found slow speed maneuvers & u-turns to be a problem. But then, I don't ride in a congested urban area so I'm not faced with the need to negotiate those obstacles & traffic.

I'm sorry, I've been unable to locate any of the notes I have regarding the current clutch & push pin springs set up on my HiT Clutch. That information will have to wait until I disassemble the works to check the current condition of my HiT Clutch --or until I'm blessed by a visit from the 'Desk Faerie' and all my notes become magically organized.

I am dealing a lot with tight passing between cars in my town, so not fully engaged clutch helps a lot.
Today I discovered that spring values I mentioned before are for V3 version of clutch.
HIT V4 for clutch uses 12,5 kg ( thats red ones), and 25 kg pillow springs (pink)
After testing clutch today I know exactly when pins start to lock - It looks like very good throttle response.
With 25 kg springs there is a little delay when pins are fully engaded, so with very fast acceleration from stop there is unwanted slippage of the clutch.

I think changing pin springs for 20 kg will help a lot
I am very please with HIT clutch so far, smooth takeoff, accelaration are for me much beter then with OEM clutch

radiolog wrote:

I am dealing a lot with tight passing between cars in my town, so not fully engaged clutch helps a lot.
With 25 kg springs there is a little delay when pins are fully engaded, so with very fast acceleration from stop there is unwanted slippage of the clutch.
I think changing pin springs for 20 kg will help a lot
I am very please with HIT clutch so far, smooth takeoff, accelaration are for me much beter then with OEM clutch

I'd go with the 16 Kg springs on the push pins.

Cosmic_Jumper wrote:

I'd go with the 16 Kg springs on the push pins.

I don't have in set 16 kg pin lock springs, only 20 and 12,5 kg, so I switched to 20 kg ang looks fine.
BTW did You change the belt for stronger one (i.e kevlar?), and what about the belt wear, is it excessive or nothing wrong?
Have You also used this flat spacer for clutch torque spring?

radiolog wrote:

I don't have in set 16 kg pin lock springs, only 20 and 12,5 kg, so I switched to 20 kg ang looks fine.

BTW did You change the belt for stronger one (i.e kevlar?), and what about the belt wear, is it excessive or nothing wrong?
Have You also used this flat spacer for clutch torque spring?

I'm using the OEM Honda belt. It is manufactured with Kevlar. There have been many negative reports of belt failure using aftermarket 'kevlar' belts. So I've been very happy with Honda's belt and not noticed any premature or excessive wear.

I haven't used the torque spring spacer(s), mainly because I've never completely understood the nature of that torque spring's operation and whether I actually needed to add it for daily use and not agressive riding use. Installing that spring does require a "special" tool, but that is something that can be easily fabricated. This link to the Italian Silverwing forum will give you some information: http://66.196.80.202/babelfish/translate_url_content?.intl=us&lp=it_en&trurl=http%3a%2f%2fwww.silverwing400.it%2findex.php%3foption%3dcom_content%26task%3dview%26id%3d79%26Itemid%3d83
You may have to use Bablefish or Google's translation though. Also you may have to scroll down (way down) to the bottom of the page to see that information.

Regarding the springs which I'm using on my HiT Clutch, I have found some of my notes and here's the info:

The HiT arrived with RD 12.5 Clutch & PK 25 Pillow (Push Pin) springs. I found that the initial engagement seemed fine, but the clutch didn't lock up until much too high revs.

After about 1500 miles I changed the Pillow (Push Pins) springs to RD 12.5 while leaving the Clutch sprins at 12.5 RD. With that configuration I decided that the initial engagement was a bit too high and also that 'everything' happened a bit too abruptly.

I discussed my findings with Paul Wu, and he sent me a a few other springs to try.
For the past ~8000 miles I've been using BL 12.0 Clutch & RD 12.5 Pillow springs and find that set up has been very satisfactory.

Tim

Thank's a lot for Your help, I will try with setup of 20 kg for pin lock and 12,5 for clutch, if I am not satisfied I will change to lighter pin lock springs.

I know SWCI forum , with google translate littlle help, most of the text can be understood, unfortunately they have very few or even none information about unionmaterial company.

Best regards Marcin

radiolog wrote:

Thank's a lot for Your help, I will try with setup of 20 kg for pin lock and 12,5 for clutch, if I am not satisfied I will change to lighter pin lock springs.

I know SWCI forum , with google translate littlle help, most of the text can be understood, unfortunately they have very few or even none information about unionmaterial company.

Best regards Marcin

Hi,

Whom did you get the HiT from ?

If the take-off rev of clutch spring SP1832565105-RD-12.5kg and pillow spring SP2032365103-YL-20kg is not the one (such as too low ) you want then you could try clutch spring SP1832565105-RD-12.5kg and mixed pillow springs ( 2 pcs SP2032365103-YL-20kg + 2 pcs SP2031565103-PK-25kg ) in alternate position.