Test and reviews RMV Speed II

Click on the pictures to enlarge them

On the  level of clutches there are all kind of types to engage the clutch bell with the engine.
But up till now all those designs lacked one major point.
They are not adjustable from the outside of the car without disassembling the engine or the clutch itself from the car.

BUT THAT IS HISTORY NOW!

German Renato Vita and his son Dario Vita have designed and make this Speed II version clutch.
Their previous Speed I design was adjustable too but not from the outside and used 1.0 mm Mugen scissor springs any way.
RMV (Reckward Modell Vertrieb) a German company owned by the Reckward brothers Daniel and Mathias have taken the commercial side of the clutch and distribute it world wide.
Daniel is known for his share number of World and European titles and have tested the final version we review here for more then 12 months.
So you can be assured it works!

What is so different about this clutch compared to all previous designs known on the market?
There are two shoes that swing around two pins.
In contrary with the previous designs there are no circular or scissor springs in this design!
Speed II uses two small compression springs that are mounted inside the shoe and attached to the clutch section by 3 mm screws.
By means of a 1.5 mm hexagon tool you can adjust the spring tension of each shoe individually from the outside of the clutch.
If you turn in the screw for one turn from the standard setting the clutch will engage later.
Other way around if you turn the screw out one turn from the standard setting the clutch will engage earlier.
So from now on for each track, engine and even driving style you can adjust the clutch in just a few seconds without the need of many tools.
To get to the tension screw there must be a hole drilled in the clutch bell.
As one hole will unbalance the clutch bell two holes on the opposite side of each other are required.

The clutch kit comes as one complete package containing:
* A flywheel (35 or 38 mm diameter)
* An adapter to fit the shoes on
* Two black colored shoes with 0.85 mm springs and screws already factory set
* 4 ball bearings size 5 x 10 x 4 mm with rubber sealing
* 14 tooth clutch bell with two holes drilled for adjusting the spring tension and three ventilation holes
* Shim washers and a 3mm hexagon screw

We received a TU9530 package for review and testing together with the optional white colored shoes and 0.9 mm springs from RMV.
Thanks Daniel!

The package!

	The TU9530 (35 mm) black shoe (75% Teflon / 25% carbon) package with it contents Recommended by RMV for use with "ECO" or 3/4 port medium power engines
	The optional white shoes (75% Teflon / 25% glass fiber) with order number TU9536 Recommended by RMV for use with 5 or more ports power engines The white shoes providing more grip then the black ones
	The optional 0.9 mm screws with order number TU9540 These springs allow a smaller and quicker setting with less turning of the screw Advised by RMV to be used in combination with white shoes with 5 or more ports power engines
	With the package comes a simple manual how to fit and adjust the clutch An online version by RMV can be found here
	The four major parts flywheel, clutch system, clutch bell and the small plastic bag with the bearings and shims
	The plastic bag contains beside 4 ball bearings with rubber shielding in the size 5 x 10 x 4 mm also two extra shim washers and a 3 mm hexagon screw to fit in the crank shaft end
	All the parts together form the Speed II clutch

Building the Speed II

	Mounting order from left to right
	Depending on the engine brand and type you are using you might have to adjust by adding one or more shim washers between the housing and the next to be placed cone
	You have to mount a cone that normally comes with the engine This cone is not provided with this clutch kit!
	Place the flywheel and make sure it is almost level with the end of the thread that is fitted on the crank shaft
	In this picture the distance between the white lines is to much and will cause problems if you have to mount the other parts coming as they will not be pressed against each other and will cause slippage. So place an appropriate thickness of shim washers between the cone and the engine case These type of shim washers do not come with this clutch kit!
	When the flywheel is placed put the large shim washer from the plastic bag over the crank shaft This shim washer prevents the anodized parts to touch each other when the next clutch section is mounted
	Turn the clutch section on the crank shaft by hand force
	Fit a 3 mm piece of steel (a 2,5 mm hexagon tool will do too) in the hole of the clutch section and turn it clock wise while holding the flywheel with a large plyer
	Fit a small shim washer over the crank shaft
	The kit comes standard with a hardened 14 tooth clutch bell Optional are other size 13 and 15 tooth available
	The clutch bell has three extra ventilation holes and a inside diameter of 26.3 mm
	Two holes opposite of each other are drilled to maintain balance in the clutch bell If you like to use your own clutch bells drill two holes of  4 mm as shown in this picture Clean the drilling edges from the inside of the clutch bell with some sanding paper!
	The clutch bell comes with 4 rubber shielded ball bearings in the size 5 x 10 x 4 mm Two of them you have to use the other two are spares Clean all the bearings be fore you use them check here for more info
	Place a ball bearing in the outside of the clutch bell and  press it firmly in
	Place a ball bearing in the inside of the clutch bell and  press it firmly in
	Slide the clutch bell over the crank shaft
	Fit first a small shim washer, then a 3 mm washer and then the 3 mm hexagon screw Secure the hexagon screw with a L-shape 2.5 mm hexagon tool
	Look if there is a little horizontal play of around 0.5 mm for the clutch bell to move over the crank shaft in the direction of the white arrows If not remove the last small shim washer or use thinner ones on both side of the clutch bell!
	The clutch ready to go

Maintenance, set up and tips

Although the clutch has a trouble free design some point have to take care of for proper use and maintenance
	My means of a L-shape 1.5 mm hexagon tool you can adjust the clutch to your needs from the outside
	The standard factory setting is 2.5 turns from completely compressed springs! If you lost your setting just turn the screws in clock wise direction fully  Then turn anti clock wise to the desired setting Use 1/2 turns to adjust with 0.85 mm springs Always perform same turns for both clutch shoes!
	To remove the or change the shoes First turn the screws clock wise and count the turns for reassembling Remove the screws on both sides first!
	Then remove the shoes This pictures shows too the simple spring and screw solution
TIP	Allow the clutch 1 to 2 laps to get used to the new setting before adjusting again
TIP	If you break in a new engine loosen up the screws 1 to 1.5 turns to prevent the clutch for overheating When break in is done set the clutch to desired setting from standard
TIP	Never lube or oil the ball bearings as this can cause extra slippage that can blow your bearings premature Check here for more info
TIP	Regularly clean the inside of the clutch bell and rough it with sanding paper
TIP	If the part of the shoe that contact the inside of the clutch bell is glazed use sanding paper to get the glaze off

Verdict

	A to easy build, setup and maintain clutch system Why have we struggled for years with broken springs of other designs?
Comment by RMV Products

Performance

04-03-2004
We mounted the Speed II on a CMB EVO 3 rally engine in a Hong Nor 9.5 Speed car.
With the factory setting of 2.5 turns we went on the track.
Engine sounded as to late engagement with the 2.5 turns factory setting and we had to much slippage..
So we pulled the car from the track and stopped the engine!
With the engine and muffler still hot you have to take care not to burn your hands!
With a 1.5 mm hexagon tool we turned both screws 1 turn anti clockwise for earlier engagement.
Changing the screw setting is more work then I thought at first (on a cold engine it is easy to do!) but was done in 2 minutes maximum.
Finding the small hexagon screw holes requires some skill.
Also mark the flywheel so you know which screw you changed the setting.

For this engine, track and my driving style this one extra turn anti clock wise was the correct setting instantly and no extra change was needed.
The option for white shoes and 0.9 mm spring we could not test due to time problems

For the 3 loads of fuel we tested the clutch ran perfect and consistent.
A club member arrived too and wanted to know if this was the right clutch for him as he is having problems with them.
So I gave it first 2.5 turns factory setting and then the 1 turn anti clockwise again to demonstrate the difference!
He was amazed.

21-03-2004
We used the black shoes and the 0.85 mm springs for an other liter of fuel on a CMB EVO 3 rally engine.
No real visible wear was there and also the consistency for the clutch setting was OK.
Daniel Reckward already said that the black shoe / 0.85 mm spring combination was mended to be for the low power engines.
As we had to try the Cipolla MC21 RE Buggy engine too we mounted the speed II with white shoes and 0.9 mm springs on this high power engine.
We did set this too first at 2.5 turns. 
The car would not leave its place when I had started it.
So I stalled the engine and gave it one extra turn to 3.5 turns.
After restarting the engine there still was some slippage but we let the engine and clutch warm up to working temp and it was almost OK.
I just turned it out one half turn more to 4 turns and it was working at the right point.
Although we did not used the same engine I could feel the difference in both clutches.
The black shoes have a longer transition time from slippage to lock up.
The white shoes in combination with the 0.9 mm springs have more direct snap.
So the transition time for the white shoes is shorter.
During the 10 minutes I drove in the 1/2 final the clutch worked perfect and with good snap.
Unfortunenatly the car broke down and we had to stop.

04-04-2004
We started our car in the morning and for a race and found out that the wheels were turning at high speed although the engine idled.
I appeared that one of the spring screws and spring was gone!
I replaced a screw and 0.85 mm spring and just gave it 4 turns out from fully in.
Did not had the time to do anything else.
The clutch worked the whole day OK without adjusting!
When I got home I disassembled the clutch and found out the 2.5 mm screws were wobbling in the screw hole and would run out of the clutch body with ease.
I put some thread lock on it and let it dry overnight.
The play was gone and the screw was not as loose as it was before.
But if this is the cure? Other suggestion was to use Teflon tape used by plumbers to seal gas pipes.
I also sent a email to RMV about this problem and this was their answer:

Hello Paco,

Yes we k now that problem, we have made a second version with another screw on the
side to safe the spring screw. If you want you can send the body back to us or directly
to our supplier to change this problem.
Or you take a little bit thread lock to the screw but after a time you will have the same problem.

Best regards
Matthias Reckward

25-04-2004

After using thread lock on the screws we have set it to 3.5 turns out.
For two liters of fuel no extra adjusting was needed and the clutch ran as supposed to be.

29-04-2004

It could be possible that if you mount the clutch, one of the shoe pins is placed to much to the outside.
When the clutch bell is placed the shoes already touch the clutch bell inner side.
Return the clutch body to your distributor for one with correct pins distances.

Renato Vita the designer advises to use shim washers of 0.2 mm in-between clutch body and clutch bell. Due to rotation the shoes can be pushed forward to the clutch bell causing unnecessary drag.

Conclusion

We ran an other two competitions without adjusting or changing anything on the clutch regarding set up.
The thread locked screws nicely stay in place although the factory modified version with extra set screws will not have that problem..
Only checked the clutch bell and bearing for wear and dirt but they look nice. Never driven that long with clutch bell bearings before!
One reason for this clutch not blowing clutch bell bearings is the fact that to get satisfactory settings the clutch does not slip as much as some 3 shoe scissor spring designs do.
A colder clutch bell means colder bearings meaning longer lifespan on them.
Remember that a good working clutch is determent by several factors like engine, track and most of all personal preferences.
I got used to the adjustable system very quickly but that is my personal feeling and might not reflect yours..
After the launch of the RMV SPEED 2 some people fairly soon gave up trying this adjustable clutch.
Now a road to adjustable clutches has been opened new designs will be soon follow.

We will keep running these RMV SPEED 2 clutches as standard on our to be reviewed TEAM TWF8 buggies after the kit clutch has been tested for working.

Paco Raap

Additional Testing

I was testing a Speed II clutch with white shoes and 0.9 mm springs in a TAG HF 2004 with RB S7. It has the additional set screws to lock the adjustment screws. The initial setting was 2.5 turns out and after a couple of warm-up laps, I was impressed by the late engagement and snap. However, the clutch bell became very hot, which indicates too much slippage. After some testing, I ended up at 4.5 turns out. This is because I used a clutch bell with ~26.8 mm inner diameter and the shoes need more travel to reach the clutch bell.
I found that adjusting the clutch is pretty easy with a 1.5 mm allen wrench if you have a 3+ mm hole in the clutch bell. The "lock screws" work very well and solve the problem mentioned by Paco. I used the Speed II during the indoor race in Glovelier and didn't have a problem with it. The only things I don't like about this clutch is that it takes a couple of laps until it grabs well and that its operational temperature is quite hot. To prevent it from becoming excessively hot, you should degrease the bearings before you mount them. Additionally, you should roughen the inside of the clutch bell with sandpaper and degrease it. After around 3.5 liters, I noticed that the wheels were turning on the starter box. I first thought the bearings were locked up, but after disassembly, I saw that a pin had worked itself loose.



I will send this clutch to Renato Vita to find out what went wrong.
After the new experience with an adjustable clutch, I am now interested in the Speed 2.5 and Speed III. The later is a very interesting, innovative and promising design."

Greetings, Thomas Weber

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