[Narada]

I am presently considering the purchase of a 1959 RE Constellation.   This bike was meticulously restored and is gorgeous, but it has one drawback that is breaking my heart, the Scissor Clutch.    I don’t know exactly what is new, but the engine and gear box were completely gone through, the crank was re-balanced with 2oz of material removed… everything is spectacular! The problem which is holding me up the most is the force required to squeeze in the clutch lever. I have seen a few things on the internet to get an overview of the situation with spring tension, ball bearing diameter, lever dimensions, plate thickness… 

Upgrading to the newer design is only possible with a complete engine case change, which is not happening.

(Here is good Britbike forum thread from 2012, still ended up with an improved, but stiff pull https://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=460509)

My question is this, does anyone here have actual experience with successfully remedying the stiff clutch pull problem? Is there a certain cure for the stiff clutch pull? 

One other thing is, there seems to be a tendency for the main shaft to bend due to the excessive weight of the scissor clutch assembly, and / or under engineered main shaft. Does anyone know how exactly one causes their main shaft to bend? Is it from sudden release of the clutch? This may occur due to hand fatigue after a long day of herculean clutch lever squeezing, lol!   Hitchcock’s did carry replacement main shafts, hopefully they continue to.

Thanks,
Ed

[grumbern]

I do ahve the scissors clutch in my Chief and it isn't really harder to pull than the push rod operated ones of my Bullets. A major drawback is that it is prone to slipping. I therefor switched to 4 plates of the 5-plate clutch, as these are thinner and fit instead of the normal three plates. I suspect there where harder springs sused on "your" machine, to prevent slipping, and this makes it hard to pull.

Anyhow, if you don't want the scissors clutch, you can quite easily switch to the push rod type. You need a 4-plate clutch (pre unit) that can also be optained with formentioned 5 plates, a drilled mainshaft and the plutch lever. The easiest way would be to get another gearbox, but also more expensive.

If you what to keep the scissors clutch, there are still some possibilities to reduce the pulling force quite easily. First, you should find the reason, why the clutch behaves, as it does. Are there stiffer springs mounted? Is the cable free and lubricated? Is the clutch itself free to move, or blocked in any way?
If all these are checked, you can still use a longer clutch arm.

The scissors clutch per se is as easy to pull than any other, so there's something else to look for, if there's any problem with the force needed.
Andreas

[Narada]

Hi Grumbern, thank you for your reply. It is just what I was hoping for, the actual experience and advise of a Scissor Clutch equipped bike owner!  I will pass it on to the seller of the bike, who is intent on setting up the bike properly before the sale.

He is presently awaiting the arrival of a set of lighter springs which Allen from H has sent.

I believe the clutch was purchased from H and Allen is confirming that heavy springs were included to prevent slippage, in the quote from corrospondence shared with me below:

"The Scissor clutches are not the lightest so it will depend on what you are comparing it to.

 I would ensure the 3 distance tubes are the correct length in case they have been shortened. They should be 1.17” long.

 The 6 springs used on this clutch are the strong springs as standard. We do a lighter spring but you may experience clutch slip. You could try 3 of each.

https://accessories.hitchcocksmotorcycles.com/18077

 You could also try a washer under the 3 distance tubes to relieve the pressure on the springs.

 Ensure cable routing is good with no snags and look at a handlebar clutch lever with a small distance between the pivot bolt and the nipple. If you can find something with 1” or 7/8” centre distance."


If anyone else has experience or advice on the Scissor Clutch please reply. I am hoping this thread will give guidance for others in the future, as well as for myself today.

I am counting Grumbern as one who says Scissor Clutches work well once properly sorted!

I am making note of your advise on the clutch disc's, in case the spring swap and / or washer addition, maybe a lever swap fail.

I hear varying advise on the conversion to the rod type as you mentioned, and have been told the gear box case itself had to be changed, as well as internal parts... if it ever did come to a clutch conversion, it would be nice to at least retain the original case.

Ed

[vintagebike]

You don´t have to change the gearbox case. Only the mainshaft and the outer gearbox cover are different. The only thing you need to change on the gearbox case is to drill a hole for the cable and a hole for the pushrod. You can not use the outer gearbox cover because the mounting for the operating clutch lever is not machined in the case of scissor type clutch. I swapped the scissor clutch in my Connie with the belt drive drive kit. It works very well but is a bit pricy..

Cheers, Rico

[Narada]

Thanks for sharing your experience vintagebike. It's good to hear from someone who has actually "been there and done that"!

I take your experience with the Scissor Clutch was not great? Did you try to change springs etc... or just bail and put in the kit? 

I'm thinking we're going to do all we can to keep this bike stock, and hopefully end up with a good, or even great result. If all else did fail though, maybe one day... who knows? I think I'd have to add a gear drive tach at that point too!   

Is your clutch itself custom also? Does the belt drive provide tangible improvement as well? I would imagine one may just change to a stock clutch, shaft and cover if preferred?

Sorry for all the questions. I'm just trying to get all the info that I can. I am pretty excited about this Constellation. They seem to be spectacular bikes once sorted! 

[vintagebike]

My Connie was in need of a complere restauration. The clutch was totally worn and rusted, so the decision was made to buy the belt kit. I didn´t read much good about the scissor clutch, and i think theres a reason why Enfield changed back the clutch after a few years to the pushrod type..

[grumbern]

It's biggest weakness in my opinion is the limitation to three plates. It's very bulky and doesn't allow much more in stock configuration. They push rod type clutch can be equipped with five plates and this means a big advantage when it comes to torque capacity

It's a bit tricky, but you can get it to work, if it's set up correctly and a good oil and plates is used. Not much tolerance though, or it will slip. It can just handle the power of my 700 twin.
Andreas

[tomcraig]

I fussed about for years trying to get the clutch in my 60 Bullet to work properly.The biggest improvement was purchasing an original clutch and robbing the springs for mine. The springs sold now are too long and are preloaded before you even pull the lever and resulting in almost coil bound spring when activated.

[TonyVanda]

Good topic. I will be assembling my scissor clutch soon. I need all the info I can get.

[Narada]

I just got a link from Hitchcocks showing thier pushrod type clutch conversion options.

https://www.hitchcocksmotorcycles.com/partsbook-pages/2927

Choose Position 1.

Looks like the first item is an economy India made clutch without cush drive.

Second is a good quality clutch for more money.

Third is a belt drive top of the line clutch kit for even more money still.

If I were to convert, I think I like option two. The belt would be nice, but the chain is not the problem. Slippy clutch vs firm hand lever pull is. And they do say the second choice is a "Superb Clutch".

Again, for me Plan-A is make Scissor clutch work. Could be "a fools errand".

Plan- B would be the second option: Superb Clutch conversion.

Plan-C looks nice, but not ready for that leap yet. Also too far from original.

One thing I'm seeing is you cannot add the belt later to Plan-B. That one would be permanently chain drive only.

 

[gogometeor]

I own a MeteorMinor500.
I too had a very difficult time with the "scissor clutch" problem.
I bought a complete set of clutch parts from Hitchcock, but the springs were very stiff.
I ended up using the old clutch springs.

I figured out how to adjust the press pressure to use the stiffer spring.
If you loosen the three bolts shown in the picture evenly, you can reduce the press pressure of the clutch spring.
And the three bolts need to be secured with wire as they could loosen during driving.
I have modified the bolts so that they can be secured with wire.
See the photo.

But even with this method, the clutch remained stiff.
I ended up using the old clutch spring.

Thanks.

[Jakub]

Few observations regarding scissor clutch if I may.

As it happens the inside cover of the clutch in my bike developed a crack. Only about fourth or fifth attempt of welding was successful. So recently I wasn’t doing anything else than assembling and disassembling the clutch. This is how I see it.

1.   Use a tip marker and mark all elements when disassembling and try to locate them in exact same position when assembling. So friction plates and flat plates in relation to the relevant sprockets are in exactly same positions. Same goes for springs. Those parts are supposed to be symmetrical but they are not and once they have been under wear and tear in certain order it’s worthwhile to assemble them in the exactly same order.

2.   I have tried original springs, Hitchcock mixed spring and strong springs. Only the last ones prevented slippage.

3.   I have also replaced Hitchcock clutch cable with one made to order, with thicker and stronger cable so there is less elongation when under tension.

4.   Once assembled make only preliminary adjustment and go for a short drive, about 60 to 100 miles would do. Doesn’t make sense to make adjustment straight after assembly because it takes some time for the clutch elements to bed in.

5.   There are two adjustment possible, clutch cable and nut on the withdrawal pin. When adjusting the nut it’s paramount to lessen tension on the cable. My method is to first count rotation of cable lever adjuster and disconnect the cable. Do the nut adjustment and install the cable as it were.

6.   It’s only my observation but I am pretty sure like the Holy Grail there is only one tiny point when both adjustments meet and clutch operates satisfactory. It’s a job of persistent rider to find this point. And the only way is trial and error.

7.   Myself, I am taking bike for a ride with flat screwdriver, socket (5/16) and clamping pliers. To adjust disconnect clutch cable, grip tightly socket with pliers, keep the pin firmly in position with screwdriver and loosen the nut. Move the pin ever so slightly, tighten the nut and do another road test. Turning anticlockwise you get more slippage, turning clockwise it’s getting harder to operate gears. While driving it’s possible to turn the lever adjuster on the cable back and forth but this is only secondary adjustment to the pin.

It could little bit irritating at the begging but once you have a hang of it it’s no more than small inconvenience. Nothing more than that.