NEB wet clutch barnyard engineering mods for P11

Looks like the Molnar clutch is a NEB clutch which he modifies?

From what I saw, you didn't have a good experience with your NEB single row wet clutch in a 2022 thread. Something about it not running true.

Based on that, I wonder if one could assume the BNR clutch bearing arrangement is better?

elefantrider said:

Looks like the Molnar clutch is a NEB clutch which he modifies?

From what I saw, you didn't have a good experience with your NEB single row wet clutch in a 2022 thread. Something about it not running true.

Based on that, I wonder if one could assume the BNR clutch bearing arrangement is better?

Click to expand...

The modifications Molnar makes to the NEB clutches are optional. You can buy it without any modifications.

The NEB single row chain wet clutch did not align well with the front sprocket using the shorter stock P11 gearbox mainshaft. It was closer with a longer Commando mainshaft, but not perfect. Plus it never mounted up on the mainshaft like I thought it should have.

The end all show stopper problem I had with that NEB clutch was gear oil weeping past my crappy home brewed clutch rod seal that worked OK with the stock clutch, but not worth a hoot with the lighter weight NEB clutch plates. It would work for about 8 miles and then the gear oil wept past the crappy seal and caused the light weight friction and steel plates to stick together and not release well or at all. Because of how NEB decided to mount the clutch the way they did I did not have enough threads left on the mainshaft to use one of the better aftermarket clutch rod seal solutions. I could have run it with a low quantity of gear oil in the gearbox possibly, but I'd had enough with it. I had it in and out 3 times, and it is a messy job with a wet clutch. So, I decided to try a dry belt clutch.

I'm using one of the RGM clutch rod seals now and it seems to work with the RGM belt clutch. That said I don't have many miles on the RGM clutch. I'm looking forward to removing the AMC gearbox from the bike. It is probably the superior choice for many Norton owners, but I'd like to see if the TTi gearbox is better for my use.

I just looked at the BNR clutch and yes that bearing and hub arrangement is probably better.

Schwany said:

I just looked at the BNR clutch and yes that bearing and hub arrangement is probably better.

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I beg to disagree. Please have a look in this thread:


The unshielded ball bearing requires frequent lubrication, and despite the comparatively large bearing race diameter, clutch drum wobble is to be expected. The stock Norton Commando clutch uses a single row ball bearing as well (35x62x14 mm), but it's a deep groove ball bearing, so it will give some lateral support. AMC and Triumph stayed with roller bearings, which is a better design in my view. Replacing the Commando's clutch drum (and belt drive derivatives ....) ball bearing 6007 by roller bearing NJ1007 will give the clutch drum improved directional stability.

- Knut

From the photos, it looks like the BNR has loose balls but has the advantage using a steel outer chain ring (teeth) on his chain driven version.
I guess I don't understand the reason for this type of bearing arrangment which requires lubrication.

Flying greese and clutch plates are not considered a good mix. This is why manual car transmission shaft pilot bearings are usually sealed or bronze.

The NEB wet clutch I have came with an unsealed 6007 C3 bearing. I replaced it with a 6007 2RSC3 sealed bearing on advice from Molnar. Helps with keeping the bearings clean of friction plate dust or any other fine dust or grit that may enter the primary.

An open bearing in a wet clutch hub will be lubricated by the oil splashing around in the primary. On a dry clutch an open bearing might not last that long.

I do like the roller bearing arrangement in the old AMC clutch. It works really well. I was tempted to go back to that heavy thing, but I don't like the mess associated working with a wet clutch.

I have two BNR belt drives and one RGM belt drive. The RGM seemed to have one leg up on the BNR in that it uses a sealed bearing whereas the BNR uses the unsealed rollers.
In actual use, the little RGM supplied sealed bearing lost most of its grease in about 500 miles.
I checked one of the big diameter BNR bearings at about 2000 miles and all grease was still nicely in place, no indication that it would ever need repacking.
That BNR clutch has about 10,000 miles on it now, I should have another look at the bearing to be sure. There is definitely much less wobble with the big diameter BNR setup vs the small diameter RGM, although both are working well
I will fit a new bearing to the RGM and hopefully the grease will stay in this time.

Glen

worntorn said:

I have two BNR belt drives and one RGM belt drive. The RGM seemed to have one leg up on the BNR in that it uses a sealed bearing whereas the BNR uses the unsealed rollers.

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Hi Glen, I get contradicting information. The thread I linked to suggests the bearing is an open ball bearing. You claim it's a roller bearing, which would be sensible.
So, is it actually a roller bearing?

- Knut

Newby (BNR) only makes them with the loose tiny ball bearings, almost a hundred of them I believe. Servicing doesn't sound fun.

It has a steel center clutch hub, which a good thing however.

It looks like the NEB and the RGM both use aluminum center clutch hubs.

Pick your poison.

I'm looking at a pic I took of the RGM pre-Commando belt clutch I have. The hub center is steel. The basket and pressure plate are aluminum. The RGM Commando clutch might have an aluminum center. I am not knowing.