Is there some special knack for removing M20 headlight rims? Mine's always been a pain to get on and off, and now it doesn't want to come off at all (I need to check the switch connections).

Naturally I'm reluctant to force it. There is a hole at the bottom and a plastic clip (if that helps identify the type). Can't see any obvious problem. But maybe I'm missing something.

Any advice, anyone? Or do I get out the tin opener?

email (option): dannydefazio@sumpmagazine.com

Hi Danny, it normally comes off if you get all your fingernails on both hands under the rim along the bottom edge and then just walk backwards away from the bike, however I can see a flaw in this system if its very stuck, hope this was of some help Rob.

email (option): robmiller11@yahoo.co.uk

Thanks Rob. That's how I remember it from when I last took it off. But it feels like it would take your fingernails off first.

The main thing is, it appears, that there's no other clip or fastener holding it back. I'll squirt a little WD around the rim and will try harder.

Thanks again.

email (option): dannydefazio@sumpmagazine.com

A plastic clip?? That doesn't sound like an original fitment, but maybe it works in the same way as the MU42 style headlamp - try pulling the clip vertically downwards to disengage it from the hole in the rim, then (with your third & fourth hands) pull the bottom of the rim forwards and upwards. And yes, strong fingernails do help.

ChrisJ

Hi Chris, thanks for that. There's definitely some kind of clip under the headlight. It's spring-loaded or something. I've got pretty strong nails (I play guitar and seem to have toughened them over the years), but the headlight rim wants to stay right where it is. There has to be some kind of clip, doesn't there? What else would keep the rim on? Maybe that clip's made of some other material. I'll check.

The main thing is that it sounds like there's no other obstacle or anything overlooked. I know where to apply the force now, but I was wondering if there is some special technique that everyone else knows about, but forgot to tell me.

Thanks again.

P.S. Have just found my military maintenance manual/maintenance book. Looks like the same headlight as illustrated, except the clip. Seems it just comes down to brute force now.

email (option): dannydefazio@sumpmagazine.com

Darlings !

If it comes down to choosing between paint finish and my nails then it's no contest

A carefully inserted screwdriver on the lower edge where it doesn't show seems like the thing to do.

Sounds like you have an MU42 (just postwar) headlamp Danny..a common fitment as a post war replacement part. The clip under the rim is an aluminium die casting.
Nearly impossible to get on and off rims are also common, even when NOS parts are used.
The rim engages with a lip formed into the upper part of the shell and is then pushed over some slightly raised pieces formed further around the shell and finally goes over the lower part of the shell and is retained by the clip.
Once you actually get the rim off you will see how it works. I usually spend a little time 'tweaking ' the top lip with a pair of pliers, then dress down the raised pieces slightly with a file/ small hammer.
With care you can 'ease' the fit of the rim without making it loose...Ian

Thanks Ian. I've had the rim off before, but it was some time ago and I couldn't remember if there was any special problem. I'm inclined to take Rik's advice and get a flat-bladed screwdriver in there. But I'll struggle a little more first before I get out the jackhammer. Clearly it must come off, and clearly I need to dress it a little rather than just take the fitment for granted.

Thanks all for advice and feedback.

email (option): dannydefazio@sumpmagazine.com

I had problems with replacing the rim on my M20 after it was removed. But when the headlamp was on the bench it was easy. My conclusion is that the fixing bolts through the headlamp brackets is distorting the shell. Try loosening those bolts first. Ron

email (option): ronpier@talk21.com

Ron. Brilliant. I think you just might have cracked the problem. That sounds exactly right. Thanks a lot for that.



(On the other hand, if it doesn't work, I take it all back)



Will let you know.

email (option): dannydefazio@sumpmagazine.com

I am currently putting together a replacement headlamp for my M20...I have a very good used shell and a NOS rim. Also another good shell with a previously used rim. Niether were fitted to the bike but I couldn't get the rim on and off either of the buggers without a real battle..I have fiddled with the best shell and the NOS rim and it is very nearly there now...Ian

sorry to resurrect this old thread, but I need a bit of experienced advice re putting my headlight back in. So new rim, perfect NOS and original reflector. Firstly, how does the reflector stay in the shell and provide the earth? As I try to fit the rim the reflector pop forward slightly and bang, the earth goes! Secondly, should there be a cork gasket ( if so can anyone supply one?) on the front of the reflector to cushion against the glass when I pop it in? Its not going in very easily and I fear needs a bit of brute force and ignorance, but as its nice and fancy in its new very smart khaki and matt black, I will have to ease it in somehow. What I dont want to do is have to take it off in a hurry to fix a cork gasket. Once its on, its staying in for a while!

email (option): andrew.honychurch@btinternet.com

Andrew the reflector and glass should be held firmly into the rim with those 'W' clips. I usually use at least four. There is supposed to be a cork gasket but I often find them more trouble than they're worth.
There should be a separate earth cable from your bulb holder to the inside of your shell. Normally little metal loops to take a bullet. I generally find an earth will occur through the headlamp fixing bolts. But others correctly run a separate earth cable to the frame.
Remember to have the fixing bolts loose when you fit the rim as they can distort the shell making it hard to fit the rim. Tighten them after the rim is fitted. Ron

email (option): ronpier@talk21.com

Those W-wire clips can be found at garden centres; they are used to fix the glass panes in green houses. Sometimes you have to shorten the legs a bit.
And are those rims always black ? And the clip underneath: also black or mud-brown/green/khaki/whatever?

email (option): viaconsu # planet dot nl

Why don't you make a hook from a thickish welding rod and hook it off?

email (option): davmax@ntlworld.com

email (option): viaconsu # planet dot nl

Hi Hans..I imagine you would use the 'hook' to engage the hole in the bottom of the rim, to aid in pulling it off..Seems like a good idea....Ian

email (option): ian@wright52.plus.com

Ah seems I have made a schoolboy error in that I have fixed the glass into the rim with the W hooks, but not the reflector as well! So I will ammend that and I suspect I will be ok after that. Will look for the earth lead conection but I think I can make that work through clearing a little paint on the touching edges. Cheers chaps

email (option): andrew.honychurch@btinternet.com

I think I didn't make myself clear enough
My rim goes off and on without any problem, and the clip engages perfectly.
My question was if the rim is always black, or was it painted the same colour as the headlamp case? And if black, was the clip also black? Trivial point, I admit...

email (option): viaconsu # planet dot nl