Crabbing the frame

I‘m probly/maybe gonna be pulling the gearbox out of Blue this coming Sunday. I’ve done a few clutch jobs on big twin Tontis before but always stripped right back. If I’m crabbing the frame – and I think I understand the basic principles, how much stuff can I leave in situ? I’m presuming all the wiring at the front end, and maybe the exhaust headers too, or will they get in the way at the bell housing anyway?

You need to come to Maldon with your bucket and crabbing line, don’t forget to bring some bacon :smiley:

yes the headers will get in the way, you will still need to unplug a lot of the electrical stuff. And remove the battery tray and drop the front & rear wheel.

Glad someones putting up sensible answers :smiley:

On which basis (apart from the bacon bits) I’m not seeing much advantage to crabbing the frame. If I crab the frame my work table is taken up for the whole two weeks I expect the bike to be down for. If I split it I can wheel barrow the bike out and under cover and then use the table for other bikes I’m working on in the interim.

What are the pluses to crabbing the frame?

Not removing the control cables and some wiring? I agree taking the top frame off with the front wheel attached has advantages as you say, and if you support under the sump the engine and gearbox will are happy on the lower frame rails and main stand. I have never crabbed my bike and have changed the clutch at least twice apart from the current re-build, but i did suggest it to my mate Stuffy who found it better than lifting the rest off as he was working on it sitting on his hydraulic table. Horses for courses old chap.

Whoops a sensible answer! :smiley:

What is crabbing the frame?

Hi, did my clutch in both my loop and Spada you can leave the engine in the frame but tip it on the front engine bolt useing a car jack and take the gearbox off to get to the clutch, I think theres a utube clip shows the meathod it works well, punch in removing gearbox on loops and it should come up, hope this is helpfull if ive got the right gist of what your doing.

Yes I had the clutch and g/box out of my Loop last winter – broken return spring. That’s a different animal; with non-detachable frame rails, and as you say you can tilt the engine up enough at the back to then pull the box off. That all went quite swimmingly really.

From the comments here I reckon I’ll be doing my usual strip and wheel barrow the bike away. As I say, that means I can clear the table for other activities whilst the box wings its way up to Nigel and then back again.

If you want an extra pair of hands, I’m free on Sunday.

When I changed the gearbox on my Breva 750 I removed the full exhaust system rear wheel, swing arm, battery, seat, tank, side panels. Loosened the air box rubbers. Remove the clutch cable and Neutral light wire. I had the benefit of a hydraulic bench and suspended the rear of the frame from the garage roof beam. I then unbolted the frame bolts on top of the engine and removed the top front bolts from bottom frame rails and loosened the bottom ones. I then slowly lowered the bench parting the frame. When I had enough clerance I could remove the bottom gearbox frame bolts and unbolt and remove the gearbox. It took around two and a half hours. I suspect the V50 will be similar. You just have to be methodical and take your time.

Hey Richard that is a very kind offer - thanks. However, there will be so much bad language going on out there that I would be too embarrassed to have you within earshot. (sexist joke alert) It’s the missus - I’m supposed to be decorating.

Catch you next time out - I can tell you how it went.

Yes all crabbing is, you don’t completely take the frame off. Yet it’s only one bolt away from being completely off. :smiley:

Mike that bike of yours must be difficult to crab with the sidecar on it! :smiley:

Can anyone explain why this known as “crabbing” ?

Because when you pull the bacon out of the water there are sometimes crabs holding onto it :smiley:

Opening the top and bottom of the frame like a crab’s claw. That’s my understanding anyway

Not half. :smiley:

I see. I have just read Chris’s link to This Old Tractor, and I see what you mean Makes sense now.