fault causing rear chain to go tight, slack, tight

[saltbox alf]

Hi Janet, you have to do the Sherlock method and once the obvious is ruled out ,then it can only be the hidden. I think that if you are feeling some grittiness in the bearings then that is not right.
There is only a set amount of possibilities for the problem you have for the chain to go tight then slack. If the chain is new then the centers of it's run must be changing due to an elliptic effect from either the sprockets, shafts, bearings , suspension or engine/gearbox mounting .

My money is on the wheel bearings but check for play in the swinging arm, a very small amount of play could result in it being amplified at the rear wheel.

I almost have the urge for a long distance run, as I see this is a most frustrating problem.
At the moment we are moving house, so no chance of a quick holiday!!

keep at it and don't let it get to you. Take a break, have a cuppa and go through the checking process from square one, it's easy to skip something thinking that's ok when it's not (how do I know!!!)

Good luck.

[Janet]

Thank you for narrowing down the possibilities. Play in the swinging arm was a bit further down my list, simply because it's a thing that moves and therefore can wear, I've never had it out and I doubt if the previous owners have either, so, again, it's probably something worth doing anyway.

The good news is that everything I'm doing is likely to be needed now or in the near future, so I'm not really wasting time or money. The bad news is that I prefer to do things one at a time, knowing what I'm dealing with and how to fix it.

Now, who were the people who asked for a sequel to 'A year in the life of....' ?

[Ozmadman]

Just a quick update although I haven't found the cause yet.
I will be attacking the bearings next.
The manual doesn't seem to say much about them and nothing at all about how to get them out, but I seem to recall Paul (Ozmadman ) saying they just knock out, one with a tap on the end of the spindle and the other, presumably, just with a tap on the bearing from the other side. Going by previous experiences of things that 'just' do something, I'm expecting a long haul.

I'll keep you posted but don't hold your breath. I may be some time.

Hi Janet
Here is my post re the wheel bearings just in case you haven't seen it

" I have just done mine, well removed the axle to put it back the correct way round. The speedo drive should pull off complete (I wouldn't take it apart if I were you). The part on the hub with the two notches in to take the speedo drive part with the two lugs on remains on the hub, you don't need to remove this to do the bearings. Once you remove the drive you will see a spacer which just pulls off as well. Put a nut on the axle and tap it with a hammer and the axle will come out with one bearing attached, the other bearing will stay in the hub so just knock it out as normal as they are just a press fit in the hub and on the axle. The original bearings had a seal and seal ring but the modern ones like mine are sealed bearings. When you put them back just tap them back in flush with the axle. Easy peesy, but make a note of which way the axle comes out as it is different each end, the "longer" side goes towards the speedo drive."

Paul

[iansoady]

Play in the swinging arm was a bit further down my list, simply because it's a thing that moves and therefore can wear, I've never had it out and I doubt if the previous owners have either, so, again, it's probably something worth doing anyway.

I would doubt the swinging arm bearings as I can't see how that would give the variation from tight to slack. Which doesn't of course mean they are OK......

[saltbox alf]

Hi Ian ,I very much doubt the arm bearings too, but it's a Sherlock improbable! Could be in conjunction with summit else.

[Janet]

Could be in conjunction with summit else.

So you think I may need to get on top of the problem before I get to the bottom of it?

[saltbox alf]

Yes very good, it's my livin in forin parts, upsets the ole eenglishe. However your thought is rather good sense, as in, you have to climb the mountain before you see the view!

[Janet]

When I get to the top of this mountain I'll be wanting someone to present me with a red polka dot jersey. I might even want a white on red ID number. Or an ambulance.

[fump]

For what it's worth......It could be the main shaft bearing in the gearbox being badly worn, caused by lack of oil, or the gear box moving under load.

[Janet]

For what it's worth......It could be the main shaft bearing in the gearbox being badly worn, caused by lack of oil, or the gear box moving under load.

Thank you for your suggestion. Yes, that's also on my list but I'm going through the easy bits first.