Kinetics 8-speed SA fitting

[srw]

I paid the money. It worked.

Bromptons are no more precision engineered than the next bike, dropouts misaligned, rear triangles poorly cold set, et cetera, et cetera.

It's almost working. Which is more frustrating than not working.

I suspect my latest problem is to with an over-tightened widget. Having over-tightened I'm not sure I can now slacken.

 

[PaulM]

I had enough slack in the cable(s) to shorten them. I've now got what seems to be a functioning gear system - but only with a slack chain. THe gizmo that screws on to the cable and then fixes to the gear changer on the hub is fouling the chain tensioner - which was, I think, the root cause of all the trouble. There's no possibility of paring a bit off the tensioner, but it looks as though if I can find a spacer to go inside the first doobrie on the drive side (the doobrie with the bent over bit that sticks in the slot in the frame) then the tensioner will be far enough out not to foul. Unfortunately (inevitably) I don't possess such a spacer. I've got a nylon washer, but the hole is too small and isn't enlarging easily, and inner tube just fouls everything and gets crushed.

Bah humbug.

Do you mean the cable anchorage nut is fouling on the derailleur when you operate the shifter? I had that at one time but it was because I had re-assembled it wrongly. I can't remember the details but the problem/solution was something to do with the spacing of the derailleur on the axle, maybe just the thickness of a washer on the axle. I might have mixed up the washer with one from the original 3 speed hub rather than used the one that came with the 8-speed kit in an ill-advised attempt to use the lightest bits. Anyhow, when I went back to how I had it originally it was fine and has operated flawlessly even after further removals of the rear wheel.

EDIT: Ah yes, it was simply the thickness of the lock-washer. I tried to use the thinner 3-speed hub lock washer rather than the thicker lock-washer that came with the 8-speed kit. Problem solved

 

[PaulM]

Also the SA hub is sensitive to indexing in the higher gears. On a couple of occasions after re-installing the wheel it's been fine in the first 5 or 6 gears but then 7 and 8 play up. When you check the hub indicator in 4th gear the yellow mark shows ok in the hub window but the gear cable can still be too tight. I found that if I slackenedd it sufficiently to get a clean shift going from 5th to 6th when pedalling, then further upshifts to 7 and 8 would be fine. The good news is that it seems to hold the adjustment well, assuming it's left in gear 8 when not in use.

 

[GrumpyGregry]

Also the SA hub is sensitive to indexing in the higher gears. On a couple of occasions after re-installing the wheel it's been fine in the first 5 or 6 gears but then 7 and 8 play up. When you check the hub indicator in 4th gear the yellow mark shows ok in the hub window but the gear cable can still be too tight. I found that if I slackenedd it sufficiently to get a clean shift going from 5th to 6th when pedalling, then further upshifts to 7 and 8 would be fine. The good news is that it seems to hold the adjustment well, assuming it's left in gear 8 when not in use.

Are you meant to do that?

 

[PaulM]

It's just sensible to have the cable under lowest tension when not in use to reduce stretching the cable. Likewise I put all derailleurs (front and rear) into their "normal" positions when the bike isn't in use.

 

[srw]

Fingers crossed, I'm now done. There's an alternative 8-speed (thumb) shifter, which is nicer, better quality, and importantly has a replaceable cable. To my surprise it fits nicely.

I've also added a barrel adjuster (taken from the 3-speed) at the back, which makes fine adjustment easier.

I've also added a cape roll and a fibre flare for full winter commuting duty.

 

[srw]

That second photo makes it obvious that I need new grips!

Sadly my plan to commute on it today has been scuppered by feeling as if I got about 2 hours sleep last night. In fact it was about 7 - if interrupted - but I decided that a day of rest would be better than sitting in the office in a fug.

 

[T4tomo]

Is that a cape or a 30 man marquee?

 

[srw]

By way of update...

The hub is now sounding a bit graunchy - as if it's not got enough lubricant. But the manual essentially says "don't lubricate". A couple of spokes have broken, which led me to realise that the wheel really wasn't well built at all, with all the spoke heads facing the same way - so I spent Saturday morning rebuilding to reduce the stress on the spokes. I now can't get the hub nuts to screw on properly - they're cross-threading badly, and since they're very soft aluminium the threads are going. And when I took the bike out for its test ride the chain slipped off the sprocket and jammed behind the adjuster. So I've got another week without a bike commute until I can get the thing fixed again, probably borrowing the nuts from my 3-speed wheel.

I'm beginning (!) to think that it wasn't a great purchase. Which is frustrating. I love the gear ratios, but I have spent more time bodging and fudging and fixing than I ever wanted to, not being especially mechanically minded. I've got a window coming up shortly to get a bike-to-work voucher, so I'm contemplating using that to get a replacement, and selling on the old bike to someone who's more of a mechanic than me.

 

[cisamcgu]

Sorry to hear of your woes, but I really appreciate your continuing story - thank you

 

[GrumpyGregry]

By way of update...

The hub is now sounding a bit graunchy - as if it's not got enough lubricant. But the manual essentially says "don't lubricate". A couple of spokes have broken, which led me to realise that the wheel really wasn't well built at all, with all the spoke heads facing the same way - so I spent Saturday morning rebuilding to reduce the stress on the spokes. I now can't get the hub nuts to screw on properly - they're cross-threading badly, and since they're very soft aluminium the threads are going. And when I took the bike out for its test ride the chain slipped off the sprocket and jammed behind the adjuster. So I've got another week without a bike commute until I can get the thing fixed again, probably borrowing the nuts from my 3-speed wheel.

I'm beginning (!) to think that it wasn't a great purchase. Which is frustrating. I love the gear ratios, but I have spent more time bodging and fudging and fixing than I ever wanted to, not being especially mechanically minded. I've got a window coming up shortly to get a bike-to-work voucher, so I'm contemplating using that to get a replacement, and selling on the old bike to someone who's more of a mechanic than me.

That's a downer.

Mine needs a new shifter cable.

 

[Flying Dodo]

By way of update...

The hub is now sounding a bit graunchy - as if it's not got enough lubricant. But the manual essentially says "don't lubricate". A couple of spokes have broken, which led me to realise that the wheel really wasn't well built at all, with all the spoke heads facing the same way - so I spent Saturday morning rebuilding to reduce the stress on the spokes. I now can't get the hub nuts to screw on properly - they're cross-threading badly, and since they're very soft aluminium the threads are going. And when I took the bike out for its test ride the chain slipped off the sprocket and jammed behind the adjuster. So I've got another week without a bike commute until I can get the thing fixed again, probably borrowing the nuts from my 3-speed wheel.

I'm beginning (!) to think that it wasn't a great purchase. Which is frustrating. I love the gear ratios, but I have spent more time bodging and fudging and fixing than I ever wanted to, not being especially mechanically minded. I've got a window coming up shortly to get a bike-to-work voucher, so I'm contemplating using that to get a replacement, and selling on the old bike to someone who's more of a mechanic than me.

I'm really sorry to see this. I've been really pleased with my kit. My only moan was about the poor instructions. However, having fitted it originally on the Brompton, it was then very easy to fit onto the Bickerton as I knew how the bits went together! My wheel is very solid and well built, so it's a shame that it seems yours wasn't.

 

[Yellow Saddle]

I have just looked at your photo in the OP and, goodness they are quite literally all facing the same way with heads out one side and heads in the other. It is as though the wheel builder just dropped all the spokes in in one go from one side. I wonder if @Yellow Saddle knows of a good reason why they might have done that.

Whoa! Long thread. I'll gladly comment if you can narrow down the post/picture where the offending wheel appears.

 

[Yellow Saddle]

Oh there, right under my nose.

I didn't read the rest of the story, it looks very sad, so I'll address your question only.

I think the wheelbuilder did the right thing but I want to give it a bit more thought.

The problem he faced is working with a large flange hub (I guess it is about 45mm whereas normal hubs are about 30mm) and small rim. This makes it very difficult to get multiple crossings without one spoke crossing over an adjacent spoke's (two spokes down) head. Look at a normal wheel and see how, if you increase the crossings eventually a spoke crosses over the head of another one. The way to avoid is is to make less crossings, in this case just 1.

If he alternated the spokes heads-in/heads-out, the crossing would not have interleaved. Interleaving is when the crossing touches the other spoke and both spokes pull the other one out of the straight line they could have followed. This crossing then serves the purpose of keeping tension on one spoke if the adjacent one is temporarily detensioned when hitting a bump. It serves to keep the spoke tight so that the nipple doesn't rattle loose.

It appears to me that if the builder on this wheel kept a `1X crossing and alternated the spokes, the interleave would have been pretty severe and perhaps created an ugly or awkward (for him) crossing. By putting the spokes both on the same side he softened the interleave.

Whether this was a real problem or even pre-meditated is another issue altogether.

That's the best I can come up with for now. It would help me if someone can tell me what flange size that hub has or indeed what hub it is. Then I can calculate the various angles for 1X, 2X and 3X and see what would happen.

A rule of thumb for determining the maximum number of crossings a wheel can do is to divide the number of spokes by 9. On a 36-spoke wheel you would get away with 4 crosses before the spoke head is fouled. On the same wheel with 48 spokes you could do 5. On tandem wheels we like to cross them 4X but standard road wheels 3X. The number goes down as the flange size increases and rim size decreases.

 

[Pale Rider]

Not sure if this comparison is valid, but here's the pattern on my Mavic/Alfine 11 wheel built by Rose.

Looks similar to the OP's wheel.

Mine has done thousands of trouble-free miles.

The hub blew up - a lot did - but that was nothing to do with the wheel build.