re scottoilers:
The traditional scottoiler motorcycle system is worked by inlet manifold vacuum, to open a valve that dispenses an occasional drip of oil from a reservoir onto the chain whenever the engine is running. They now make this system (which they call V-system scottoiler) as well as various (allegedly cleverer, certainly more expensive and fiddly) electronic versions. In the past high mileage/offroad motorcyclists used scottoilers and cheap (non-O-ring) chain. The back of a roadgoing motorcycle (including the tyre sidewall but not usually the tread itself) ends up covered in oil this way, but chains last longer. The oil used is 'special' in that it costs a fortune from scottoiler; it contains a stringing additive so that one drip is distributed over several links, not just one. Most folk just use something like chainsaw oil which is vaguely similar much less expensive. However the system is flawed in that
a) modern motorbikes use 'O' ring chains; all any lube on the outside of the chain has to do is to keep the rollers happy and keep the O-rings from drying out.... and
b) the centrifugal forces on a motorbike chain are extreme; any oil on the chain (or the tyre sidewall, fortunately) gets flung off almost instantly. Lubes that stay put for more than a few seconds are much, much stickier. Arguably if you use a scottoiler on a modern road-going motorbike with an O-ring chain, its main function is to keep the chain clean by helping the dirt to be thrown off the chain more quickly than it might be otherwise.
Now, years ago, I idly wondered if such a thing could be made for a bicycle. However I dismissed the idea on the basis that a) there would be extra junk on the bike and that b) any oil would just make a sticky mess everywhere. Well it didn't stop the folk at scottoiler; they produced a small version of their oiler (which was lightweight, and required that the rider occasionally worked a control to dispense fluid onto the chain) and used a water-soluble oil (which they called 'active fluid') so that cleaning was maximised and mess was minimised. This system did not sell terribly well, but some mtbers used it and liked it. You can see the scottoiler cycle oiler (~2005 version) here
https://web.archive.org/web/20051227122219/http://www.scottoiler.com:80/active.aspon the bike it looks like this
Fluid is dispensed into a special lower pulley and thence onto the chain. The special fluid was sold pre-diluted with water (thus maximising cost and the needless shipping of stuff) and was quite pricey. How it actually differs (if at all) from, say, water soluble machining oil is unknown to me.
I looked on their website about three years ago and the system appeared to have been discontinued. They were still busy selling 'active fluid' in trigger sprays though, claiming that regular use of their fluid allowed easier clean-up; a partial benefit. However they hadn't given up.... they (somewhat bafflingly) have modified and rebranded the oiler product as 'Flaer'
http://flaer.com/products/and the fluid is now dispensed electronically. There is a road version 'revo via' and an offroad version 'terra'. Claimed battery life seems pitifully short to me, but maybe the automatic dispensing makes up for that. I can just about see the point for an MTB but for a road bike, I wonder if keeping the reservoir full and the battery charged is more faff than maintaining the chain by other means, but what do I know....?
I used a motorcycle scottoiler for some years and a friend has used the (old) cycle version (on a roadgoing bike). Since whenever I saw the bike the reservoir was (apparently randomly) either empty or just as full as it had been before, I wondered if the thing was being used at all or if it leaked and/or syphoned the contents out automatically; it didn't seem that the chain lasted any longer than normal and there seemed to be a reluctance to buy any more of the 'special fluid' (the cost of which may exceed the value of a chain through its life.....*) so the system has been off the bike for the last couple of years. If more conventional methods work less well (for them, in their use) then it may go back on. This will be more likely if a (more reasonably priced/available) substitute fluid can be found.
(*) Currently 'Revo' (and 'terra') fluid is sold in £250ml bottles which cost £10 a go. This works out to £40 a litre, which is comparable to a lot of other cycle chain lubes. The difference is that this lube is mostly coloured water and you will probably get through a lot more of it than with other systems. Basically you are paying about £400 per litre for the concentrate (assuming it is 10:1 diluted; it may not be) so it could be that you will spend more on the fluid than the chain is worth. (By contrast water soluble machining oil (concentrate, so maximum dilution between 10:1 and 20:1) can be bought for about £4-5/litre. A 10:1 solution of that costs about £0.40 per litre......
and may work as well as the stuff that costs x100 as much.....)
So my take is that it is an interesting approach, but there are some actual and some potential pitfalls; it might work for some folk, but most will be put off by the simple fact there is more junk on their bike, and one source of faff/expense is simply replaced by another.
cheers