Rear derailleur with a difference; lets call it 'Blinky'

[Brucey]

I found this picture recently;




here;

http://www.disraeligears.co.uk/Site/SunTour_XC_derailleur_(3_pulley_system).html

where the comments include; "Fantastic - except for the fact that it looked so weird that, as you cycled by, dogs barked, babies cried and your friends laughed. At you, not with you. "

I thought I knew my rear mechs, but I've never seen one of these in the flesh.

'Blinky'? -it seemed like the right name for it....



from 'The Simpsons'

cheers

[thirdcrank]

It would have been interesting to see a pic of one on a bike, or at least with a chain on. Does the chain go over the top jockey after going under the other two, or does it go over the first lower jockey it meets, and then take a conventional route around the other two?

[Brucey]

I think the chain goes around the outside of the lower pair. Shimano market derailluers with extra large lower pulleys 'megarange' etc and these have additional capacity because of the extra wrap-round. This SunTour one looks to have worked in the same way.

cheers

[531colin]

I think the chain goes around the outside of the lower pair. Shimano market derailluers with extra large lower pulleys 'megarange' etc and these have additional capacity because of the extra wrap-round. This SunTour one looks to have worked in the same way.

cheers

Thats how I had it figured........the third pulley only comes into play when the jockey cage is a fair way back, in order to take up a bit more chain.

[reohn2]

Yep,definately a dead end in the evolutionary "chain"

[Redvee]

Shimano will rebadge it and people will buy it cause its Shimano.

[reohn2]

Shimano will rebadge it and people will buy it cause its Shimano.

Like they bought the "low normal" rear mech which revolutionised cycling,NOT

[BigG]

The Suntour rear mech shown was technically successful, but not commercially so. The objective seems to have been to get the overall tooth range of a long cage mech within the physical constraints of a short cage. It is not very different in philosophy from the modern rear mechs such as the recent (current?) Suntour RD-XCR650.SGX that use a large diameter tension jockey wheel to achieve the same thing. Both ideas work well enough, but most people seem to manage without them.

Edit: A rough measurement suggests the the mech shown would have about an 8 tooth greater range than a similar length mech with only two jockey wheels. The maximum increase available commercially by using a larger jockey wheel is 5 teeth with a 15 tooth jockey wheel (as on the Suntour 650 mech mentioned above) instead of the normal 10 tooth one.

[thirdcrank]

It looks to me like an elegant solution to the "dangling derailleur" problem. (Now I've had the chain path explained. )

I'm no off-roader so I've no experience of a longer arm hitting rocks etc., but I have a Birdy so the smaller wheels take the cage near the road and care has to be taken to avoid damage.

[[XAP]Bob]

And looks sane for small wheelers...

[reohn2]

And looks sane for small wheelers...

Though same effect can be achieved by large(r) jockey wheels.

[Tonyf33]

These are ideal on early/mid 80s tourers & not just from a looks POV, I've had many an older Suntour RD work fine with indexed gears so not just friction shifting. Such a shame that Suntour went to the wall, they had lots of fantastic bits of kit and their designers sure knew how to make stuff elegant as well as functional something Shimano have rarely been able to boast about...
Their high end rd's were so light too, only superceded by very late Campagnolo Record carbon & some silly uber expensive stuff, beat the hell out of the Campag components at a much more affordable price range.

[gaz]

I thought I knew my rear mechs, but I've never seen one of these in the flesh.

https://www.ebay.co.uk/itm/NISHIKI-Trav ... SwSXFd7SK6

[Brucey]

still have not seen one in the flesh, but found more pictures including of a model called LePree



which appears to be a close relative of 'XC' otherwise and indeed Cyclone MkII with the same cage on it too (although this may be a conversion).

I have even found this conversion picture



which is more than slightly horrifying....

cheers

[gaz]

which is more than slightly horrifying....

Would that be Suntagnolo or Camptour?