A 9spd Mirage that appears to function on a 10spd cassette ?

[TheCyclingRooster]

Hi to you all out there.
I have just discovered something rather odd whilst considering a wheel-swap on my Bianchi Via Nirone7 Alu Carbon from Mavic Open Pro (black rims) to Mavic Aksium (silver rims).
Without removing the cassettes I just fitted the Aksium 10spd into the frame and turned the rear wheel with the pedals to engage the chain onto an appropriate sprocket.
To my surprise the 9spd Mirage Lever functions perfectly well (whilst upside down) on the 10spd cassette !!
I am going out for a short whiz.

Why is this so ?

 

[Yellow Saddle]

"Perfect.y" being each and every gear without clickety-click noises?

 

[TheCyclingRooster]

"Perfect.y" being each and every gear without clickety-click noises?

Hi Yellow Saddle. Yes - oddly enough whilst upside-down - but I have not been out for a whiz in the local lanes. That will happen in the next couple of hours and just after fuelling-up at lunch-time.

 

[Globalti]

You'll have to ride upside-down.

 

[TheCyclingRooster]

Hi Globalti. I was waiting for one like that - but without a cycle helmet my already thinning hair would be at a more serious risk of abrasion.

Off topic - your signature is not necessarily totally accurate in that there are a few users of mobile-phone cameras that really do make excel in their compositions and end results. I have a long-time friend in Frigiliana that spent many many years as a photographic journalist ,photographic artist and writer that has put his professional cameras away and has been working for many years with a Samsung Galaxy S3 & S4 albeit with some very classy attachments when appropriate.

 

[TheCyclingRooster]

Hi again all. Having been for a tootal up the road and around the lanes - it would appear that the rather strange combination actually works albeit there is a bit of intermittent 'undecided' around number 5/6 sprockets from the lowest down.
The exercise was initially performed on the middle ring of three.
Theoretically this just should not/could not happen as the indexing is on the lever.
Because of chain length/ring/sprocket issues/choices there is a no-go on the 50/25 and chain slack on the 28/12 but in reality one would not go there anyway.

 

[raleighnut]

Campagnolo have strange spacing on their 10spd cassettes, apparently to aid shifting.

Campagnolo
9-speed 4.55 mm 1.75 mm 2.8 mm 38.2 mm
Shimano
9-speed 4.34 mm 1.78 mm 2.56 mm 36.5 mm
SRAM
9-speed 4.34 mm 1.8 mm 2.54 mm 36.5 mm
10-speed
Campagnolo
10-speed Variable (note) 1.7 mm Variable (note) 38.8 mm
Shimano
10-speed 3.95 mm 1.6 mm 2.35 mm 37.2 mm
(note)
11-speed
Campagnolo
11-speed Variable (note) 1.6 mm Variable (note) 40.1 mm
(note)

 

[TheCyclingRooster]

Hi raleighnut. The set-up on the Bianchi is 9spd Mirage throughout albeit the bike came with a compact double (now a Stronglight triple BUT using the same lever) - indeed I have just removed the cassette for a thorough cleaning.
Strange spacings indeed but it still does not explain/equate to how an indexed 9spd lever will allow the 10spd cassette to shift through all sprockets albeit on the centre of three rings.
I can live with the 'no-go' on the 50/25 and the 28/12 - the cage appears to be a medium at 55mm pin to pin,I might change the 50t ring for either a 48t or a 46t as riding 140mm cranks effectively ups the gear ratios by the equivalent of 2t anyway.

 

[raleighnut]

Hi raleighnut. The set-up on the Bianchi is 9spd Mirage throughout albeit the bike came with a compact double (now a Stronglight triple BUT using the same lever) - indeed I have just removed the cassette for a thorough cleaning.
Strange spacings indeed but it still does not explain/equate to how an indexed 9spd lever will allow the 10spd cassette to shift through all sprockets albeit on the centre of three rings.
I can live with the 'no-go' on the 50/25 and the 28/12 - the cage appears to be a medium at 55mm pin to pin,I might change the 50t ring for either a 48t or a 46t as riding 140mm cranks effectively ups the gear ratios by the equivalent of 2t anyway.

On an 'indexed' system the top jockey wheel has a certain amount of sideways 'float' built in to the pulley (that's how they got 'indexing' to work and also why the pulley wheels are marked 'top' and 'bottom')

 

[TheCyclingRooster]

On an 'indexed' system the top jockey wheel has a certain amount of sideways 'float' built in to the pulley (that's how they got 'indexing' to work and also why the pulley wheels are marked 'top' and 'bottom')

Hi again raleighnut. Yes but that surely is not sufficient to allow the 9spd lever to function on a 10spd cassette. After-all the sound of the indexing system can be heard in the lever and especially on the selection of the higher gears,there is a decided thump upon depressing the selector button.

 

[GrumpyGregry]

cable stretch, wear, sheer chance, poor setup, et cetera.

because a thing can be done does not mean it should be done.

 

[TheCyclingRooster]

cable stretch, wear, sheer chance, poor setup, et cetera.

because a thing can be done does not mean it should be done.

Hi GG. Whilst I cannot refute any of those probables - the bike was perfectly fine on the 9spd original Mirage. All I did was swap a wheel + 9spd cassette for a wheel + 10spd cassette.

 

[Smokin Joe]

Hi GG. Whilst I cannot refute any of those probables - the bike was perfectly fine on the 9spd original Mirage. All I did was swap a wheel + 9spd cassette for a wheel + 10spd cassette.

Sure you're not just skipping a cog on the way through the cassette?

 

[raleighnut]

It is a Campagnolo set-up though, where Shimano 'snicks' nicely in to the next gear Campy does tend to shift with a 'THUMP' although I'd describe it as a 'KERCHUNK................... THUMP' with an added CHING when the gear engages. I've had car drivers looking worried when I change gear in traffic.
Mind you certainly know it has changed gear.

 

[TheCyclingRooster]

Sure you're not just skipping a cog on the way through the cassette?

Hi Smokin Joe. No that is not the case. That said the range is smoother on the way up (highest to lowest) than down (lowest to highest).
I am actually test riding the bike,it is not mounted on a service stand. I really cannot understand why it is happening.