RIght hand dura ace shifter issue

spasypaddy

Ive had my dura ace (7900) shifters since august, upgraded from old style ultegra. They are lovely. however the right hand shifter which has never been raced/crashed/out in really bad weather has developed an issue that when im in the biggest gear on my rear cassette it keeps on pushing through.

For example, climbing a steep hill you reach for another gear hoping its there but the shifter shouldnt budge when you are out of gear. Mine doesnt stop clicking through. It doesnt move my mech but its as if the ratchet has gone.

Obviously this isnt good enough and needs replacing. However to take it off and get it replaced leaves without a geared bike for 2-3 weeks.

Does anyone have any suggestions?


edit: I have no STIs lying around at home as i sold my ultegras and im not willing to dismantle my CX to swap the shifter over as im not a good enough mechanic to get them both working again.

Also i cant use my CX on the road (for club runs) as its not geared properly.

Down the Road

Sounds easy for your bike shop to repair. My first guess is the cable is in wrong

way2go

I am having exactly the same problem. Is this a common problem with 7900 shifters? Does anyone know what's causing this? And is there a solution?

way2go

I have taken the faulty shifter from the bike to take a further look. It seems the little paul lever on the inside of the shifter is rounded a bit due to wear. When I apply force the paul lever just slips over the ratchet. In my case it started doing this in the lowest gear (largest cog), but now it is also happening in higher gears (smaller cogs).

spasypaddy

hi way2go,

i ended up changing the shifter body but kept the levers. so they swapped over. it took me 2 years to get round to doing it though as it was on my summer bike and didnt get enough mileage before this year to warrant it

way2go

Thanks for the reply. I just went to the LBS. They told me it's not possible to get separate parts. Where did you get the shifter body from?

southdownswolf

Have a look on Madisons website - distributor of Shimano in UK

http://www.madison.co.uk/products/cycli ... ano-spares

southdownswolf

Breakdown of shifter parts:

http://bike.shimano.com.sg/media/techdo ... 683887.pdf

spasypaddy

as southdownswolf says, direct from madison

this is the right one
http://www.madison.co.uk/products/cycli ... ssembly-1/

and this is the left one
http://www.madison.co.uk/products/cycli ... ever-unit/

you'll need two special tools to do it
http://www.madison.co.uk/products/cycli ... or-e-ring/
http://www.madison.co.uk/products/cycli ... or-e-ring/