Servcing STi Levels
- Thread starter xc_gumby
- Start date
I wouldn't unless there is a specific problem traceable to the shifters. They come packed with proper grease. Over time, and depending on conditions, they can get crudded up or the grease stiff. They can also go years without needing attention.It's possible to hose them out with a suitable solvent, and relube with a suitable spray. Trying to take them apart gets ugly.
I might like to find that guy. I have a Dura Ace STI lever that is misbehaving and I'm considering the disassembly route. Symptom: right lever will usually not shift from larger to smaller cog using the small inner lever unless I hold the larger outer lever still. Shifting from smaller to larger cog works fine. The outer and inner levers seem to move together when I try to shift larger to smaller using the inner lever and nothing happens. I have tried cleaning thoroughly with a spray degreaser followed by lube with tri-flow spray. It didn't make a difference. Any thoughts?xc_gumby said:
The levers are connected to a cog with a ratchet mechanism on both sides, which permits the cog to move in one direction only depending on the lever you move. Moving a lever (the outer one for example) disengages the forward pawl to move to the next slot. The reverse pawl slides along the opposite slots, still engaged. Moving the opposite lever does the reverse.65cmFixie said:
Moving the inner lever should not cause the outer lever to move. My guess is that there is something wrong (broken(?)) with the ratchet mechanism, esp. for the outer lever. Sorry, just because they're DuraAce shifters doesn't mean they're indestructible
Disassembling those STIs are a real pain, and sadly, Shimano provides neither service instructions replacement parts for the shifter mechanisms.
xc_gumby said:Anybody got any ideas about how to clean & lube the mechanism?
I've got some service diagrams from Shimano but it really doesn't look obvious.
I've got 1999 105s.....
As far as I know, Shimano STI levers aren't serviceable. Or rather, they aren't meant to be serviced or taken apart by the average bike mechanic. As for lubrication, a good spray lube called Boeshield T-9 works great on pivot points and general squeaks. It dries clear and isn't messy- I imagine it would work for your particular application.
I've stripped down and reassembled Ultegra and DA sti's.
The Ultegras took me about 10 hrs to get it back together and the DA took about 4.5 hours. They are quite different inside and real bastards to get back together.
In short they aren't made to service and you can't get parts anyway. If its stuffed you have to change the entire guts of the lever in one hit.
However if its stiffening up then the Shimano grease is probably drying out which is a common problem. I flushed mine out with Kerosene which disolved the grease but left the plastic bits intact. Then used CRC 226 liberally squited everywhere inside to re-lube it.
1000's of kilometers and still working fine.
The Ultegras took me about 10 hrs to get it back together and the DA took about 4.5 hours. They are quite different inside and real bastards to get back together.
In short they aren't made to service and you can't get parts anyway. If its stuffed you have to change the entire guts of the lever in one hit.
However if its stiffening up then the Shimano grease is probably drying out which is a common problem. I flushed mine out with Kerosene which disolved the grease but left the plastic bits intact. Then used CRC 226 liberally squited everywhere inside to re-lube it.
1000's of kilometers and still working fine.
I have 105 STI levers from a few years ago, and today they started acting up. The right lever (for the rear derailleur) gets stuck when I shift to a larger cog (the whole brake lever points inward, and down toward my front wheel). I actually have to pull pretty hard to get it to pop back into normal position. I had this happen once before, but I think with the other side, but it did not last. I tried dropping some oil (Pedro's dry lube) in the parts that looked like they might be sticking, but it did not work. Any advice for this?
If its the same as Ultegra, which it most likely is, then the screw is essential for correct shifting. Without it the Ultegra's have very imprecise shifting.drebro said:
The screw is available as a spare part.
I lost one and never had any luck getting anything else to fit so just buy another one.
cheers
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