Shimano Right-Hand Ultegra ST-6700 Shifter Ratchet Slipping

[burgesstribe]

Hi, my Shimano Right-Hand Ultegra ST-6700 Shifter is intermittently slipping gears when trying to shift to the lower gears (i.e. larger cogs, cable under tension, using large lever). I've changed the cables as the prior one was fraying (in the shifter guide, so I thought this could be the cause) using top-spec Dura-Ace 9000 (polymer coated) but the problem is still there. Looking at the mechanism during shifts, it is clear that the part that is meant to catch on the ratchet wheel (pawl?) is occasionally slipping over the teeth, due to teeth wear / excessive freeplay (if I apply downward pressure to help maintain contact, it doesn't slip).

Clearly I could spend money to buy a new shifter (from £80 in UK) but does anyone have advice on how to fix e.g. putting a 'shim' in place to prevent the pawl from moving away from the ratchet wheel? Or advice about buying 2nd hand (I'm a bit reluctant given my current issue)?

Note: the bike is 2nd hand - I've probably done about 300miles only & I don't know its history - but it does seem surprising to me that Ultegra shifters should wear out in this way... perhaps I should write to Shimano to see if they'll replace at a discount

 

[TissoT]

Hi TissoT, yes, at Velotech we'll repair anything Campagnolo (or indeed any other brand but our main expertise is Campagnolo) that is repairable, as long as the parts are available and we have a reasonable expectation that the repair will last. Our mantra is generally one of repair being preferable to replacement but there are times when it's either just not economic and we'd be doing the customer a dis-service by making a repair when there are better options available - and there are occasions where we could make a repair but we'd have the expectation of a failure occurring again within a short time.

This may help you, Graeme works for Velotech and they specialise in repairing shifters
http://www.velotech-cycling.ltd.uk/index.shtml

 

[Drago]

Surely not, all the no-nothing's tell us how brilliant and obviously superior in every way Ultegra is.

On a serious note, I found a site once whee a guy stripped a brifter himself that many be of use. Stand by while I fire up the desktop PC.

 

[Drago]

Ok, can't find it (yet - I'll keep trawling my internet history, but there's a helluva lot of dwarf porn in there) but I found this that might give you some idea...

http://www.norvil.net/pedal/service/shimanosti/duraace9sti/strip.php

 

[User6179]

Make sure the bolt that goes through the shifter and holds the mechanism together is not loose , you have to remove the shifter to locate the bolt underneath.
Had this happen on two L/H shifters 6700 ,unfortunately I lost the retaining nuts as I kept shifting on a ride .
The symptoms start as the bolt loosens and the ratchet does not line up with the pawl so you cant shift up .
Could be just wear and tear but my R/H shifter has 25000 miles on it and still shifts perfectly.

 

[accountantpete]

The bad news is that AFAIK Shimano shifters are not made to be repaired and you need to be the original puchaser of the item for Shimano to consider helping you.

The good news is that it is usually the left hand shifter that breaks so you could get a used one on ebay for £40-50 if you can wait.

 

[themosquitoking]

@burgesstribe I have a brand new right hand Ultegra shifter in my shop i think. Not sure if it's 6700 or not though, i'm pretty sure it's a ten speed one. If you can wait until monday for me to check i'm sure i can sort you out with a deal on it.

 

[burgesstribe]

@burgesstribe I have a brand new right hand Ultegra shifter in my shop i think. Not sure if it's 6700 or not though, i'm pretty sure it's a ten speed one. If you can wait until monday for me to check i'm sure i can sort you out with a deal on it.

@themosquitoking thanks very much for this offer. It seems like the issue may have resolved itself (or at least I can't replicate now) so for now, I'll see how I get on. Perhaps you can post anyway if it is 6700 RHS with a price, in case I do need it.

 

[burgesstribe]

Make sure the bolt that goes through the shifter and holds the mechanism together is not loose , you have to remove the shifter to locate the bolt underneath.
Had this happen on two L/H shifters 6700 ,unfortunately I lost the retaining nuts as I kept shifting on a ride .
The symptoms start as the bolt loosens and the ratchet does not line up with the pawl so you cant shift up .
Could be just wear and tear but my R/H shifter has 25000 miles on it and still shifts perfectly.

@Eddy thanks for the advice. Unfortunately, because I thought it was fixed with the new cables, I already wrapped the bar before it started going wrong again, so a bit of hassle to re-unwrap & check... and as it seems to be behaving again, I'll leave it wrapped & see if I can get away with it... but if not, I'll definitely take apart & check.

 

[burgesstribe]

All, thanks for the advice, much appreciated. When I went out today to try out ideas, I couldn't get the shifter to slip again (i.e. it worked 100%). I went out for a quick ride & again got perfect shifting (and so much smoother than it had been with my old, fraying cables!). So for now, I'll carry on riding & hope that it is resolved / isn't related to temperature or something else intermittent.

In case it helps others, I reckon that ratchet/pawl slip could be minimised by taking up some of the 'freeplay' between the outer (carbon, logo'd) lever & the inner metal lever that is attached to the mechanism, making sure to keep it over to the left from the saddle point-of-view (i.e. in direction of lever action). This could either be achieved by adding material to the metal lever or to the carbon lever, but probably to the metal lever is safer so as not to risk damage to the carbon (e.g. superglue on additional metal). If it starts slipping again and Eddy's advice on a loose bolt isn't the issue, I'll see if I can make this work & repost the results.