One for the mechanics out there.

Napalm100

We have a number of bikes in the shop that I work in with some real shifting issues.

We have two Cannondale Super6's, one Trek Domane and one Chinese carbon frame, none of which will shift properly.

Three different mechanics have tried various things on the bikes so it isn't just me and between us we have nearly 25 years experience. We have tried various combinations of new chains, cassettes, cables, Rear mechs, STI levers, mech hangers and still nothing seems to work. One the Trek we even got a replacement frame from Trek to try.

The main symptoms seem to be that the initial shift from 10th to 9th is very sluggish (if at all) and then one all the way up to 1st it will take two shifts to bring it back to 2nd. Or vice versa but never both ways as it should.

These bikes seem to have nothing in common other than they all use Shimano of some sort, but they are either 105, Ultegra or a mix of the two. The Cannondales and the Trek are externally routed and the Chinese carbon is internally routed. All are 10 speed. :?

We have had two of the bikes shifting correctly if we run a full length piece of outer cable from the shifter to the rear mech without going through the frame.

The only way we got the Trek to work was by fitting a very basic Shimano Arcera MTB mech and the shifting was perfect!

Has anyone experienced anything similar to this before and if so do you know of any solutions? We really are starting to tear our hair out over this one. :x

Any sensible suggestions welcome.

Thanks

Anthony

BillyMansell

The 10th to 9th issue sounds like some slack cable tension and if that's not right to start with then it can cause shifting problems across the whole of the cassette that you can't then trim out.

Firstly put it into 10th and set the cable tension so the mech is 'eager' to shift up. Then when you go up and down the cassettes try trimming the cable adjustment for smooth shifts.

Napalm100

Its not cable tension. Like I said we've done enough bike builds and repairs to know it certainly isn't the basics like cable tension but thanks for the suggestion.

taon24

Something up with the cable outers? The fact that full length outer cable solved the problems would make me suspicious. What happens if you replace all the outers with really nicely cut and maintained ones?

majormantra

I had a real head scratcher on a bike with internal cabling, which I solved when I realised the cables must have been crossed inside the frame. This mean you could set up the shifting perfectly in one or other chainring, but not both, because the two cable tensions were affecting each other.

I'm struggling to believe all these bikes have the same issue though, unless they've all got some cabling feature (e.g. missing ferrules at the shifter) in common.

Napalm100

All have had brand new cables with good ferrules fitted throughout.

On the internally routed one I thought it might be something to do with the BB guide in the frame but everything is smooth and doesn't snag anywhere.

jermas

It definitely sounds like a cable problem. Have you tried PTFE or polymer coated inner cables? Polymer for 9000 series.

The Mechanic

Strange. Mind you, I have part of that problem in one of my bikes with Ultegra 6700 shifters. It will not shift from the biggest sprocket to the next one on the cassette. I have to go up two gears and then back down one to get the second largest sprocket. I have tried everything I can possibly think of and, otherwise, everything works perfectly. My other bike, a new Felt Z4, also with 6700 , works perfectly throughout the range.

with your problem Mr Firestorm, could it be that the mech hangers are out of alignment. I know you said you have tried new hangers but maybe the new one is still out due to the frame being slightly out. I guess you may have already checked the alignment.

Barrie_g63

if you've tried all possible combinations of changing, shifters, mechs, cables and outers it must be something to do with the frames, cables getting too much friction at the stops maybe, or a poor batch of outer causing friction on the cables, try stripping a good system from another bike and fitting to one of the problem bikes and see how it works on the problem bike

6wheels

Hi Anthony,

After trying all the straight forward checks/changes, I would want to get a lot more technical.

For me, the next move would be to check/measure the pull and drop of the shifters. You would have to set up a reference point close to the rear mech and measure the distance of each pull (probably off the rear mech roller cage) and off each drop. You should be able to do this with a vernier or dial gauge. If the pull and drop movements are within tolerance ( Shimano for spec) , you are fairly certain all is good up to the rear mech and need to look at everything beyond that point , even chainrings/bb. If the tolerances are out , obviously , you need to chase everything up to and including the shifters.

Hope this helps, and it will be interesting to hear what the solution is, maybe Shimano have a made bad batch of components ( any common denominators?).

Garryboy

Derailleur hanger alignment? - know it's a simple one, but haven't seen it mentioned.
Can be out even on new bikes or new hangers...

imposter2.0

I had a similar problem once and traced it to the cable run around the bars being too tight. Turned out the cable outer had to turn much too sharply around the bend in the bar, meaning that the cable itself was not running smoothly enough through the outer, around that corner.

I think I got round it eventually by running the cable outer around the outside edge of the bar, rather than the tighter inside edge.

crankycrank

Imposter wrote:

I had a similar problem once and traced it to the cable run around the bars being too tight. Turned out the cable outer had to turn much too sharply around the bend in the bar, meaning that the cable itself was not running smoothly enough through the outer, around that corner.
I think I got round it eventually by running the cable outer around the outside edge of the bar, rather than the tighter inside edge.

This seems to be a common problem with some of the first Shimano under bar tape cable groups. Has the OP tried shifting with the bar tape removed but everything else setup as normal? If on two of the bikes the problem was solved with just using full length housing I would look to something all along the cable routing that could be causing some drag. When cutting off the ends of housing, especially where it enters the shifters, make the cut while applying a similar bend to the housing. If cut with the housing straight the inner strands of the housing curve will protrude farther out the end than the outer strands which may fecker up the shifting.

trooperk

If your cables and BB guide is lubed then wipe clean and use a different type or brand of grease/oil, maybe not use any lube at all on the BB cable guide after washing it clean.

raymond82

Just to add an option, I've had something similar which in the end was caused by a washer too few (or too many, I don't really remember) at the hub and therefore a misalignment of the cassette.

Napalm100

Barrie_g63 wrote:

if you've tried all possible combinations of changing, shifters, mechs, cables and outers it must be something to do with the frames

We had a new frame for the Trek and it didn't make the slightest bit of difference, Thanks

Garryboy wrote:

Derailleur hanger alignment? - know it's a simple one, but haven't seen it mentioned.
Can be out even on new bikes or new hangers...

Yes I did all of this, Thanks

Imposter wrote:

I had a similar problem once and traced it to the cable run around the bars being too tight. Turned out the cable outer had to turn much too sharply around the bend in the bar, meaning that the cable itself was not running smoothly enough through the outer, around that corner.

I think I got round it eventually by running the cable outer around the outside edge of the bar, rather than the tighter inside edge.

Worth a try, Thanks

crankycrank wrote:

This seems to be a common problem with some of the first Shimano under bar tape cable groups. Has the OP tried shifting with the bar tape removed but everything else setup as normal? If on two of the bikes the problem was solved with just using full length housing I would look to something all along the cable routing that could be causing some drag. When cutting off the ends of housing, especially where it enters the shifters, make the cut while applying a similar bend to the housing. If cut with the housing straight the inner strands of the housing curve will protrude farther out the end than the outer strands which may fecker up the shifting.

Yes, we've tried shifting without fitting the bar tape. all of our cables are lined and I always make sure to run something like a fine screwdriver down the cable to make sure each cut is free running.

raymond82 wrote:

Just to add an option, I've had something similar which in the end was caused by a washer too few (or too many, I don't really remember) at the hub and therefore a misalignment of the cassette.

That shouldn't make any difference, so long as all of the spacers are correct in the cassette then it doesn't matter what position the cassette is in, so long as it is not so inboard that the chain is being overly twised to reach 1st gear.

mattv

Are they all larger frames? I've seen a few larger (58 or 61) frames do this now. It's simply flex in the frame.... Use shimano outer only if you get these problems, that's all you can do.

chrisw12

Since we're all chucking suggestions in. As said above try different routing around the bars, crossing the cables as discussed in other threads on here can help I've found. Also extending the length of housing going into the rear mech can help, try a much bigger loop. These have all helped sloppy shifting in my limited experience.

Please post the solution if you find it and don't leave this thread hanging as so many do. It could be quite informative for future reference.

Napalm100

chrisw12 wrote:

Since we're all chucking suggestions in. As said above try different routing around the bars, crossing the cables as discussed in other threads on here can help I've found. Also extending the length of housing going into the rear mech can help, try a much bigger loop. These have all helped sloppy shifting in my limited experience.

Please post the solution if you find it and don't leave this thread hanging as so many do. It could be quite informative for future reference.

The only problem with the routing round the bars is that one of the bikes is running older 105 (5600 series) STI levers which don't route under the tape at all.

I'll post the solution if I find one!

penguin_of_death

Had something similar with an internally routed Quintana where one of the metal plugs in the frame that the gear cable outer went into had a grove worn into it that caused drag on the inner that was most noticeable in higher gears

ride_whenever

Have you tried a shimano cable set??? Or are the ferrules all really snug in everything. The fact you've got this issue on all the bikes suggests you/your setup might be causing. (Don't take that the wrong way, but it's kinda the only link)

If you've replaced everything then it's something your done or used, if it's all shimano gear then...

Napalm100

Penguin of Death wrote:

Had something similar with an internally routed Quintana where one of the metal plugs in the frame that the gear cable outer went into had a grove worn into it that caused drag on the inner that was most noticeable in higher gears

I had another look at the internally routed bike, specifically the cable lugs and I too found a slight mark on the inside edge where there was a tiny bit of rub. All filed off now, just need to check inside the frame for any snags.

Napalm100

ride_whenever wrote:

Have you tried a shimano cable set??? Or are the ferrules all really snug in everything. The fact you've got this issue on all the bikes suggests you/your setup might be causing. (Don't take that the wrong way, but it's kinda the only link)

If you've replaced everything then it's something your done or used, if it's all shimano gear then...

Three of us have had a go now and at least 2 of us have recabled it. I have used these cables on hundreds of customers bikes as well as my own and never had an issue.

ride_whenever

What bikes do you usually do? 10 speed stuff is a lot more finicity than the lower speed stuff .

If you've got new cassettes, chains, hangers, sti's, and multiples mechanics then cables or some part of the cable system

Napalm100

ride_whenever wrote:

What bikes do you usually do? 10 speed stuff is a lot more finicity than the lower speed stuff .

If you've got new cassettes, chains, hangers, sti's, and multiples mechanics then cables or some part of the cable system

We work on everything from klunkers to £300 mtb's, and this week alone I've done 3 separate £5k+ road bikes.

I've had one idea that I want to try: all of the bikes are fitted withe the newer mechs designed to fit up to 30tooth cassettes. While all the bikes ARE less than 30t I'm going to try a 32t max rear mech to see if that makes a difference.

mattv

I mentioned earlier, we have noticed exactly this issue before. 6700 groups. Shimano outer cured it mostly, although one was frame flex. We now have a roll of Shimano outer fir just such picky bikes.

ride_whenever

If you wind both stops right out can you adjust it to shift? Possibly try indexing without the chain on if there is a reusable quick link???

Also any b-screw fiddling???

Napalm100

mattv wrote:

I mentioned earlier, we have noticed exactly this issue before. 6700 groups. Shimano outer cured it mostly, although one was frame flex. We now have a roll of Shimano outer fir just such picky bikes.

Mattv, the 4mm with the silicone grease? Its worth a shot. Cheers

mattv

Yup, the SP41. Same price RRP as Clarks etc, but way stiffer.

fosst

I have been here before....the 6700/5700 series doesn't particularly like mixing with 6600/5600 especially the *700 shifters with *600 mechs, it can work with some careful setting up But sometimes it just won't. Try to get matching shifters and mechs from the same series ( Ultegra mixed with 105 is fine as long as they are *700).
I always use Shimano (DA)or Jagwire (racer kit) cables and never noticed a difference
If all else is fine then fit a chain in small/small and back the tension right off. Initially fit the chain uncut, go very carefully on a workstand but it should work straight off. Go for the longest chain you can get away with and the least possible tension.

Napalm100

Just to clarify here are the specs of the bikes we have:

1. Cannondale Super Six - Shimano 105 (5700) levers and rear mech.
2. Cannondale Super Six - Shimano 105 (5700) rear mech, 105 (5600) STI levers.
3. Trek Domane 2.3 - Shimano 105 (5700) levers and mech.
4. Chinese Full Carbon - Shimano Ultegra (6700) levers and mech.