Problems with down-tube shifters

[ChrisF]

I have an ageing Dawes Galaxy with down-tube shifters. A few yeras ago one of the shifters broke and was replaced with a newish DuraAce set that a friend had to spare.. It's never been quite right since, but I didn't use the bike that much so didn't worry. Now I'm wanting to use the bike more, but the problems have got worse.
The front shifter isn't indexed, but it won't stay in position. I have tightened the 'nut' (actually a little folding handle) as much as I can, but it still slips fairly quicky and the cage moves towards the small ring, causing rubbing. I have taken it apart and cleaned off any grease on the parts, but the problem persists.
The rear shifter is 10 speed, as is the cassette, and is indexed, but it behaves as if it was an 8 or 9-speed shifter. Some single clicks result in a change of two cogs, or (much worse) halfway between two cogs. Other cogs of the range work fine. If I adjust the tension at the derailleur end, the problem persists but on a different pair of cogs.
I have tried releasing the cable from the derialliuer and pulling on the cable by hand as I click the shifter. It may be my imagination but it does feel as if some clicks are pulling the cable more than others.
I have taken this side apart as well; nothing looks broken inside. Maybe I just assembled it all incorrectly?

[slowster]

With regard to the front shifter, it sounds like you are experiencing what Brucey referred to as pull-back - see this post viewtopic.php?p=1472048#p1472048. This seems to be much more likely to occur with older frames with narrower, more flexible tubes. As detailed in my post after Brucey's in that thread, I cured the problem on my bike by fitting ratchet levers, which had more resistance than the Retrofriction levers I was using. It may be that the friction mechanism of a Dura Ace lever is not sufficient to resist the pullback of a flexible frame like the Galaxy.

As for the rear shifter, I suspect that the problem lies with the derailleur or the derailleur hanger, and that one or both are slightly out of alignment, and I imagine that any pullback will potentially make everything more sensitive to misalignment. I would try fitting a new/spare rear derailleur to begin with to see if that made a difference. If the hanger is out of alignment, you would probably do best to take it to a shop to fix.

https://www.parktool.com/en-int/blog/re ... -alignment

DIY methods here:

https://www.youtube.com/watch?v=TnwreRrorIA

https://www.youtube.com/watch?v=sWdO4dnu18g

[irc]

I find bar end shifters which are pretty much the same as downtube shifters to be very trick to index. It works but has to be absolutely spot on.

It is the same with both Shimano and Microshift 9 speed bar end shifters.

So as suggested I would check the gear hanger alignment as suggested.

Thereafter before adjusting the gear cable you need to make sure the stop screws are adjusted spot on. If the deraileur starts a fraction off then the first couple of changes might be OK but further up they could be off enough to give the problems you describe.

https://www.sheldonbrown.com/derailer-a ... l#indexing

[ChrisF]

Thanks for the suggestions.

Regarding pull-back, it seems Brucey's comments were in relation to a rear mech, not the front one. It my case, it seems like the front derailleur spring has too much tension, although that seems unlikely since it's the original and hence over 30 years old. Anyway I think I may have improved things by replacing a shakeproof washer that was underneath the tightening bolt - maybe the splines of the old washer had just flattened over time.

The rear changer is more complex. I have checked the hangar and the end-stops, and both appear to be set correctly. The critical observation is that it takes only seven clicks, not nine, to move from the smallest cog to the largest - so it appears that too much cable is being pulled per click. The final two clicks don't do anything.

Maybe I'll just go for new friction shifters https://www.sjscycles.co.uk/gear-shifte ... n-control/ - the original bike didn't have indexing anyway!

[slowster]

Pull-back is caused by the flex in the frame during the pedal stroke. It will affect derailleur cables equally whether they are for the front or rear derailleur. Variation in the impact of the pull-back will result from the differences between front and rear derailleurs, e.g. spring strength etc., and/or differences in the resistance of the shifters (LH friction vs. RH indexed).

The rear changer is more complex. I have checked the hangar and the end-stops, and both appear to be set correctly. The critical observation is that it takes only seven clicks, not nine, to move from the smallest cog to the largest - so it appears that too much cable is being pulled per click. The final two clicks don't do anything.

Check which side of the derailleur clamp bolt the cable is routed, and compare with Shimano's set up instructions for that derailleur (usually found online by searching for the derailleur model no. and the word 'manual'). Routing the cable to the other side of the clamp bolt alters the amount the derailleur moves for a given amount of cable pull.

[Audax67]

Shimano still make cable stops that fit over the pivot points for down-tube shifters. If all else fails you could fit a pair and a set of STIs on the bars. You might have negative fun matching the shifters to the cassette, though...

[bluespeeder]

Possibly a 7 spd shifter? My set up is 7spd shifter, 8 spd cassette, 9/10 spd rear mech which somehow works. I think the 7 spd shifter shifts more cable per click so the 9/10spd rear mech moves more than it would normally but this matches the 8spd cassette spacing.

[Steve]

I use Dura Ace 9 speed down tube levers and get a little bit of return in the left hand lever when climbing out of the saddle, but nothing I can't live with. Could be that something was missing from your set, if second hand.
Are you sure the rear cable and outer are in perfect condition? I take it you've tried to set up the indexing with chain on second sprocket in the first instance.

[531colin]

Possibly a 7 spd shifter? My set up is 7spd shifter, 8 spd cassette, 9/10 spd rear mech which somehow works. I think the 7 spd shifter shifts more cable per click so the 9/10spd rear mech moves more than it would normally but this matches the 8spd cassette spacing.

Except that there is no such thing as a 9/10 speed mech., thats exactly what I would expect with Shimano.
Apart from some exotica, 7,8 and 9 speed rear mechs. have the same cable pull, so you can mix levers and mechs.
It wasn't until 10 speed that Shimano "improved" it all so that you couldn't mix them up.
.....and many or most 7 sp shifters have an extra click or an extra bit of travel which suits 8 speed.
7 and 8 sp. cassettes have spacing which is close enough to the same to be interchangeable in use.

[drossall]

I have tightened the 'nut' (actually a little folding handle) as much as I can, but it still slips fairly quicky and the cage moves towards the small ring, causing rubbing.

Of course, you can put a screwdriver blade or similar into the loop (folding handle) and get a bit more leverage. I'd have looked first at the washer(s) to see whether the lever was one short or there was other slippage, but you've done that.

[slowster]

Further to my previous post, check likewise which side of the clamp bolt the cable is routed on the front derailleur. Routing the cable to the non-drive side of the bolt results in less tension on the cable, reducing the likelihood of the down tube lever slipping. It also increases the amount of cable pull required, but that is academic with a non-indexed shift.

[ChrisF]

Further to my previous post, check likewise which side of the clamp bolt the cable is routed on the front derailleur. Routing the cable to the non-drive side of the bolt results in less tension on the cable, reducing the likelihood of the down tube lever slipping. It also increases the amount of cable pull required, but that is academic with a non-indexed shift.

Yes, tried both sides, no apparent change. But... the rear mech is a Deore XT, maybe not compatible with the DuraAce shifter?

Possibly a 7 spd shifter?

The part number is mostly wiped off but it does have '10S' at the end (not '105' since it also definately says DuraAce!)

I use Dura Ace 9 speed down tube levers and get a little bit of return in the left hand lever when climbing out of the saddle, but nothing I can't live with. Could be that something was missing from your set, if second hand.
Are you sure the rear cable and outer are in perfect condition? I take it you've tried to set up the indexing with chain on second sprocket in the first instance.

The front lever was slipping even with hardly any pressure on the pedals, let alone out of the saddle.The rear cable is newish; the outer is very short anyway (just form the rear frame corner. I've tried all sorts of indexing adjustments, but it's not the beginning or the end that's the issue, it's that 7 clicks produces 9 shifts.

Thankyou for all your input.

[Bice]

Thanks for the suggestions.

Regarding pull-back, it seems Brucey's comments were in relation to a rear mech, not the front one. It my case, it seems like the front derailleur spring has too much tension, although that seems unlikely since it's the original and hence over 30 years old. Anyway I think I may have improved things by replacing a shakeproof washer that was underneath the tightening bolt - maybe the splines of the old washer had just flattened over time.

The rear changer is more complex. I have checked the hangar and the end-stops, and both appear to be set correctly. The critical observation is that it takes only seven clicks, not nine, to move from the smallest cog to the largest - so it appears that too much cable is being pulled per click. The final two clicks don't do anything.

Maybe I'll just go for new friction shifters https://www.sjscycles.co.uk/gear-shifte ... n-control/ - the original bike didn't have indexing anyway!

I am an enthusiast of downtube shifters, having them on 4 bikes. I particularly like these Suntour racketed but not indexed shifters, which I have on two bikes: https://www.ebay.co.uk/itm/203959396823 ... R-yvvqK2YQ

I use them on this tourer, first with 10-speed, but that did not work well:



The shifters were fine and shifted all the through the 10 gears, but keeping the chain on a particular gear was a problem: it would skip and try to shift. In other words, getting 10-speed friction shifting to be spot on was an issue.

I actually abandoned the idea. I replaced the 10-speed wheel with an eight speed one (could have just changed the cassette) and the shifting was frustration-free and enjoyable again. I guess the shifting did not have to be that precise in 8 speed. So I am dubious of friction shifting at more than 8 speed. I would be cautious at spending out on downtube friction shifters if you are set on 10 speed.

I like 10 speed, but have them with Shimano STI and Campagnolo Ergopower.

Shifting the triple front mech with Suntour friction shifters has been absolutely fine.

Although I have seven speed indexed downtube shifters on two bikes, I far prefer friction shifting with this few number of gears.

Others are helping sort the problem you have - of which I have no experience - but if it does not work, perhaps consider 8 speed friction.

[slowster]

the rear mech is a Deore XT, maybe not compatible with the DuraAce shifter?

Shimano 8 and 9 speed rear derailleurs have the same cable pull ratio for both road and MTB models. The cable pull ratio for Shimano 10 speed road rear derailleurs is the same.

Shimano 10 speed MTB rear derailleurs use a different cable pull ratio and are only compatible with 10 speed MTB shifters.

If you are happy to give up indexed rear shifting but want to continue to use your current rear derailleur and cassette, I would buy the Dia Compe levers below, which have a larger RH barrel to pull more cable, making it more suited to 11 speed and also to 10 speed MTB rear derailleurs. The ratchet mechanism in the LH lever should be better able to resist slipping compared to your Dura Ace friction lever.

https://www.sjscycles.co.uk/gear-shifte ... -shifters/

Alternatively, if you want indexed shifting and to keep your 10 speed down tube lever and 10 speed cassette, then you need to replace the derailleur with a 9 speed model, either road or MTB. I presume you would need an MTB model for the greater tooth capacity, e.g. one of the models below:

https://www.wiggle.co.uk/shimano-deore- ... 360539794&

https://www.sjscycles.co.uk/derailleurs ... nd=shimano

NB Some of the Shimano 9 speed MTB rear derailleurs do NOT have a barrel adjuster, so you would need to fit an inline cable adjuster or insert one of the adjusters below into the derailleur cable stop. I would want to avoid that if possible and fit a derailleur with a barrel adjuster, e.g. the RD-M591. It has slightly less tooth capacity than the later RD-M592 which lacks an adjuster.

https://www.sjscycles.co.uk/cables/jagw ... -per-pair/

[bluespeeder]

Possibly a 7 spd shifter? My set up is 7spd shifter, 8 spd cassette, 9/10 spd rear mech which somehow works. I think the 7 spd shifter shifts more cable per click so the 9/10spd rear mech moves more than it would normally but this matches the 8spd cassette spacing.

Except that there is no such thing as a 9/10 speed mech., thats exactly what I would expect with Shimano.
Apart from some exotica, 7,8 and 9 speed rear mechs. have the same cable pull, so you can mix levers and mechs.
It wasn't until 10 speed that Shimano "improved" it all so that you couldn't mix them up.
.....and many or most 7 sp shifters have an extra click or an extra bit of travel which suits 8 speed.
7 and 8 sp. cassettes have spacing which is close enough to the same to be interchangeable in use.

My mistake, RD6500 mech is 9 spd. I seem to remember about 4% spacing difference (5mm to 4.8mm) between 7 and 8 spd cassette so you dont notice if it is set up correctly in the middle of the cassette. I assume a 9spd cassette would be incompatible at 4.35mm spacing?