I have recently fitted a Shimano Tiagra front changer.
At first it worked perfectly, but after about 1500 miles it started to go 'stiff' at the little ring end of its travel.
I changed the cable, without really investigating the cause, because in my experience, cable gremlins are the usual cause of such problems.
However, the problem persists, and I cannot locate the cause. I have discussed the matter with my LBS (local bike shop), and they tell me that the problem is not unknown, and offer the comment that Shimano no longer grease parts when they are assembling components; the recommendation is that I flush it out and clean it as best I can, and ensure regular lubing.
I do keep my machine clean and lube it well and regularly, but after carrying out the above recommendation, and now after 2600 miles, the changer still does not operate properly.
To be fair, the occurance of the problem is erratic - it changes fully about 20% of the time, but usually My chain is rubbing on the changer cage when I am in little ring/big cog gear.
Has anyone else had this problem - has anyone solved it? My LBS suggests that stripping the mech down is probably the final investigation, but I find that reassembly becomes tricky at the stage of re-engaging the spring, even on the old Campag Record front changers, whicg were designed to be looked after.
JohnW
Shimano front changer
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reohn2
Hi John nice see you back on the boards,
I'm all Shimano and I've never had that problem(though haven't had that particular mech),what do you lube it with? I find GT85 because its so thin gets into anything.You mention stripping it down,I think you'll find that they're not made to be stripped as the pins are riveted.I suppose you could try soaking the whole mech in some very thin oil overnight,see if that does the trick.Its quite strange it not returning to the stop because the spring on a front mech is quite strong.
I'm all Shimano and I've never had that problem(though haven't had that particular mech),what do you lube it with? I find GT85 because its so thin gets into anything.You mention stripping it down,I think you'll find that they're not made to be stripped as the pins are riveted.I suppose you could try soaking the whole mech in some very thin oil overnight,see if that does the trick.Its quite strange it not returning to the stop because the spring on a front mech is quite strong.
Hello reohn - I was waiting to see if anyone else could help me from experience. Indeed the components are riveted - it was the LBS who suggested stripping down. I've tried flushing out the spring enclosure with WD40, and the lube that I use is "SUPERSPRAY LUBE" - it comes in a small aerosol stamped "Recommended by The British Cycling Federation" - it's a thin colourless but slightly milky lube which contains PTFE : I've used it for years. I'll have to give it some serious attention this weekend - the puzzling thing is that it works sometimes.
Hello georgew - I've not had a go at the adjustment screw, that's adjusted ok, in fact when the cage fails to make full travel, I can push it over into place with the finger. Having said that, there could be some gunge around the screw end.
The changer is at the low end of the Shimano range, winter bike fodder really - but it should work. I notice that you've had inconsistent changes too.
Regards all,
JohnW.
Hello georgew - I've not had a go at the adjustment screw, that's adjusted ok, in fact when the cage fails to make full travel, I can push it over into place with the finger. Having said that, there could be some gunge around the screw end.
The changer is at the low end of the Shimano range, winter bike fodder really - but it should work. I notice that you've had inconsistent changes too.
Regards all,
JohnW.
I have an LX f/mech that does something similar, and I thought it was knacked but I reckon it was just very caked with crud that had dried out. I took it off and cleaned it up, lubed it and manually worked it back and forth and it was right as rain until the next time I had to do it. Toothbrushes and degreaser, etc.
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thirdcrank
- Posts: 36781
- Joined: 9 Jan 2007, 2:44pm
This is more by way of commiseration than anything. What was once my best bike (bought 1980) has the then state-of-the-art Campag Super Record rear mech. It is 5/6 speed. I originally used it as 5, then got six (I do not think the term 'upgrade' had even been coined.) In spite of any amount of cleaning, adjustment etc., it can be very lazy about shifting onto the sixth (smallest) cog. It is not a range issue because with the stop moved, it can change right off the block. This is completely unpredictable and started happening when the bike was always reserved for good weather - it didn't just come on when it dropped down the hierarchy into year round use. It probably is no help at all but you are not alone.
This thing has happened to me, but only on mountain-bikes, when some particularly cementiferous mud has accumulated around the front mech.
I guess that road salt could likewise get into, corrode and stiffen the pivots of a road mech. I can only guess about that though, since all my road bikes have full rear mudguards.
Suggest take mech off bike, clean and soak in oil, then sit in front of telly working it to and fro, having first backed off the stops so it works in a range of movement even greater than you need. If you can work out which of the pivots causes the stiffness you might be able to ease it by inserting a screwdriver between the moving parts - or something.
Another thought: does your front gear cable, at the bottom-bracket, pass through a closed tube (rather than an open groove or channel) or a section of outer casing? Anything U-shaped and closed-in like that tends to accumulate grit, water and rust, and get awful sticky in bad weather. In cold weather the water in there may even freeze. That used to happen to me when I fitted my first front mech back in the 70s. Soon realised that a peice of outer casing with an upward-pointing end was a really bad idea!
I guess that road salt could likewise get into, corrode and stiffen the pivots of a road mech. I can only guess about that though, since all my road bikes have full rear mudguards.
Suggest take mech off bike, clean and soak in oil, then sit in front of telly working it to and fro, having first backed off the stops so it works in a range of movement even greater than you need. If you can work out which of the pivots causes the stiffness you might be able to ease it by inserting a screwdriver between the moving parts - or something.
Another thought: does your front gear cable, at the bottom-bracket, pass through a closed tube (rather than an open groove or channel) or a section of outer casing? Anything U-shaped and closed-in like that tends to accumulate grit, water and rust, and get awful sticky in bad weather. In cold weather the water in there may even freeze. That used to happen to me when I fitted my first front mech back in the 70s. Soon realised that a peice of outer casing with an upward-pointing end was a really bad idea!
Chris Juden
One lady owner, never raced or jumped.
One lady owner, never raced or jumped.
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ricardolamos
- Posts: 110
- Joined: 16 Jan 2007, 1:45pm
Lazy front mech
I agree with other comments in that front changers normally don't go wrong very often and the problem is most likely muck at some point or other.
Another point worth mentioning is that some Shimano mechs have an adjustment feature to enable you to alter how strongly the return spring operates.
If you have this feature,it may be worth checking it is on the max setting as this will ens.ure the mech pulls onto the little ring with most force.
Another point worth mentioning is that some Shimano mechs have an adjustment feature to enable you to alter how strongly the return spring operates.
If you have this feature,it may be worth checking it is on the max setting as this will ens.ure the mech pulls onto the little ring with most force.
I disassembled the offending front changer.
It is a triple, and of typical front changer construction with a cast alu main body which bands on to the seat tube, two parallelogram arms connecting the main body (both in alu) to the cage, which is of pressed steel. The bottom pivot points (at the cage) are riveted and the top pivots are made with allen-key bolts through the parallelogram arms into threaded holes in the main body. The return spring is on the bottom (riveted) pivot between the rear parallelogram arm and the cage, and the travel restriction feature is cast in to the top pivot between the main body and the front parallelogram arm. The travel restriction is actually totally cast in to the main body and the top of the parallelogram arm, and all you see from the outside is the heads of the grub-screws; this keeps the travel restriction mechanism concealed and protected from gunge, but makes de-gunging, if it becomes necessary, impossible without disassembling the whole changer.
When I removed the changer from the frame, it was so stiff that I couldn’t move it with my bare hands – there is no way that an ergo-shift system could have operated the mechanism - I still use down-tube friction levers on this bike. The spring was clear and quite free from gunge and operating freely.
I do look after my bikes and keep them clean (and, according to my wife, dearly loved), and there was no gunge on any part of the mech, and no apparent reason for the failure. I released the front arm pivot first, and that released the whole mechanism to operate freely. Removing the bolt was easy, but to take the mech apart one must also remove the top pivot bolt to the inner arm, which is also easy – no brute effort necessary. The initial evidence from this partial disassembly (partial because the bottom pivots are riveted) was that no grease had been used at any stage of the assembly, and whilst my own lubing had penetrated the rear pivot bearings, the front bearing surfaces were 50% bone dry, indicating just how tight the pivot bolt had been. It didn’t help either that the bearing faces were dog-rough, and I smoothed these off to give an even and polished bearing face to, hopefully, the whole of the intended bearing faces.
However, it seems to me that the basic problem is neither the bad finish to the bearing faces nor the lack of greasing at assembly, bad though these both are; the problem is that in tightening the top pivot bolt sufficiently to ensure that it does not slacken and unscrew itself in use, the bearings are tightened together so tight that they don’t move! The pivot bolt is threaded for only part of its length – it has an un-threaded shank between the threads and the bolt-head, which does form a very thin shoulder, but without a washer to engage on the shoulder and prevent it from tightening fully into the threaded hole in the main body, it simply tightens the bearing faces together.
I thought about and began to attempt my own solution. I’ve been seriously cycling for fifty years now - I rarely if ever throw anything away – and one would have thought that I would have had a suitable washer somewhere in a spares bucket, but I haven’t; the nearest was a little brass spoke-head washer (anybody remember these?) but even these are too big but too thin, the inner hole being too small but the outer diameter too great. The sheer time consuming bother of altering little brass washers didn’t seem to me to be worth the twenty quid that the perishing changer had cost me!!!! Another approach is the depth of the threaded hole in the main body – this is far greater than the length of the pivot bolt, and offered no restriction to the travel of the bolt into the hole. Theoretically, restriction of the depth to which the bolt would screw into the hole would allow the bolt to be fully tightened without over tightening the bearing faces. I thought of inserting something here, but we are talking of accuracy in microns and again probably more frustrating and time consuming that the cost of the changer is worth.
I also have a completely unused Shimano Ultegra triple changer; I compared this with the Tiagra, and the construction appears to be slightly different – certainly the basic defects noted on the Tiagra do not seem to be present on the Ultegra. I shall see how the Ultegra behaves before I make a total judgment on Shimano changers. My only previous Shimano front changer has been a Dura-Ace double changer, which I have had for about 25 years, in regular use, and never given any cause for concern – including the last ten years on winter/work bikes. Normally, I swear by Campag, but Campag no longer make band-on changers to fit 531/631 seat tubes.
I have now re-assembled the changer, but not tightened the top pivot bolt to its absolute fullest extent – I will do a few miles on it and keep an eye on it to see how it goes – if you are still interested I will report back.
My own conclusion is that the Taigra is either an inept design or that the fiendishly clever guys on the assembly line used some wrong components or missed something out (the Friday afternoon syndrome being international). CJ - the cable was running freely all the time, and went slack right up to the changer, and this was not the problem on this occasion; I don’t know whether you are in touch with the Shimano distributors (Madison Cycles I believe), but if you are, could you ask for their comments? I don’t have the option of returning the changer for replacement, having had a go at it myself, and in any case replacement with another Tiagra would have been pointless – I have learned a little by experience, and its cost me twenty quid.
My solution is to henceforth use Campag and buy one of the less-than-poser band-on brackets to fit the Campag to the seat-post.
OK chaps, is everybody bored stiff now? Any comments?
It is a triple, and of typical front changer construction with a cast alu main body which bands on to the seat tube, two parallelogram arms connecting the main body (both in alu) to the cage, which is of pressed steel. The bottom pivot points (at the cage) are riveted and the top pivots are made with allen-key bolts through the parallelogram arms into threaded holes in the main body. The return spring is on the bottom (riveted) pivot between the rear parallelogram arm and the cage, and the travel restriction feature is cast in to the top pivot between the main body and the front parallelogram arm. The travel restriction is actually totally cast in to the main body and the top of the parallelogram arm, and all you see from the outside is the heads of the grub-screws; this keeps the travel restriction mechanism concealed and protected from gunge, but makes de-gunging, if it becomes necessary, impossible without disassembling the whole changer.
When I removed the changer from the frame, it was so stiff that I couldn’t move it with my bare hands – there is no way that an ergo-shift system could have operated the mechanism - I still use down-tube friction levers on this bike. The spring was clear and quite free from gunge and operating freely.
I do look after my bikes and keep them clean (and, according to my wife, dearly loved), and there was no gunge on any part of the mech, and no apparent reason for the failure. I released the front arm pivot first, and that released the whole mechanism to operate freely. Removing the bolt was easy, but to take the mech apart one must also remove the top pivot bolt to the inner arm, which is also easy – no brute effort necessary. The initial evidence from this partial disassembly (partial because the bottom pivots are riveted) was that no grease had been used at any stage of the assembly, and whilst my own lubing had penetrated the rear pivot bearings, the front bearing surfaces were 50% bone dry, indicating just how tight the pivot bolt had been. It didn’t help either that the bearing faces were dog-rough, and I smoothed these off to give an even and polished bearing face to, hopefully, the whole of the intended bearing faces.
However, it seems to me that the basic problem is neither the bad finish to the bearing faces nor the lack of greasing at assembly, bad though these both are; the problem is that in tightening the top pivot bolt sufficiently to ensure that it does not slacken and unscrew itself in use, the bearings are tightened together so tight that they don’t move! The pivot bolt is threaded for only part of its length – it has an un-threaded shank between the threads and the bolt-head, which does form a very thin shoulder, but without a washer to engage on the shoulder and prevent it from tightening fully into the threaded hole in the main body, it simply tightens the bearing faces together.
I thought about and began to attempt my own solution. I’ve been seriously cycling for fifty years now - I rarely if ever throw anything away – and one would have thought that I would have had a suitable washer somewhere in a spares bucket, but I haven’t; the nearest was a little brass spoke-head washer (anybody remember these?) but even these are too big but too thin, the inner hole being too small but the outer diameter too great. The sheer time consuming bother of altering little brass washers didn’t seem to me to be worth the twenty quid that the perishing changer had cost me!!!! Another approach is the depth of the threaded hole in the main body – this is far greater than the length of the pivot bolt, and offered no restriction to the travel of the bolt into the hole. Theoretically, restriction of the depth to which the bolt would screw into the hole would allow the bolt to be fully tightened without over tightening the bearing faces. I thought of inserting something here, but we are talking of accuracy in microns and again probably more frustrating and time consuming that the cost of the changer is worth.
I also have a completely unused Shimano Ultegra triple changer; I compared this with the Tiagra, and the construction appears to be slightly different – certainly the basic defects noted on the Tiagra do not seem to be present on the Ultegra. I shall see how the Ultegra behaves before I make a total judgment on Shimano changers. My only previous Shimano front changer has been a Dura-Ace double changer, which I have had for about 25 years, in regular use, and never given any cause for concern – including the last ten years on winter/work bikes. Normally, I swear by Campag, but Campag no longer make band-on changers to fit 531/631 seat tubes.
I have now re-assembled the changer, but not tightened the top pivot bolt to its absolute fullest extent – I will do a few miles on it and keep an eye on it to see how it goes – if you are still interested I will report back.
My own conclusion is that the Taigra is either an inept design or that the fiendishly clever guys on the assembly line used some wrong components or missed something out (the Friday afternoon syndrome being international). CJ - the cable was running freely all the time, and went slack right up to the changer, and this was not the problem on this occasion; I don’t know whether you are in touch with the Shimano distributors (Madison Cycles I believe), but if you are, could you ask for their comments? I don’t have the option of returning the changer for replacement, having had a go at it myself, and in any case replacement with another Tiagra would have been pointless – I have learned a little by experience, and its cost me twenty quid.
My solution is to henceforth use Campag and buy one of the less-than-poser band-on brackets to fit the Campag to the seat-post.
OK chaps, is everybody bored stiff now? Any comments?
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thirdcrank
- Posts: 36781
- Joined: 9 Jan 2007, 2:44pm
A very interesting read.
I suppose the point is that the Japanese, especially Shimano, gave cycling a real kick up the bottom bracket in terms of advancing technology. Even their top quality stuff is not engineered to the same high quality as classic Campag (but is that really necessary when they are moving things along so quickly?) The Shimano approach brings the most sophisticated technology down to their cheapest equipment so something else must suffer. It seems inevitable to me that each step down from Dura Ace/XTR is going to involve compromises on quality. Otherwise, their cheapest stuff would be just as good as their most expensive.
I suppose the point is that the Japanese, especially Shimano, gave cycling a real kick up the bottom bracket in terms of advancing technology. Even their top quality stuff is not engineered to the same high quality as classic Campag (but is that really necessary when they are moving things along so quickly?) The Shimano approach brings the most sophisticated technology down to their cheapest equipment so something else must suffer. It seems inevitable to me that each step down from Dura Ace/XTR is going to involve compromises on quality. Otherwise, their cheapest stuff would be just as good as their most expensive.
Hello Thirdcrank - I think you're right, but is 2500 miles (its mileage this weekend when I stripped it down) reasonable for a front changer, and is such bad design or workmanship pushing the frontiers of cycle technology?
My experience is that Shimano performs very well indeed but soon wears out (with the exception of a Dura-Ace front changer, bought abaout 25 years ago, and has spent the last ten years on a winter/work/everything bike) - butr this was a duff item.
Regards,
JohnW.
P.S. will you be at Addingham?
My experience is that Shimano performs very well indeed but soon wears out (with the exception of a Dura-Ace front changer, bought abaout 25 years ago, and has spent the last ten years on a winter/work/everything bike) - butr this was a duff item.
Regards,
JohnW.
P.S. will you be at Addingham?
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thirdcrank
- Posts: 36781
- Joined: 9 Jan 2007, 2:44pm
I am never too sure about how long stuff used to last in the past. I started in 1958 age 13. My dear old Dad bought me what I now realise was an ancient second-hand Carlton. In those days, the absence of frequent technological advances meant that pretty much everything was compatible with everything else on a ‘lightweight’ bike. Bits and pieces were swapped about, rebuilt and so on. (Back to Trigger’s brush.) My memories of those days seem to involve a lot of buckled wheels. (I probably came off a lot more.) Many people stopped cycling through the winter and there was much less gritting of the roads. Fixed-wheel was pretty much universal in winter and quite widespread all the year round.
I think it is fair to say that Campag did for quality what the Japanese did for technology and a lot of pre-Campag stuff was junk whatever Hillary whatnot says. My views on brakes have been aired enough. The sort of old-fashioned derailleurs that seem to be reviewed regularly in Cycling + had a habit of ripping out all the spokes if a cable broke. Talking of spokes, I remember so-called ‘rustless’ spokes being rubbish. I think it is also fair to say that classic Campag was so expensive that most people cherished it and might not always have given it a lot of hammer. I was interested to read Groveller on the ‘I’d rather walk…’ thread say he had a Campag bike for summer and Shimano for winter.
I agree that 2,500 miles does not seem a long life for a double-clanger but on reflection I am not sure. Multiple bike ownership is now common among keen cyclists, which reduces the mileage on their individual bikes. Modern production is down-to-a-price and the tribologists (?) rule. For the sort of bike that is probably intended to last an occasional cyclist a few years till technology changes or they graduate to a motorbike, that might be a typical mileage. They do say more bikes are sold here than cars so an awful lot must languish at the back of garages. As you suggest, yours may be a particularly bad one. Nowadays, customers are often used as honorary quality control inspectors for many sorts of product.
I would be interested to know what some of the really big mileage riders – the ones who must ride a big mileage every day – use and what are their experiences of equipment durability. Probably too busy riding to bother.
I do know that the nine years between learning to ride a bike, and getting married when I nearly forgot, seemed to pass much more slowly than the nine years since I retired.
Unfortunately, neither Campag nor Shimano do ticker replacements. Mine is a 1944 Utility model and since it went on the blink my cycling has been curtailed, partly by Mrs A. ‘Cycling Weakly’ rather than ‘Cycling Weekly’ so I am out-of-form and out-of-touch and unlikely to be at any events.
I think it is fair to say that Campag did for quality what the Japanese did for technology and a lot of pre-Campag stuff was junk whatever Hillary whatnot says. My views on brakes have been aired enough. The sort of old-fashioned derailleurs that seem to be reviewed regularly in Cycling + had a habit of ripping out all the spokes if a cable broke. Talking of spokes, I remember so-called ‘rustless’ spokes being rubbish. I think it is also fair to say that classic Campag was so expensive that most people cherished it and might not always have given it a lot of hammer. I was interested to read Groveller on the ‘I’d rather walk…’ thread say he had a Campag bike for summer and Shimano for winter.
I agree that 2,500 miles does not seem a long life for a double-clanger but on reflection I am not sure. Multiple bike ownership is now common among keen cyclists, which reduces the mileage on their individual bikes. Modern production is down-to-a-price and the tribologists (?) rule. For the sort of bike that is probably intended to last an occasional cyclist a few years till technology changes or they graduate to a motorbike, that might be a typical mileage. They do say more bikes are sold here than cars so an awful lot must languish at the back of garages. As you suggest, yours may be a particularly bad one. Nowadays, customers are often used as honorary quality control inspectors for many sorts of product.
I would be interested to know what some of the really big mileage riders – the ones who must ride a big mileage every day – use and what are their experiences of equipment durability. Probably too busy riding to bother.
I do know that the nine years between learning to ride a bike, and getting married when I nearly forgot, seemed to pass much more slowly than the nine years since I retired.
Unfortunately, neither Campag nor Shimano do ticker replacements. Mine is a 1944 Utility model and since it went on the blink my cycling has been curtailed, partly by Mrs A. ‘Cycling Weakly’ rather than ‘Cycling Weekly’ so I am out-of-form and out-of-touch and unlikely to be at any events.