I am putting together an tourer/gravel/utility bike based around a 1989 Raleigh Appalachian MTB frameset. The chainset I intend to use has been cobbled together from a Stronglight Impact crank, with 42-34-26 chainrings. None of these rings have any shifting aids (ramps, pins, shortened teeth etc). They were chosen because they were in my box, are the correct BCD and create a semi-sensible set of ratios. I think the 34 middle ring is designed to be the inner ring on a 10 speed compact double.
The front mech I wish to use is a Shimano 700CX (FD-C700) triple. Bottom bracket is a 110mm UN-55, which gives a chainline of roughly 45mm to the centre of the middle ring.
My intention is to go with a nine speed transmission and I harboured faint hopes that by modifying the cable mount on the mech as described by Chris Juden here it might work with the pair of Tiagra 4400 STIs I have knocking about. However, I think the plain rings on the chainset make that highly unlikely.
So, my question is: how likely is it that the front shifting will be ok with a friction (bar end) shifter? When I operate the front mech by hand (admittedly with a bone dry nine-speed chain running on 10 speed rear wheel with someone else operating the rear mech by hand!) it doesn't look promising. The range of the mech is no problem, but it seems very reluctant to downshift from the middle to small ring.
I ask because the nine-speed bar end shifters aren't cheap and if it's not going to work well, it might be better to go with a different chainset/chainrings and use the Tiagra shifters.
I'm quite open to different options for how this bike turns out, but using WTIH rather than buying new bits is a priority...
Edit: Looking at the photo of the Stronglight Impact triple on Spa's website, the chainrings it comes with don't seem to have any shifting aids.
Triple chainset with no shifting aids on the chainrings
Re: Triple chainset with no shifting aids on the chainrings
Shifting from middle to small ring does not involve ramps even on chainrings that have them. The ramps are for going up the chainring sizes.
If you lack the bar end lever a down tube lever could fill that role temporarily, just to test the principle. You are very much more likely to get that lot working with a friction bar end lever than with STIs, so I am sure you are going about it the best way.
If you lack the bar end lever a down tube lever could fill that role temporarily, just to test the principle. You are very much more likely to get that lot working with a friction bar end lever than with STIs, so I am sure you are going about it the best way.
Re: Triple chainset with no shifting aids on the chainrings
Most of my riding over the decades was on a Stronglight 99.
No ramps at all.
Double and triple 6sp and 7sp with friction DT levers.
I never got ramps until I was dragged kicking and screaming into indexed 9sp
Even now, on my 10sp triple Moulton, I changed the outer ring on the triple to one without ramps. No issues at all.
No ramps at all.
Double and triple 6sp and 7sp with friction DT levers.
I never got ramps until I was dragged kicking and screaming into indexed 9sp
Even now, on my 10sp triple Moulton, I changed the outer ring on the triple to one without ramps. No issues at all.
Mick F. Cornwall
Re: Triple chainset with no shifting aids on the chainrings
I couldn't find much info on the mech with a quick search.
However, it dates from early/mid 1990's, and is for hybrid bike use. I'd say the odds are it is designed for 48t outer rings (but might be wrong). This means you might have to mount the mech too high for decent down shifting.
NB Too high because:
1. The cage might foul the chainstay before the mech is low enough.
2. The inner cage plate might foul the middle ring before the mech is low enough.
Using a friction lever would help get round this to some extent as you can over shift the lever to some extent (harder into the small ring due to L screw adjustment).
However, it dates from early/mid 1990's, and is for hybrid bike use. I'd say the odds are it is designed for 48t outer rings (but might be wrong). This means you might have to mount the mech too high for decent down shifting.
NB Too high because:
1. The cage might foul the chainstay before the mech is low enough.
2. The inner cage plate might foul the middle ring before the mech is low enough.
Using a friction lever would help get round this to some extent as you can over shift the lever to some extent (harder into the small ring due to L screw adjustment).
Re: Triple chainset with no shifting aids on the chainrings
Ok, thanks. Perhaps I had the inner limit screw screwed too far in, and I'll experiment with the height of the FD. I did set it quite low, just clearing the big ring.
Thinking about it, I might have a pair of band-on Suntour DT shifters somewhere, which I can use to test the whole system properly. Maybe I'll keep them on, although I was originally aiming for indexed rear shifts and bar-mounted shifters...
Thinking about it, I might have a pair of band-on Suntour DT shifters somewhere, which I can use to test the whole system properly. Maybe I'll keep them on, although I was originally aiming for indexed rear shifts and bar-mounted shifters...
Re: Triple chainset with no shifting aids on the chainrings
Shifting-wise I have been through almost this exact scenario and en route I made the following observations (in no particular order);
1) the bigger the interval between middle and big, the worse the middle to small shift becomes
2) if the middle ring has a skip (truncated, largely missing) tooth this may help the downshift.
3) chains vary in their side-plate shaping and flexibility, and this makes a difference.
4) 9s chain (and higher) is 11/128" rather than 3/32", so whilst it will run on 8s chainrings, some shifts will be adversely affected and this will be the first (and worst affected) one. This is just a 1/128" difference.
5) tooth top shape has an effect on this shift
6) used chainrings can behave anomalously (better or worse), due to tooth wear.
Of the six things above, it seems to me that 4) was easily the most significant. 1/128" seems like virtually nothing, and it is, it is not even 20microns, quite, (less than eight thou, in inches). Yet it is part of the lateral clearance between the chain and the teeth, and if a modern chain can't twist on the teeth, it will be most reluctant to start to derail. Derailing is important here, because unlike rear downshifts certainly, possibly all rear shifts, and unlike front upshifts, all of which rely on the chain catching on another sprocket to initiate the shift, only derailing is of any significance in this shift.
The middle to small shift is very often the first one to go bad, when things are not quite right. [The other commonly troublesome shifts are the upshifts; middle to big shift and small to middle shift; both these shifts are always made worse by a smaller middle ring and are likewise improved by a larger middle ring.]
1) occurs because the chain is being pushed at an increasing distance.
2) encourages the chain to derail. If you are going to modify a chainring, making two teeth (one in line with each crank) about half the original height may do the job, and probably won't do any harm. If you have an odd number of teeth on the middle ring, you can't go wrong. But if you have an even number they arguably shouldn't be exactly opposite to one another. The reason is that derailing is or isn't made easier depending on whether the short tooth sits between inner or outer side plates. With an odd number of teeth, you always get one of each, but with even teeth, and modified teeth exactly opposite one another, you get two of one sort and none of the other. Further elaborations to tooth shaping are relieving the RH side of the two teeth immediately preceding the short tooth, diagonal side chamfers on the short tooth (and its immediately preceding neighbour) as well as chamfering the LH side of the shortened tooth.
3) Shaped inner side plates are (within limits) designed to help the chain stay on any one chainring. {Without this, the slightest misalignment of the RD would lead to chattery running at the rear]. By contrast shaped outer side plates are designed to help the shifts onto a neighbouring chainring or sprocket which is of comparable or larger size, by engaging with the destination sprocket. In other words waist features on the inner side plates are 'anti-derailing' and features on the outer side plates encourage shifting onto neighbouring sprockets, so are (if you like) 'enrailing' features. In the case of the middle to small shift, the outer side plates are virtually irrelevant. Chains vary in their shaping somewhat. In the case of my 'problem shift' it was worst with a SRAM chain and was much better with a KMC or Taya chain. Whether this was exclusively because of side-plate shape differences or whether there were also tiny differences in absolute clearances I'm not certain. Also chains which are more flexible also discourage derailing.
4) surprised me. I did some measuring and it turns out that 6/7/8s chainring teeth are about 0.1 or 0.15mm fatter than 9/10s chainring teeth. So normally there is about 0.2mm lateral clearance between chain and chainring teeth (more I think in some MTB setups, presumably because of mud) which means that 11/128" chain will run on any chainring, but it won't want to shift on and off 6/7/8s chainring teeth. So on the workstand, some chainrings seem to work OK, but on the road, the slightest tension in the chain can make a front downshift terribly baulky with 9s chain where it goes perfectly with 8s chain.
5) tooth top shape affects the shift e.g. because the chain (inner) side plates have to snag on something to initiate derailing. If a chainring is intended to be a double inner it may have different tooth top chamfers vs the middle ring of a triple. So for example chamfers on the RHS of the inner chainring teeth (of a double) may help avoid a dropped chain but will likewise actively inhibit the middle to small shift if the same chainring is used as the middle ring of a triple.
6) side wear can make teeth on used 6/7/8s chainrings thin enough that they work OK with 11/128" chain when really they shouldn't. Some MTB chainrings may start out thinner anyway (as well as mud clearance, IG chain compatibility -or not- may have had something to do with this...?). The flip side is that some chainrings 'flare' slightly at the most loaded point and this makes the chain a tighter fit on the teeth than normal, which affects the middle to small shift more than any other.
[In point of fact shift-wise there is usually no reason worn (non-flared) 8s double chainrings can't be used with 11/128" chain; the chainring shifts are likely to be only slightly worse than normal on a double. The thing that usually trips you up is that the external width of the chain is narrower too and this leads to the possibility that the chain will sit on top of the small ring, 'in the gap' between the inner and outer chainrings, if you like. This remains a problem in modern road transmissions, such that in 10/11s transmissions, you can't always pair chainrings arbitrarily; the dishing of the big ring is slightly different depending on which inner chainring it is designed to work with and in some cases the inner chainring of a double is laterally offset differently too.]
So given all the variables it is always worth trying an unknown chainset with a narrower chain and just seeing what happens; sometimes it works OK even when it perhaps shouldn't. If you hit problems, most likely it will be with the shifts involving the middle ring; my suggestion is that you get the Vernier calipers out and measure the chainring teeth carefully, comparing them with teeth on chainrings which (with the same chain) do shift well, and act accordingly. Experiment with different chains and see what difference it makes. Past that you are looking at using a larger middle ring (or a smaller outer I suppose, this too will bring the FD closer to the middle ring), and/or modified tooth shapes.
In many cases a simple solution is to buy a new 9/10s chainring (of good quality, like a TA one) which is definitely meant to be a middle ring on a triple, rather than the inner of a double, and is likewise definitely meant for use with the internally narrower 11/128" chain. I have a feeling that not every chainring which is sold as '9s compatible' actually has narrow enough teeth to work well as the middle ring in a triple.
hth
cheers
1) the bigger the interval between middle and big, the worse the middle to small shift becomes
2) if the middle ring has a skip (truncated, largely missing) tooth this may help the downshift.
3) chains vary in their side-plate shaping and flexibility, and this makes a difference.
4) 9s chain (and higher) is 11/128" rather than 3/32", so whilst it will run on 8s chainrings, some shifts will be adversely affected and this will be the first (and worst affected) one. This is just a 1/128" difference.
5) tooth top shape has an effect on this shift
6) used chainrings can behave anomalously (better or worse), due to tooth wear.
Of the six things above, it seems to me that 4) was easily the most significant. 1/128" seems like virtually nothing, and it is, it is not even 20microns, quite, (less than eight thou, in inches). Yet it is part of the lateral clearance between the chain and the teeth, and if a modern chain can't twist on the teeth, it will be most reluctant to start to derail. Derailing is important here, because unlike rear downshifts certainly, possibly all rear shifts, and unlike front upshifts, all of which rely on the chain catching on another sprocket to initiate the shift, only derailing is of any significance in this shift.
The middle to small shift is very often the first one to go bad, when things are not quite right. [The other commonly troublesome shifts are the upshifts; middle to big shift and small to middle shift; both these shifts are always made worse by a smaller middle ring and are likewise improved by a larger middle ring.]
1) occurs because the chain is being pushed at an increasing distance.
2) encourages the chain to derail. If you are going to modify a chainring, making two teeth (one in line with each crank) about half the original height may do the job, and probably won't do any harm. If you have an odd number of teeth on the middle ring, you can't go wrong. But if you have an even number they arguably shouldn't be exactly opposite to one another. The reason is that derailing is or isn't made easier depending on whether the short tooth sits between inner or outer side plates. With an odd number of teeth, you always get one of each, but with even teeth, and modified teeth exactly opposite one another, you get two of one sort and none of the other. Further elaborations to tooth shaping are relieving the RH side of the two teeth immediately preceding the short tooth, diagonal side chamfers on the short tooth (and its immediately preceding neighbour) as well as chamfering the LH side of the shortened tooth.
3) Shaped inner side plates are (within limits) designed to help the chain stay on any one chainring. {Without this, the slightest misalignment of the RD would lead to chattery running at the rear]. By contrast shaped outer side plates are designed to help the shifts onto a neighbouring chainring or sprocket which is of comparable or larger size, by engaging with the destination sprocket. In other words waist features on the inner side plates are 'anti-derailing' and features on the outer side plates encourage shifting onto neighbouring sprockets, so are (if you like) 'enrailing' features. In the case of the middle to small shift, the outer side plates are virtually irrelevant. Chains vary in their shaping somewhat. In the case of my 'problem shift' it was worst with a SRAM chain and was much better with a KMC or Taya chain. Whether this was exclusively because of side-plate shape differences or whether there were also tiny differences in absolute clearances I'm not certain. Also chains which are more flexible also discourage derailing.
4) surprised me. I did some measuring and it turns out that 6/7/8s chainring teeth are about 0.1 or 0.15mm fatter than 9/10s chainring teeth. So normally there is about 0.2mm lateral clearance between chain and chainring teeth (more I think in some MTB setups, presumably because of mud) which means that 11/128" chain will run on any chainring, but it won't want to shift on and off 6/7/8s chainring teeth. So on the workstand, some chainrings seem to work OK, but on the road, the slightest tension in the chain can make a front downshift terribly baulky with 9s chain where it goes perfectly with 8s chain.
5) tooth top shape affects the shift e.g. because the chain (inner) side plates have to snag on something to initiate derailing. If a chainring is intended to be a double inner it may have different tooth top chamfers vs the middle ring of a triple. So for example chamfers on the RHS of the inner chainring teeth (of a double) may help avoid a dropped chain but will likewise actively inhibit the middle to small shift if the same chainring is used as the middle ring of a triple.
6) side wear can make teeth on used 6/7/8s chainrings thin enough that they work OK with 11/128" chain when really they shouldn't. Some MTB chainrings may start out thinner anyway (as well as mud clearance, IG chain compatibility -or not- may have had something to do with this...?). The flip side is that some chainrings 'flare' slightly at the most loaded point and this makes the chain a tighter fit on the teeth than normal, which affects the middle to small shift more than any other.
[In point of fact shift-wise there is usually no reason worn (non-flared) 8s double chainrings can't be used with 11/128" chain; the chainring shifts are likely to be only slightly worse than normal on a double. The thing that usually trips you up is that the external width of the chain is narrower too and this leads to the possibility that the chain will sit on top of the small ring, 'in the gap' between the inner and outer chainrings, if you like. This remains a problem in modern road transmissions, such that in 10/11s transmissions, you can't always pair chainrings arbitrarily; the dishing of the big ring is slightly different depending on which inner chainring it is designed to work with and in some cases the inner chainring of a double is laterally offset differently too.]
So given all the variables it is always worth trying an unknown chainset with a narrower chain and just seeing what happens; sometimes it works OK even when it perhaps shouldn't. If you hit problems, most likely it will be with the shifts involving the middle ring; my suggestion is that you get the Vernier calipers out and measure the chainring teeth carefully, comparing them with teeth on chainrings which (with the same chain) do shift well, and act accordingly. Experiment with different chains and see what difference it makes. Past that you are looking at using a larger middle ring (or a smaller outer I suppose, this too will bring the FD closer to the middle ring), and/or modified tooth shapes.
In many cases a simple solution is to buy a new 9/10s chainring (of good quality, like a TA one) which is definitely meant to be a middle ring on a triple, rather than the inner of a double, and is likewise definitely meant for use with the internally narrower 11/128" chain. I have a feeling that not every chainring which is sold as '9s compatible' actually has narrow enough teeth to work well as the middle ring in a triple.
hth
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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9494arnold
- Posts: 1208
- Joined: 21 Jan 2007, 3:13pm
Re: Triple chainset with no shifting aids on the chainrings
I have run Stronglight 80/90/100 and SR Apex triples on machines, no ramps on the rings, no issues.
Have run a trike and 2 bikes with bar end shifters to the front Mech, again no issues.
Suntour Ratchet non indexed bar end shifters are the business, love them.
(A lot of racing fraternity used to use Suntour Ratchet down tube shifters in preference to Campagnolo 'in the day' ,before index gears became the 'norm' , Campag levers had a nasty tendency to slip')
If you have something you think is an 'inner' you want to use as middle, just check the area below the teeth, I have seen an odd chainring that more of a shoulder at the 'back' , which wouldn't help if you are trying to unship the chain to another ring. Probably rare but worth checking.
Have run a trike and 2 bikes with bar end shifters to the front Mech, again no issues.
Suntour Ratchet non indexed bar end shifters are the business, love them.
(A lot of racing fraternity used to use Suntour Ratchet down tube shifters in preference to Campagnolo 'in the day' ,before index gears became the 'norm' , Campag levers had a nasty tendency to slip')
If you have something you think is an 'inner' you want to use as middle, just check the area below the teeth, I have seen an odd chainring that more of a shoulder at the 'back' , which wouldn't help if you are trying to unship the chain to another ring. Probably rare but worth checking.
Re: Triple chainset with no shifting aids on the chainrings
My experience too.9494arnold wrote:I have run Stronglight 80/90/100 and SR Apex triples on machines, no ramps on the rings, no issues.
I think ramps and pins make for crisper changes much required by the racing fraternity perhaps.
We mere mortals don't need them IMHO.
Mick F. Cornwall
Re: Triple chainset with no shifting aids on the chainrings
Great, many thanks. Love this forum!
The decision to go nine speed was really based on the fact that I had the Tiagra shifters and the availability of the BS-77 bar end shifters. If I'm not using either of those, I can use an eight speed chain and cassette.
I don't currently have suitable wheels, so tests will have to be done on the stand-only with a 700c wheel, but I'll see what happens and report back.
On the subject of DT shifters, it turns out I have both Shimano 600 and Suntour ratchet in band-on form. The Shimanos look sleeker and more in keeping with the early-nineties XT/LX Shimano kit (cantis, rear mech) that I'll be using, but the ratcheting of the Suntours sounds good. Obviously there's no pip on the downtube to stop the shifters sliding down, so that might be a problem.
The decision to go nine speed was really based on the fact that I had the Tiagra shifters and the availability of the BS-77 bar end shifters. If I'm not using either of those, I can use an eight speed chain and cassette.
I don't currently have suitable wheels, so tests will have to be done on the stand-only with a 700c wheel, but I'll see what happens and report back.
On the subject of DT shifters, it turns out I have both Shimano 600 and Suntour ratchet in band-on form. The Shimanos look sleeker and more in keeping with the early-nineties XT/LX Shimano kit (cantis, rear mech) that I'll be using, but the ratcheting of the Suntours sounds good. Obviously there's no pip on the downtube to stop the shifters sliding down, so that might be a problem.
Re: Triple chainset with no shifting aids on the chainrings
on older triples you will still have tooth tops which are chamfered correctly for middle chainrings and shifting may well 'go' OK in most cases. By contrast the inner ring of a modern double is specifically designed not to encourage the chain to shift leftwards off it, and I suspect this is the problem in this case.
cheers
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Triple chainset with no shifting aids on the chainrings
I don't know the answer, but details of that front derailleur and the other components in that groupset are in this scanned german Shimano catalogue.
The groupset chainset is 42/32/29, and the triple chainline is 45mm/47.5mm, so seemingly not inconsistent with your set up. I know that using a wider (lower speed) chain with a higher speed front mech can cause chain rub with the narrower cage, and I wonder if the reverse might be a factor in your case, i.e. wider 7 speed cage having to 'overshift' before it comes into contact with a narrow 9 speed cage.
Maybe the particular specification of the middle ring is a factor, i.e. if designed for a compact double, I wonder if the gaps between it and the other chainrings differ slightly from a normal triple middle ring.
SJS have some cheap new old stock TY30 front derailleurs, but it doesn't look like the specifications differ much from your current one, so presumably would not be worth trying.
If you decide to get some Shimano 9 speed bar end shifters, I suggest you do not delay. I think they have been discontinued and stocks are probably low at the few remaining retailers who still have them.
The groupset chainset is 42/32/29, and the triple chainline is 45mm/47.5mm, so seemingly not inconsistent with your set up. I know that using a wider (lower speed) chain with a higher speed front mech can cause chain rub with the narrower cage, and I wonder if the reverse might be a factor in your case, i.e. wider 7 speed cage having to 'overshift' before it comes into contact with a narrow 9 speed cage.
Maybe the particular specification of the middle ring is a factor, i.e. if designed for a compact double, I wonder if the gaps between it and the other chainrings differ slightly from a normal triple middle ring.
SJS have some cheap new old stock TY30 front derailleurs, but it doesn't look like the specifications differ much from your current one, so presumably would not be worth trying.
If you decide to get some Shimano 9 speed bar end shifters, I suggest you do not delay. I think they have been discontinued and stocks are probably low at the few remaining retailers who still have them.
Re: Triple chainset with no shifting aids on the chainrings
slowster wrote:I don't know the answer, but details of that front derailleur and the other components in that groupset are in this scanned german Shimano catalogue.
The groupset chainset is 42/32/29, .
doesn't it say 42-32-20?
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Triple chainset with no shifting aids on the chainrings
slowster wrote:I don't know the answer, but details of that front derailleur and the other components in that groupset are in this scanned german Shimano catalogue.
That's also available in English
https://na.s-tec.shimano.com/s3_assets/ ... anuall.pdf
Re: Triple chainset with no shifting aids on the chainrings
I don't think that the lack of shifting ramps and pins will necessarily be a problem. Its much more likely that the 8 tooth difference between middle and outer rings will cause problems.
Most front mechs both past and present are made to work with a 10 tooth or more difference between middle and outer rings. Anything less and setting the mech at the correct height becomes problematic. My experience with these things is that most combinations can be made to work with friction shifting but if you want indexing and sti's all bets are off. A road triple front mech with a shallow inner cage plate might work or a similar mtb mech with an altered cable attachment as described by Chris Juden.
Most front mechs both past and present are made to work with a 10 tooth or more difference between middle and outer rings. Anything less and setting the mech at the correct height becomes problematic. My experience with these things is that most combinations can be made to work with friction shifting but if you want indexing and sti's all bets are off. A road triple front mech with a shallow inner cage plate might work or a similar mtb mech with an altered cable attachment as described by Chris Juden.