Hello. I have an old Trek Pilot 1.0 that I am very fond of and would like to keep running. It has an 8 speed cassette and 8/9 speed Tiagra triple groupset. Yesterday the front mech shifter died.
I was wondering if Claris or Sora shifters are compatible replacements. If I should choose a new double 10 speed groupset, Tiagra , will I have to replace my new Mavic wheels too? There is a shim on the free hub to accommodate the 8 speed cassette, will a 10 speed cassette be ok when the shim is removed?
I am in your hands! Thank you for any help given. David
Tiagra 8/9 speed shifter broken - What replacement ?
Re: Tiagra 8/9 speed shifter broken - What replacement ?
Surely it is an 8-speed ? Why do you think it is 9-speed also ?
The number of gears that a control can deal with tends to be a primary defining feature/constraint.
( Although the complex world of Shimergo hybrids is a well-known exception . . . . but let us keep it simple here. )
The number of gears that a control can deal with tends to be a primary defining feature/constraint.
( Although the complex world of Shimergo hybrids is a well-known exception . . . . but let us keep it simple here. )
Re: Tiagra 8/9 speed shifter
You are talking about a bike with dropped handlebars, 8s gearing and dual pivot brakes, right?
Before you condemn the shifter as 'dead', note that they very commonly just dry up internally and this makes them stop working. Remove/peel back the lever hood, and douse the insides with WD40 or similar, then 'exercise' the lever. Deliberately flick the downshift lever. It may well just come back to life after one or two repeat treatments. If this works this is the easiest fix for your bike by far.
If you want to fit a 10s groupset you can do. You wheels will be fine but you ought to have
RD,
FD,
shifters
cassette
chain
chainset
bottom bracket
all cabling
bar tape
brakes
The actuation ratio of nearly all 10s brake levers is different from 8s ones, and the combination of 10s shifters and your brakes will 'work' but badly, i.e. it is liable to result in pretty rubbish brakes. Similar concerns apply to more recent Claris and sora units; they have the same brake actuation ratio.
10s chain is a different internal width than 8s chain, so it won't work properly on (new) 8s chainrings. In reality once the chainrings are worn 10s chain might seem to fit but the net result is usually rubbish shifting, for ever.
Some 8s FDs will 'work' in a 10s setup but it is not a perfect marriage.
If you replace all the parts required you will have comfortably exceeded the value of the bike, so it would definitely be a 'love not money' route.
If the parts are otherwise in good shape I'd fix the LH shifter or replace it with a good used unit.
cheers
Before you condemn the shifter as 'dead', note that they very commonly just dry up internally and this makes them stop working. Remove/peel back the lever hood, and douse the insides with WD40 or similar, then 'exercise' the lever. Deliberately flick the downshift lever. It may well just come back to life after one or two repeat treatments. If this works this is the easiest fix for your bike by far.
If you want to fit a 10s groupset you can do. You wheels will be fine but you ought to have
RD,
FD,
shifters
cassette
chain
chainset
bottom bracket
all cabling
bar tape
brakes
The actuation ratio of nearly all 10s brake levers is different from 8s ones, and the combination of 10s shifters and your brakes will 'work' but badly, i.e. it is liable to result in pretty rubbish brakes. Similar concerns apply to more recent Claris and sora units; they have the same brake actuation ratio.
10s chain is a different internal width than 8s chain, so it won't work properly on (new) 8s chainrings. In reality once the chainrings are worn 10s chain might seem to fit but the net result is usually rubbish shifting, for ever.
Some 8s FDs will 'work' in a 10s setup but it is not a perfect marriage.
If you replace all the parts required you will have comfortably exceeded the value of the bike, so it would definitely be a 'love not money' route.
If the parts are otherwise in good shape I'd fix the LH shifter or replace it with a good used unit.
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Tiagra 8/9 speed shifter broken - What replacement ?
Hello Brucey, Thank you for your time and expert reply. I shall take the WD 40 to it straight away. If unsuccessful then I shall go for a new 8 speed shifter. Having been been on a bike for 50 years i usually rely on local bike shop for repairs. I am just getting around to the idea that I should enjoy having a go at some repairs myself ! Thank you once more for your help. David
Re: Tiagra 8/9 speed shifter broken - What replacement ?
Before you exercise the lever ensure the gear cable is free to move. Its not uncommon for a failed shifter to be caused by the strands of the gear outer pushing through the end cap and protruding into the shifter housing.
The older I get the more I’m inclined to act my shoe size, not my age.
Re: Tiagra 8/9 speed shifter broken - What replacement ?
Hello Peetee, Thank you for your comment. I am slightly embarrassed since upon closer examination the cable at the "runner" by the bottom bracket had frayed. This had prevented the smooth running of the cable. I had a fun afternoon at Halfords and Dr YouTube learning how to re cable. Just finished and it seems to work! Thanks, David