8 speed to 9 speed

powenb
powenb Posts: 296
edited July 2007 in Road beginners
Can I change the Sora 8 speed that I have for a Tiagra 9 speed?

If I do, so i need new everything?

Thanks

Comments

  • John C.
    John C. Posts: 2,113
    Afraid you need every thing including a new back wheel as the free hub is a couple of mill to short to take a nine speed cassette, A groupset is about 200 pounds plus a new back wheel.
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • oldwelshman
    oldwelshman Posts: 4,733
    I changed 8 speed to 9 speed ultigra casette no problem fitted perfect just had to change sti's.
    I had the STI's so thats why I changed the cassette.
  • Dombo
    Dombo Posts: 4
    I'm not sure that John C is right. I've recently changed from Sora 8sp to 105 9spd. I only changed the cassette, the chain and of course the shifters. The new 9 speed cassette fitted perfectly and gear changes are very sweet. Check the distance accross the locknuts on the hub is 130mm, if so, you should be fine (the older 7spd versions were on 127mm).
  • whyamihere
    whyamihere Posts: 7,698
    John C. wrote:
    Afraid you need every thing including a new back wheel as the free hub is a couple of mill to short to take a nine speed cassette, A groupset is about 200 pounds plus a new back wheel.
    Incorrect. 8 speed and 9 speed freehub bodies are identical.
  • nicklouse
    nicklouse Posts: 50,675
    and a mech does not mind how many gears it shifts. but 9spd jockey wheels might help if you have any chain problems.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • jibi
    jibi Posts: 857
    powenb posted
    _________
    Can I change the Sora 8 speed that I have for a Tiagra 9 speed?

    If I do, so i need new everything?

    Thanks

    ___________________________

    I would think this would be better answered in Gear and Knowhow.

    with a bit more info as to what hub you have etc

    george
  • Big Red S
    Big Red S Posts: 26,890
    You will need a new 9-speed shifter. Your existing left-hand shifter will keep working, but most come as pairs anyway.

    Your chainrings will be wider than 9-speed ones, but this is rarely of any consequence. It's likely that you've already got 9-speed rings. If not, try keeping them. At worst you'll find you're more succeptible to chainsuck as the chain wears.

    Your front mech will be wider than a 9-speed one, but again this rarely makes much difference. Stick with it, and at worst you'll have slow shifts which are rectifiable with a new mech.

    Your rear mech will be fine - 8 and 9 speed cassettes are the same width. Narrower jockey wheels will speed up shifting, though.

    Your freehub body will be fine - if it's got an 8 speed cassette on it, it's an 8/9 speed freehub body.

    You will need a new chain and cassette.
  • oldwelshman
    oldwelshman Posts: 4,733
    In a nushell just change the cassette from 8 to 9, look on ebay for sti for 9 speed ( american sites sell individual often, I got dura ace pair for £120) then just try it.
    My chain had little wear so no need to replace.
    Check out Sheldon Brown website for technical info.
    You can even replace the old ultra glide 6 and 7 speedhub bodies for the newer 8/9.
  • supersonic
    supersonic Posts: 82,708
    Big Red S has summed that up to perfection.
  • rafletcher
    rafletcher Posts: 1,235
    nicklouse wrote:
    and a mech does not mind how many gears it shifts. but 9spd jockey wheels might help if you have any chain problems.
    Well sort of - it rather depends on the geometry of the mech, and the amount of movement you get per mm pull of cable, and how much cable pull you get on the 9sp STI vs the 8sp. From answers above it would seem that in this case there is ne need to replace the mech - but it may not be so for other changes - say from 9 to 10 :D
  • jibi
    jibi Posts: 857
    I thought this page explains it very clearly

    http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946

    Not :twisted:

    george
  • nicklouse
    nicklouse Posts: 50,675
    rafletcher wrote:
    nicklouse wrote:
    and a mech does not mind how many gears it shifts. but 9spd jockey wheels might help if you have any chain problems.
    Well sort of - it rather depends on the geometry of the mech, and the amount of movement you get per mm pull of cable, and how much cable pull you get on the 9sp STI vs the 8sp. From answers above it would seem that in this case there is ne need to replace the mech - but it may not be so for other changes - say from 9 to 10 :D

    a mech is just a dumb bit of kit. as long as it can swing far enough it will work. (it is the shifter that is Clever).

    currently the amount of cable moved by the shifter is common through the shimano range.

    yes the cable pull on the road front mechs is not quite the same as for the MTB mechs but they could be used at a push. (i have a MTB with a braze on mount).

    re 10 spd not had the desire to look at it and what has it got to do with the question?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • rafletcher
    rafletcher Posts: 1,235
    nicklouse wrote:
    rafletcher wrote:
    nicklouse wrote:
    and a mech does not mind how many gears it shifts. but 9spd jockey wheels might help if you have any chain problems.
    Well sort of - it rather depends on the geometry of the mech, and the amount of movement you get per mm pull of cable, and how much cable pull you get on the 9sp STI vs the 8sp. From answers above it would seem that in this case there is ne need to replace the mech - but it may not be so for other changes - say from 9 to 10 :D

    a mech is just a dumb bit of kit. as long as it can swing far enough it will work. (it is the shifter that is Clever).

    currently the amount of cable moved by the shifter is common through the shimano range.

    yes the cable pull on the road front mechs is not quite the same as for the MTB mechs but they could be used at a push. (i have a MTB with a braze on mount).

    re 10 spd not had the desire to look at it and what has it got to do with the question?

    Your assertion that rear mechs are "dumb" implied ALLl rear mechs would work with ALL shifters. Thats not true, and I was just pointing it out in general terms. And remeber the world is not totally Shimano driven 8) So chill....
  • John C.
    John C. Posts: 2,113
    I know I said change everything and I have been challenged. Price up a tiagra group set and then price up indavidual parts, sti will be about 120-130 a cassette 20 and 10 for a chain you are well up to the 150 mark and will end up with a hash job, why not get the group for 200 and put the sora kit onto a winter bike or you'll probably get 50 for the used group on e-bay.
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • acorn_user
    acorn_user Posts: 1,137
    JohnC might not have been right about the cassette body, but he might well be right about the economics. Shimano shifters are very, very expensive. If you buy the whole Tiagra group, then you will be able to ditch the dodgy OEM parts your bike came with. More work to swap them over though.
    I don't think it is worthwhile. It's a lot of money for very little benefit. The shifters are slightly different in operation (better for racing), and you get ONE extra ratio, but really? That's a pretty bad return for the money! Wheels would be a better upgrade.
  • nicklouse
    nicklouse Posts: 50,675
    rafletcher wrote:
    Your assertion that rear mechs are "dumb" implied ALLl rear mechs would work with ALL shifters. Thats not true, and I was just pointing it out in general terms. And remeber the world is not totally Shimano driven 8) So chill....

    yes all mechs are dumb.

    ok use a shimano shifter with a Sram or Campag. rear mech and you will have problems. unless it is a "named" Sram shifter (or some of the older ones). Do Campag. do a 2:1 shifter? don't think so. But again you could use one of those cable movment converters (not a good idea for an MTB).

    the mech is Dumb in that it only does what it is told to do by the shifter.

    who uses shimano? :wink: ok i use there cassettes on two bikes but i am trying out some sram cassettes on the other 2. but the rest is Sram. i did consider running an old campag. rear mech that i had aquired but thought it would be a waste.

    and by all accounts i will have to try some campag. out on the road bike if i build one.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • dazzawazza
    dazzawazza Posts: 462
    Looking at Shimano prices it appears very expensive to buy separate components, especially the shifters.
    Unless buying second hand isn't it better to buy the entire groupset and replace everything?
    Then try selling the 8spd components on Ebay.
  • mackdaddy
    mackdaddy Posts: 310
    nicklouse wrote:
    and a mech does not mind how many gears it shifts. but 9spd jockey wheels might help if you have any chain problems.

    Am i right then, that I could directly replace an 8sp Sora Rear mech with a 9sp Ultegra rear mech without having to change the STI (yet) and experience no problems (notwithstanding the improvements the 9sp jockey wheels would make)?
  • mackdaddy
    mackdaddy Posts: 310
    Thanks Big Red
    Sorry to be hijacking a thread, but what is the difference in use between long cage and short cage? Where/Why would you use one instead of the other?
    Actually, thinkI have sussed it. One is for triple, short is for double correct?