Replacing Sora chainset for a compact. HELP!!!

Unknown
edited May 2007 in Workshop
I have previously asked about whether I could put a 9 speed compact on an 8 speed Allez. The general consensus is yes.

Now what I am unsure about is whether I need to buy cups etc with it. Someone recently said that, as the bb should sealed I will not need to change the cups.

It is an 05 Allez, can I just take the old chainset off and put the new one straight on?

If anyone knows any good websites about this I would be very grateful.

many thanks,

Ed

Comments

  • nmcgann
    nmcgann Posts: 1,780
    If it's to replace a sora chainset with a Shimano compact you will need the hollowtech 2 BB cups as well.

    You may be able to use something like the Stronglight Impact compact with the existing square-taper BB (may need a different BB spindle length, but you'd probably get away with it).

    To go hollowtech2 you should really have the BB shell faced by your LBS with the appropriate special tool.

    Neil
    --
    "Because the cycling is pain. The cycling is soul crushing pain."
  • Mr P
    Mr P Posts: 548
    Ed, this IS a good website!
    Let us know what compact you are thinking of using and someone will know the correct bb replacement approach...
  • maddog_2cp
    maddog_2cp Posts: 73
    Ed, I've already answered this in the last post.

    If you go with any of the new HT2 chainsets then you'll need new BB cups.

    If you go with some other chainset then you need to tell us which one it is, obviously.

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    Drop bars are a historical accident...... discuss
  • Old Nick
    Old Nick Posts: 77
    I did a similar thing a couple of years ago, swapped out a shimano 52/39 for an FSA square taper 50/34. Same bottom bracket, needed to lower front mech a couple of mm. About œ60-ish from memory.
    Very easy to do. Tools needed: crank extractor, long allen key for crankbolts.
  • Sorry maddog this is true, but just having one person saying the opposite had me querying....me of little faith.

    So now it looks like FSA compact or Stronglight Impact.

    Which is best? I imagine they are much are muchness. The only thing is that the Stronglight is available with a 48 large ring. It also has a possibility of a 165mm crank. I have short 30" inside leg so would a 165mm be good for this?

    Sorry a million questions. Cheers for the support as I am broke and cant afford LBS.

    Many thanks

    ED
  • gkerr4
    gkerr4 Posts: 3,408
    30" inside leg isn't that short - I'd have thought 170mm cranks would have been fine to be honest.
  • nmcgann
    nmcgann Posts: 1,780
    Either the FSA CFJ chainset (JIS 113mm BB) or the Stronglight Impact Compact (JIS 107mm BB) will work. I have a Stronglight one myself and it's fine quality-wise.

    The FSA CFJ will probably work with your existing BB length (assuming it's not one of the new octalink sora BBs), the stronglight impact will probably need a new 107mm BB. However, the stronglight JP400 BB is very cheap so the overall cost of either solution is going to be similar.

    Note the use of "probably" - as soon as you are off the complete groupset page there is uncertainty about how well something will work with your bike and you have to be prepared to experiment a bit.

    Neil
    --
    "Because the cycling is pain. The cycling is soul crushing pain."
  • maddog_2cp
    maddog_2cp Posts: 73
    I've had both the CFJ and the Impact and the Impact is the better crank IMO. Better finishing.

    I'd go with above that 170 will be fine.

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    Drop bars are a historical accident...... discuss
  • nmcgann
    nmcgann Posts: 1,780
    <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by maddog 2</i>

    I've had both the CFJ and the Impact and the Impact is the better crank IMO. Better finishing.

    I'd go with above that 170 will be fine.

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

    As an aside - have you ever had to take a ring off the Impact? There's one bolt in a very stupid place where if it spins the crank is scrap since you can't get a tool in to hold it.

    I was toying with the idea of putting a 36 on mine instead of a 34, but I'm a bit shy of that bolt behind the crank. (I recently had to hacksaw a seized ring bolt off a brand new 105 octalink crank, so I use caution where ring bolts are concerned!)

    Neil
    --
    "Because the cycling is pain. The cycling is soul crushing pain."
  • maddog_2cp
    maddog_2cp Posts: 73
    yep, the ring thing is silly I agree.

    Personally, the cheaper HT2 chainsets looks very good value. The R600 is œ56 at Ribble. For that kind of money, that's what I'd go for.

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    Drop bars are a historical accident...... discuss
  • nmcgann
    nmcgann Posts: 1,780
    <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by maddog 2</i>

    yep, the ring thing is silly I agree.

    Personally, the cheaper HT2 chainsets looks very good value. The R600 is œ56 at Ribble. For that kind of money, that's what I'd go for.

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

    Yes, me too - or the Tiagra 4500 one, it's œ37.95 - œ53 with a set of BB cups.

    I do think that facing the BB shell wouldn't an easy job to organise round where I live - I'd be surprised if any of the LBS's had the slightest clue what I was talking about.

    Neil
    --
    "Because the cycling is pain. The cycling is soul crushing pain."
  • maddog_2cp
    maddog_2cp Posts: 73
    have a look at your frame. My roadie didn't need facing (bare ti) but my mtb did (painted steel)

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    Drop bars are a historical accident...... discuss
  • many thanks for your help all. I have ordered this as I will just change the bb at the same time. This seems to be the cheapest option. As I can do it myself.
    http://www.pearsoncycles.co.uk/index.ht ... 0&brandID=
  • nmcgann
    nmcgann Posts: 1,780
    <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Edddddd</i>

    many thanks for your help all. I have ordered this as I will just change the bb at the same time. This seems to be the cheapest option. As I can do it myself.
    http://www.pearsoncycles.co.uk/index.ht ... 0&brandID=
    <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

    You couldn't have found a more expensive place to buy it from.

    http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0102130875 œ55.49 inc postage.

    Everywhere else is over œ10 less than pearsons.

    Neil
    --
    "Because the cycling is pain. The cycling is soul crushing pain."
  • maddog_2cp
    maddog_2cp Posts: 73
    his price includes the BB though............

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    Drop bars are a historical accident...... discuss
  • nmcgann
    nmcgann Posts: 1,780
    <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by maddog 2</i>

    his price includes the BB though............

    <font size="1"><font color="purple">
    Drop bars are a historical accident...... discuss</font id="purple"></font id="size1">
    <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

    Ah - I didn't spot it in special offers, I was just looking at the chainsets page. I take it back - it's a good deal for œ60 (+p&p) with a BB included.

    I wonder what the shifting is like on the FSA rings? It's OK on my Stronglight Impact, but not as good as the cranks I've got with stock Shimano (& Campag) rings.

    Neil
    --
    "Because the cycling is pain. The cycling is soul crushing pain."