• 02-19-2010
    theMeat
    1990 fisher prometheus 88mm bb shell? question
    Hi all and thanx 4 looking. Let me start by saying that I'm pretty much a newbie to wrenching on bikes. I recently acqiured a 1990 prometheus titanium frame and I'm having a problem finding a suitable cranset for this build. I'v tried a few different cranks from that era with not much luck. The cranks stick out to far for the derailleur to reach. The only crank that I could manage to get to work is an old sugino impel with riveted steel rings, which r strong and durable, but just don't give this frame the respect that it deserves. I've since learned that suntour xc comp cranks where supposed to come on this frame if built to spec by fisher. Been googling and ebaying trying to figure this out. Read sheldon browns page, which is very thorough, but with this odd size bb, and me not completly getting it, I'm still a bit confused. :madman: Need a book "vintage crankset for dummies" LOL. I found this old unused ritchey logic crankset on ebay, that is supposed to have low "q", but again I'm not to sure. I'm hoping that someone could provide me with a list of usable cranks with the right "dish" for my latest project. Thanx, Pete
  • 02-19-2010
    XR4TI
    Your bottom bracket has to be the right size for the crank you want to use.

    So, for an example, if the crank you choose requires a (assuming the bottom bracket shell is 68mm on this frame) 68x113mm bottom bracket (113mm is BB spindle length), that's the size bottom bracket you need.

    You can't just use any bottom bracket with any crank.

    Choose the crank you want then buy the correct size bottom bracket for it.
  • 02-19-2010
    Shayne
    @XR4TI No, that wasn't a typo. The frame has Fishers extra wide BB shell. It uses press fit bearings and a straight spindle.

    Your other point is pretty much right on.

    theMeat: What spindle length are you dealing with? With that info it will be much easier to make recommendations.
  • 02-19-2010
    theMeat
    I'm guesing that finding a bb for this size bb shell is going to be imposible. The shell measures 3.5 inches or 88.8mm. From what I can gather this uncommon size was experimental for fisher in the early 90's. Thankfully the frame a good one istalled.
  • 02-19-2010
    XR4TI
    My bad.
  • 02-19-2010
    yo-Nate-y
    Okay, the BB is fine. Good. So, what is the spindle length then?
  • 02-19-2010
    theMeat
    Wow, Ah da, that makes sense. I'll measure and post findings. Thanx guys
  • 02-19-2010
    babbalanja
    Mavic cranks take a wide spindle (124+) and the arms come relatively close to the chain stay. Toplines (and Grafton?) take a 127.
  • 02-19-2010
    yo-Nate-y
    Indeed. And old Suntour was pretty wide too (125.5~127mm, wasn't it?), which makes sense if that was stock.
  • 02-19-2010
    muddybuddy
    Quote:

    Originally Posted by theMeat
    I'm guesing that finding a bb for this size bb shell is going to be imposible. The shell measures 3.5 inches or 88.8mm. From what I can gather this uncommon size was experimental for fisher in the early 90's. Thankfully the frame a good one istalled.

    I have that size on my 91 Super Caliber. Although the bottom bracket is an odd size, It should be easily rebuildable. Just pull it apart and take the cartridge bearings to a bearing supply place. For cranks, I'd go with Toplines if you happen to have some lying around or Suntour as previously suggested. A lot of the cranks from that era used really wide spindles though. Even the M735 Shimanos used 122.5 mm.
  • 02-19-2010
    theMeat
    The spindle measures (drum roll please)////// 127 mm
  • 02-20-2010
    theMeat
    Does anyone know if ritchey logic crank will work? It's described as regular but I suspect it's a compact from the photo. Thanx
  • 02-20-2010
    babbalanja
    I believe the older (sugino-made) 110bcd Logic cranks take 120-122m spindles
  • 02-20-2010
    DeeEight
    127 if you wanted a narrow chainline, 131 for the wider one. I have one of those fisher spindles still i think. Old ritchey, Suntour, shimano, or many others would work. The ritchey would probably be the most correct as I think that's what the prometheus was spec'ed with.
  • 02-20-2010
    theMeat
    Prometheus was speced with suntour xc comp. Haven't seen any mtb cranks with 131. The spindle that's on there now is 127. Mavic's, which somone above posted above, are 124, and come close to chainstay. So I'd think that would b as narrow as I could go but IDK. Wonder what my range is. I'm not doubting you, I'm just still a bit confused, so your help is apreciated.
  • 02-20-2010
    ckevlar
    I remember the two Prometheus we sold at the shop had a pair of the Gary Fisher spec. Sugino XP cranks on it. They sit pretty far in on the spindle. I can get a better pic of the pair i have if you would like to see what they look like.
    Like these.:
  • 02-20-2010
    theMeat
    Thanks 4 that enlightnment. I found this website, "first flihgt bikes" that showed prometheus with the complete suntour xc comp groupo as spec but I trust your first hand experience more. Did prometheus come any other years other than 1990? Do you remember what groupo it come with? Does any one know if the ritcheys will work? According to sheldon brown the logic need 120 and logic compact 113, and this frame has127, so I wouldn't think so but I'm getting conflicting info. Thanx
  • 02-20-2010
    proto2000
    Are the chain-stays wider than normal? I run a 122 on a Bontrager Race Light that has Toplines on it due to the extreme inward invasion of the chain-rings. Looks like a high maintenance fork with all of those pivot points which are probably bushings. I'd still like to have one though.
  • 02-21-2010
    ckevlar
    The bike had Suntour XC whatever (pro or comp I dont remember) the catalog said it was suppose to have but the cranks were not as listed. I specifically remember it coming with that xc crank. It stood out , had the XC-pro quality and finish but with the one hidden arm.
  • 03-02-2010
    theMeat
    OK so I bought a mavic 637 on ebay and the chain line looks good but wham!.The left side hits the chainstay, by a few mm, and the drive side just touches. So back on ebay they go. Been looking and looking for suntour xc but nothing at a reasonable price. Does anyone know what decent sugino's might fit? Any other ideas? Thanx, Pete
  • 03-02-2010
    babbalanja
    Try a Sugino AT or an early 90s shimano XT or LX (M730 or M550).
  • 03-02-2010
    DeeEight
    I have a set of the right ritchey model for that spindle, but the arms look a bit tired and they're 177.5s.
  • 03-02-2010
    XR4TI
    Quote:

    Originally Posted by theMeat
    OK so I bought a mavic 637 on ebay and the chain line looks good but wham!.The left side hits the chainstay, by a few mm, and the drive side just touches. So back on ebay they go. Been looking and looking for suntour xc but nothing at a reasonable price. Does anyone know what decent sugino's might fit? Any other ideas? Thanx, Pete

    I have a Suntour XC Comp that we could probably work out a trade on. PM me.