balfa Posted November 7, 2007 Report Share Posted November 7, 2007 Just got a Onza T-Rex and in the process of fitting the cranks.I'm using a square taper BB 128mm Axel and middleburns with a 22T chainring. The problem is there is no way the chainring can clear the chainstay!I don't believe a longer BB is availible in square taper.Is this setup impossible? Any options short of getting the super pro/heatsink bash? Quote Link to comment Share on other sites More sharing options...
Village Idiot Posted November 7, 2007 Report Share Posted November 7, 2007 Hmmm. I've got the same set up but I'm running a 20T chainring. I've never tried a 22T on, so don't know whether there's enough clearence for one or not. You could maybe try a 20T chainring with a different sized sproket/cog at the back to keep the gear ratio the same. Quote Link to comment Share on other sites More sharing options...
balfa Posted November 7, 2007 Author Report Share Posted November 7, 2007 Hmmm. I've got the same set up but I'm running a 20T chainring. I've never tried a 22T on, so don't know whether there's enough clearence for one or not. You could maybe try a 20T chainring with a different sized sproket/cog at the back to keep the gear ratio the same.Only problem with that is I have a 18T Freewheel on the rear so i'd then have to buy a 16T freewheel. Quote Link to comment Share on other sites More sharing options...
dave85 Posted November 7, 2007 Report Share Posted November 7, 2007 Get some spacers between the BB and the shell, Onza full builds had to do it so it's a recognised problem. Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted November 7, 2007 Report Share Posted November 7, 2007 tis tight....i remember steve had a 5mm spacer (....that's about the limit!) and a 20t ring and it still rubbed....that was on ddg cranks though...front freewheel Quote Link to comment Share on other sites More sharing options...
Ross McArthur Posted November 7, 2007 Report Share Posted November 7, 2007 You always moan about those cranks any way, get new ones. Quote Link to comment Share on other sites More sharing options...
Token Posted November 7, 2007 Report Share Posted November 7, 2007 Grind the frame, cheap and easy. Bodgetastic! Quote Link to comment Share on other sites More sharing options...
basher Posted November 7, 2007 Report Share Posted November 7, 2007 Go on tarty website and it tells you what bb works best i think its a 73shell 128 lenght with spacers in it. Quote Link to comment Share on other sites More sharing options...
Phil H Posted November 8, 2007 Report Share Posted November 8, 2007 Just got a Onza T-Rex and in the process of fitting the cranks.I'm using a square taper BB 128mm Axel and middleburns with a 22T chainring. The problem is there is no way the chainring can clear the chainstay!I don't believe a longer BB is availible in square taper.Is this setup impossible? Any options short of getting the super pro/heatsink bash?I'm confused because I'm preety sure I got my Middleburns (22t) before I snapped my factory BB so I'm preety definite it does fit on.But anyway now on my T-Rex im running the 127.5mm Echo/VP BB and I can garuntee its long enough. Echo/VP BBPhilOnly problem with that is I have a 18T Freewheel on the rear so i'd then have to buy a 16T freewheel.Don't do that! 22 - 18 is the best setup for a T-Rex in my opinion. Quote Link to comment Share on other sites More sharing options...
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