basher Posted April 1, 2008 Report Share Posted April 1, 2008 Got a simtra frame it has a 68mm shell like my czar had, decide to go ffw so ive just but it on me cranks. I have a 73mm x 128mm bb with a spcaer on driveside. Worked fine on my czar with fixed cog but now no matter how i try fiddleing things the freewheel rubs on the bb. I dont understand why its doing it as its a 128 axel and surely the fact its a 73mm shell shouldnt matter.Anyone any ideas or should i just buy a new one.The only thing i could think o is on the bb spline usually a little washer goes on and i havnt got that on but thats only 2mm max and i dont think that would make the difference needed. The bb is a fsa platinum. Quote Link to comment Share on other sites More sharing options...
James Quigley Posted April 1, 2008 Report Share Posted April 1, 2008 i does make a difference if you have a 73mm body.73 is 5 larger than 68 therefore there is 2.5mm less space on either side. doesn't sound like much but it does make a difference.also different bb's will have different designs/shapes or whatever so even with the same axle length two different bb's will differ in how close the cups are to the cranks etc. Quote Link to comment Share on other sites More sharing options...
Mark W Posted April 1, 2008 Report Share Posted April 1, 2008 The 73 thing won't make a difference, as the actual distance from the tip of the BB spindle to the end of the BB cup is gonna be the same, you're just spacing the centre of the BB 'cartridge' (Shit term...) a few mm over to the right? Did you use the 73x128 on your old bike, or did you have an actual 68x128?If it's an FSA one, you've made sure you've still got the little silver ring on the splines to stop the crank arm f**king up? Quote Link to comment Share on other sites More sharing options...
monkeyseemonkeydo Posted April 1, 2008 Report Share Posted April 1, 2008 What freewheel and bash are you using? I know certain setups, like GU bash with an ENO doesn't work without grinding the centre of the bashguard down a bit (I've also had to take a bit off the freewheel tabs too). Wouldn't matter what size BB shell/BB you use, some setups just don't work without modification. Quote Link to comment Share on other sites More sharing options...
basher Posted April 1, 2008 Author Report Share Posted April 1, 2008 (edited) The 73 thing won't make a difference, as the actual distance from the tip of the BB spindle to the end of the BB cup is gonna be the same, you're just spacing the centre of the BB 'cartridge' (Shit term...) a few mm over to the right? Did you use the 73x128 on your old bike, or did you have an actual 68x128?If it's an FSA one, you've made sure you've still got the little silver ring on the splines to stop the crank arm f**king up?i used the exact same bbNo i havnt got the spacer things on, could that be it? but there only like 2mm wide if thatecho forged cranks zoo bash and tensile freewheel Edited April 1, 2008 by basher Quote Link to comment Share on other sites More sharing options...
monkeyseemonkeydo Posted April 1, 2008 Report Share Posted April 1, 2008 echo forged cranks zoo bash and tensile freewheelWouldn't have thought that setup would cause a problem...Definitely use the spacer if you're using a 73 BB in a 68 frame, otherwise even if you cure the freewheel rub you could end up hitting brake cylinders with your cranks. Shouldn't make any difference to your current problem though. Quote Link to comment Share on other sites More sharing options...
Mark W Posted April 1, 2008 Report Share Posted April 1, 2008 i used the exact same bbNo i havnt got the spacer things on, could that be it? but there only like 2mm wide if thatecho forged cranks zoo bash and tensile freewheelDo you mean the spacer that goes around the 'big' bit of the BB, or the spacers that go on the end of the ISIS interface bit? On FSA BBs they have a little silver ring that goes onto the splines that butts up against the end of the crank so it doesn't deform your crank arms - if you don't have them on, not only are you gonna be killing your cranks, but you'll be losing a bit of clearance too. If you mean the big 2.5mm spacer that goes on the main body of the freewheel though, maybe slip that on too... Quote Link to comment Share on other sites More sharing options...
basher Posted April 1, 2008 Author Report Share Posted April 1, 2008 Do you mean the spacer that goes around the 'big' bit of the BB, or the spacers that go on the end of the ISIS interface bit? On FSA BBs they have a little silver ring that goes onto the splines that butts up against the end of the crank so it doesn't deform your crank arms - if you don't have them on, not only are you gonna be killing your cranks, but you'll be losing a bit of clearance too. If you mean the big 2.5mm spacer that goes on the main body of the freewheel though, maybe slip that on too...No i havnt got the little spacer on the spline the crank goes on, ill go find one and try it.Cant find it supose ill just have to buy a new bb. Quote Link to comment Share on other sites More sharing options...
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