Does anyone know if you can use a chainguide with an external BB and if so would it be the same as a standard BB length? or do I need a biger one I use a 68/73 do I need to get an 83?
X-type bbs do not come in any sort of lenghts or sizes. They are two threaded aluminum cups with bearings..and that is it (ok some have a little plastic tube that is different lenght for a 68/73 vs an 83 vs a 100mm...but those lengths are frame dictated and have absolutely nothing to do with the cranks or any chain guide or lack there of).
All the info you could want is available at various crank/bb/chainguide mfg sites in their instalation instructions...
Installation of a BB type chain guide for xtype cranks, first for 68mm then for 73
For both, you will want to have your BB faced, that goes with any external BB system and most olderstyls bb's. On a 68mm SHell you will put one spacer on the non drive side and your chainguide and one spacer on the drive side with the guide against the frame.
for 73, you will have one spacer on the non drive side, and you will have just the chain guide on the drive side.
Then space your cranks with the chainline spacers to get the desired chainline for your particular bike!!!
If you really want I can Link you the instructions directly. But thats exactly how its done
X-type bbs do not come in any sort of lenghts or sizes. They are two threaded aluminum cups with bearings..and that is it (ok some have a little plastic tube that is different lenght for a 68/73 vs an 83 vs a 100mm...but those lengths are frame dictated and have absolutely nothing to do with the cranks or any chain guide or lack there of).
All the info you could want is available at various crank/bb/chainguide mfg sites in their instalation instructions...
Exactly, The only system out there that has an external bb bearing that anything to do with shell width and spindle length is the Howitzer system, which will install exactly the same way for the guide system, and you decide what length spindle for your chainline.
Installation of a BB type chain guide for xtype cranks, first for 68mm then for 73
For both, you will want to have your BB faced, that goes with any external BB system and most olderstyls bb's. On a 68mm SHell you will put one spacer on the non drive side and your chainguide and one spacer on the drive side with the guide against the frame.
for 73, you will have one spacer on the non drive side, and you will have just the chain guide on the drive side.
For 73, shouldn't you be running no spacers on the non drive side and just the chain guide on the drive side?
The two 2.5mm spacers that are needed for the 68mm BB are to make up for the 5mm difference between 68 and 73 BBs. If you run one spacer plus the chain guide plate on a 73mm BB you'll be 2.5mm too wide.
My apologies, that is correct, non drive side will have a spacer only for a 68mm shell. My bad, I was getting mixed up in the head between the Cup spacing and the Chainline spacing for the RF stuff.
Here, Link to the RF PDF for installing. went and checked it myself.
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