……so what the hell am I doing wrong. The BB shell is 73mm, I thread the drive side through first, then the non drive side, tighten the cups, push the crank through and tighten the non drive side bolt.

Except when I tighten the non drive side bolt it causes the BB to seize and stop rotating unless you have to bolt so loose there is play.

Sensible answer would be to go to LBS, however this is the first frame I have built up from scratch and am so nearly there I want to finish it off myself.

Where are the spacers?

You’d think not….others would disagree.
Is the nds seal on the right way round?Also…no spacers.

I have one spacer on the drive side between the cup and the frame to push the crank out slightly for a better chain line, I am using a 2 by crank set with a single ring, on a frame designed for single ring only. Though I have tried without any spacers also, i think with a 73mm BB shell its intended to be used without spacers. NDS seal is on, though I didn’t realize there was a right way round so I will check that thanks

Are you sure it is bb, not crank/frame collision?

“one spacer on the drive side between the cup and the frame to push the crank out slightly”
Does’nt make any difference.The crank spindle is ‘captured’ by the nds cup (bearing sits on the slightly narrower section) and the ds cup effectively ‘floats’.That’s why there is no preload adjuster.

Are the cranks designed for a 73mm shell?

Definitely no crank frame contact, I didn’t realize cranks are designed for different BB widths. I bought this as a first full sus frame whyte g150 (2015) on a bit of a whim and thought I could build it up fairly cheaply using a few spare parts.

Seemingly not the case! The crank is a SRAM FC S1000 taken of a whyte 901, cannot find out what width BB they are intended for.

S1000 only works 68/73 I believe. Which should be fine. The issue sounds like spacers. Once its done up tight how big is the gap from drive side BB to crank?

It’s as difficult as reading the instructions 68 spacer each side 73 no spacers.

It’s as difficult as reading the instructions 68 spacer each side 73 no spacers.

Does somewhat depend on what BB you’re using though, SRAM do GXPs for 73 in no spacer and 1 spacer flavour.

Good frame you have chosen, I have an X1 crankset off my G150 coming up for sale is any use to you

If only it were Baznav, I have tried with no spacers, no joy 🙁

So how much of a gap is there from BB to crank arm, should be about 3mm.

Just measured and it is about 4mm, I have just reversed the non drive side seal and that seems to have sorted it, have now torqued up the bolt and the cranks spinning freely :P.

I still have the two spacers on the drive side, I needed to do this because my NW ring is fitted to the inner ring of my old 2 by crank, so without the spacers the chain ring sits to close to the chain stay. Its a bit of a bodge but will have to stay like that until I can save for a 1 x 11 group set, role on 1 x 11 shimano slx.

Thanks hive mind.

Makes sense – the seal has a lip on the inside – run it the wrong way round at it will contact the inner and outer bearing races (not good). Pleased you’re sorted.

Me too this whole build has been a steep learning curve.

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