What chainring would go with PRIMO aluminium crank arms?

[skyway or the highway]

Kahoonas. I've recently got myself a pair of nice lightweight PRIMO crank arms (aluminium and in silver), but am now needing to find a compatible chainwheel plus bolts, as they came up different from what i was anticipating, and i'm now a bit stuck, in stuckyville. Please help me out of stuckyville back to working cranksville.
Does anyone know the parts? Has anyone got the parts?
Thanks for any and all response.
Martin

[mark j]

Hi Martin, A way of finding out is measuring what's called the BCD (bolt circle dimension). Measure it as if there was an imaginary circle running through the centre of the bolts and then measure it in mm across. For instance a sugino has a bcd of 110mm, takagi got 130mm, Tuf Neck got 110mm and 130mm. Let us know what you've got, I've probably got something for you.
mark

[Sanmarcopizza]

S.O.T.H. what chainwheel have you tried to put on the cranks. Not clear from what you have said, what the actual problem is. Mark has made suggestions based on you using a separate spider and chain ring, but I am guessing your problem is different. Which bolts are you referring to also.

[skyway or the highway]

Eh up, back in the room. er yeah, San Marco, I tried a sort of generic unmarked sugino type copy with it, but it is well thick and the bolts don't go any where near through, plus which, there is a little attachment on the reverse side of the spider, around the underside of every bolt hole - kinda like two semi circles together, or like two letter 'C's facing each other, like you get on the sugino bolts, and these are not helping matters.
Mark, hi, cheers for the drop in, er yeah, erm same bcd as regular sugino - 110, all checked out in that regard, but as above, all too damn thick to fit together. The sugino copy is well thick, but then i have never clapped eyes on a genuine one, but i would assume, judging by the genuine sugino bolts i have, that they must be alot slimmer. Over.

[skyway or the highway]

Additional message - the spider is part of the crank arm.

[Sanmarcopizza]

I can't say I have seen them cranks. I had Powerbites in my mind. Maybe you need to go to a bike shop and buy some chain ring bolts for an MTB. They do them in different lengths for if you are running 1, 2 or 3 chainrings on your crank.

[skyway or the highway]

Yeah, that may well be worth checking out.

[mark j]

Regular old school chainwheels are 3mm thick, I'm presuming the one you measured is more modern to handle grinding kinda tricks.....

[skyway or the highway]

I think i've identified what the problem is. I've got two sets of crank arms in all, both with built-on spiders. The other one i have is a sugino setup with diamond back written on the arm aswell. With the bolt holes on that one, there's an inner recess, a kind of an inner circular ring where the bolt sits on, and through this it sinks almost flush on the front outside, in other words it lets the bolts sink deeper, thereby they can screw up better. The trouble is, i don't really want this crank, as i consider it too heavy.
With the primo set i've got, the bolt holes are much smaller, in fact they are the exact fit for the sugino bolts to screw into, but owing to the fact that there is no inner recess and they cannot drop down at all into the bolt hole, they hardly even come out the other side (if you see what i mean). So i is a bit between one place and another. I'm in limbo. Not quite sure how to proceed, I Know it would be simpler to go with a complete sugino setup, although usually quite expensive, but i kinda like the primo arms, they are very light, and i have them now. I probably wouldn't have got them if i knew they had different bolt sizes, but i didn't. It's all a bit like ggggrrrhhh. 
Can you suggest anything dude?
Martin

[mark j]

I'm all lost now, take some pics and a more experienced brain might know the answer. Sounds like what San says, get longer bolts. But if you want any chainrings, chainwheels etc I got enough to sink a battleship........