sjanzeir

... and replace them with bolts?

Andrew R Stewart 

Why? Andy

Crankycrank

I don't see it as a big deal whether you drill them or not but if there are no issues with them now why bother. It could be a big headache finding the right sized fasteners to fit. A good example of "if it ain't broke, don't fix it".

rumrunn6

is their room for nuts (& lock washers, etc) on the other side? looks like chain ring bolts actually require a recessed (countersink) notch to sit in

'nother question tho, if you try to drill out a rivet won't it just spin?

sjanzeir

As Yvonne Criddle would say, dem rivets lookin' damn fugly like dat. And it's very likely that they're too corroded to be safe...

dsbrantjr

I would suggest not, unless you are prepared to machine the spider and rings to properly accept chainring hardware. You will likely have difficulty maintaining concentricity with, and may run into clearance issues from the heads of, standard nuts and bolts.
What problem are you aiming to solve? If the minor rust is bothering you, use a conversion treatment and a little Rust-Oleum-type paint, although I would not bother. Rivets make a very strong connection. Never Fix A Running Piece.

sjanzeir

Thank you!

AnkleWork

Future thread: "Why is my modified crankset creaking so much?"

'02 nrs

try some of this with Qtips.https://www.walmart.com/ip/Chromax-C...SABEgJC5_D_BwE

sjanzeir

sjanzeir

I'm sure I can find the same or similar products locally. I wonder what ever happened to Walmart setting up shop in Saudi Arabia... 🤔

sjanzeir

That makes perfect sense. Thank you.

79pmooney

Don't even think about it until it is time to replace the chainrings. If you drill out the bolts and the replacements don't fit exactly, ie if there is even a little slop, the crankset will do a slow death as the blot holes elongate. Standard crankbolts holes are 10mm exactly. Chainring bolts are also. Snug fit, not the clearance fit of the usual bolt and hole.

I'm guessing those rivets are doing a good job of being tight, no play at all. Don't disturb them until you have to!

Ben

sjanzeir

79pmooney

Actually, the recess is not necessary for the chainrings. It helps with clearance with the chainstays and makes for a nice clean appearance. Chainring bolts are sized assuming the recess, so yes, we now need the recess. but not because there is any magic to the recess itself. I have a crankset where the outer ring sits only on the bolt and the recess is there but not used. Bolt extends past the chainring. There is a large washer and nut.

This works (very well) because the bolt is a tight fit with the chainring (and was a very interesting project). That crankset is a triple with 3 1/8" chairing for a fix gear chain. A short bottom bracket is used to bring the entire crankset inboard, both for chainline and to reduce the Q-factor for my knees. Inside chainring sits on the usual inside position of a double crankset. Middle on the usual outside position. Outer chainring is spaced out into the gap between chainrings and crankarm.

Crankarm bolts are standard 8mm stainless flathead bolts with a generous shoulder. The inside chainrings were countersunk for the flathead bolts. The bolts were brought out to the tight fit 10mm by fabricating sleeves that fit tightly over the bolt shoulders.

This was done by Dave Levy at TiCycles, an expert machinist on a very high quality milling machine. Not cheap. We were very conscious that extending the bolt out unsupported meant that any play at all would be quickly fatal. especially since it would be seeing the rigors of fix gear use.

Ben