Changing rings on a rivetted chainset

stubs

Fixing up a bike to be used as a commuter and general cycle path hack. The chainset is a budget Suntour sq taper with rivetted chain rings, big and granny are fine, middle ring is sharkfinned badly and cant keep the chain on. I was wondering was it possible to drill out the rivets and use proper chainring bolts to fit a 2nd hand middle ring I have in my bits box.

The lad whose bike it is is a skint student so a new chainset is not in the budget.

nicklouse

not happening as you can not get spares. the BCD is different.

stubs

BCD is the normal 104mm it was first thing I checked. Just wondered what I was going to find when I drilled out the rivets. Will have a go tommorow see what horrors lie beneath the rivets.

supersonic

Assuming the BB is the right length, I think I'd just buy a new chainset, something like:

http://www.parker-international.co.uk/5 ... gn=pid5561

Quality piece of kit.

Or mega cheap:

http://www.jejamescycles.co.uk/ice-cran ... 80562.html

At least you know the chain will work the same on all rings.

bikaholic

I did once drill out the rivets of a silver SR Suntour crank for the sole purpose of replacing the outer ring for a single-speed build.

Though, I can't remember the exact model number, it had a standard 104 BCD spider, but no bolt holes for the smallest chainring (it was pinned together onto the middle ring).

The bolt holes in the spider were exactly the correct diameter for standard chainring bolts - if that's any help...

nicklouse

odd. you may be lucky,

stubs

The budget for the job is a nought followed by another nought so trying to get the lad pedalling for nowt. Will fire up the pillar drill tommorow see what happens. If it goes horribly wrong might have to lend him the cash for a cheapo chainset.

supersonic

I'll have a look in the loft, migth have a spare one.

Giraffoto

supersonic wrote:

. . .I think I'd just buy a new chainset, something like:

http://www.parker-international.co.uk/5 ... gn=pid5561

Quality piece of kit.

When you look at the pictures of the M410 Alivio Chainset or M430 Alivio Chainset, it looks as if the four arms that the chainrings bolt to are a separate piece from the drive side crank arm (i.e., they're not all cast/machined from one piece of aluminium). Is that how they really are? If that's the case, how are they attached together?

nicklouse

most are. press fit on the cheap cranks and the more expensive had a spline fitting and a lock ring.

even the new ones many are just a press fit, maybe with splnes.

stubs

Got it all sorted but those rivets were a bit tougher than I expected though, took some careful drilling with the pillar drill. It looked like a normal spider when I got the rings off so I just bolted on a spare big and middle ring and the lad pedalled off into the drizzle happy as Larry.