Classic & Vintage - When should I worry about servicing the cotterless cranks/bottom bracket?

I've just got an old Raleigh GP back on the road and am loving every mile. However, in the back of my mind I'm worried about what the innards of the bottom bracket must look like. It's a 38 year old bike and I'm almost sure the BB has never been serviced.

Servicing these seems like a hornets nest, so I'd like to avoid doing it as long as possible and ultimately swap in a cotterless crank. Question is, what signs should I look for to detect an imminent failure? Given that the bike really doesn't have that many miles on it for its age (has basically sat in a garage for last 25 years) is it safe to assume I don't need to start worrying right away? Also please keep in mind that riding it until it breaks and then trashing it is not an option, as the bike has sky high sentimental value.

Oh, just learn to deal with cottered cranks! It's no big deal, and a properly adjusted / greased cotterless BB will last more or less for ever. Take a look at the "$16 cotter press" thread, or any of the threads that describe how to service cotters with a vise or even a C-clamp. Just don't use a hammer, and you'll be fine.

Changing a Raleigh cottered crank to a cotterless one can be complicated, depending on the BB of the bike. Raleighs used different BB threads (26 tpi rather than 24 tpi) and wider shells than most cranks. So to change to a cotterless crank you need to find a certain spindle that is getting increasingly diffficult to find.

Probably would run forever as is, however, nice to have a maintained bottom bracket.

Grab a crank arm and pull away from the bike to check for excessive play. Unfortunately, hard to tell condition of cups/bearings/grease without having the arms off.

Worth a trip to the shop if you don't want to do it and you like the bike.

I'd service the bearings or have them serviced before everything gets torn up in there, I clean and grease the crank bearings in every bike I work on and the condition of the grease and the stuff I find in there is kind of crazy some times.

I just did an 80s vintage Fuji and when I pulled the non-drive side cup out I found the bottom bracket to be full of seeds that a mouse must have been dumping down one of the frame tubes, Poor little guy lost all his food.

dont fear the cotter - get in there and overhaul that baby - get the bikesmith cotter press - its a sweet tool (though pricey)

An update based on further research. My Raleigh was built in Holland under license by Gazelle. According to what I've read elsewhere on the forum, those used standard 24 TPI. Curious, I measured my BB shell against a Nottingham built, '78 Mixte I'm fixing up (with cotterless cranks, oddly enough) -- my bike is definitely narrower, looks like less than 70 millimeters compared to ~71 millimeters for the Mixte (hard to be more precise with my measuring tape).

Does all this indicate I'm dealing with standard threading? If so, does it change the equation at all? That is, if I'm able to do a straightforward conversion to cotterless, is it worth it? Again, I should note I'm not actually experiencing any trouble with the cottered cranks. I'm mainly looking to do preventative maintenance and to scratch the everpresent upgrade itch.

Do the bearings immediately. Riding an old, left to sit bicycle, without renewing the lubricant is a mistake. Often times, and I do mean often, the grease in the bottom bracket, head set and wheel hubs has lost its ability to lubricate. I have even seen grease that has turned to rust dust, believe it or not.

What to look for - no grease extruded near the spindle opening is not good. Rough feel with chain off while slowly rotating the cranks, or being able to wiggle the cranks because the bottom bracket is improperly adjusted.

The point is, no-one knows what is in there until you open, clean, look and then do what needs doing to make things right.

Hope that is a help. For a bit more help, have a look at How To Rebuild A Bottom Bracket (http://www.mytenspeeds.com/My_TenSpeeds_1/FREE_SITE_1/FREE_SITE_12_BB_Rebuild_1_Intro.htm).

I brought it by a LBS, one that specializes in old bikes, and the guy there speculated that the cotters would come out with relative ease since the bike has no corrosion. He said if he serviced the bottom bracket he'd prefer to swap in a cotterless crankset (I'd probably start on my own and take it over to the shop if the cotters didn't press out easily). Any recommendations for places to look for new bottom brackets/cotter less cranks and what I should be looking for? I've spent some time on Harris Cyclery and have been amazed/intimidated by the selection. I'd obviously want to maximize weight savings while keeping the budget reasonable (ie: no Phil Wood, as sweet as those look).

If it's a 68mm bottom bracket and 24 tpi cups you can do whatever you want with it. I'd keep the cups if they're not pitted. If you really want to go cotterless, here's some advice on spindles;
http://mountainbikers.hubsystems.com.au/pdf/barnetts/chapter9.pdf
they're usually $5 or $10 on ebay and then find the crank you want. I'd watch the dumpsters for a dead mountain bike with a triple and get the whole set up from that.
I had one of those Gazelle GPs. They're nice bikes. There was a thread on them going last year. Worth looking up.
Mine had a flip flop rear hub. A nice feature that I never got around to taking advantage of.

OK, sorry to revive my dead thread, but I am preparing to bite the bullet and redo the crankset on the GP and am very confused. Based on the bracket width (narrower than 70 mills, measuring on the outside with two different tape measures) and the country of origin (built by Gazelle in Holland) I thought my Raleigh would be 24 TPI. However, I brought my bike over to a shop that specializes in old bikes, where the tech looked at my bike for half a second and said "Oh Jeez, Raleigh threading." Is he wrong? Is there a way to be sure before I go through the massive PITA of getting off the cottered cranks?

Beyond that, I'm also wrestling with the cornucopia of cranksets and widths out there. I just want to replace my Stronglight double with a new double of the same size. I'm not really sure where my BCD and chain width come into play.

OK, sorry to revive my dead thread, but I am preparing to bite the bullet and redo the crankset on the GP and am very confused. Based on the bracket width (narrower than 70 mills, measuring on the outside with two different tape measures) and the country of origin (built by Gazelle in Holland) I thought my Raleigh would be 24 TPI. ...
Probably not. See http://sheldonbrown.com/raleigh26.html
It's likely that your bike has the Raleigh threading of 26 TPI instead of the more common 24 TPI.
However, unless your current bottom bracket is in really bad shape, you can probably upgrade to a new crank, spindle, and bearing balls while keeping the existing cups with their 26 TPI threading. See the above site for details.