decline

dutret

don't replace the bb and get a different one.

abeyance

Are you familiar with cottered cranks. If not, I suggest www.sheldonbrown.com for more info. If you do replace the crank, make sure to replace both cotter pins as well. If the crank is loose ( flops a bit while rotating) you might have to replace the cotters, about $5. You might have to do a bit of filing to get it to fit correctly though. Look at the bb, if it is at all rounded, i suggest getting a new bb and crank, square taper, octolink, isis, whatever. Cottered cranks, while beautiful, can be a bear to deal with.

sivat

Cottered cranks are about the heaviest things you can find. I'm sure they made lighter cottered cranks, but the non-drive arm from the crankset I took off my girlfriends bike weighed nearly 2 lbs. The easiest way to replace it, is to replace the bb and crankset together. You can do this for about $60.

decline

can someone point me to a good bb and crankset that i could use on this bike? i need it to be cheap, thanks for all your help

also how much does it cost to have a bike shop do the install usually. thanks!

dutret

what bike is it?

Shimano makes cheap bbs if the threading isn;t weird. You can get cheap square taper cranks off ebay, from a local bike recycling place.

Retem

as long as it isn't french you are golden

Boss Moniker

Do an eBay search for Bulletproof Cranks.. the lettering is hella ugly, but it scratches clean off with a razor in five minutes (and it looks fine, no scratches in under layer of paint). The nice thing about the Bulletproofs is that they come in a variety of lengths, are really cheap ($20-25), and are shaped to hold one chainring only (mounted inner or outer), so the "spider" is nice looking.

Keep in mind that if you get updated cranks you'll need to get a chainring too, and that it should be the right size to screw onto the cranks (match the BCD, it'll be 110 or 130 or whatever). For a cheap chainring, go to www.danscomp.com, and on the last page of the "Chainwheels" section, there's a "Universal Chainring". They're cheap, but they cost like $14.

As for a bottom bracket, get a sealed bearing one, like a Shimano UN73 or UN51, 52, or 53. The 50s are cheaper. Make sure the threading and width matches your shell (68 or 72mm), and that the spindle length can give you the correct chainline.. might take some experimentation.

These are the cheapest options, and are what I'm going with.. they seem to work fine together. I got the black cranks, black chainring, black chainring bolts, and black eggbeater pedals, and they look sexy as hell.

sivat

^^^ I agree with everything he said except that the bb width should either be 68 or 70mm. The older italian frames are the only ones that use 70mm. What kind of frame is it? I just bought a set of bulletproof cranks that were 22.95 before shipping. The only difference between the UN7- and the UN5- is that the 50's series have a solid axle and the 70 series have a hollow axle. Since the frame is probably already pretty heavy, you can save some money and get the 50 series. Most bike shops will have them for around $20.

recneps

Those cranks tend to seperate themselves from the crank arms when running fixed.

i suggest replacing them, sugino RD/XD is a good crankset to replace them with, im sure you can find a shimano BB (un73) is a 107 spindle BB and would probanly work

ultraman6970

get a new bike hehehe will be cheaper...

Aeroplane

Doubt it, especially if they've already got this stuff worked out. Here's a price breakdown for replacing it:

Shimano BB (if standard threading): $20
Bulletproof/Dotek/FMF cranks: $30
Rocket Ring: $12
Chainring bolts: $5

So, for $67 you get a fully modernized, easily upgrade-able crankset. DO IT. And for another $12 you can buy a BB tool and not have to pay for installation.

dutret

plus another 12 for the tools to get the old one out. Plus a few hours of work trying to get it out. plus $5 for a can of liquid wrench. plus another hour trying to get it out. plus $20000 for chemo after the liquid wrench causes cancer.... and that is just the BB issues.

If the bike is a cheap junker it is not worth either $67 or the work. If it has a non-standard BB it definitely isn't. Sell it for $25 and buy another slightly newer plumbers special, one that already has square taper. If it is a really nice old bike the work/money is probably worth it but that is unlikely.

Aeroplane

I've done it twice with a hammer and a screwdriver, plus a bolt, nut, and lockwashers to get out the fixed cup. It's doable.

Have one of the hoodrats spray on the liquid wrench, thus avoiding the cancer risk.

ryand

working on bikes isnt worth it. buy a new bike and when something goes wrong, sell it and buy another.

dutret

Is indeed not worth it when a lesser amount of money could get you a better bike.

ryand

yeah, forget having fun and working on a project. i mean, my parents should have just sold their house but they replaced the floors instead. go figure.

dutret

there are better projects to work on that will cost less money and end with a nicer bike in many cases though. Why dump money into some outdated POS when a newer less POSsy bike could be had and fixed up for less then the cost of replaceing the outdated parts.

Would it really have been cheaper and easier for your parents to buy a new house with the floors then wanted then fixing thier old one?

ryand

well since the kids are gone and they don't need as much room, i'm sure they could have sold the house and bought a newer one that fit their needs a little better and came off with a little extra money.

and also, working on bikes is fun. he can always buy a second bike and work on that one too. oh gasp, now hes becoming a consumer. for shame!

xthugmurderx

working on bikes is amazing...and dutret always has a bad attitude. buythe tool, or find a friend that has it. bb are amazing (except you'll need way more than one tool. the sealed bb tool for the un-whatever, and the hook spanner, pin spanner and whatever they call that other tool for the other side of the bb...) but the drive side is reverse threaded (if i remember correctly...hard to recall when i'm not about to do it)

-jason

dutret

working on bikes is great but picking the right bike to work on is key. Some bikes are worth dumping money into others are not and just becasue you can fix something up doesn't mean you should. Your time and money can be better spent elsewhere.

xthugmurderx

true, but if it's his first time working on a bike, it's better he muck up that one than a good one, eh?

-jason

ryand

dutret:


oh, and:

dutret

I was thinking some more in $0-40 dollar range with less rust and more modern parts. Still not a big deal if he messes up but easier and cheaper to replace those messed up parts.

ryand

i stick by it would be a fun project. if you want to play with that bike, don't let somebody who has been enough of an ******* to other members to make them want to leave the board convince you that it isn't worth it.