Bicycle Experts. Upgrade my sentimental old clunker or repace?

[Bourbon]

I picked up an 80's era Nishiki bicycle, nothing fancy, a little over a decade ago.  I came close to selling it a year or so ago but decided to keep it because  I get attached to things.  Apologize if the terms are wrong, I've pulled up a diagram of a bicycle and am working form it.

I was having an issue riding it before we moved and I believe it is because the outer chainring is bent.  I took it to two shops, both adjusted it and didn't charge me a thing but the problem keeps coming back.  I bent it back into shape myself this weekend and then put together the kid carrier.  Got halfway through the ride to the library with our 3 year old and I think it bent itself out of alignment.  This causes the chain to pop some and it doesn't like to stay on the large chainring.  Chain can pop off entirely. 

With the extra weight of the books and kid hauler, I wasn't up for pedaling on the larger ring much anyway, but went to commute on the bike myself today and I'm running slow, the rear derailleur did something funny and the chain popped off again.  I've figured out a schedule that may let me bike to work 3 days a week, maybe more if I can manage to haul a kid to daycare in the kid hauler. 

Does it make sense to DIY and replace the working components on the bike?  If so, what parts and any recommendations on specifics?  Alternative is to take it a shop and get their take and have them do it or to let the bike go and get one of these modern things.  My wife is in need of a bike and I am pretty sure she will be leaning towards a new one, but might be able to bring her back to vintage if this project is successful.

[eil]

If the rest of the bike is in good shape and it's a bike you want to keep indefinitely, it would be highly Mustachian of you to buy replacement parts and learn how to fix it yourself.

[TrMama]

If one of the front chainrings is bent, replacing it with a new one will be a simple and cheap fix. The teeth eventually wear out anyway, so this is a normal maintenance item.

Another cause of the chain coming off the front ring is when the front derailleur isn't adjusted quite right. It sounds like the shops have tried adjusting it and it's still not working. I'd go ahead and replace the part. It should be under $50.

[Bourbon]

If one of the front chainrings is bent, replacing it with a new one will be a simple and cheap fix. The teeth eventually wear out anyway, so this is a normal maintenance item.

Another cause of the chain coming off the front ring is when the front derailleur isn't adjusted quite right. It sounds like the shops have tried adjusting it and it's still not working. I'd go ahead and replace the part. It should be under $50.

Great! 

I had intended to get some part numbers and pictures of the bike, but unfortunately after I made it to the office I realized I left some important papers and left the bike at home when I rode it back.  Any guide on finding the right chainring?  Just count the teeth?  I've seen nashbar recommended and they seem to have a sale going on. 

If I can keep up with the biking habit I may also look into adding clips.

[Glenstache]

You will need to know the number of bolts for the chainring and the bolt-circle-diamter (BCD) to get the right ring. The number of teeth is usually printed on the side of the ring (or you can count em).

http://www.sheldonbrown.com/gloss_bo-z.html

A worn chainring can also spit the chain off as you describe. SO, if your chainring is worn such that the teeth look like asymmetric sharkfins your current chain may no longer mesh with the new chainring. Your chain should probably be replaced anyways unless it is has been replaced in recent memory. This can also mean that your rear cassette is worn and would similarly no longer mesh with a new chain. That sheldon brown site should help you evaluate this a bit before you start buying parts.

[Rollin]

It is very unlikely that your front large chain ring is worn as there is hardly any force on that ring (less than all the others).  More likely tht your chain is having issues and possibly needs replacing.  If you had issues in the rear as well I'd say chain, plus potentially the rear set of cogs.

I don't know where you live or how fit you are, but most people do not need the large front chain ring.  When fixing bikes of people who don't have the cash or desire for new I take the front off derailleur and large chain ring off altogether.

However, back to your original question.  Replacing parts can get quite expensive.  A chain or rear set of cogs (if still available from a 80's Nishiki as some were Sun Tour) is not bad, but if you get into wheels etc. it really adds up.

Also, if you are going to ride a lot it is hard to beat one of the newer bikes.  The shifting and braking is usually great and hardly ever need adjusting, even with lower priced models.  The ride is usually smooth too.  Just don't get one from a department store.

If you do decide to get a replacement go to bikeforums and ask your questions.  They are very helpful there.

[frugaliknowit]

As much as I would love for you to save money, unless you have a good work area, tools and possibly a working bike stand, and lots of time on your hands, the learning curve is pretty steep on this so that you'll likely invest a lot of time fixing this bike such that you might want to ditch it and buy a new one. 

[Bourbon]

It is very unlikely that your front large chain ring is worn as there is hardly any force on that ring (less than all the others).  More likely tht your chain is having issues and possibly needs replacing.  If you had issues in the rear as well I'd say chain, plus potentially the rear set of cogs.

I don't know where you live or how fit you are, but most people do not need the large front chain ring.  When fixing bikes of people who don't have the cash or desire for new I take the front off derailleur and large chain ring off altogether.

However, back to your original question.  Replacing parts can get quite expensive.  A chain or rear set of cogs (if still available from a 80's Nishiki as some were Sun Tour) is not bad, but if you get into wheels etc. it really adds up.

Also, if you are going to ride a lot it is hard to beat one of the newer bikes.  The shifting and braking is usually great and hardly ever need adjusting, even with lower priced models.  The ride is usually smooth too.  Just don't get one from a department store.

If you do decide to get a replacement go to bikeforums and ask your questions.  They are very helpful there.

If I can figure out how to make a gif with a cellphone video I can post what I am seeing.  I can see it by looking down while riding, or by placing the bike upside down and spinning the crank.  A noticeable back and forth walk of the path on the larger ring.  I've seen someone suggest it can occur either by a hard bump or by poor shifting technique. 

Not sure on the fitness question as I don't ride terrible often.  I lift free weights(squat/bench/deadlift) as my main form of exercise, cycling is more of a utility/free cardio/mode of transportation/time with kids.   My default riding gears are the large one up front and the smaller one in back.  Seems to be the hardest to pedal on.  Have a great little downhill as I leave my house and a heinous uphill as I finish my ride home, otherwise I pretty much default to the harder setting.  Pulling the trailer would probably have been too hard for very long if the bike would have stayed in this gear, but the smaller chainring and smallest rear gear seemed about right.  Current ride to work is only about 2.7 miles one way,  thinking about trying out dropping the kids off in the trailer, that would be a little over 3 miles with the trailer and another mile on into work.

I'm open to it being something else, as I'm not an expert bike mechanic.  It may be my best option to go by and discuss this with them again, the last time was ~ a year ago with not much riding occurring between then and now.  Was hoping to use this opportunity to become more familiar with maintenance on a bike, but don't have too much free time to dedicate to it.  Alternative is to just delay riding while I get it sorted out or pay up and get back on the bike sooner.

[Bourbon]

As much as I would love for you to save money, unless you have a good work area, tools and possibly a working bike stand, and lots of time on your hands, the learning curve is pretty steep on this so that you'll likely invest a lot of time fixing this bike such that you might want to ditch it and buy a new one.

Called quickly down to the shop that is on my route just now.  As long as it has removable crank bolts(I'm pretty sure this is what he said and I literally got off the phone lest then a minute ago) which I think it does, he ballparked it at $20-30 for the chainring and another $10 or so in labor. 

[PindyStache]

Could it be the bottom bracket?

I don't think excessive use/wear would BEND the chainring. But if the bottom bracket has a bearing out or something else wrong then it may cause the chainring to wobble back and forth.

I am no bike maintenance expert, but this happened to me recently. If you grasp both pedals in your hands and shift weight back & forth, holding the pedals in place, do the chainring/pedals/cranks move back and forth or stay still?

[Bourbon]

Could it be the bottom bracket?

I don't think excessive use/wear would BEND the chainring. But if the bottom bracket has a bearing out or something else wrong then it may cause the chainring to wobble back and forth.

I am no bike maintenance expert, but this happened to me recently. If you grasp both pedals in your hands and shift weight back & forth, holding the pedals in place, do the chainring/pedals/cranks move back and forth or stay still?

Will check tonight.  Was reading http://sheldonbrown.com/straighten-chw.html and he mentions that as well.  Check the bracket, check the spider, then the chainring.
 

[kendallf]

Easy fixes, in any of these cases.  Even if you needed an entire crankset, you can buy a square taper one (almost certainly what you have on an 80s Nishiki) for $20-30.

One example:

http://www.amazon.com/Sunlite-Alloy-Double-Crankset-Square/dp/B003CO2RTS/ref=sr_1_13?s=cycling&ie=UTF8&qid=1402348273&sr=1-13

Changing the chainrings will only require a hex tool; if you need to do more you'll need a few bike-specific tools, but none of them are very expensive.

[Bourbon]

Grabbed a quick photo last night from the side, should have gotten one from the top as well, but toddler attacked me shortly there after.

Forum does not seem willing to let me attach though. Need to track down some image hosting. I had to make the post and then go back to modify to get the attachment on.  Goofed up every time I tried to include the attachment while writing the post.

[Posthumane]

I have an 80's era nishiki as well which I "upgraded" with a 3 chainring crankset from a mountain bike since I almost never used the large ring. I went from having 52 and 42 tooth chainrings to 44-34-28. Much better for hills. So I'm a bit biased, but I say definitely fix it.

I don't see anything obviously wrong looking at that picture, although it's hard to tell from a photo. I also doubt that your large sprocket is worn, although it could be the chain guard (outer circle without teeth) that gets bent from hitting things. Sometimes this can cause the chain to come off the large sprocket when it's bent it too much and contacts the chain.

Changing cranksets is very easy (although you may need a puller tool, which is about $15) as almost all old bikes use a square taper bottom bracket. You can also take your bottom bracket apart and clean/grease the bearings at the same time, or you can change it out to a sealed bearing bottom bracket if you like.

[Bourbon]

I have an 80's era nishiki as well which I "upgraded" with a 3 chainring crankset from a mountain bike since I almost never used the large ring. I went from having 52 and 42 tooth chainrings to 44-34-28. Much better for hills. So I'm a bit biased, but I say definitely fix it.

I don't see anything obviously wrong looking at that picture, although it's hard to tell from a photo. I also doubt that your large sprocket is worn, although it could be the chain guard (outer circle without teeth) that gets bent from hitting things. Sometimes this can cause the chain to come off the large sprocket when it's bent it too much and contacts the chain.

Changing cranksets is very easy (although you may need a puller tool, which is about $15) as almost all old bikes use a square taper bottom bracket. You can also take your bottom bracket apart and clean/grease the bearings at the same time, or you can change it out to a sealed bearing bottom bracket if you like.

Hmm.  My 50ish tooth chainring is my favorite one, but you are the second person to have said that.  Did you have to change out the derailleurs to accommodate the 3rd ring?

The number stamped on the bottom of my frame is S0110082, so according to wiki/bikeforums I believe that makes it a 72-75 model. Not sure if that is correct though, the rear derailleur is a Shimano 600, front had a different number that I didn't write down. 

http://en.wikipedia.org/wiki/Nishiki_(bicycle)#Serial_Numbers

"Kawamura manufactured frames (1972-1987*)

Serial number format XYZZZZZ where:

X is a letter indicating the market using the following codes:
A= Australia
C = Canada (pre-1985)
E = Europe
K = USA (pre 1985)
W = USA (1985-1987*)

Y is a letter indicating the last digit of the manufacturing calendar year, where A =1, B = 2, C = 3… J = 0. Exception is letter S, used on all frames prior to 1975. "

[Posthumane]

I didn't change out deraileurs on my bike, the one I had on there had enough travel to accommodate three chainrings with a bit of adjustment of the stops. I did have to flip the bottom bracket around compared to how it was installed in the mountain bike as MBs typically have a larger offset which would cause chain misalignment. I like to spin the pedals at about 90 rpms, with occasionaly 80-100rpm excursions, maybe you like to spin slower.

I'll have to take a look at my bike's serial number when I get home - I actually never thought to look it up.

[Bourbon]

Probably not real clear, but tried to get a video -

via Imgflip GIF Maker

It appears to me on inspection that where the hex bolts are, the chain ring it tight to the outer guard and in between each of them it bows in towards the bike a little bit.

The cranksets on amazon all seem to have the "arm" to attach the pedal as part of the unit.  I think mine are separate on this bike, and what is up with that slot where the arm connects?  Is there a special tool to remove this?

[Glenstache]

Yep, it looks like the chainring is bent in near the crank arm. This isn't super common, but it does happen. Loose chainring bolts can be a contributing factor. IIRC, the teeth didn't look too worn in the side view, so as long as the spider (part of crank arm that holds the chainrings) is not bent, a new ring should get you on your way.

[Guses]

but most people do not need the large front chain ring.  When fixing bikes of people who don't have the cash or desire for new I take the front off derailleur and large chain ring off altogether.

Really?! That's a pretty broad statement.

I literally only use my large front chain ring. I was actually considering removing the smaller ones to save a bit of weight. Is the chain ring smaller on a MTB?

Suggestion to OP: Have you considered replacing your bike with another used one in good condition?

[Bourbon]

Yep, it looks like the chainring is bent in near the crank arm. This isn't super common, but it does happen. Loose chainring bolts can be a contributing factor. IIRC, the teeth didn't look too worn in the side view, so as long as the spider (part of crank arm that holds the chainrings) is not bent, a new ring should get you on your way.

Chainrings seem like they cost more than cranksets.  Is this a quality issue?

Thinking this one looks to be a match http://www.amazon.com/Sugino-52t-130mm-Outer-Chainring/dp/B001GSOCFE/ref=sr_1_2?s=sporting-goods&ie=UTF8&qid=1402675049&sr=1-2&keywords=130mm+chainring+52 I can measure the distance from my bolt holes to the teeth on my existing ring, I don't see this info posted on the listings for the chainrings but some of them seem to have the holes offset from the teeth more than others.

[Glenstache]

Chainrings seem like they cost more than cranksets.  Is this a quality issue?

Yep. The new one will probably be nicer. Also, individual parts are always more expensive than buying a package. If there is a used bike shop with parts in your town you might be able to find a replacement there. In Seattle we have a shop called Recycled cycles that literally has bins of used bike parts and you could probably find a replacement for $5. Just take the old one in and if the bolt holes are in the same spot, the replacement should fit.

[Bourbon]

Chainrings seem like they cost more than cranksets.  Is this a quality issue?

Yep. The new one will probably be nicer. Also, individual parts are always more expensive than buying a package. If there is a used bike shop with parts in your town you might be able to find a replacement there. In Seattle we have a shop called Recycled cycles that literally has bins of used bike parts and you could probably find a replacement for $5. Just take the old one in and if the bolt holes are in the same spot, the replacement should fit.

Well I may just take it in to the LBS then.  They quoted me ~20 for a part and $10 for labor over the phone, but I might have asked specifically about a crankset.

[daveydinner]

My shop sells a made-in-USA 46t Aluminum ring for $38. It'll last you a long time and is head and shoulders above the one you've got in terms of quality.

Consider ditching the 50 tooth ring as someone else mentioned. They are ridiculous for most riding, only useful for accelerating downhill! Our stock cranksets come with 24/36/46 and nobody complains.

[PindyStache]

I'm curious--what is the difference of a "high quality" chain ring? Does it just last a lot longer?

[Bourbon]

My shop sells a made-in-USA 46t Aluminum ring for $38. It'll last you a long time and is head and shoulders above the one you've got in terms of quality.

Consider ditching the 50 tooth ring as someone else mentioned. They are ridiculous for most riding, only useful for accelerating downhill! Our stock cranksets come with 24/36/46 and nobody complains.

Hmm.  Read up a bit on cadence, any good way to count that?  I might be able to bend the big crank back into place temporarily to see how fast I am pedaling it.  As I said, I default to the larger ring but haven't paid that much attention.  Certainly not standing up while riding, but does take a crank or two from a stop before it picks up speed.

[Posthumane]

There are bike computers that can measure your cadence with an additional sensor, but I usually just estimate mine by counting the pedal rotations over a few seconds. That being said, the actual number is not as important as what gets tired first - your leg muscles or your cardio vascular system. If your muscles are getting sore before you're breathing hard then your cadence is too slow, and if you're running out of breath or simply unable to pedal fast enough (i.e. bouncing in your seat) then cadence is too fast. You can also calculate your cadence from your speed, working back through wheel size to wheel RPM, then dividing by your gear ratio.

I find the 44t large ring with 14T smallest sprocket to be adequate for anything other than steep downhills so I usually just relax a bit on those and coast down. The 28T ring with 30T largest sprocket is rarely useful as you end up spinning very fast for little speed, but once in a while on a very steep climb I'll use it.

[Rollin]

but most people do not need the large front chain ring.  When fixing bikes of people who don't have the cash or desire for new I take the front off derailleur and large chain ring off altogether.

Really?! That's a pretty broad statement.

I literally only use my large front chain ring. I was actually considering removing the smaller ones to save a bit of weight. Is the chain ring smaller on a MTB?

Suggestion to OP: Have you considered replacing your bike with another used one in good condition?

Yep, broad but true.  If you are using your large chainring and your chain line is correct, on many bikes you are traveling in excess of 18 mph or so.  Yes, you can probably ride that fast or faster, but most people don't, at least not for long.  Besides, you can spin and ride just as fast by using the small chain ring and a smaller rear sprocket.  I think 53s on most road bikes are a joke.  Especially given an 11 tooth rear.  I spun one out ONCE and I was doing 55 mph!  You cannot tell me that the average rider needs this.