Bicycle Mechanics - new crankset w/ old compnents

I have a bike around 20 years old. I like the ride, fit, etc., and I was not planning on replacing it. The components are old suntour "honors" and suntour "spirit" derailleurs. I was looking at the crankarms the other day though, and they look like big, heavy peices of steel, and also the chainrings were looking a tad worn. I was wondering if I could put Ultegra cranks (or any other modern crankset) on my bike and have it work with my old front derailleur. I'd probably need a new bb, but they're not that expensive. Is this just more trouble than its worth?

If not, is it possible to put new chainrings on my old suntour crankset?

You shouldn't have any trouble except you need a new front derailuer and a matching BB for your new crankset. My TT bike I built this year has 9 speed DA crankset, DA 9 spd chain, 7 speed freewheel with 8 speed bar end shifters. The disc wheel is 18 years old with fixed 125mm spacing and was 6 speed. I threw a 7 spd freewheel on it and popped it into a new 130 mm drop-out frame. It all works great! The Fife

It depends. What kind of BB threading do you have? New Ultegra BB's are splined, whereas your old one is tapered. If your BB uses, say, French or Swiss threading, you are S.O.L. Also, mixing 9-speed rings with 5 or 6-speed stuff is not likely to have great results. Maybe with an 8-speed chain it might work, but with anything wider, it probably won't. Besides, ask yourself, is it really worth spending $200 for an ultegra crankset on your old bike? What is the brand? What is the quality? Chances are, you'll just be making a silk purse out of a sow's ear.

You wouldn't really accomplish anything. If the chainrings are worn replace them. Clean and repack the bearings - bb, headset, hubs, replace the cables and housings, clean, lube and adjust the brakes and derailleurs, put on some nice new bar tape and you will have a bike that feels like new for $50-60. If you want to really go wild, replace the brake hood covers if the old ones are getting dry and grungy.

Put the other $150 in the cookie jar to save for a new bike. :D

What a pile of crap....you do not need a new front derailer if you change cranks or rings. Not likely that a bike with suntour stuff has fench or swiss BB threading. Make of bike would be helpful.If it's oriental, the BB threading is english. There are all kinds of crank options.Just make sure to match crank to BB.Tapered cranks can be iso or jis taper. Splined cranks have to have the proper BB spline pattern and there are several. BB spindle length has to match the crank.Although it may not be worth a brand new ultegra crankset, there are lots of other possibilities that may be better than what you have and may even be cheaper as a crankset than just replacing rings.

What a pile of crap....you do not need a new front derailer if you change cranks or rings.

Ummm.....who mentioned changing the front derailleur (note correct spelling)?


Not likely that a bike with suntour stuff has fench or swiss BB threading.

Mid-70's Motobecanes did. So there!

:rolleyes:

Check what 'the fife' had to say about needing a front derailer.

Sorry, perhaps a new front derailleur is not needed without index shifting. The front derailleur had to be replaced on old bikes I have upgraded due to shifting problems. I changed the front derailleurs to an STI era model as a fellow rider/ bike shop mechanic recommended and bingo problem was gone. The shop had replaced every single one they upgraded to STI.

If the bike has British BB threads, look for a good used aluminum crankset and BB on eBay. If you like the frame and the other components, the crank is a reasonable upgrade. (I performed the same operation on a 1960 full-531 Austrian classic and was able to find a crank spindle whose bearing spacing accommodated my Swiss-threaded BB cups.)

The Fife...correctomento,about replacing non index capabable front derailers when changing old bikes out to SIT indexed front shifting.It's the indexing bugaboo,not the cranks.

its a bianchi steel-frame bike from "back in the day" On the bottom braket, it says that it was made in Japan. It has friction shifters, and honestly, i like my friction shifters better then my friend's 105 index shifters, they're much smoother and require less adjustment (the adjustment is for YOU not your bike)

Will any chainrings fit any crankset? I noticed when looking around that there are ultegra chainrings and dura-ace chain rings, as well as several other no-name chainrings.

Also, what is the difference between an italian BB and a english BB? All I think is that the threades maybe go different ways?

If it's aBianchi,made in Japan, it has English thread BB. English thread is 1.37x24 tpi,68mm shell width and the drive side is left hand thread and non drive side is right hand thread. Italian thread is 36mmx24 tpi,70mm shell width, and both sides are right hand thread.Should be marked on the BB.You have to match chainrings to crank BCD(bolt circle diameter). Save your money and put no name or inexpensive Sugino rings on it.

Yeah, what Pokey said.

MOST modern road cranks, except Campy, have 130 mm bolt circle diameter, the diameter of a circle drawn throught the crank bolts. You are probably safe to assume yours are 130.

Out of curiosity, are your crank arms cottered, ie, is there a bolt that goes across the end of the crank? Or are the cotterless with a bolt that screws into the end of the bb spindle?

That's a generalization about BCD that does not work very well. Suntour used 135, Campy and others 135 and 144, and I have run into 110 in that vintage.It pays to measure.

they are cotterless. I took a pic, but i cant figure out how to post it...

Also, there is a ring around the outer chainring, and I was wondering if i took it off if it would mess up my bike

here we go:

It's a chain guard.If it's separate and not riveted on or attached to a chainring it can be removed.Somehow them cranks do not look like steel.Tried a magnet on them?

you think they're aluminium? hmm...that might defeat the purpose of my whole quest...

What purpose?Eleminate all doubt.Use a magnet.

well, the magnet didn't stick, but i also heard that if the steel has a high chrome content (like a lot of high quality stainless steels) then it wont be magnetic. Even if it is aluminum, I might want to replace it, because new cranks are lighter and sexier.

Originally posted by pokey
That's a generalization about BCD that does not work very well. Suntour used 135, Campy and others 135 and 144, and I have run into 110 in that vintage.It pays to measure.

Look at your inner chainring. You can probably tell by inspection whether your bolt circle diameter (BCD) would permit you to install something with a smaller diameter (and fewer teeth). Sheldon Brown has a comprehensive discussion of BCDs, tooth counts, brands, years, etc. Summary:

151mm BCD --> 44T minimum chainring size
144mm / 41T (common in 1970s)
135mm / 39T (Campag only)
130mm / 38T (common in 1980s and 1990s)
128mm / 38T (Nervar only)
122mm / 38T (Stronglight only)
110mm / 34T (common in 1980s and 1990s)

Originally posted by Phatman
well, the magnet didn't stick, but i also heard that if the steel has a high chrome content (like a lot of high quality stainless steels) then it wont be magnetic. Even if it is aluminum, I might want to replace it, because new cranks are lighter and sexier.

You have a low-end, possibly dangerously flimsy, cotterless crank whose outer chainring cannot be replaced, and whose bolts and spacers are probably of smaller-than-standard diameter. You probably also have smaller-than-standard spindle shanks with nuts, instead of bolts, affixing the cranks. I vote for a new BB and new crankset. Almost anything made within the last decade would be an improvement.

Originally posted by pokey
"What a pile of crap....you do not need a new front derailer if you change cranks or rings. " edited

Pokey you are obviously a very knowledgable guy about bikes and I am certain your technical input is very welcome on the forum but I would suggest that your interpersonnal communication skills suck!..

I enjoy reading your posts generaly but personally find your comment on this occasion objectionable and quite unnecessary.

The problem is this . I would guess that by far the greater number of forum members probably haven't a clue when it comes to basic bike maintenance and even fewer have any experience of upgrading an old spec bike with newer componants but the opportunity to discuss these issues with others on the forum is what makes this such a brilliant forum.

There have been 209 members and guests read this thread so far and I should think that your verbal `put down' would have put off most from contributing to this thread or any other for that matter for fear of readicule. No one likes to be told that there contribution is a pile of poo so a little less aggression and a little more tolerance eh?:)

Originally posted by earleybird
edited

No one likes to be told that there contribution is a pile of poo so a little less aggression and a little more tolerance eh?:) With all due respect, a pile of poo is a pile of poo, especially on a so called tech forum. Just because it is a 'contribution',does not validate it.Iwill try to come up with something more PC.Someone else can shove the rainbows.

Well its good to see you didn't take offence at my comment pokey, because none was intended. says a lot for your character.respect dude:beer:

Some people may not have such strength of character or resilience and I suppose I was simply suggesting there might be another way of saying what you felt that perhaps might not cause offence. I always try to bear in mind that there are children, senior citizens and ladys reading these posts as well as us `rednecks':D

I remember not so long ago that I made what I thought was a helpful suggestion in this topic and another member corrected my mistake without causing me undue embarassement for which I was very grateful.
I had shot my mouth off without putting my brain in gear! :o

will any english BB fit in my frame? (is there a standard size) Will the age of my bike keep me from finding a BB that fits? I have heard that there are different BB shell diameters and widths.

Originally posted by Phatman
will any english BB fit in my frame? (is there a standard size) Will the age of my bike keep me from finding a BB that fits? I have heard that there are different BB shell diameters and widths. Think it was established it's english thread. There are 2 english shell widths road is 68 mm and mtb can be 68 or 73. Would not hurt to measure to be sure. Modern Cartridge BB are ordered by shell width and spindle length. Spindle length and type of spindle has to match the crank chosen. Be aware that in tapered cranks/ BB there are JIS,shimano for example and ISO,campy for example tapers.Newest trend is to splined spindldleBB/cranks of which there are several incompatible varieties.

ok, guys, this has got me spooked. I was on E-bay, looking for a new crankset, and i saw several nice cranksets (for really good prices) but some of them say, for instance, "Shimano 105 crankset 9 speed" Will it work with my 5-speed freewheel? Also, fife, mentioned something about putting a new freewheel on his bike, and I'm not really looking forward to doing something that extensive.

Phatman, I went from 6 speed freewheel to 7 speed with a 9 speed crankset and chain. 7 speed would allow you much more gearing options which is nice. It makes a big difference.
The 9 speed crank should work with your 5 speed freewheel but you will want a 9 speed chain so it will shift properly.
I can't beleive that after 20 years this stuff is not worn out.

A 9-speed chain is too thin to work with 5-speed cogs. the spacing between the cogs is too large for a narrow chain, like used on 9-speed stuff. Also, a 9-speed shimano 105 crankset uses a splined BB. Just go out and buy a cheap ols Tiagra 7-speed unit-it's comparable to the old junk you have, and won't cost you more than the bike is worth. Don't put a $150 crankset on a $50 bike. The fact that your bike has a stamped-steel ringset (with a chainguard, yet!) tells me that you have just such a bike. You can go ahead and buy an expensive new crankset, maybe you can even make it fit (do you know how to check your chainline, btw?), but in the end, you'll have wasted good components on a cheap, obsolete bike, and it won't work worth a d@mn. Save your money.

Personally, I don't think there is a thing wrong with your crank. Suntour was a good brand. In fact, a VERY serious young racer-type friend of my just built up a gorgeous old Somec frame with "retro", mostly Suntour parts, including a crank that looks exactly like yours. This guy has a very nice Bianchi, his brand new team-issue Orbea, and other bikes. Guess which bike he has been riding the four times I have run into him in the last couple of weeks?

Originally posted by The Fife
Phatman, I went from 6 speed freewheel to 7 speed with a 9 speed crankset and chain. 7 speed would allow you much more gearing options which is nice. It makes a big difference.
The 9 speed crank should work with your 5 speed freewheel but you will want a 9 speed chain so it will shift properly.
I can't beleive that after 20 years this stuff is not worn out. You do not need a 9 sped chain to work with a 9 speed shimano road crank.

Originally posted by D*Alex
A 9-speed chain is too thin to work with 5-speed cogs. the spacing between the cogs is too large for a narrow chain, like used on 9-speed stuff. Also, a 9-speed shimano 105 crankset uses a splined BB. Just go out and buy a cheap ols Tiagra 7-speed unit-it's comparable to the old junk you have, and won't cost you more than the bike is worth. Don't put a $150 crankset on a $50 bike. The fact that your bike has a stamped-steel ringset (with a chainguard, yet!) tells me that you have just such a bike. You can go ahead and buy an expensive new crankset, maybe you can even make it fit (do you know how to check your chainline, btw?), but in the end, you'll have wasted good components on a cheap, obsolete bike, and it won't work worth a d@mn. Save your money. As usual, this guy is fuff of applesauce. If you buy a 9 speed shimano crank, make sure you also get the matching splined BB. you will need one set of tools to remove your crank and BB and another set to install a cartridge BB. You do not need a 9 speed chain just because it is a 9 speed crank. A sram 8 speed chain will run on 6,7, and 8 speed and likely 5 too. Kmc make a slighyly wider 5,6,7 speed chain.If you buy a crank, think chain and freewheel too.That way it is al new and will work well together.No point in a new chain on a possibly wore out freewheel. You may be money ahead if you buy a slightly older 7 or 8 speed tapered spindle type crankset. Cranks are speced to work with a spindle length or a narrow range of length.You buy the BB to match the crank, and no worries about the chainline as the expert D*alex implies.Even if the chainline is off a bit,the universe will not implode and you will not suffer catastrophic consequences.It's just more applesauce. I have never seen so much hooey on the simple act of switching an old crank.

Originally posted by RainmanP
Personally, I don't think there is a thing wrong with your crank. Suntour was a good brand. In fact, a VERY serious young racer-type friend of my just built up a gorgeous old Somec frame with "retro", mostly Suntour parts, including a crank that looks exactly like yours. This guy has a very nice Bianchi, his brand new team-issue Orbea, and other bikes. Guess which bike he has been riding the four times I have run into him in the last couple of weeks? Suntour made a whole range of stuff, some pro quality,some not so good.I have alot of the better stuff , and it is worht putting on a good bike. His crank does not even look like suntour. No doubt it is a cheap crank,but probably functional.Not likely the rings are worn as chainrings last a long time. Personally on a bike of this apparent quality I would not waste time or money on just changing a crank unless there was compelling reason,like also havng to replace the BB too.Then I would go for an inexpensive tapered type and cartridge BB and be done with it.

Originally posted by pokey
As usual, this guy is fuff of applesauce. If you buy a 9 speed shimano crank, make sure you also get the matching splined BB. you will need one set of tools to remove your crank and BB and another set to install a cartridge BB. You do not need a 9 speed chain just because it is a 9 speed crank. A sram 8 speed chain will run on 6,7, and 8 speed and likely 5 too. Kmc make a slighyly wider 5,6,7 speed chain.If you buy a crank, think chain and freewheel too.That way it is al new and will work well together.No point in a new chain on a possibly wore out freewheel. You may be money ahead if you buy a slightly older 7 or 8 speed tapered spindle type crankset. Cranks are speced to work with a spindle length or a narrow range of length.You buy the BB to match the crank, and no worries about the chainline as the expert D*alex implies.Even if the chainline is off a bit,the universe will not implode and you will not suffer catastrophic consequences.It's just more applesauce. I have never seen so much hooey on the simple act of switching an old crank.

http://www.humorasylum.com/pics/pic146.jpg

Originally posted by RacerX


http://www.humorasylum.com/pics/pic146.jpg Sharing your current class picture? Love a good laff:lol: :roflmao:

Phatman,
My experience with running an 8-speed chain on 9 speed cranks has shown me they are not compatible. If you like "dropping a chain" all the time because the chain is too wide to drop onto the lower chain-ring then you can give it a try.
I don't have personal experience with the 5 speed freewheel and the 9 speed chain but I know the 9 speed chain works well with 6, 7 and 8 freewheels. I wouldn't mind knowing the spacing difference between 5 and 6 myself, as someone stated 5 speed won't work. I would recommend a 7 speed freewheel though just for the additional gearing options and you can buy nice, used freewheel built wheels later rather inexpensively.
Don’t use an 8 speed freewheel unless you want to get involved with re-dishing the wheel.
Others on this thread have mentioned that your bike may not be worth investing new components on. I would suggest to go ahead with your plans to upgrade. It would be good experience and you may get a few modern tools. If you want to build another bike someday, you will always have these components and tools to use. Next year you may find a lighter frame or wheel-set.

Actually,I'm doin it.Dropping a chain has more to do with derailer mal adjustment.He is also running friction front shifters rather than STI. Totally different concept and principals involved when it comes to shifting.Consider context and the fact that there is life without 9 speed and sti.

These ARE suntour cranks, it says it right on the back of the crank-arm. I dont think that the components are that crummy, they shift pretty nice. I dont really know how much the bike cost new, because my grandfather won it in a raffle, but it was too big for him. He gave it to my dad, who never rode it. I fixed it up (replaced dry-rotteed tubes, brake pads, bar tape, etc) and rode it to work this summer when my Wal-mart Huffy MTB got flats. As it turned out, I like the ride of my road bike on the road better then my MTB.

Fife, You ask, how could that have lasted for 20 years? It hasn't. I'm 16, and im the only one in the chain of owners to ride it seriously.

As for the "low-end crap" on my bike, it is a Suntour "honors" rear derailler, and a Suntour "Spirit" front derailler. I looked up the honors part on harriscyclery.com and found that the honors set was the older equivilent of 105 or tiagra stuff. They didn't however, have any info on the front derailler. Judging by the rear-derailler (a part bike manufacturer always seem to skimp on for some reason) I would say that my bianchi is the equivilent of about an 800 or 900 dollar bike now. There are better ones out there, but i dont think that my bike is THAT crummy (probably worth more than $50). Besides, i would like the experience of tooling around wiht my bike.

I think that my price limit for this upgrade will be about $65-75. I think I can get a lightly used 105 crankset for around $35 on e-bay, and a new 105 bottom bracket for about $30. I would get used, but i dont want a screwed up BB as iseems like it is one of those parts that is difficult to see if it is damaged.

Originally posted by Phatman
[B

I think that my price limit for this upgrade will be about $65-75. I think I can get a lightly used 105 crankset for around $35 on e-bay, and a new 105 bottom bracket for about $30. I would get used, but i dont want a screwed up BB as iseems like it is one of those parts that is difficult to see if it is damaged. [/B] You are on the right track.Don't forget tools.One set to remove the old BB and another to install the new cartridge type. Crank puller too.Tools are good to have and last a lifetime.Don't forget there are double and triple 105 cranks and the BB spindle lengths are different for each.Also remember 105 BB will have english or italian threading.Be sure of what you ae buying.Some e-bay sellers are clueless, so don't always depend on them.This stuff can make sense if you buy right and do it yourself. How else do you suppose all the 'experts' beccame such? Maybe they are still payin someone else to do it?:D

Phatman,
I hope you are not confused at this point. We do seem to have some differences of opinion on the type of chain(8 speed vs 9 speed). Let those who ride decide. It doesn't matter whether you have STI or friction trying to use 8 speed chain with 9 speed crank-set, you will eventually have problems with wear and or shifting problems. If you hang your bike in the garage most of the time you will not have many problems. There is approx 2mm difference in spacing betwen 8 and 9 speed chain rings; thats alot! When you replace the chain get 9 speed, it works with everything except Record 10 and that is questionable as I have not tried it yet.
I'm still waiting for a response as to why the 5 speed will not work with 9 speed chain. Is 5 and 6 spacing different? I don't have any 5 speed stuff any longer and have not ridden the combination for any substantial distance to comment.
I would sincerely appreciate someone answering my question in a thread I started regarding replacing my MTB bike chain rings.
The Fife

Originally posted by The Fife
Phatman,
I would sincerely appreciate someone answering my question in a thread I started regarding replacing my MTB bike chain rings.
The Fife You got an answer.You sure seem to ask alot of questions for a guy whe thinks he knows so much. the real issue with the chain is trying to run 8 speed chain with 9 speed cassettes. A shimano 9 speed chain will run on a campy 10 system with some exceprions dealing with chain stay length and size of rear cogs.my stuff does not hang in the garage.

Phatman,
Another problem associated with using an 8 speed chain on 9 speed cranks is the chainring pick-up teeth (pins) rubbing the chain even during minor cross chaining. It will be noisy.
Keep asking questions! The day you stop asking questions is the day when you stop learning. The Fife