djb

The times I've worked on bb are so far and between, I have to ask at a bike store of go over you tube vids to get it right in my head.
If you end up doing it on your own, you'll figure it out, just be sure before you crank the hell out of something.
You could also ask at a good bike shop how much they'll charge to do that facing thing if you go with external bb.

Cycco, as you say, if his spindle length isn't right, then that's another 25 or whatever for the right square taper one--I assume this bike has a loose ball bearing cup bb.

I wish someone from Toronto could recommend a reliable experienced shop for him to get good answers for parts and work costs.

When I started doing stuff on my own, it was nice to have a good relationship with local shops who often would check stuff I did on my own, especially pre trips. I always paid them to check my wheel spoke tensions before trips too.

LesterOfPuppets

Yep. Right side (drive side) will be reverse threaded. I'll have to watch the vid to see what he's talking about. maybe 68 or 73mm BB shell. The Deore crankset/BB mentioned earlier says it's good to go for either 68 or 73. I'm more of a square taper guy, myself. Only one non-square spindle in the house and I've yet to take it apart.

(watched whole vid)

Yep, like cyco said. different cup design. spacers, etc.

saddlesores

hey don,

have you checked whether you have a freewheel or cassette?
if freewheel you can just pop on one of the famous megarange thingies
for about $20. ............. 14 - 16 - 18 - 20 - 22 - 24 - 34
there's a recent thread about megarange on the forum

Shimano 14-34 Thread-on 7-speed Freewheel "Megarange" - Harris Cyclery bicycle shop - West Newton, Massachusetts

you don't absolutely have to change the crank. i think the smallest
ring yours will take is a 26. you could just put on some new rings,
maybe 26-36-48. with the megarange, that would give you a 20" low
gear, assuming 700c tyres. if 24 will fit, then 18.7" low gear.

i had similar gearing for touring (about the time your bike was built) with
four bags and trailer.

a handy gear inch calculator: BikeCalc.com - Bicycle Gear Inches Chart

and while you're at it, you don't need to change the bottom bracket NOW.
you're good with tools and stuff. the bb is probably fine, just needs new
bearings and grease. then you can research spindle lengths and chain
lines and stuff at your leisure....some day.

Sixty Fiver

Any halfway competent mechanic should be able to figure out bb specs.

djb

ya, and with an Alivio crank like this, on this page for it, it does specify a 113mm spindle, and heck, on this same page they sell un-55 shimano sealed square tapers for $18, pretty darn cheap for a very good quality square taper (I replaced my mtn commuter bb with a un-55 a bunch of years ago)

Shimano Alivio M430 Crankset > Category | Jenson USA

seems to me a 48/36/26 and a square taper would be great, I have had very very long life out of un-55 level square tapers, years and years of quiet service with no issues, like 25,000km life.

bobbyl1966

11-13-15-17-19-21-24-28-32 or 11-12-14-16-18-21-24-28-32 wich one is better i ride in flat bike trail but also in hilly bike trail. i want one cassette to give me high speeds in flats not much gaps between gears but also i want the low gears for the hills.

djb

six of one and half a dozen of the other bob.

put both in a gear calculator and look at the results.

DonValley

Been pondering another tack that kinda keeps the look and character of my 1991 in it's original era. If I was to find two rings , say a 24 and a 36 and keep the 50 Biopace and then go 13 34 on the back my gear inches would be at 19.2 to 104.5 . Seems to be in the window that many have said is desirable. (and suggested in the beginning of this thread of course!!) . Is it OK to mix and match different brand rings? even with the 50 tooth Biopace for now? Do they all space about the same between them? One of particular attraction is a Race Face made in Canada. I have a very big weak spot to buy anything made here, as our manufacturing industry has been slipping away much like the USA. My Kona has them and they appear to be beautifully made.
At this point I am not just about being practical with this bike, as I am sure many can understand. I do want to maximize quality on it and keep it long term.

bradtx

DonValley, Aesthetically it's nice to keep "period correct". At least on a restoration, but as you are going to be using, and depending on this bike to work reliably on a tour, over a wide range of possible conditions, I'd choose the Alivio crank set mentioned earlier along with the UN55 bottom bracket. It looks like the available options are 170 mm or 175 mm long crank arms, but the only gearing available is 22-32-44T, which works well with a 30T cassette cog to obtain a ~20 GI granny. Reprint of the link: Shimano Alivio M430 Crankset > Category | Jenson USA . A budget friendly option, IMHO.

While a lot is written about which granny gear combination is best, I look at what's in the middle of the gearing range for the gears I'm likely to use the most. That's why I liked the 13-30T cassette mentioned earlier: https://jet.com/product/product/3b8f...FQemaQodiBYD7g .

Brad

djb

-re chain rings, comes down to finding ones at your bolt pattern but at what cost. If you find a 36 and a 24 or 22 then you can change them yourself, assuming you can take off your crank (crank removal tool at MEC is inexpensive)
-you will still (I assume) have the original bb, which would be loose ball bearings/cup type-which as mentioned by someone else, probably is in good shape, but could do with new grease--again, you need the tools to do this and experience to adjust it properly when putting it back together.
- re bb, if you want to keep and use this bike, its nicer to have a sealed bb, either a square taper one like the un-55 or whatever, or as per cyccos recommendation, an outboard type that may come with a new crank if you go that route--but with this, you may need the frame to be prepped before installing bb, facing, at what cost I dont know.probably not much.

jot down all the options with various costs beside to tally up, then make a decision based on that.

the 48/36/26 (or 24 or whatever) vs the 44/32/22 debate--unloaded the bigger one is nice, just cuz the 36 mid ring is nice for a majority of riding from slowish to 30+kph so less front shifting in lots of riding. The smaller crank however works very well too, especially with a load on the bike, but then you get into some diff spindle length issues and stuff that as has been said, can be addressed and answered by a competent bike mechanic.

cyccommute 

Yes, it's okay to mix rings and the spacing is the same. Be aware that modern rings have pins and ramps that make shifting quicker and smoother, however. You don't have to use them but they do work better than rings from the Biopace era. You'll need to know the bolt circle diameter (BCD) on your current crank for replacement rings, however. To determine that, measure from one chainring bolt to the next chainring bolt and multiply by 1.7. That will give you the BCD in millimeters. Here's a page that explains how to do it.

Race Face is good stuff. Their external bearing cranks aren't quite as simple to install as the Shimano but they are still good cranks. I have several...including the current one on my touring bike. They are going to be a bit more expensive than the Shimano and the current configuration uses a 42/32/22 ring set which would spin out at a pretty low speed (go play with that on the gear calculator I linked to above). A 44 outer would be better and a 46 or 48 would be better still but I don't think Race Face makes either the 46 or 48. There might be some NOS (new, old stock) available if you hunt around for them.

djb

absolutely a 44, especially if you go with a cassette that could be 12 or 13, instead of 11.
My 42-11 combo (on a 26in wheeled bike with 1.5 in tires) gives 95 gear inches and on downhills I spin out at about 50kph (a really fast spin though, meaning, mucho rpms, I have no idea what number tho)
I now have a 12-25 which is 87 g.i. which means about 45kph, but I can live with that cuz I like the closer shifts compared to the 11-28 it replaced. (8 speed cassettes btw)

on your bike, a 44-13 combo gives 91.4 g.i so inbetween my two examples. Just remember, on a loaded bike, or heck, even an unloaded bike, you will NEVER be able to hold more than 30kph for any extended periods on the flats unless with a down hill or a tailwind, so take this all into perspective--yes, you will not be able to pedal while going downhill at 70kph but that happens far and few between.
I have said before, the times I have gone really fast on a bike, over 80kph I was not pedalling anymore anyway so gearing is not a factor.

Yes there are advantages to higher gearing, especially to someone like cycco who lives in the mountains and being able to pedal on long downhills is nice to keep your legs warm, but we dont have those sort of mountains out here, and unless you know the road, and are comfortable and competent at speed, regularly going at high speeds just isnt always a smart thing to do, and it just wont happen for us out here much.

cycc, good for explaining bcd and the link to avoid any errors when he searches for rings.

cyccommute 

According to this gear calculator, you are doing 105 rpm which is a pretty fast spin.

I'm not pedaling at that speed either...I'd need to do more than 120 rpm on my set up...but I do like getting to the speed faster than just coasting through from around 35 kph.

Eastern hills are somewhat shorter than what we have in the west, although I did find lots of very long downhills in my travels there. However, I find the ability to get a lot of speed up on the shorter downhills to be advantageous when the roads inevitably turn uphill again. I can get further up those stupid steep hills further without having to go down to the absolute bottom of my range. I still end up in my lowest gear but I don't have to suffer in it for a few extra yards

By the way, the longest downhill I've ever done was in the eastern US on the Great Allegheny Passage. Going east to west, I had almost 140 miles of solid downhill with only a few minor rises. The longest downhill I can do in Colorado without any substantial rises is the Rio Grande Trail from Aspen to Glenwood Springs. That has a little steeper downhill grade but it's only 42 miles long.

DonValley

My BB has been replaced and is now a cartridge style. I have found some rings on Ebay that are in great shape (Race Face and FSA) and overall this would be my lowest cost option. I'd kinda like to keep the Biopace 50 tooth top ring for now and see what that was all about (or is it totally bogus and just a gimmick?)

My BCD is 110 and 74 from what someone told me earlier in the thread.

djb

stuart, thats a neat graph, I admit I never really played with it, but the cadence/speed thing is neat.
I was sceptical at the 105rpm quote, just seemed toolow to my by gut instinct. I put in my road bike details, 28-622 and a 50-12 combo and sure enough, I get 120rpm at 65kph and on a ride I do regularly on Mt Royal here in Montreal (where the pro grand prix day race goes over umpteen times, happened just last weekend) I routinely hit 70kph pedalling on the downhill, but my legs are going to hell and back, so this 120 at 65 kinda fits with that.

my 42-12 setup now can get up to almost 50 but again, legs are like a hamster on catnip, or hamsternip.

I certainly agree with you on liking to get up to speed more than just coasting, its a great joy of mine with cycling and I figure its teh payback for all the hard climbing. My loops over Mt Royal are a case in point, I do repeats on it and there is a nice hard right hander on the way down that I particularly like taking as fast as I can to get my max up to 70 right after, each km more through the corner pays dividends on the straight, just like in motorsport.

I agree also on getting a run as much as you can, I will always take every kph more and every yard less to start working hard again.
The case here with this fellow, with 7 spd and new to touring with weight, I figure less jumps in the mid range will be of help to him, hence my steering away from a 11, but as you say, in the end it will work whatever he puts on, and having the lows is what is important.

very neat and yowser downhills, even if gradual they must be a real slog going the other way, endless false flat...."am I tired, do I have a slow leak, are my brakes rubbing" sort of thing.

remember too concerning speeds going downhill--a lot of folks just arent as comfortable as you and I going fast, this gets to the whole "brake dragging" subject that we have both commented on. Lots of riders I know are not comfortable going over 40kph, so for lots, higher gearing is really a moot point.

PS, just redid the graph for the mtn bike, with 40mm tires (my 1.5 are 38mm) 42-12 at 50k gives 117rpm, so this matches up the 120 or so that I must regular hit on both bikes. I had no idea what cadence I was at, so thanks again for the graph and the pointing out cadence.

djb

great on the bb, take off the crank and allen keys to take off the rings to put new ones on, what teeth numbers then?
Biopace---meh, my Kuwahara came with them but my knees just didnt like them. Im skinny and have always been a faster spinner, just easier on my knees, and the weird feeling from a not round ring made my knees feel weird. I took them off after my first trip and threw them out. I had had a knee problem on that trip and distrusted them because of that, hence the garbage, never a temptation to use them again. I know pro racers still use non round rings, so I guess it depends on your pedalling technique and other factors, so you can try it, and anyway, its the 50 so you wont be in that often. Just be aware of listening to your knees if they complain, maybe just dont do high cadences, do what feels right in other words.

DonValley

I suppose I can poach the standard 50 tooth Sugino chain wheel off my Kuwahara if I don't like it. My Son also has the two smaller sprockets I need on a bike I found in the garbage last winter and fixed up (An early 90's Bianchi Grizzly with XT components) while hesitant to like this bike initially because of it's 80's colour scheme, he is now very proud of it and won't let me touch it as a few bike enthusiasts commented that it was a very interesting bike.

These Origin chainrings look nice…I am swayed by made in USA
https://www.ebay.com/itm/New-Origin-8...item58c4a3e2a5

Anyone tried these?

djb

honestly, just get the cheapest ones you can, I havent had a downside to buying "cheap" rings. I suspect a 24 is the smallest you can put on your 74 bcd, and if you can put a 36, then that would work well at minimum cost, plus perhaps an inexpensive cassette.
Do you have panniers and all that whatnot? Tent etc?

PS, I just took a look at my 110/74 crank and yes, 24 looks like it is the smallest you can put on there, and for the mid ring, mine is a 40 and looks like a 36 would go on.

bobbyl1966

for 53/39 crank wich cassette is good. 12-32? or 13-32? And on ebay i see 11-32 cassette with different tooth count. One cassette is have 16 and 18 cog. the other have 15 and 17. wich cassette is better for high speeds in flats.

saddlesores

i really think you should probably consider maybe getting the other one.

bobbyl1966

You mean the 11-32 cassette have the 15 and 17 cogs? I be looking online again i see one 13-32 cassette. I be thinking about the 13-32 because i not know how many times i go use the 11 cog.

Walter S

+1