Bicycle Mechanics - 2 questions about rebuilding bike

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View Full Version : 2 questions about rebuilding bike


dynikus
09-29-12, 08:09 PM
alright, so I'm almost finished with this bike uhh.. restoration I guess you could call it. But I just need help with a few things
1. what goes on the end of this spindle to keep the crank arms on? Is it just a big (not sure the size) nut?
275594
2. How do I measure and cut brake cables? I'm thinking cut the small ball thing off the end, run the cables how they would be on the bike, then just cut off however much excess there is. wire cutters and tin snips don't really seem to do the job though, so also how do I cut cables? I'm assuming there's another specialty tool I'm gonna need to buy.


FBinNY
09-29-12, 10:13 PM
Those need a spindle nut (http://www.ebay.com/itm/Bicycle-Axle-Spindle-Nut-Crank-arm-nut-1-Pair-/200669926943). Not sure of the thread offhand, since I always use the nuts that come with spindles.

For cutting cables and housings, you need? cable cutters like these (https://www.google.com/search?q=bicycle+cable+cutter&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=fflb). The 2 crossing V jaws keep the wire together while shearing it off clean. They can also be used for index or brake housing, though brake housing is often easier to cut with regular diagonal cutters.

BTW, I have a good stock of spindle nuts, and various cable cutters, and can offer you an excellent deal. PM me if interested.

DannoXYZ
09-30-12, 05:42 AM
1. what goes on the end of this spindle to keep the crank arms on? Is it just a big (not sure the size) nut?Yep, you need a 10x1.25mm flanged serrated nut. Any bike-shop should have plenty in stock.
http://i42.photobucket.com/albums/e346/DannoXYZ/Cycling/equipment/BottomBracketAxleFixingNut.jpg
Be sure to tighten it to 25-30 lb*ft with a torque-wrench. This is amongst the highest-torque fasteners on a bike and you need an automotive-style torque-wrench with at least 12" handle. You get just one chance to tighten this nut and if it's not tight enough, it will eventually fall out and then the cranks will wobble on the square-taper end of the bottom-bracket axle and get gouged to death. Just do a quick search for "loose crankarm" on this board to see how frequent a problem it is.


2. How do I measure and cut brake cables? I'm thinking cut the small ball thing off the end, run the cables how they would be on the bike, then just cut off however much excess there is. wire cutters and tin snips don't really seem to do the job though, so also how do I cut cables? I'm assuming there's another specialty tool I'm gonna need to buy.Cables usually come with a ball on one end and a barrel on the other. Cut off the one that you don't need. I find the Shimano cable cutters to be the best. They have higher-leverage than the others and they use thin crescent-shaped blades. This causes them to operate more with a slicing/cutting action than the squeeze & crimping movement of the others. You'll find they cut cable-housing better without crimping and require less after-cut repairs than anything else. The procedure is this:

1. slice off unused end of cable, remove from cable-housing

2. test-fit the housing on the bike. Install in brake-lever and push, do not pull, the housing through the frame-guides to the brakes.. You do not want to stretch out the housing by pulling it through. This will end up elongating the housing which requires compressing whenever you squeeze the brake-lever. Causes excessive lever-squeezing before the brakes actually grabs.

3. make a mark on the housing where it would end on the brake-caliper. Spin our handlebars lock-to-lock on each side to make sure you don't have too-short of cable-housing. All the bends should be gradual and no kinking of the housing anywhere when you sweep the bars fully from side to side. Only once you've confirmed you've got the length determined correct then cut the housing. Look at the cut end to make sure you don't have a crimped curled-in end blocking the inside of the housing. If so, bend it back out with needle-nose pliers.

4. install inner-cable through brake levers, then the cable-housing.

5. clamp cable on brake's fixing-bolt

6. cut off excess, leave about 2" extra beyond the bolt.


cny-bikeman
09-30-12, 07:53 AM
Two things to add:

There is hardly an item more critical than your brakes, so it's important to get it right. There are many tutorials and videos available regarding brake cable installation and brake adjustment, so in addition to the good instructions above I encourage you to check several other sources. You have given no information at all as to what type of brake levers, calipers or cable/housing routing you have, so you need to look for the instructions that fit your situation. Depends on the type of housing set you have but you probably need to lubricate the cable where it passes through housing to prevent corrosion and ease friction. Sizing the cable is pretty self-evident - you just leave a couple inches past the clamp. Housing needs to be sized so that it does not bind when the bars are turned or the brakes fully applied, but not so long so as to introduce extra flex and friction.

I'm concerned the fact that you have done what you consider a "restoration" of a bike but do not know how to secure a crank arm or how to install brake cables. I don't know how you managed to overhaul or install a bottom bracket without somehow coming across info about attaching cranks. Therefore I am concerned that there are quite possibly other parts of the bike that are not adjusted for proper and safe operation. I would strongly advise you to have at least a very knowledgable friend, if not a bike shop, do a once-over to make sure everything is correct.

Kimmo
09-30-12, 09:28 AM
Look at the cut end to make sure you don't have a crimped curled-in end blocking the inside of the housing. If so, bend it back out with needle-nose pliers.

4. install inner-cable through brake levers, then the cable-housing.
I reckon it's far easier just to cut the bent bit off; once you can come at the end of the housing instead of cutting through it, it's a different proposition.

Also, before step 4, you should grind the end flat and/or fit a ferrule, particularly where the housing sits in a barrel adjuster. When grinding go slow and keep dipping it in water so you don't melt the lining.

Speaking of which,

Depends on the type of housing set you have but you probably need to lubricate the cable where it passes through housing to prevent corrosion and ease friction.
You don't need lube with lined housing, and you shouldn't use unlined housing - it's rubbish.

cny-bikeman
09-30-12, 10:18 AM
You don't need lube with lined housing, and you shouldn't use unlined housing - it's rubbish.

Rubbish it is not. Yes, you should only use lined housing - it's false economy to use the unlined stuff that is so vulnerable to rusting. However, lined housing does not insure either smooth or rust-free operation. Not all liners or cable are of the same quality. A qood quality oil like Phil Wood or other light lubricant (but not grease) can help greatly in reducing friction and does no harm.

More importantly it is a false belief that a cable will not rust just because one is using lined housing. The microenvironment inside a lined housing and unlubed cable still has everything necessary for rust - iron, water vapor and oxygen. If one lives near the ocean or in a place where road salt is spread it's also likely to have at least some salt. The lubricant provides a moisture barrier to isolate the cable from the environment.

Unless one has worked extensively on bikes it's easy to believe otherwise, but this is not just theory - I saw many cables rusted inside lined housing during my time as a mechanic and service manager.

Kimmo
09-30-12, 10:58 AM
Uh, who's not using SS cables? That's a false economy right there.

cny-bikeman
09-30-12, 11:40 AM
I'm sorry but plenty of people are still not using SS cables. A full set of stainless shift and brake cables can be out of reach for some folks.

Kimmo
09-30-12, 11:45 AM
I'm a pauper and I'd consider $20 for a set well spent, even on a BSO; control cables are crucial.

FBinNY
09-30-12, 11:50 AM
I'm sorry but plenty of people are still not using SS cables. A full set of stainless shift and brake cables can be out of reach for some folks.

I'm sort of between Kimmo and Cny-bikeman here.

I think die-drawn cables are very important for gear wires, though somewhat less so for brake. For gear wires which are mostly exposed and need to run very smoothly the difference between stainless and galvanized is fairly small and worth the difference. However the cost difference is more for brake wires, and the benefit less since they're usually enclosed for most of the length.

My bikes are typically set with SS gear, and gal brake wires, including the commuter which sees a great deal of foul weather.

Kimmo
09-30-12, 11:55 AM
Die-drawn cables aren't all that pricey then? I hardly ever see em.

FBinNY
09-30-12, 12:05 PM
Die-drawn cables aren't all that pricey then? I hardly ever see em.

The vast majority (if not all) of stainless wires are die drawn, as are good quality galvanized. Die drawn wires, where the outside is smoothed is just about critical to the performance of index shifting. It's less critical for brakes but still valuable when using modern brakes with light action springs. A non-die-drawn wire will fairly quickly saw through the housing liner at the insides of sharp curves.

For those who don't know what this is, a gear wire is made of 19 strands arranged in 2 layers around the central strand. To see how, find 19 pennies, arrange 6 around one then the other 12 around that. That's what a gear wire looks like in cross section. As you can see the outside would e a bit rough with the outer arcs of each wire and the gaps between them. Now imagine if you squashed the outer pennies down so they were sort of pie wedges flowing into each other forming a smooth surface on the outside. That's what the die-drawing does.

In the usual order of improvement for bike cables, there are basic 1x19 galvanized wires, next is die-drawn, then stainless, and finally coated stainless.

Kimmo
09-30-12, 12:19 PM
The vast majority (if not all) of stainless wires are die drawn, as are good quality galvanized.

Uh... no? Not in my neck of the woods, anyway. I've seen like, half a dozen, ever.

Okay, maybe I've seen plenty from a distance, on high-zoot rides I guess, but I've come across almost none of em.

Every SS cable I've ever bought has been plain. And they don't really saw through the linings in a hurry, IME. I'd say it's mostly just about the friction.

FBinNY
09-30-12, 12:32 PM
Uh... no? Not in my neck of the woods, anyway. I've seen like, half a dozen, ever.

Okay, maybe I've seen plenty from a distance, on high-zoot rides I guess, but I've come across almost none of em.

Every SS cable I've ever bought has been plain. And they don't really saw through the linings in a hurry, IME. I'd say it's mostly just about the friction.

Is it possible that you have die drawn wires and don't know it? The major producers of gear wires generally do the upgrade sequence I described, even if they don't say "die drawn". The difference is subtle and hard to see with the naked eye, but if you had 19 strand wires from 20-30 years ago for comparison you'd probably see it. Ever since SIS came out, the wires sold as suitable for it have usually been die drawn.

Obviously, I can only speak from the perspective of what we see in the USA and on OEM form the orient, so it's possible that offerings down under are different.

mike6024
09-30-12, 02:11 PM
I was taught to solder the cable before cutting it. That was to prevent the strands from fraying once it was cut. I did that successfully many times and was easy. Even could file the end to a point after making the cut.

Then I started encountering stainless steel and found I cannot solder it. Also can be a problem threading it though the housing after cutting.

FBinNY
09-30-12, 02:24 PM
You can solder stainess gear wires when they're brand new, but it requires the use of special solders and fluxes (and some more heat). Another option if you have an oxy-acetylene torch is to flame cut the wires, which nicely fuses the ends.

Otherwise I now prefer shrink fit electrical tubing to the crimps because I can remove it without fraying the wire if I later want to re-thread the wire.

Kimmo
09-30-12, 02:29 PM
Is it possible that you have die drawn wires and don't know it?
Doubt it; I came across an obviously die-drawn brake cable at the co-op the other day and I was like wow. Snaffled it.

FBinNY
09-30-12, 02:39 PM
Doubt it; I came across an obviously die-drawn brake cable at the co-op the other day and I was like wow. Snaffled it.

Well now you know. Here, I don't know of anybody offering index cable kits that don't have DD wires, though there are still low end double ended replacement wires sold separately. When I imported JagWire, I brought in some "economy" wires for the low end world, and everything else, both brake and gear was die-drawn.

Kimmo
09-30-12, 02:43 PM
http://i.imgur.com/M5zDI.jpg

When I pull these through my fingertips I feel a zzzip. It was ever thus; die-drawn cables seem like a real luxury since these seem to work fine.

I'll ask around the co-op come the weekend and see what the consensus is. Maybe we're missing out here... looks like it from where I'm standing.

FBinNY
09-30-12, 02:52 PM
When I pull these through my fingertips I feel a zzzip. It was ever thus; die-drawn cables seem like a real luxury since these seem to work fine...
. Maybe we're missing out here... looks like it from where I'm standing.

There's fine and there's better yet. Those definitely aren't die-drawn, and that's fine for the brake and FD wire, but you'll find a noticeable improvement with a DD wire on any system with a classic ?-shaped RD loop. You may not want to try it though, because then you'll be spoiled.

Kimmo
09-30-12, 04:07 PM
A die-drawn RD cable is totally in my near future, as of the other day when I spotted that brake cable... dunno where I stashed it, though

FBinNY
09-30-12, 04:13 PM
e... dunno where I stashed it, though

Kimmo, are you maybe as old as I am, and suffering the beginnings of that German sounding disease, (alte-cockers?) who's correct name I can't remember.

DannoXYZ
09-30-12, 08:50 PM
I was taught to solder the cable before cutting it. That was to prevent the strands from fraying once it was cut. I did that successfully many times and was easy. Even could file the end to a point after making the cut.

Then I started encountering stainless steel and found I cannot solder it. Also can be a problem threading it though the housing after cutting.Solder with acid-flux core will allow you to solder stainless. I find it's easier to just drip a drop of superglue onto the end and smear it around the last 5-6mm.


On the die-drawn cable, you just have to look closely at Shimano's shifter cables under a magnifying glass and you'll find all of them have a perfectly smooth outer surface. Very critical in making upshifts to smaller cogs in the rear work smoothly because the only thing pulling the cable back out is the rear-derailleur spring. Shifting to larger cogs isn't so critical because your hand can apply more than enough force to overcome friction.

For brake cables, smooth outer surface does make a difference, but not significant since you can always squeeze harder to overcome the extra friction. But there are a lot of configurations with older sidepull or centrepull brakes that require every last bit of hand-squeeze force to make it to the calipers.

Kimmo
09-30-12, 11:05 PM
Kimmo, are you maybe as old as I am, and suffering the beginnings of that German sounding disease, (alte-cockers?) who's correct name I can't remember.
Heh, only around 1.2 billion seconds on the clock here...

you just have to look closely at Shimano's shifter cables under a magnifying glass and you'll find all of them have a perfectly smooth outer surface.
Pretty obvious to the fingertips. I'll swear blind none of the dozens of SS cables I've bought over the years have been die-drawn, even though the one I came across the other day was gal, which would tend to back up FB's call about the hierarchy. It was old, though...

Anyway, I'll be investigating this question at some length, I reckon... fondling the cables on every nice bike I come across.