Where's the dumb questions thread?

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Andrew_Squirrel
Andrew_Squirrel's picture

plop wrote:
Is it a dumb idea to 3D print crank spindle spacers? I’m trying to install a 190mm RF Turbine crank (old 24mm spindle, not cinch) on an ice cream truck, and I need 8mm of spacer for each side. The ones that come with the crank are 11 or 12mm, and the only ones I can find to purchase are 1mm thick. I’d rTher not have a huge pile of spacers on each side, nor try to cut down the stock ones.

Do the tolerances of 8 spacers add up to be an issue or are you opposed to them for some other reason?
I personally wouldn't get a 3D printed anything anywhere near my bottom bracket.
Is the plastic in your printer UV resistant?

Tue, 10/31/2017 - 18:49
VT regularbike
VT regularbike's picture

I'd just take the stock ones to a belt sander...

Miguel wrote:
i mean as long as we're spending money, lets just set the wallet on fire ok

Tue, 10/31/2017 - 19:48
plop
plop's picture

The tolerances aren't an issue, it's just aesthetics, and a nagging sense of doing a hack job with that many 1mm spacers. I don't have a printer, or know anything about 3d printing, but I just had a case for my mobius cam printed from a local fellow on 3dhubs and it got me thinking. It's sounding like a pretty sketchy idea, so now I'm thinking of taking VT's advice and belt sanding, or cutting them down ~1mm undersize, and using the 0.5mm and 1mm delrin spacers for some flex room to get it exact.

Tue, 10/31/2017 - 20:42
dorth
dorth's picture

metal would probably be a good choice since the spacers are probably in compression.

a tube/pipe with 7/8 (id) could be cut down relatively easy into a spacer. bronze bushing stock maybe?

Tue, 10/31/2017 - 21:03
dorth
dorth's picture

Oh wait, you said 24mm - that's like 31/64 or something weird.

Tue, 10/31/2017 - 21:07
crowding
crowding's picture

They're under the barest amount of compression to take the play out of the system. -- and isn't there a spring washer or elastomer spacer somewhere in the stack? So I don't think strength is an issue. Parallellness of the faces is probably a bigger issue, but that's just as much of an issue if you're grinding down a big spacer.

Tue, 10/31/2017 - 21:25
euclid
euclid's picture

Trim w b b facing tool?

Tue, 10/31/2017 - 23:18
aerobear
aerobear's picture

this seems like an awful lot of work for something you can buy for like 99 cents

https://www.google.com/search?q=24mm+bb+spacers

crowding wrote:
Every time i eat Dick's I just wind up disappointed that I'm not getting In-n-Out.

Tue, 10/31/2017 - 23:40
plop
plop's picture

Did you read my post?

edit: that came of more rude than I intended, sorry. I've been searching for thicker 24mm spacers for a while, but as you'll see in all of those google results, the thickest ones available are 1mm.

Wed, 11/01/2017 - 02:37
plop
plop's picture

Euclid, that's a great idea. My apprehension for trimming them down was losing the squareness of the face, that would probably maintain it to an acceptable level.

Wed, 11/01/2017 - 02:39
iwillbe
iwillbe's picture

Who makes a decent downtube bottle cage doubler?
I'm looking for something like this:
https://www.wolftoothcomponents.com/collections/b-rad-products/products/b-rad-double-bottle-cage-adapter

but in stock now, and well built enough to not loosen up instantly. I have no idea if these things can clear a leg under normal ranges of pedaling, but I'm interested in trying it as a workaround for the space used by a half frame bag, and as an alternative to my current setup (normal bottle cages + triathalon buttrockets off the seatpost).

Amazingly, Problem Solvers doesn't sell something like this, it seems like it's exactly in their wheelhouse.

Wed, 11/01/2017 - 10:53
Tail Hook Lengthener
Tail Hook Lengthener's picture

Until this moment, I never knew anything like this existed. It seems like a good way to rip a rivnut out of a frame (but I still kind of want one).

Sneaky Viking wrote:
when you look back at your life sometimes you see a set of hands on your keyboard and a set of paws, but sometimes there's only a set of paws and that's when Tarckbear was typing for you.

Wed, 11/01/2017 - 11:03
fixed
fixed's picture

i am quite certain i would be smashing my knees on that thing regularly

Wed, 11/01/2017 - 13:52
iwillbe
iwillbe's picture

Someone on this forum has tried one, I think, and said no knee smashing. I'd be using it with 26oz normal width bottles and a slim cage.

Wed, 11/01/2017 - 13:56
guccipolo
(Reply to #2265)

iwillbe wrote:
Who makes a decent downtube bottle cage doubler?
I'm looking for something like this:
https://www.wolftoothcomponents.com/collections/b-rad-products/products/b-rad-double-bottle-cage-adapter

but in stock now, and well built enough to not loosen up instantly. I have no idea if these things can clear a leg under normal ranges of pedaling, but I'm interested in trying it as a workaround for the space used by a half frame bag, and as an alternative to my current setup (normal bottle cages + triathalon buttrockets off the seatpost).

Amazingly, Problem Solvers doesn't sell something like this, it seems like it's exactly in their wheelhouse.

QBP has these in stock, so your local shop can get em. I was interested in seeing how these would work clearance wise without using the b-rad adapter to move it all further up the downtube.

Mon, 11/06/2017 - 12:34
iwillbe
iwillbe's picture

I'm still planning on doing this, but now that the weather in the South/Piedmont/Mid-Atlantic has stopped being 95f with 80% humidity, I'm feeling less totally panicky about carrying enough water on long rides. That, and a liter bottle from the gas station fits fine in a half-frame bag. That won't work for actual touring, but it's more than good enough for 4-6 hour rides.

Thanks, though, for noticing that downtube cage doublers are available from Q. I'm headed to my local shortly to pick up some rims and spokes. I'll order a couple and report back on whether the bottle cage snaps or the whole thing gets ripped out of the frame when you clobber it with your knee.

Mon, 11/06/2017 - 13:23
y
y's picture

what's the best option for singlespeed chain tensioner? want to convert my geared cx rig before sunday.

Mon, 11/06/2017 - 19:13
NOVELTYNAME
NOVELTYNAME's picture

Old derailleur
Or the shimano alfine tensioner (available in silver and black)

"Folks want options!"

Mon, 11/06/2017 - 19:17
fixed
fixed's picture
(Reply to #2269)

y wrote:
what's the best option for singlespeed chain tensioner? want to convert my geared cx rig before sunday.

i have had great luck with the performance spencer $19 "conversion kit" that's basically just a little wheel on the end of a piece of metal.
the rennen designs one is functionally identical but 3x the price. i have a new one of those if you want it, i will send it to you for not much of the moneys.

Tue, 11/07/2017 - 08:42
euclid
euclid's picture

If it’s temporary, replace shifter cable with a piece of cable with the end nubbin in the derailleur cable stop, clamp in desired gear

Tue, 11/07/2017 - 08:57
fixed
fixed's picture

if it's really temporary just zip tie that shit

Tue, 11/07/2017 - 10:33
yonderboy
yonderboy's picture

I've seen an entire 10s cassette with same toothed cogs. Makes for an easy swap back to geared.

Tue, 11/07/2017 - 13:42
jamesacklin
jamesacklin's picture
(Reply to #2273)

fixed wrote:
if it's really temporary just zip tie that shit

Pro. Do this

Tue, 11/07/2017 - 14:16
deadforkinglast
deadforkinglast's picture
(Reply to #2274)

plop wrote:
Euclid, that's a great idea. My apprehension for trimming them down was losing the squareness of the face, that would probably maintain it to an acceptable level.

These ideas all sound like a lot of work. 8 x 1 = 8. Do that.

Wed, 11/08/2017 - 01:36
plop
plop's picture

You are so incredibly right about that. These things are made out of some hard ass aluminum. Facing tools didn't work, because they rely on a lot of clamping force to get the cutters to engage, which made it impossible to keep the spacer immobilized when the tool was rotated. Belt sander was a no go, after over five minutes of burning my fingertips from the heat buildup, I had removed ~0.1mm of thickness. I dropped them off with my brother who is going to put them on a lathe.

Wed, 11/08/2017 - 11:59
VT regularbike
VT regularbike's picture

Use a cup of water to dip the parts in next time. You generally don't want that much heat to build up also it keeps you from burning your fingers. Also sounds like it's not aluminum if its that hard.

Miguel wrote:
i mean as long as we're spending money, lets just set the wallet on fire ok

Wed, 11/08/2017 - 12:03
iwillbe
iwillbe's picture

Are there any things to watch out for when drilling a drain hole in a bb shell? I've been getting some water pooling in there, and want to give it a path of egress.

Fri, 11/10/2017 - 10:02
mander
mander's picture
(Reply to #2278)

iwillbe wrote:
Are there any things to watch out for when drilling a drain hole in a bb shell? I've been getting some water pooling in there, and want to give it a path of egress.

The simplest and dumbest: Get the hole right at the bottom (mark and measure that with wheels on the spence); mark it with a punch or mail or something to keep the bit from wandering

Fri, 11/10/2017 - 10:07
Tail Hook Lengthener
Tail Hook Lengthener's picture

With two wheels in the frame, I put a ball bearing in the shell to see where the absolute bottom is, and I have a better idea of where to drill.

Sneaky Viking wrote:
when you look back at your life sometimes you see a set of hands on your keyboard and a set of paws, but sometimes there's only a set of paws and that's when Tarckbear was typing for you.

Fri, 11/10/2017 - 11:08
JUGE FREDD
JUGE FREDD's picture

counterpoint: getting it perfectly at the bottom isn't super important, but you do want to deburr where it punches through inside so that water can actually flow

I usually just drill through the unused hole in the plastic shift cable guide

you're never gonna get 100% of the water to drip out, especially when it's in tiny amounts

most of the value is as a breather hole so that moisture can evaporate out

It's a struggle, but you cut out his tongue, and his last words are "atmo atmo Atmo ATMO ATMOOOOOGORIHGGHRSHGGRLMGGMMGMgrrglegurglegrr....."
– akasnowmaaan

Fri, 11/10/2017 - 13:13
iwillbe
iwillbe's picture

yeah, I'm not hoping for absolute dryness, just not a lil waterfall of stinky rust water when I pull the seatpost and turn the frame upside down.
the ball bearing trick is cool, I should give that a try, it won't idiotproof the process, but it might idiot-deter it.

followup dumb question / million dollar idea: Are there any hollow screws that can be washered to sit flush with the inner diameter of the bb shell, thus making a breather/drain without my having to drill anything?

Fri, 11/10/2017 - 13:22
daedelus
daedelus's picture

Maybe a barrel adjuster screw?

totallynotsol wrote:
"free love feminist vegan bicyclist"

Fri, 11/10/2017 - 13:47
iwillbe
iwillbe's picture
(Reply to #2283)

daedelus wrote:
Maybe a barrel adjuster screw?

yeah, if the threading is right, I don't see why that wouldn't work. one sec... ...okay yeah, it threads in. Sticks out a bit, and I don't have a great way of making sure that it's flush, but as a breather and easily removed drain, it should be better than the solid screw I had in there before. The depth of the barrel should keep it from getting too much random spray up in there, too.
thanks for the suggestion, it seems as if it will work well.

Fri, 11/10/2017 - 14:13
drwelby
drwelby's picture

On my frame builds I've always wanted to braze a short section of presta valve stem to the bottom of the bottom bracket shell and drill down the bore through the shell. Then use it as a stud for the cable guide, with a presta nut holding it in place.

Fri, 11/10/2017 - 14:43
jimmythefly
jimmythefly's picture

For future reference, McMaster has "vented" stainless metric screws. But the vent diameter is so tiny (1.2mm diameter) that I wonder if much water would actually drain out.

https://www.mcmaster.com/#93235a331/=1a75w44

DQ: can someone point me to the origin of the "spencer" wordfilter please.

deadforkinglast wrote:
But honestly, I have no idea how I am going to follow through on that plan and I already have a pretty rad spencer. I think I just like fucking with my bikes.

Fri, 11/10/2017 - 16:02
Andrew_Squirrel
Andrew_Squirrel's picture

Yeah, there must be a point where the surface tension of tented water in a very small hole will prevent effective evaporation.

Fri, 11/10/2017 - 16:05
iwillbe
iwillbe's picture

I just built some new wheels (coming soon to the post your Spencer/Raleigh stickied thread), and was looking at the valve cores as I was reinserting them, wondering if something like that could get finagled into a bb shell, so that I could just unscrew, drain, and re-seal. That or a little rubber plug or something.

Re: mailordering vented screws - just put some vented m5 thread screws in my Amazon cart. If they work well in this application, it will massively rule.

Thanks again to everyone for the suggestions, it's neat to get good ideas for this spencer nerd problem.

Fri, 11/10/2017 - 16:09
iwillbe
iwillbe's picture
(Reply to #2288)

Andrew_Squirrel wrote:
Yeah, there must be a point where the surface tension of tented water in a very small hole will prevent effective evaporation.

But I bet the vibration from normal riding will break the tension and send the water sluicing down even a very narrow hole. It would depend on riding somewhere dry, I guess.

Fri, 11/10/2017 - 16:10
drwelby
drwelby's picture

Use another vented m5 on a water bottle boss, grab your compressor and a nozzle tip, and use it to pump pressurized air into the frame to help force the water out the drain vent.

Fri, 11/10/2017 - 16:23
iwillbe
iwillbe's picture

attach mini pump to downtube, power it off the hub dynamo, create a constant positive pressure system inside frame tubes, maintaining perfect dryness at all times.

store rare scrolls inside frame?

Fri, 11/10/2017 - 16:36
JUGE FREDD
JUGE FREDD's picture
(Reply to #2291)

drwelby wrote:
On my frame builds I've always wanted to braze a short section of presta valve stem to the bottom of the bottom bracket shell and drill down the bore through the shell. Then use it as a stud for the cable guide, with a presta nut holding it in place.

but then you're stuck tightening presta nuts with channellocks, since that thread pitch is so odd

It's a struggle, but you cut out his tongue, and his last words are "atmo atmo Atmo ATMO ATMOOOOOGORIHGGHRSHGGRLMGGMMGMgrrglegurglegrr....."
– akasnowmaaan

Fri, 11/10/2017 - 18:37
Endpoint
Endpoint's picture

Fred’s answer is best. It’s what we do to at least one spencer every week.

Fri, 11/10/2017 - 21:23

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