nlerner

I recently made this shop stool out of a trashed Motorbacon frame:

Andrey

I do get a lot of comments on every brevet that I did n 2014. The box was made in 2014 after I got lost 3 times and rode over 20 bonus miles on a 300k brevet in Westfield, MA.

I am in Rosendale and I do follow the Riding the Catskill blog. Are you one of the writers?

southpawboston

Yep, I am. I'm the guy up in the western end of the Catskills, near Andes. I only get there a few times a year but get in as much riding there as I can.

noglider 

Hey, Andrey, my wife and I are in High Falls most weekends! We visit Rosendale often.

GrayJay

You can get significantly more mechanical advantage from those MAFACs if you set them up more like a medium profile design (or at least the neo-retro angle as described in the excellent analysis of cantilever geometry at;
https://www.circleacycles.com/cantile...i-geometry.pdf

Your alpha angle now is pretty close to 90°. Benefit of this setup is that the mechanical advantage is very linear as the brakes are actuated (but the mechanical advantage is relatively low). A medium profile setup with narrower alpha will yield higher initial mechanical advantage but the down side is that the pads need to be setup closer to the rim and the dynamic response is regressive, the mechanical advantage decreases as the brakes are pulled.

First - Push the pad mounting post all the way into the cantilever arm, so that the arm will swing inward more. You want the alpha angle as defined in the link above to be as narrow as possible to maximize the mechanical advantage. It may be necessary to cut/grind the protruding ends off the pad mounting post so the saddle cable does not interfere them.

Second- Shorten the saddle cable as much as possible (and lower the saddle hangar height).

Another option to double the mechanical advantage of cantilevers is to instead use a link of roller chain as the saddle hangar. Instead of fixing the main brake cable to the hangar, use a long piece of brake cable that loops through the chain link hangar, back up toward the cable stop and then anchors back onto the frame (custom anchor needed). This forms a 2:1 pulley that doubles the mechanical advantage (at expense of the lever travel pull distance)

southpawboston

What's the rake on that fork, Neal? Seems to take low trail to the next level!

Italuminium

Thanks!

jimmuller 

Good advice but with this caution. Shortening the straddle cable works only if the anchor, i.e. end of the cable where it attaches to the arm, is higher than the arm pivot (when the pad is in contact with the rim). If the pivot and straddle cable anchor are the same height then the effect of shortening the cable is exactly canceled by the loss of mechanical advantage, with the net effect being just more stress in the whole system. However it looks like your brakes already have the anchor higher than the pivot, and would go higher still if the pads were pushed further into the arm, so this doesn't apply to you.

nlerner

A rake!! That's brilliant. I need to swap in a rake for that fork.

crank_addict

While on the subject of brake mods, has anyone made a straddle cable 2 pulley similar to the Alex Singer? I realize it will use more lever travel, but I'm considering modifying a chain link and use on centerpull Mafac Comp calipers (not cantilever). Good or bad idea?

southpawboston

Depends. This will double the ME and therefore double the pull, correct? Will you have enough lever travel? Are you only using half of your available travel currently?

crank_addict

^Certainly was going on doubling the ME, rim crusher. I would like them for both a tandem with Mafac cantilevers and also for a current build vintage gravel rider w/ Mafac Comp- centerpulls.

Lever travel might be an issue. Does it double the travel? Curious if I need to change the lever fulcrum or other to make it all work. I don't even know how the modulation would feel.

I'm sure there's many ways to improve brakes but my goal is to keep within the vintage components and visual appeal.

Pompiere

This reminded me of a mod I made to my daughter's bike after she broke the Shimano bell crank in a crash. Without the bell crank, the 3 speed hub defaults to high gear. I used an acorn nut and a ball bearing to push the shift rod into second gear, making it into a single speed. I also found an aluminum tent peg could substitute for the original shift rod.

Italuminium

there's just so much going on in this pic in terms of custom parts and gizmo's..... wow! that wire FD is still one of the coolest parts ever.

bikinbruce

Did you just cold work these or did you heat them up? I have a set of Schwinn rando bars that I would like to try this with for my mid eighties scott sawtooth.

vqstaphbeard

The ole handlebar flask. Cool mod, I'd like to see it in use. I bent some bars a few years ago to a more 'randonneur' bend.

crank_addict

Bending the bar was done at ambient room temp. At first I was over-thinking it. I have a press and mandrel tube bender but it really wasn't necessary. Its something I've never done before, the bars had no name and were scored with nasty scratches, so I figured why not?! The plus side was the nice compliance, flexibility properties and lightweight.

To prevent tube kink or damage, it was done by clamping between wood bracing, leverage pulled closest to the area I wanted to bend. I only took a few pulls, stop and inspect. The goal was not overdoing it and certainly wouldn't reverse the bend. I used an angle gauge as a guide and keep both sides uniform. I haven't completed this build to test it yet while static feels just right and more natural for my wrist. I had a few mishaps years ago on moto-X and age is catching up with me. If the new angle helps, I might do the same for a few other bikes.

The flask cap was something I've wanted to do for years so this was the bar to experiment with. Its an aluminum pill container with o-ring. (samples found on Amzon / fleabay for only a couple of bucks. Also available in anodized colors). The container is cut in half. The ends of the bar were slightly undersized so I reamed them to where the container half press fits tightly. Its a one time press fit and once in, its not coming out but just to be sure, I used a Loctite metal sealant (very small amount smeared to the ends) before inserting. Positively is leakproof. For a test, I poured boiling water to lacquer thinner in it. Surely its a novelty and its funny how the liquid has an air-lock on the drop style bars. I have to lean the bike to the side allowing flow to the closed end. Holds 9 oz.. Could be neat for a flat bar setup.

jimmuller 

Re that straddle cable pulley - a clever idea. I'd be concerned about fatiguing the main cable where it is always bending and unbending as it passes around the pulley. They aren't but so flexible. Keep an eye on it for strands breaking.

rootboy 

I thought your rake was bent?

elcraft

The SA hub threading is NOT Whitworth threading. It is 13/32" x 26tpi BSC (British Standard Cycle) Threading. The thread pitch is 55 degrees rather than the usual 60 degrees. I saw a tap for this threading once listed on UK eBay for about $180!!!!!! They are otherwise unobtainable.
I recall reading on BF that the proprietor of Bikesmith Tools is rumored to have one of these taps. Perhaps, he could be persuaded to re-tap your NDS wing nut. Good luck finding a solution for ths situation- I am creating a similar set up and recently purchased a set of GB lever style wingnuts on eBay that were mismatched in the same way as yours, the NDS side wasn't correct. The seller was less than "timely" about making an adjustment (monetarily speaking) concerning this nearly useless set.

Trakhak

About bending handlebars: I read many years ago that, to avoid creating kinks and stress risers at the bend, the handlebar should first be filled with sand.

crank_addict

Thanks for the info! Goofy price for that one in the UK. I scoured around with an old timer tool and die maker with no such luck. Difficult believing a tap like this is virtually non-existence. If I find one, will gladly loan it. Might be a good idea starting a specialty loaner tools for C&V / CR members. I only need the one wing-nut to finish this bike.

However for the non-drive side, I'm temporarily using a -drive side- and inserted a crank cotter / nut through the indicator hole.

--edit: Out of my league trying to figure out differences between Whitworth, BSC (Brit. Std. Cycle), BSB (Brit. Std. Brass)-- Whew! Apparently and depending on the UK suppliers, they all use a 26 tpi. Difference could be in the thread angles of 55 or 60 degree. So far nothing for 13/32" diameter.

AND.... It’s a German bike thread standard called FG 10.3, it means 10.3 mm diameter and 26 TPI, (also called 13/32″). I haven't verified this but found it in some obscure site.

Funny thing, my IGH is an Austrian made Styria, a clone of SA. I have the original documentation and even specifies the parts interchange. The only difference might be in the shell or design.

---edit II: Forgot to mention CEI (Cycle Engineers Institute).

Cycle Engineers' Institute (CEI) or British Standard Cycle (BSC)

These are different names commonly used for the same threads. 60 degree thread angle, rather than the 55 degree of BSW and BSF. For sizes from 1/4" through 1/2" by far the most common are 26 tpi, although 24 tpi appear as well. Most, but by no means all, fasteners on post-War BSA's (through the late '60's, when it got more complicated) were CEI. Although the thread form and pitch is different, the head sizes on CEI-threaded fasteners use the same wrenches as BSW/BSF.

----edit III: Think its time for a dedicated thread on threads
Anyhow, has anyone tried a cobbled DIY tap by cutting grooves in an old SA axle?

dddd

Here's a caliper I modified for more-solid delivery of braking forces. Anchor cord straps control forward flex, homemade booster plate controls post splay flexing, and for leverage I had to take the caliper pivots apart to install the super-short Suntour straddle that I think was once part of a "Power Hanger".
Good enough for the steeper, wet descents of XC racing, which was the goal here.


Here I had to adjust the claw-hanger's b-pivot stop with a file (and modify the red-marked para link in order to get just enough travel) to get the Allvit to shift fully and solidly across a modified 6s Uniglide freewheel.
2nd-smallest cog needed "kicker ramps" beveled into the tips of a few teeth to achieve a reliable shift out to top gear.
All three of my Allvit-equipped bikes are now similarly fitted with 6-speeds, using three different Allvit variants.


This is one of the tools that I've made from re-purposed parts, this one I made in the late 70's.
1940's fish-tank pump reversed to pull a vacuum by tilting the cylinder mounting using a 4mm screw as a wedge.
Pickle jar would have been trash but has since served all these years as a reservoir for vacuum-extracting brake fluid during system flush/bleed.

elcraft

[QUOTE=dddd;17362058]Here's a caliper I modified for more-solid delivery of braking forces. Anchor cord straps control forward flex, homemade booster plate controls post splay flexing, and for leverage I had to take the caliper pivots apart to install the super-short Suntour straddle that I think was once part of a "Power Hanger".
Good enough for the steeper, wet descents of XC racing, which was the goal here.


Is this a Dursley Pedersen???

elcraft

--edit: Out of my league trying to figure out differences between Whitworth, BSC (Brit. Std. Cycle), BSB (Brit. Std. Brass)-- Whew! Apparently and depending on the UK suppliers, they all use a 26 tpi. Difference could be in the thread angles of 55 or 60 degree. So far nothing for 13/32" diameter.

AND.... It’s a German bike thread standard called FG 10.3, it means 10.3 mm diameter and 26 TPI, (also called 13/32″). I haven't verified this but found it in some obscure site.

Funny thing, my IGH is an Austrian made Styria, a clone of SA. I have the original documentation and even specifies the parts interchange. The only difference might be in the shell or design.

---edit II: Forgot to mention CEI (Cycle Engineers Institute).

Cycle Engineers' Institute (CEI) or British Standard Cycle (BSC)

These are different names commonly used for the same threads. 60 degree thread angle, rather than the 55 degree of BSW and BSF. For sizes from 1/4" through 1/2" by far the most common are 26 tpi, although 24 tpi appear as well. Most, but by no means all, fasteners on post-War BSA's (through the late '60's, when it got more complicated) were CEI. Although the thread form and pitch is different, the head sizes on CEI-threaded fasteners use the same wrenches as BSW/BSF.

----edit III: Think its time for a dedicated thread on threads
Anyhow, has anyone tried a cobbled DIY tap by cutting grooves in an old SA axle?[/QUOTE]

I think I looked at the same site, in German, on "Fahrad Gewinde". The 13/32" measurement should be more accurately rendered as 10.34 mm. Since this threading is securing a rear axle, I just feel like it needs to be more precise. These antique wingnuts are so scarce that one would be loathe to mess one up! I did as much research as I could about this threading for my IGH project.