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Chainrings are definitely a much more complex part, although I imagine there is far more documentation on how to make them. I run a narrow/wide ring which I imagine would be quite interesting. If it breaks I will fix it!

Are you saying what I think you’re saying...

I went to the nunatuk gear workshop, based out of the owners garage and can vouch for the unbelievable quality of their work. Their jackets feel like what i imagined clouds would feel like when i was younger. They're also open to custom work (just did a ventile jacket i believe) only catch is the waiting list.

Yeah the correlation between digital input, especially ‘theoretical’ inputs and real outputs can be almost spookily accurate. Speaking of digital accuracy it’s especially cool when the cnc has an analogue indicator on it and you zero the spindle by ‘hand’ because you can set it to move a micron at a time and watch the precision on the indicator. For reference spider web silk is around 3-8 microns. But to answer your question I’ve only got my legs, I’ll keep you updated

It’s survived the biggest 5cm bunny hop you’ve ever seen so here’s hoping to many more. We did actually leave a pretty conservative 2mm overall material (offset on each side) which is why the spider doesn’t look exactly like the model.

There is! although as you can see the al gore rhythm is pretty keen to fuck it off. There is some lateral load applied to the model but I had more concern over this than my mate so we’ll see if it explodes. I hope I’m wrong

It was 1009nmm(millimetres not a typo*) The chainring holes were also under load and a bit of lateral load, although we thought the crank and bb would take most of that. All total it feels like a pretty huge number.

https://www.researchgate.net/publication/22663484_Forces_applied_to_a_bicycle_during_normal_cycling

I believe I got 318nm out of here somehow ps I have no idea what I’m doing. I’m also puzzled why it’s so irregular since the model itself is perfectly symmetrical. although there are moments of similarity it’s not the rule. The final spider is only the 11th iteration for material loss concerns previously alluded to and it didn’t seem to be trending towards similarity. Perhaps it may be a more meta symptom of machine learning in that the algorithm hasn’t yet got perfect logic or more likely the machine knows something we don’t or perhaps this is way above my head. It seems maybe @Rik_Van_Looy might know a bit more than me.

If mine works I’d be open to making some more if my mates cool with it. (maybe out of titanium #fullbodycume) although warning they will be trick as fuck but they’re likely to be pretty expensive as well.

• attached pic is of a spider modelled to hold 109nmm because we’d misread it the first time
  
  

Edit: just realised this spider is very symmetrical. We never tried this but I’m not sure if you run the same model twice that you’ll get the same results which is interesting to think about

Appreciate it

I will let you know on Sunday!

Middleburn make a 110bcd road double but my bikes 1x10 and the spider is £70 (with shipping) which is mental. The aluminium stock cost me £40 overnight shipping and I don’t pay for machine time so ostensibly i did it because it’s cheaper. Beige answer is I like to make stuff and in this case the spider was a perfect excuse to do that. Also I only had to model the spline profile and chainring holes and the computer filled in the gaps. My mate has to figure out all the tool paths and deal with bullshit nuance of his machine which is most of the effort but also good practice, so everyone’s a winner. @Skülly
Edit: something else I forgot to mention is that cnc machining the first one of something is a much longer process than any subsequent parts. Once you know that your code is good you can run multiples at the same time and churn them out.

Bike is a 1993 kona hahanna, for more details see: https://jmwl.blogspot.com/2021/03/my-bike.html
p.s the blog is back baby

after multiple messages back and forth with the ebay seller to make sure the crank was exactly what i wanted i got this.

every cloud has an aluminum lining so I decided to use my mates big brain (and his cnc machine) to mill a new one.
Fusion 360 has just come out with generative design which takes force input and then uses an algorithim to find the optimum amount of material to perform the task. This is obviously massively simplified but it's worth a google.
Enjoy the following image dump.

6061

early iteration

I was a little bit worried because the later iterations seemed to be held together with aluminum toothpicks and faith. But this one seemed viable

All toolpaths

rearside complete

and it fits! Pretty pleased as I modelled the spline with a pair or calipers and a lot of assumptions

And the front. We added 2mm material overall to be on the safe side as i needed it asap. Lime bikes were putting me in debt.

in all honesty a bit of fettling was required as i had modelled the angle of the crank from the face incorrectly, nobody's perfect.

cut the tabs and filed.


Tada. Unfortunately it looks a lot better from the back since much more material is removed as it flares towards the spline profile. All you need is good ideas, better machines, and sick mates. Get to it!

Excuse the shite editing, I'm lazy! will put future skill points into patience and photography.

It’s some ancient law like it being legal to shoot someone with a bow and arrow over a fence at midnight on April 1st. but apparently if five individuals want an allotment the council has to provide a one, new or old. Anyway the Southwark thing is slightly more legit and the council has an active interest in it so no need to invoke medieval law

Southwark council is currently going through an allotment expansion scheme. Apparently if 5 or more people are interested in an allotment the council have to provide one which is essentially the barrier for entry into this particular scheme. If anyone from Southwark is interested let me know

And a beautiful thumb but that’s NFS

I’ve got this which is 1 1/8” if you’re interested? I also have a 1” (22.2mm) kona velocity stem + bars

I was the only other bidder went crazy low

Bit of a longshot but does anyone have the castle tool and SPA-1 park tool pliers for servicing Headshok forks?

Does anyone have the park tools SPA-1 and a castle tool for working on a headshok fork.
In the london area sil vous plait

For 30 squids I’ll take it

Howdy all. I recently purchased a Saint 10 speed derailleur because they look pretty and i thought i'd be able to buy the pictured OneUp RadR cage mod so that i can run larger cassettes, 11-42 sunrace specifically. However i appear to be about 3 years to late and i cant find one for sale anywhere. Is the goatlink a viable alternative for this rear mech or did i make a boo boo. any advice would be appreciated.

Howdy all. I recently purchased a Saint 10 speed derailleur because they look pretty and i thought i'd be able to buy the pictured OneUp RadR cage mod so that i can run larger cassettes, 11-42 sunrace specifically. However i appear to be about 3 years to late and i cant find one for sale anywhere. Is the goatlink a viable alternative for this rear mech or did i make a boo boo. any advice would be appreciated.

nice in moc toe too, but I dont know how you guys feel about moc toes.

http://www.present-london.com/files/gimgs/8995_bass-larkin-burgandy.jpg

sorry about previous post.