Adjustable swb

Joined
May 31, 2013
Messages
3,980
Location
South Benfleet, Essex, England, UK
Have you tried pedaling under load yet?
I found that without an anti-turn keyway the QR clamps were often inadequate to prevent the inner tube from turning in the outer one.
Which is rather disconcerting when you chainring is suddenly at 45 degrees or on its side with no chain on it.
 
Joined
Feb 3, 2017
Messages
102
Location
australia
lengthen the cage of that derailer. just focus on getting it rideable as soon as you can.
Oh yeah thanks, i forgot i could still consider a modified derailer or even something more custom but possibly simpler with 2 rollers and a spring or manual adjustment.
And thanks for the tip. I had a real "oh cr*p" moment for timeline there. My seat idea is more complicated than usual so it's very slow getting to rideable.
The seat has to fold away.

Showing off how many magnets i can use.
I wanted a plastic not wood chair.


But this nice seat shape also creates attachment problems because of it's shape so i think I'd be crazy not to just change to nice flat wood.

But the backrest can stay. (I was always planning to add padding to both btw).
 
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Joined
Feb 3, 2017
Messages
102
Location
australia
I welded on the seat hinges thinking that they will lock in position "somehow". I'm struggling to decide how to do this. Suggestions anyone?
 
Joined
Feb 3, 2017
Messages
102
Location
australia
I've still been putting in plenty of work for this bike over the last 2 weeks. Many hours but i can't think off the top of my head what I've actually been doing. Documenting hasn't been high on the priority list.
I had my first test ride today. Only a couple of seconds before the chain popped off. Had a few more rides after adjustments with the amount of time before failure increasing. I'm not really sure where im at, so close or so far away.
I'm using rollerblade wheels with grooves cut into them at the moment for chain guide roller wheels. Not great, but workable for now. Still can't find a physical shop in the city to buy pulley wheels from. I was keen to hold in my hand and inspect before buying but i maybe should've order some online anyway.
 
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Joined
Feb 5, 2008
Messages
563
Location
Fernley, NV
Website
miscdotgeek.com
That's what I'm doing on my Tri-Meridian, it works great. Don't knock it until it doesn't work :) and then I re-read your post, and realized my reply was dumb :p All you need to do is cut the grooves deeper. Here's how I made mine:

 
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Joined
Jan 16, 2011
Messages
712
Location
Vilvoorde / Flanders / Belgium
Pity P&P to Down under is prohibitive.
But I can make UHMWPE chain rollers easely enough. Have a nice supply of cut offs , and can get more of that for a beer*. Just tell me what bearings to be used.

*actualy, I exchange my scrap metal for HDPE, PP, PVC or POM cut offs.
(For EU based Atomic zombies, simple designs can be turned and send with affordable P&P)
 
Joined
Feb 3, 2017
Messages
102
Location
australia
All you need to do is cut the grooves deeper.
Thanks for assuring me they CAN work, but If you look closely at my picture these rollerblade wheels are different to skateboard wheels. They have a white plastic in the middle that isn't solid. Skateboard wheels are too wide for me to have 2 side by side (why i went rollerblade). So i can't go too deep.

I used a vice ,a grinder ,and a file to cut my grooves. It worked, but obviously not as smooth as a lathe method would. So i did the drill thing today after i read your comment.
I don't know if it was definitely this but the chain is running fine now it seems. It was jumping off the rear sprocket not the rollerblade wheels yesterday.
 
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Joined
Feb 3, 2017
Messages
102
Location
australia
But I can make UHMWPE chain rollers easely enough.
I think i have access to a lathe and a block of that stuff.. well by 'access' i mean i guy said he would do it for me if i gave him plans and measurements. We've both been too busy with other stuff to make it happen so far though.
 
Joined
Feb 3, 2017
Messages
102
Location
australia
Other updates:
I made this monster chain tensioner for the large amount of front boom adjustment.
Originally i tried to use the torsion spring from a derailer but it couldn't handle the load or amount of movement.

upload pic
I am using this pull spring now, but it looks like it might not handle the full movement amount either. I might remove the spring alltogether and just make it a manual adjustment... obviously i probably should've realised this earlier. I thought a spring would remove some effort for the user when adjusting but you have to get out a spanner and your muscles to tighten the front boom anyway... in fact the boom tubes don't telescope without herculean effort when the clamp is loosened anyway, it remains too tight when loose 🤔.
 
Joined
Feb 3, 2017
Messages
102
Location
australia
I wonder, is anything i make ever truely "finished"? There's plenty of room for improvements and alterations but this project had a hard deadline, 1 November, so that means it is almost done. I have been slack with the progress photos again, but the parts have been painted and tomorrow is assembly.
Would anyone like to guess the colour/s? I'd like to offer a prize, but... its the international internet.
 
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