Jump to content

TF Makers


JD™
 Share

Recommended Posts

4 hours ago, isitafox said:

Next project we're thinking of doing a drift trike, just need to source a pit bike engine.

You're doing it wrong, find an old oil burner gixxer motor and hammer that in there :D

  • Like 1
Link to comment
Share on other sites

57 minutes ago, monkeyseemonkeydo said:

Sweet! What are your plans for it in terms of use?

I really want to put one of these in...


62573EE8-570F-4B5B-B4F9-B0B712273B2D.jpeg.eb3e1f18272380e7a553872e2e449a5c.jpeg

 

a 3D printer and a bit of a geek out space - maybe some soft seating maybe a ps5. But mostly I just really want a full sheet cnc machine. 
 

one of the original plans was to air condition it, but doing it diy seems a lot harder now as no one wants to sell them anymore. It’s the best way to heat it and the summers are getting more and more intense so a chill out zone would be nice... 

  • Like 4
Link to comment
Share on other sites

Been running single speed for a while, love it, it’s great for simplicity and shitty north west winters but if I want to do some tech climbs or Trialsy stuff the gearing is never quite right.

So I had the idea of using one of Shimano’s newer side swing front mechs to add an extra gear up front. They use a cable stop built into the body so you can fit them to any frame even if they’re not designed for front mechs like most modern bikes.

I’ve been able to keep the single gear out back and the heavy duty chain, the front mech has enough clearance to accommodate easily without a wild chain-line from a huge cassette. Dropper lever has been put on the right. I used an older triple chain set so I could fit a bash which stops over shifting. The Trialtech tensioner copes fine with the switch between gears, I just backed off the tension a little. The KMC Z1ehx is quite happy on 10spd chainrings and as it’s narrower is happier running through a front mech with enough flex to allow a smooth shift. I purposely chose ramped chainrings (SLX M660) to facilitate a smoother shift from a bulkier chain.
 

The whole set up works flawlessly! The weight is centred and I have a gear for Trials and nadgery climbs but can still run a high gear for miles, what more do you need??! Best of all the XTR mech was a tenner off wiggle because no one wants them anymore and I won’t be sweating over the lack of transmission parts from the dreaded COVID.

 

 

96C852B7-12C5-41A7-86BF-A5997AD32B97.jpeg

7A0CABA4-A202-4C2A-B60F-7BBD2BCB3F3E.jpeg

519AF59E-3439-41E3-B989-06DDA2BE75C0.jpeg

5866258A-38BC-4168-8C8F-41CB4349AC36.jpeg

  • Like 5
Link to comment
Share on other sites

39 minutes ago, isitafox said:

Nice, what gearing you running? 

20 out back and 24 / 32 upfront. The 32/20 combo is about 48 gear inches which is a nice middle ground for single speed. I tried a 22 and 26 but it’s a hefty bike, too small and you can’t actually move it anywhere, too big and it’s hard work to keep it balanced so this works nicely.

Link to comment
Share on other sites

Didn't fancy dingle speed then?

I've got an old 26" budget xc frame thinking about setting up with 2 or 3 gears at some point in the future. Keep thinking about adding a gear to my Inspired Console so I get to the skatepark a mile and a half down the road a bit quicker. Just biding my time looking at options as they crop up. Briefly thought about dingle speed on that but decided it would be a step too far for that bike. Did you see people talking on Trials UK FB about old-school friction levers on chain stays for triple gears on rear wheel?

Edited by marg26
  • Like 1
Link to comment
Share on other sites

25 minutes ago, marg26 said:

Didn't fancy dingle speed then?

I've got an old 26" budget xc frame thinking about setting up with 2 or 3 gears at some point in the future. Keep thinking about adding a gear to my Inspired Console so I get to the skatepark a mile and a half down the road a bit quicker. Just biding my time looking at options as they crop up. Briefly thought about dingle speed on that but decided it would be a step too far for that bike. Did you see people talking on Trials UK FB about old-school friction levers on chain stays for triple gears on rear wheel?

I like the simplicity of one gear out the back and two ratios. I had a similar issue with a commuter, never quite the right gear. I ended up fitting a Sturmey Archer Kickback S2 hub to that which gives a 30% ratio difference and doesn’t need a shifter just a kick back of the pedals to toggle between the two! I’ll use the 32 80% of time but having the 24 in the bank opens up a lot more lines on the Trail. Suicide shifters are cool, I built a custom wheel with a 5 speed hub and s-shifter for an older customer a while ago. There are a tonne of options to gear up a non geared bike if you dig a little deeper!

Yea I saw that thread, think it was a Leeson they were talking about? In theory you could do this mod to a street or stock bike with a low BB and some kind of normalish seat tube, you’re not changing the rear where the big stresses are and up front the small gear is the same. Most front mechs will work with any shifter for changing between two chainrings so if you can find somewhere to put it a suicide shifter would work. For bikes with odd shaped tubes you could look at BB mount e-type mechs. Tinkering is fun!

Link to comment
Share on other sites

On 27/02/2021 at 9:00 AM, Adam@TartyBikes said:

Haha, @Topsy, you ain't seen my welding yet :lol:

Quoting yourself, is that an internet faux pas? Probably.

Anyway I don't mind doing things differently. They say you can't or shouldn't TIG braze a bike frame or bad things will happen. So guess what I've been experimenting with?

20210309_173256.thumb.jpg.439f70b68c934e92656e1c01d1340c30.jpg

This technique is a weird hybrid of brazing and welding, not the same as fillet brazing people like Curtis and Leeson use, or regular TIG like most of the mass produced frames.

For TIG brazing you use the TIG torch as your heat source (instead of a blow lamp), but a copper based filler material (hence the lovely colour!) which melts at a much lower temperature than the steel tubing. There's an advantage - less heat being used means a reduced HAZ, in theory anyway.

Like brazing, you never melt the parent metal, so the filler just sits on top, and you need nice big fillets for strength / adhesion.

Therefore: TIG brazing.

I tested some joints back to back against normal TIG welding, and I'm happy it's strong enough... both failed in exactly the same way and with little to no difference in force required.

20210303_125550.thumb.jpg.32714c0cf3cd82c61a054bdd5c2df415.jpg

20210303_125147.thumb.jpg.f976d6045ee1d6b1fb532c986438c00e.jpg

20210303_125218.thumb.jpg.2b09e79bf25dad6e9d5d5df26cbcc15e.jpg

So maybe I'll die, maybe I won't. Although the legendary Frank The Welder says he used to stick brake mounts onto Yeti frames using this technique and never had one fail...

Either way its been fun playing with new stuff, and my original thoughts of a candy orange paintjob have gone out the window - clear coat, or maybe boiled linseed oil, it is!

  • Like 4
Link to comment
Share on other sites

Short answer, no.

Long answer, the filler material is different to the fillet (torch) brazed stuff you see that has been smoothed off. That is brass based and relatively soft, so you can tidy it up pretty easily (though it still takes ages).

If you attack this stuff with a file or hacksaw it basically just skates right over. Its really tough, much more so than the T45 / 4130 tubing I'm using. This is how I know :D

20210301_175056.thumb.jpg.5576774685c9be669a2d84aa2cb807ef.jpg

I'm happy with the slightly more 'rustic' look (after all the frame will end up with rust patches long term), and using bronze is much more stone-age. I also have some silver to braze the bottle cage mounts in. Just need to find some gold to complete the trio... ha.

  • Like 2
Link to comment
Share on other sites

So weird seeing cracks just in tubing rather than at a weld. So conditioned to seeing them there that it's weird them further out from the join! Good call on testing it to find out though, interesting to find that kind of thing out rather than going on received wisdom (Y) 

  • Like 1
Link to comment
Share on other sites

Yeah, not used to seeing that - but its function of...

- The heat affected zone:

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSlDXDSOT6NB9LX3nAbg4az74aJg8wjTRe-hA&usqp=CAU

- And the failure type - (deliberately) taking the material past its ultimate strength, which exposes the HAZ.

 

Most bike frame failures are from fatigue (lots of cycles rather than one big load), and the stress riser related to this is right at the edge of the weld. Especially common on aluminium obviously, as the ductility (percentage elongation before the yield point of the material is found) is about half that of steel - so that's the usual places you see cracks.

This silicon bronze stuff has a super high elongation percentage of around 60% (aluminium 10, steel 20, ish) so I'm hoping that will give the tubing an easier life and maybe even 'soften' the ride of the frame...

 

But yeah, doing my own research even if it is in an unconventional direction has worked for me in the past, so thought I might as well do the same again!

  • Like 2
Link to comment
Share on other sites

4 minutes ago, monkeyseemonkeydo said:

I just wanna know how!! When I got our TIG set at work I specifically got some some brazing rods but the bastarding stuff just spits like crazy and I can't get it to wokr in the slightest. That looks wicked!

You have the wrong stuff mate. 

And I know this because I did exactly this hahahaha I got brazing rods which you absolutely can't use with tig. You need dedicated silicone bronze for tig. You'll know you have the right ones because they are expensive. 

  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...