[Lowly]

Looks like magura Direct Mount but it's long, the forks can take a 24" or 26" and the mounting holes line up with both 24" & 26" rims.
Not sure how best to mount the Magura IDM mountings to the frame mounts
Different angle of the forks.

And a piece of blue foam I cut to what I expect the original spacer /mounting hardware to look like

Sorry if this is the wrong placei only acquired these about a week ago, and don't have any trials friends I can ask about this kind of stuff

 

[De_Nada]

Hey welcome! You're in the right place. I'm not sure what's going on there but hopefully someone who knows more can help you.

 

[Lowly]

Hey welcome! You're in the right place. I'm not sure what's going on there but hopefully someone who knows more can help you.

Thanks for the reply, I hope someone can shed some light on what is going on, I've spent about 3 hours of googling with different terms and clicking on links and looking at forks to try and find something with a similar mount, but it seems the majority of new forks are disc only these days

 

[De_Nada]

I don't suppose you know who made the fork?

If you haven't already, you should head over to Trials-forum and post there as well.

 

[Lowly]

I don't suppose you know who made the fork?

If you haven't already, you should head over to Trials-forum and post there as well.

I'm waiting for the confirmation email to finish up my membership with them, it's been over half an hour, hopefully get it by tomorrow, and the forks have no markings on them at all. I have a feeling they have been resprayed

 

[bentmettle]

If were guessing, something like that foam spacer you've mocked up exists and it's flipped either top or bottom depending on which wheel size is being used.

Although if that bolt hole is lined up in the first picture, it's probably basically just a Tee shaped standoff with clearance hole for that mounting bolt.

 

[Lowly]

If were guessing, something like that foam spacer you've mocked up exists and it's flipped either top or bottom depending on which wheel size is being used.

Although if that bolt hole is lined up in the first picture, it's probably basically just a Tee shaped standoff with clearance hole for that mounting bolt.

My thinking of the spacer is that the bolt holes do line up but the standard 30MM m6 bolts used in the Magura mounting kits, only make about half a turn of contact with the bolt holes, so I was thinking either this frame came with extra long 50mm bolts (cheap enough to source online) or the spacer was threaded and then bolted into the free hole for extra aecuritybut them I'm like, I'd these exist somewhere, I'd rather buy them instead of making them myself

 

[bentmettle]

Practically speaking since the m6 bolts thread into the fork, there’s no spacer design that wouldn’t have been a through hole.

I’m torn between thinking the spacer needs to attach to the other part of the brake mount. It’s possible that it’d take some bending load,

you could slot both clearance holes and render the distance measurement completely uncritical.

do you have a mill? Or 3d printer?

 

[Lowly]

Practically speaking since the m6 bolts thread into the fork, there’s no spacer design that wouldn’t have been a through hole.

I’m torn between thinking the spacer needs to attach to the other part of the brake mount. It’s possible that it’d take some bending load,

you could slot both clearance holes and render the distance measurement completely uncritical.

do you have a mill? Or 3d printer?

I don't have any of these advance engineering tools, I only have the basic lathe, vice, drill press, workbench setup.
And same, I was thinking either it's just a through hole space with a longer bolt, or it bolts into the unused end and then is threaded at the spacer section to take the regular bolt length
Of course there is also the possibility it originally shipped with a different asymmetrical mount that made use of both end fixings, one mourning hole, longer then the other

 

[bentmettle]

If you take some measurements I can post you something. I have some domestic activities to attend to today but I’ll post a preliminary idea sometime this weekend.

 

[Lowly]

If you take some measurements I can post you something. I have some domestic activities to attend to today but I’ll post a preliminary idea sometime this weekend.

I have a cheap digital measuring tool too, I can measure everything up if I need too, and sure let me know what sort of images you need,
This is currently my long term project since I have 2 other working trials frames built as working bikes atm

 

[bentmettle]

Cool. I think we can sort something. I have a small mill that I could be able to mangle some aluminum with well enough.

 

[Lowly]

Cool. I think we can sort something. I have a small mill that I could be able to mangle some aluminum with well enough.

You sound like a wonderful person, thank you for offering your help to me

 

[bentmettle]

What about this? I can't sort out what function the notch would have aside from eliminating the chance of a burr making an adapter not fit flush

I see the riser is also angled - angain, I dont know that this is function. Do they look like they're extrusions that are cut from some long stock and then drilled/tapped/welded ?

 

[tda]

Bad ass.. This is why the forum is great !!

 

[bentmettle]

oh wait, the angled side is to clear the Magura mount - I wasn't looking at how it sat into that saddle. So the notches are the only mystery design element.

I think the Magura spacing is supposed to be 45mm - and I see the the spacer either needs to not have the extra material on it to pick up the bottom of the mount, or have a notch in it. I think at some point, you could just do a turned bushing and face down to the correct height.

 

[Lowly]

oh wait, the angled side is to clear the Magura mount - I wasn't looking at how it sat into that saddle. So the notches are the only mystery design element.

I think the Magura spacing is supposed to be 45mm - and I see the the spacer either needs to not have the extra material on it to pick up the bottom of the mount, or have a notch in it. I think at some point, you could just do a turned bushing and face down to the correct height.

Sorry I didn't get back to you, I was struck with the extreme tiredness yesterday, I'll try and comprehend what you are asking and with more measurements and a drawing (hand drawn) with measurements tomorrow

 

[Lowly]

What about this? I can't sort out what function the notch would have aside from eliminating the chance of a burr making an adapter not fit flush

I see the riser is also angled - angain, I dont know that this is function. Do they look like they're extrusions that are cut from some long stock and then drilled/tapped/welded ?



View attachment 42009

Thats a great image but due to the clearence of the mounting hardware for the brake, the highest point of the right side needs to be the same exact level as the lowest point of the left side
I think this is the reason for the sloped section on the mount, if it was all square cut, then there would be no space for the spacer to clear the mount and mounting hardware

Ok to clear up terms so I don't confuse anyone,
mount will refer to the part of the fork,
Moutnign hardware will refer to the silvery /green/flourescent allot things in the picture
And the thing that doesn't exist (shown initially as a blue piece of foam, will be refered to as spacer.
This is as much for me so I don't get confused by myself as it might be for anyone else

 

[Lowly]

oh wait, the angled side is to clear the Magura mount - I wasn't looking at how it sat into that saddle. So the notches are the only mystery design element.

I think the Magura spacing is supposed to be 45mm - and I see the the spacer either needs to not have the extra material on it to pick up the bottom of the mount, or have a notch in it. I think at some point, you could just do a turned bushing and face down to the correct height.

Ok so the notch, looks to be 2mm ± paintso I'd guess this is used as either an alignment aid, to make sure the spacer just slots in nicely. Also it looks as though (having tried another M5 default bolt, yep they are M5 I measured wrong before) the bolt doesn't reach the bottom of the notch, so my guessing is the original spacer was threaded for the moutning hardware screw (the replacement does not need to be as I can easily source some M5*60 and cut them down to size) , the notch would then possible either aid to stop any sideways twisting from excessive breaking,
Or be a little spacer gap to prevent any cross threading should a bolt enter the lower threaded section or perhaps be over engineered to have a post that enters the lower notched threaded hole(this is unlikely as the holes are threaded)
Anyways, I'm no computer engineer so I drew up some pen and paper
This is what I imagined along with some measurements

I've shown the moutnin hardware at maximum intrusion into the spacer

The only number I didn't measure was the 3.8mm but I used pyhtagoras thereom to get that 3.8mm
The mount is 10mm across the board on one fork and 10.5 on the other forkthe height of the left side is obviously a design element and can be a lot shorter, but I made it the same height as both half's of the moutning hardware for aesthetic reasons, hence the curve
also I'm not perfect so I made 2 mistakes, one on top view and one in bottom view so I put multiple little crosses through those mistake lines
further also, the sloped but on the right side, after the through hole spacer, may not need to exist, I wasn't sure how strong it would be having that through hole close to the end of the material so added some more material in the design

 

[bentmettle]

I think you’ve landed on the notch as an assembly aid - the photos look like they're undercut , so you could slide in the spacer, and it couldn't fall out while you are wrestling with the brake mounting hardware.

It adds a lot of complexity to the the spacer if you are machining them in small batches and if you can put up with having to hole the spacer while you mount the brake, you don't really need any protrusion at the bottom.

I really think you can get away with a single hole and only worry about the height dimension. - I don't think there is enough cross sectional area in anything that would pick up the other "main" mount- to do more than the properly tightened bolt does.

If you had these front brakes mounted, could you ride it and test it or is that ways off?