[Closed] FAO doubters III (carbon brake mount & potential FLAME-AGEDDON content)

No spoon?

😀

Things have moved on from cutlery...but steel is still in use!

Cynic Al's fresh goods friday
IS mounts are so last year, it's a about post mounts now 😉

looks good al.
I missed the build. What did you use to bulk out the metal plate to get to the OD of the leg before carbon wrapping?

I went hi-tech - car body-filler 😎

The proper stuff from Halfords like.

makes sense, was thinking alraldite but would have cost a bit.

Do you need to key the existing lacquer first?

I bonded the steel mounts directly to the fork first (after keying it), bolted the lower one to the fork-end, then added the filler, then put a few layers of carbon on top.

I started off with araldite but then bought proper layering epoxy which is way cheaper but less viscous.

Got a few more ideas for it 😎

did you make a jig to get the IS mounts in the right place relative to the drop outs?

That actually looks quite good. Good effort sir!

Oooh another compliment, thanks 😀

Stoner I just tightened a BB7 caliper onto a disc and did it that way. I used a rear adaptor so I could keep the mount smaller. Not like I'll ever sell the fork on!

Looking good.
When are we going to see the 30mph to zero stoppie on youtube?

*disappointed that no cutlery was harmed in the making of this disk mount*

Looks quite neat.

Chapeau Al - that's pretty neat for a DIY job. I never said you couldn't do it 😉 A couple of thoughts:

- One leg is now way stiffer than the other - do you notice this in the handling?
- Why put the mounts on the front (is it just to keep access to the mudguard eye?)? All the braking forces are putting your handywork into tension
- You've got a lovely stress concentration at the lower edge of the upper eye, where the fork section changes from very thick to very thin as it tapers toward the dropout. The caliper brace will add stiffness across the gap, but I'd keep an eye on this area as being the first place to give you problems (all else being equal).

Will it blend?

😉

Only joking, that looks a neat botch to me.

IanMunro - Member
Looking good.
When are we going to see the 30mph to zero stoppie on youtube?

I'll do what I can (with a static camera) over the weekend.

bristolbiker - Member
Chapeau Al - that's pretty neat for a DIY job. I never said you couldn't do it A couple of thoughts:

- One leg is now way stiffer than the other - do you notice this in the handling?

Not at all - I am not convinced it is actually stiffer

- Why put the mounts on the front (is it just to keep access to the mudguard eye?)? All the braking forces are putting your handywork into tension

1. Mostly to avoid the mounts compressing the carbon and possibly cracking it.
2. also to stop the axle lifting out of the fork-end....
3. and to make mounting mudguards easier.

- You've got a lovely stress concentration at the lower edge of the upper eye, where the fork section changes from very thick to very thin as it tapers toward the dropout. The caliper brace will add stiffness across the gap, but I'd keep an eye on this area as being the first place to give you problems (all else being equal).

Possibly - but hopefully the carbon wrap along the length of the upper mount is spreading the stress - the mount is actually pulling it down the fork leg as well as away from it.

Not at all - I am not convinced it is actually stiffer

It is - there is no way you could [b]NOT[/b] increase the second moment of area of the section by doing what you've done - the question, more accurately, is by how much is one leg stiffer than the other, or (back to my original Q) is it enough to notice in the real world?

Possibly - but hopefully the carbon wrap along the length of the upper mount is spreading the stress - the mount is actually pulling it down the fork leg as well as away from it.

The corner is so tight on the inside edge of the upper bracket, you're stress concentration on the surface is effecitvely geometric, rather than material driven. Just keep an eye on it, that's all I was saying.

bristolbiker - Member
It is - there is no way you could NOT increase the second moment of area of the section by doing what you've done - the question, more accurately, is by how much is one leg stiffer than the other, or (back to my original Q) is it enough to notice in the real world?

Maybees....as you say though it's all relative - the leg itself is already pretty stiff to start with. I certainly didn't notice any difference. It's arguable that the added stiffness counter-acts the neding force created in that leg when braking - but I'd say that's BS also!

The corner is so tight on the inside edge of the upper bracket, you're stress concentration on the surface is effecitvely geometric, rather than material driven. Just keep an eye on it, that's all I was saying.

Ah - you mean the point just above the brake bolt-hole?

There and (bare with me on this....)..... in your photo, if you drew a line through the centre fo the dropuout on THE OTHER fork blade, through the centre of the mudguard eye on THE OTHER fork leg, then put an arros head on that line, it would be pointing to the corner I was talking about.

I don't want to dragged into these details really - you've done a cracking 'man-in-a-shed' job, so lets wallow in this success and see how it goes, rather than decending into the usual STW bun fight!

Ah OK gotcha - the steel plate ends there, I'm no concerned but will keep an eye on it ta.

I was so hoping for a bun-fight 🙁

Poor Al. He tried so hard, yet all people did was be nasty and cruel. 🙁

We need people like this; trying out new ideas, risking their own lives so's we can learn to do stuff ourselves.

Lots of pioneers died so that we can now fly in almost complete safety to wonderful places around the World.

Please try not to get mash up an bash up an ting though Al.

Looks tasty al. Nice work.

Poor effort, its on the wrong side. 1/10

roadrat forks have the mount on the wrong side as well..

OK here's a video, didn't manage 30mph but probbers 20, brake not the strongest for whatever reason, but I think you'll agree this is pretty impressive:

no endo followed by a trackstand ******* amateur
No idea as to safety but it looks cracking 😀
IGMC

bonus points for sandals 🙂

Sandals and shorts for as long as possible - I am a celt!

cynic-al - Member

Sandals and shorts for as long as possible - I am a fluffy bunny!

Oops wrong place

I think you'll agree this is pretty impressive:

Yep.
The way you owned that kurb at the end of the video showed it who was in charge.

Both missing the sarcastic joke (I rarely make them though so they must be tough to spot 🙄 ) and point scoring in one post?

sarcastic joke?

I'm being dead serious that kurb was propper owned.

It'll be a long time before it dares to get between you and the footpath again.

Ah well some of us don't need to post up stuff to big ourselves up and don't take ourselves too seriously 🙄

Anyway if you don't like this crap then I know it's personal:

[url= http://farm7.static.flickr.com/6082/6062662465_41f4b91b3c_z.jp g" target="_blank">http://farm7.static.flickr.com/6082/6062662465_41f4b91b3c_z.jp g"/> [/img][/url]
[url= http://www.flickr.com/photos/7693620@N05/6062662465/ ]IMG_1399[/url] by [url= http://www.flickr.com/people/7693620@N05/ ]alan cole[/url], on Flickr

[url= http://farm7.static.flickr.com/6063/6063220208_4044851136_z.jp g" target="_blank">http://farm7.static.flickr.com/6063/6063220208_4044851136_z.jp g"/> [/img][/url]
[url= http://www.flickr.com/photos/7693620@N05/6063220208/ ]IMG_1401[/url] by [url= http://www.flickr.com/people/7693620@N05/ ]alan cole[/url], on Flickr

Upside down bike [b]next[/b] to a washing line?

You could have at least hung it [b]from[/b] the line.

*Walks away dissapointed*

that doesn't look at all shabby. Good Carbon Fibre Skills!

Nice bike, shame about the tragic end it will come to 🙁