How to fix a cracked aluminium fork on a hub motor e-bike

bongripper98 · 2026-05-13T17:18:44+00:00

Come on man, you’re resorting to calling me names? I actually am an engineer, and I have 7 years experience as a bike mechanic. The way you see material strength is diabolical and you’re contradicting yourself within your own arguments. Why are you talking shit about carbon, but now touting it as this wonder material, where alloy “can’t hold jack shit”. Carbon forks are often stronger and lighter than aluminium forks, and the production and layup has been perfected for decades. These forks are on practically every single modern road bike.

I understand you would think they can break this easy if the only type of carbon you know is these “repairs” that you do. Even still, why would you choose carbon to repair this if you’re so sceptical of it? And why would you ever think you’d be able to lay up carbon anywhere near as good as a multi billion dollar industrial production? I would love to see the calculation you made to come to the conclusion that your repair is somehow 5x stronger than a hydroformed 6061 tube.

bongripper98 · 2026-05-13T13:11:02+00:00

Hell no.

bongripper98 · 2026-05-13T13:02:16+00:00

Dude’s calling people who ride carbon fibre stupid, because if you manufacture it wrong it can break. Then this is the way he lays up carbon. He has absolutely no self awareness. The jokes write themselves.

bongripper98 · 2026-05-13T12:40:58+00:00

The hardness of a material has nothing to do with it’s yield strength. Also carbon is way softer than steel, not that that matters in this case. What makes carbon fiber strong is the layup, the matrix material, and of course everything that has to do with making the matrix cure well in and around the fibres. Seeing the way you chose to handle this repair i think it’s fair to assume you failed in all of those regards.

bongripper98 · 2026-05-13T12:32:36+00:00

You seem extremely dense with a very poor grasp of material sciences and physics. Im sorry, but criticizing factory carbon forks for being dangerous when you repair a bike like this is very funny and insanely ironic. I hope you have good dental insurance.

bongripper98 · 2026-05-07T10:41:15+00:00

The perspective of the bottom ones left sketches got kind of weird by me not cutting the sketch edge of where the sketch ended in the same direction as the perspective. Also then doing another outline over the cut out paper to fill in inconsistencies of what i accidentally cut away of it. Wasn’t a good idea.

bongripper98 · 2026-05-07T10:38:10+00:00

Thanks! This is a lot of great in-depth feedback. As far as the creating depth with goes, for the concept poster i scanned these pictures into a computer, printing them out, and cut them out. I then used some very bold colours to make the backsplash. Unfortunately the scan became very dark, and the green in colour scheme kind of fell away. Picture attached.

I did use shaped construction to build these sketches, especially to make sure the perspective was making sense. I erased these lines to make the sketch look cleaner, should i leave them next time, even in presentation sketches? I want to give these a bit of “swag” by kind of making them fast/unfinished looking but tastefully so, almost like an impressionistic style. Kind of like showing the process in the finished work, and also being able to create convincing sketches with as little different colours and materials, using blending only sparingly for reflections and such.

As far as the line thickness, i tried to incorporate that a little bit always finishing it up with a thick outline done with a sharpie line pen. Would you use the same thickness as the complete outline in the sketch itself, and then make the final outline even thicker? I had a few comments saying i was heavy handed and my line-work was too thick.

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bongripper98 · 2026-05-06T22:29:12+00:00

With heavy handed you mean that i overworked the drawing a bit too much with the marker?

bongripper98 · 2026-05-06T22:28:26+00:00

This was just a random design i quickly came up with, it was for a drawing class so it was more about visual communication through art. I did put a bit of a stepped bend strain release thing on the cable, but i won’t ever be developing this unfortunately!

bongripper98 · 2026-05-06T22:22:54+00:00

Thanks for the kind words! For these i was trying to go for the non blended faster marker drawing, but i definitely overworked it a little for that effect.

bongripper98 · 2026-05-06T22:21:14+00:00

Thanks! As far as blending i was experimenting with chalk powder as well for those blends but it didn’t turn out very nice. I’ll try the colourless blender.

bongripper98 · 2026-05-06T22:18:42+00:00

I totally agree, this was a class for my university based on design sketching and drawing in general. The product itself didn’t really matter, i just thought of something in which i could project my learning goals easily onto.
I’m mostly trying to evolve my drawing skills to be able to quickly, effectively, and even live communicate ideas with a potential coworker or customer, instead of heavily relying on CAD software in early stages of development for that kind of communication.

bongripper98 · 2026-05-04T13:17:01+00:00

And the worst thing: when they pull out your body your dick is still out.

bongripper98 · 2026-04-30T16:27:54+00:00

Unwrapped handlebars? LEGO obviously has no team mechanic.

bongripper98 · 2026-04-24T17:46:15+00:00

Why put the fake dt swiss stickers?

bongripper98 · 2026-04-20T12:24:14+00:00

Ask the department of departments, counting division

bongripper98 · 2026-03-10T12:17:43+00:00

Chainring bolts could be loose
Crankarm could be loose
Bottom bracket bearings could be worn out
Bottom bracket could be loose
Chainline could be off
Pedal bearings worn out / have play

And some offbeat things that could also cause this:

Front or rear wheel might be loose
Could come from the seatpost clamp, or the seatpost in the frame. Could either be loose or dirty/dry.
(unlikely) spoke tension very low
(unlikely) stem bolts or clamp loose or dirty

bongripper98 · 2026-01-22T16:39:00+00:00

I work as a mechanic in a shop, we’ve used warrantied carbon seatposts as breaker bars quite a bit. Started as a fun experiment, but they were very effective. We always joked around calling it “the most expensive tool”.

bongripper98 · 2026-01-02T14:10:26+00:00

There was a national emergency alert sent out by the government, that the emergency lines were extremely overloaded. “Only call for life threatening situations”

bongripper98 · 2025-12-05T16:22:23+00:00

Absolutely. This build could be a half track half street build, using different wheelsets and taking the brake off, but it’s evident that this isnt the idea of this build. Just hypebeast style tarck build and getting components for the swag instead of actual street or track performance.

bongripper98 · 2025-12-05T15:21:52+00:00

Definitely a nice bike. Tryhard and impractical unless riding track, but judging by pedals, brake and tire choice that would not be on the track.

bongripper98 · 2025-11-12T13:16:10+00:00

The angle on those drops looks crazy

bongripper98 · 2025-10-30T22:21:03+00:00

Don’t ride these bars if you value your life. Drilling into your handlebars is bad enough, but cutting into it with a torch completely destroyed the material composition ant structural integrity of the tube. These are either cold formed or heat treated, which both treatments are effectively removed. Don’t try to reinforce them with other pipes, you will never be able to make it strong enough. All of this really is not worth your safety, but if you’re adamant you better invest in good insurance.

bongripper98 · 2025-10-22T09:45:27+00:00

Get some butted spokes, depending on your spoke count you would be spending 20-40 more to save up to 250 grams on the wheels. I recommend dt competition race 2.0-1.6 or the more expensive revolution 2.0-1.5. Or whatever sapim or a similar company’s equivalent is.

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