Unique GT issue

[Jinra]

I’ve had my GT for about a month now and I’ve been loving it so far. However I’ve run into a couple mechanical issues over the last week. The first is the CF board made a loud crack noise when riding normally. I later found out that the board has a small split in it shown here…

The second issue is that somehow, probably due to too loose of a belt, the belt skipped over the pulley lip and started running against the motor cover until it cut through. I stopped within a second of noticing this but it still cut through the motor cover. I had the belt loose to avoid tension and heat and it never skipped, but I’m probably going to tighten up my belt and forego motor covers after this.

[barajabali]

oh man i didnt expect this from the GT.

I think @Mr_Mahal had a similar issue with the deck though.

[Jinra]

Well he had his deck run over by a car, I was just cruising along . The belt skip thing seems to more my fault for having the tension so loose. I’ll contact Evolve once I get my DIY running so I wont be out a board for 2 weeks.

[barajabali]

oh yes thats right! well it is carbon fibre so its strong… So it must be a defect in the deck.

[CSN]

Carbon is great until it develops a crack.

Kind of like getting a stone chip in a windshield. It’s going to spread over time.

I think most of the carbon boards out there will start degrading after impacts or just repeated stresses.

It took the bicycle industry many years to refine bike frames to not crack easily.

Still lots of crap frames out there.

[evoheyax]

This is what happens when you don’t put a flange on the pully. I believe it was onloop who said something about this back in hype stage before they released this board.

The carbon fiber, this is what I’m afraid will happen if you don’t use a strong enough core. You can’t put the majority of the stress on the carbon fiber, your core needs to do this, and the carbon fiber should only re-enforce the core. Hummie and I are testing different build processes and materials, and this is my fear with a non wood core. This is why I’m build a wood core before I do an carbon fibering. And the edges will be wood, so no cracking like this, weather or not a crash occurs.

[torqueboards]

Yeah, they should of had a flange on there… It’s not that difficult. Surprised they didn’t even bother.

[Jinra]

Hummie was talking about doing a foam core, or mentioned it when I met up with him. What is the Raptor’s core made of? I’m leaning to this being a manufacturing defect more than a structural issue with the materials.

@torqueboards There’s a flange on the pulley, which I assume would be enough given adequate belt tension. My belts are very loose in this case.

[evoheyax]

It seems like a flange on in the inside, but not the outside. If there is on the outside, its too small. You can clearly see the teeth from the side angle, and with a proper flange, you shouldn’t be able to see that.

Hummies trying a few different options. Right now, he’s sold on this divini cell core idea with a vacuum infusion of carbon fiber. I hope it works, as my method takes too long. It take an hour to delicately clamp and cut a 1/16th an inch sheet with my cnc milling machine, and we just glued the last 2 sheets yesterday, to total 17 sheets. That simply takes too long for main stream production, and that doesn’t include time to polish (which will be a lot of today) and re-enforce. What I might do is make a few special quad boards like this with the wood core once I can prove to myself it will hold up to daily abuse, but I can’t turn out 100’s of board like this. A few lucky people might be able to buy one in the near future though, as I really think this will result in the nicest looking, feeling, and riding board possible. (did I mention the 16 ah 12s battery built in? )

[Jinra]

The flange is a bit small, but it’s definitely on the outside, not the inside. If you were referring to my third picture, it’s because the belt is on top of the flange since it skipped out. You can get a better idea of where the flange is from the second picture. It’s hard to say what’s at fault at the moment. I haven’t heard of anyone else having this issue, and it’s most likely just because of inadequate belt tension.

[evoheyax]

I might be switching inside and outside up, but my point is you see a flange in the second photo clearly on one side, and on the third photo, I would expect to see a flange on the other side, but instead I see teeth. Can you confirm there’s a flange on both sides of the pulley?

It seems like a loose belt could ultimately cause this to happen, but the flange should prevent even a decently loose belt from doing this.

[Kaly]

Back when @Mr_Mahal posted the pic and video of his incident with the board i notice a design flaw on the GT deck but stop my self from posting because the GT guys are very sensitive about any criticism of the board.

So this is the issue: The carbon fiber construction method use by evolved consist of a composite sandwich with 2 carbon fiber shells with a foam core. The main structural deficiency its on the mold parting line of this construction method, since they aim to have a rounded edge for aesthetics, they did not allowed the layers of CF to overlap at this critical junction to compensate for the internal forces that are produce in the material.

This can be seen in the shape of the fracture that is a straight line alone the deck parting line.

[LastingFX]

Hey guys, yeah I had the same issue with my CGT deck… cracked in the same spot too… It’s currently back at Evolve USA getting the CF deck swapped out. I’m just thinking it’s first production run quality issues. Well at least I’m no the only ‘lucky’ one. Just wondering if this issue is something common at the moment. I thought it was just me… I tend to be a bit aggressive in the carves… I guess it’s instinctive like on my snowboard or surfboard where I’m pumping the rear.

If it’s a flaw I hope they address it soon.

[Jinra]

The flange is only on the outside, which should’ve prevented it from skipping out given adequate tension. There is no flange in the inside (closer to the board). In my experience there usually isn’t a flange on the board side.

[magnetvox]

Wow. The carbon deck crack is the concerning part (because tensioning should resolve the other issue, although the flange would be an improve). Could be a combo of both a manufacturing defect, and a design issue (not enough strength tolerance built in, and a slightly weaker form found the limits??). It’ll be interesting to see if we have made more pop up. @Kaly to be fair some blokes might be too sensive to legit critisms, on the flip side there were plenty of poorly informed armchair critics too. They tend to feed off each other and the wisdom gets lost in the noise, it’s a shitty culture in most forums for whatever reason. Probably ego. Your assessment on the design flaws is very valuable to the other blokes looking to build carbon decks.

[mrd7]

Well I found this video posted on the inboard Facebook page, just for the record this is NOT my video. I do have a bamboo gt on order

[magnetvox]

Lol. Sorry, I gave up after noticed the same post scrolled past for a second time, zoomed in hard, with the music reaching a dramatic crescendo.

I was waiting for an image of a GT eating a baby but was left disappointed.

The trick with the Internet is to locate reputable sources of information… (Not saying that stuff hasnt happened, but without a trusted source what value is it). It’s why I come here rather than Reddit or YouTube for e-skate research. Competitor fanboy Facebook pages is probably the last place I’d think to go to form an opinion!

Good for a laugh though.

[Lebram]

OMG Its like a propaganda film.

[Fiori]

I am definitely super late to the party here digging up an old thread. But… Just wanted to say that my CGT deck broke in this exact same place(i had a pretty large reddit post).

I received a replacement deck from Evolve and i swapped everything over myself. Two days later the new deck is cracking in the exact same spot…Feeling like they still have not fixed this issue. It’s clearly a design defect.