Hot-cast & cold-cast Urathane

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I have learned something new and interesting – the difference between hot-casting and cold-casting of polyurethane wheels (I did not even know there were two processes for making polyurethane wheels).

There have been a growing and significant number of posts on various e-board forums about how the polyurethane of hub-motors is cracking and breaking up far too quickly; and not just the usual budget companies, top end boards like Entertion’s Raptor seem to also have batches with the issue (Entertion aparently identified a bad batch). A few companies, inc. Backfire, Entertion and Verreal, offer replacement polyurethane for the motor; however, there is a concern, which I share, that there is a fundamental problem here with a lot of the hub-motors in the market right now.

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https://www.reddit.com/r/ElectricSkateboarding/comments/88ttji/raptor_new_97mm_already_cracking/

Part of the challenge, and why hub-motors require high-quality and not cheap low-quality polyurethane, is that the polyurethane unlike with a real wheel is effectively just a wrap or sleeve around the hub-motor. Not only this the amount of polyurethane much less than a real wheel (why there is more vibration to the ride), but the hub-motor will also be getting hot and heating up the core of the wheel.

One of the posts on /r/electricskateboarding highlighted (thanks Predator Boards) that the potential biggest issue is how the sleeve is made, namely if the polyurethane has been cold-cast or hot-cast. In summary (and I am far from being an expert here): hot-cast, where the wheels are baked in an oven, is more expensive but produces high-quality polyurethane wheels (all duros); as opposed to cold-cast, where it is set in a mold at room temperature. In addition, cheap cold-cast wheel often don’t use a vacuum as part of the process, to take the air (micro-bubbles) out of the wheel.

And, in response to “how do we spot if a wheel has been cold cast or hot cast?”:

This isn’t a guarantee, but hot-casted thane usually goes through a vacuum/compression process. You can inspect the inner edge of the wheel and see if there are any air bubbles. If there are, then it’s likely cold-casted. If there aren’t any, then it may still be cold-casted and vacuumed.

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I have not 100% understood all of this, and I need to do more reading, but it has first-off helped me with the question: “why don’t I just buy those cheap wheels from Ebay?“. As for hub-motors on e-boards, I just think that you have to accept it as part of the downsides (against their upsides), especially if you are buying a budget board which will almost certainly use cold-cast urethane sleeves. Having replacement sleeves is a distinct advantage with some makes, although there is an argument that just replacing the whole hub motor is actually the right/safer option. I think it all just reinforces the recommendation to only buy an e-board where you can fix and replace the parts easily. Cold-cast wheels are just going to damage easily and need replacing.

 

 

 

 

 

Boa Wheels

New US maker Boa (might just be new to me), has brought out two longboard wheels, which interestingly have the same core hole system as the Orangatang Kegel, meaning that they can be used as a direct replacement, with no change of pully or belt, with Boosted V2 boards.

The wheels, both 83a, are the Constrictor at 100mm and the Hatchling at 90mm.

UPDATE (7/4/18): Ordered some Constrictors and will write a review when they arrive.

Slick Revolution wheel kit for Boosted

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The UK company Slick Revolution are now offering for pre-order (available June 2018) an interesting wheel kit for Boosted Boards, to work both with their own large 110mm Rough Stuff Wheels with treads or, usual favorites, the softer 75a ABEC 11s.

The kit is a really good value at £29.99, for the 56-teeth pulleys and belt-covers. The Rough Stuff 87a duro wheels, which come in red and black, are extra at £74.99 (including bearings); although, I don’t know how they will perform against the slightly more expensive ABECs. on vibration and ride. Equally, I need to check the compatibility with existing belts and the torque and speed impact with the new 56t pulleys and 110 wheels, compared to the stock 50t pulleys and 80mm wheels. Different gearing can increase speed, but reduce torque, or visa-versa; personally, I would like to keep the torque and am not bothered about increasing the speed.

UPDATE: I checked with Slick and it works with the existing belts, with the gearing giving it an increase in speed (and decrease in torque).

 

I have been looking at various wheel-kits, including the excellent Booster Box kit, for the last month. Much as I like the Orangatang (Loaded) Kegels, at 80mm, on the Boosted they don’t give much clearance for the belt guards and we constantly grind them when traveling over our local rough Victorian pavements and roads; running a 110mm wheel would give greater clearance.

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Interesting Gear: Alkimist Longboards

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I found another small European maker, the French company Alkamist Longboard, with some nice looking downhill boards and some very stylish wheels. I will have a look more at the wheels and am very tempted. Never been one for white wheels, but these are the first that got my attention.

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Choosing Wheels

img_20171125_104251.jpgOver the last year, we have used 11 different wheels, including various models from: Orangatang, Hawg, Walzen, Metro, Atom, Abec & Blood Orange, and thought it worth documenting our experiences and preferences.

First off, it is important to note, that all this is in the limited context of our cafe-cruising, street pumping and carving, limited trick ability and tentative deck foot-work (calling it “dancing” is a bit much). We don’t live with streets or paths where we can downhill safely or (yet) have the ability to do big dancing and tricks.

 

Info-graphic from w82.com

For what we do, I suspect just about any wheel would work, but our choice usually comes down to the following four characteristics:

  1. Larger diameter (70mm+) – to smooth out the local rough roads and pavements. We don’t push our boarding that much to notice any subtle acceleration difference from using smaller wheels (smaller wheels accelerate faster than a larger one), but do notice immediately when smaller wheels rebound against old rough pavements.
  2. Colour – hey, aesthetics are important to us; when cafe-cruising, it is important to have a cool board with colours that work together.
  3. Lip edge & contact width – either:
    • a square/sharp lip with a larger contact width, like the Hawg Mini Monsters and big Orangatang Kegels, for max grip in the turn when cruising; or,
    • a rounded lip with a smaller contact width, like the Blood Orange Liam Morgans and Metro Red Motions, for the boards we like to throw around and do basic tricks on.
  4. Built-in Lights – my 8-year-old son will only use wheels on his board with built-in lights 🙂

I initially thought that the durometer rating would be a big factor for us, but have ended up happily using wheels from 78a to 84a with no issues.

None of the wheels we have used have given us any problems and I would happily buy any of them again.

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big 80mm pavement-crushing 80a Orangatang Kegels