I got a second set of linnpowers to try the softener on also, hopefully that lets them heat up quicker.
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Front truck setup to 37.5 degrees now (up from 35), rear still on 12.5. Hopefully it makes short track a bit easier on my legs.
Iāll just have to do the tire treatment tomorrow and then itās ready for the races!
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Personally I think ASA is a great choice for this application. I printed my BRP hubs out of ASA and theyāve lasted a couple races and many practices with no signs of wear.
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Mad props for the tire warmers, Iāve never seen one for esk8s before. Is the heat uneven because the nickel band fits loose? I wonder if you could attach the pads to a piece of fiberglass tape or other flexible backing material, so it could wrap tight around the wheel.
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Brady had some this year at esk8con, not sure if they were custom or if they were from gokarts or something
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What about a little insulation? Make a little tea cozy to keep the heat in and make it more even? Probably wouldnāt take more than a litt reflective bubble mailer insulation or a pot holder and some duct tape.
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Damn itās good to know that hubs this style can be made 3d printed! I mighttt need to consider that if I end up going the BRP way.
I agree ASA is nice, PETG is plenty strong for the widener use case though, and easier to print on my printer.
At the moment my plan is to try out the tires that are on the new stooge WTF, I found them from china for a good price - but I need to sort out the rims.
I wonder if I could 3d print lip adapters to go from 4" lip to 5" lip on my current widened mbs rims, but I am worried if those would hold up. I have ideas how to slice it so it would be hopefully strong enough.
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Yeah the nickel band is loose and the heating is more even on the exway venators where the nickel fits tight.
But part of the issue comes because thereās like 2 cm unheated part between the heating pads, and thereās no way fixing that without starting from scratch.
Wrapping something around the wheel with even heating in the whole material would be the way to go.
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The kapton tape is actually fairly okay heat insulation. I originally tested with a couple paper towels wrapped around the thing and those didnāt seem to make much of a difference. And they tended to get caught between the nickel and the tire when pushing the assembly onto the tire or pulling it off.
It might help a bit, but this is fundamentally not perfect. Iām probably going to return the heating pads to amazon to get my money back and opt for a more sophisticated option from China. I am not in a rush now anyways. Probably canāt even ride until they set the clock back end of March.
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Prague trip race updates.
On the way there Iāve fallen asleep on the highway and touched the barrier 
And the worst thing is this is my friends car so Iāll be paying to get it fixed. 3 parts are damaged, and on 2 more the paint is a little scuffed but nothing serious, probably good enough if rubbing it a bit with gasoline. This is very much not good for my esk8con budget, but Iāll still be trying to make it happen some way if I can.
Then Friday kartplanet session the track was pretty wet and I only had a couple laps of ride time. We did the wet half closed layout though, which was pretty fun and a first for me.
Then a night ride with some beers
Then there was Pitland next day, but first a paragraph of bushing talk about the raceday setup.
I swapped in a softer bushing setup, because pitland is a very tight track - 93/93 WFB tall barrels front, 95 WFB tall chubby / tall barrel rear. First the front was feeling harder than the rear, so I needed to decrease preload to like 0.75 turn in the front and increase preload to like 1.75 turn in the rear. This made the setup feel significantly looser, arguably for many people too loose, not very supportive. But I enjoyed it on this track, which is very short, top speed probably about 50 km/h / 31 mph even for me. I would definitely want more support for longer tracks though. @Titoxd1000 Iāll go more detail in PM, but TLDR is now I am pretty much convinced dual chubby is too much volume for WFB, unless we are talking about long track exclusively, and I have some ideas of things to try which might yield even more improvements in truck feel. Now back to the race. [Edit: unproven theory - maybe temperature affects bushing feel, and what I felt now might be gone in the spring when itās not freezing?]
First heat I started up very strong
Second heat I was leading the pack and I am not really good at that, donāt know how much to push myself, so I dropped down a little bit but not too bad. Third heat my rear thigh cramped up but I continued racing. When I got off the track I couldnāt move that leg for 5 minutes, couldnāt even bend down to release the binding. Then I got the same cramp just to a lesser degree every subsequent heat - and with that my position dropped down to 6th by the end.
I was also using the tire warmer setup and the WD40 as pre race wipe treatment for some of the races (didnāt bother for all) and they definitely helped with grip. Oh and the tire softener softened these by 8A. So a decent improvement. I think they could take a bit more softener for sure. Thereās one downside to this though - they stink quite badly. I wouldnāt want to keep the tires in my room unless they are in sealed bagsā¦ I hope the smell will go away eventually. If it doesnāt, I will need to get a board bag.
After that there was an unofficial 5 lap position race just for some fun, there I started 6th (official race finishing position) and couldnāt get the jump on the start because both sides started pulling to the middle so I had to brake. I ended up 2nd due to not making mistakes and being able to take positions when a fall or mistake happened. Then defending the position even though I was slightly slower and having the hardest fight against my own legs 
Not really the way I wanted to achieve a podium, but a podium is a podium nonetheless 
And hereās a video of the race from spectator POV
Then the next day there was another kartplanet session. It started out feeling slightly wet and icy, but in the end it was dry just really cold, somewhere around freezing temperature. The tires needed some time to start working at all, but then the track was usable.
Did a 56.77, my current record is 51.99 but that time I had close to 2x as much grip, so given the conditions I think this is a good time. Now I was loosing grip around 0.7G, I had sustained 1.3G turns last time while staying within the limit. Canāt wait to get back in good weather though, with a potentially even better setup 
Then I did some Prague sightseeing and Christmas markets today and Iāll be on my way home tomorrow morning.
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interestingā¦ what do you think would work better then? maybe a barrel and a chubby?
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YEahā¦ That is a VERY different load case and I would have little faith in even CF nylon holding up to something like that
MAYBE PPS but most people canāt print that
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Thatās unfortunate to hear about the car accident but also luckily it wasnāt worse. Hopefully you can still make it to esk8con.
The the reason to run chubby bushings in the rear is to be able to be relatively soft but still supportive. From what you described barrel/chubby rear is not super supportive which would be expected . If you were to run barrel/barrel in the rear and compensate by going up a duro it will feel stiffer and still feel less supportive vs chubby/chubby. It seems like front might be to hard if you barely have any preload. (37.5 has less leverage over the bushings than 35 degrees.)
What I would like to see you try is this setup. 35/15 angles, 93a barrels front and 93a chubbys rear. 35/15 since that will scrub less than 37.5/12.5 making it easier to turn. For the bushings you want front and rear to feel similar taking into consideration the leverages are different. If you want softer I would go down duro on one bushing in front or if you want harder I would go up duro on one bushing in the rear.
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Honestly, for short track I want the linear but divey feel that the soft bushings in the front with less bushing volume in the rear provided, just with a bit stiffer center. In my experience more bushing volume means that for a given stiffness in the center, you have more support while leaning in deep. For short track, itās the opposite of what I want.
Therefore, going lower in bushing volume, but up in bushing duro, should feel like the jump from APS to WFB did. I should be able to go up in center stiffness, without going up in stiffness at high lean angles. Or go down in stiffness at high lean angles, and keep current center stiffness.
Your suggestion meanwhile seems like a more long track focused setup. You need much more support from the bushings while cornering on long track vs short track. I want this setup to work well for like medium sized tracks and short tracks - I donāt need to be able to take corners at 40mph.
I think what made the previously well working bushing setup feel too stiff was at least partly the super low temperatures - we were racing close to freezing temperature, versus having the setup tuned in at around 20C celsius / 70F. I havenāt measured the durometer of the bushings, but the tires measured like 13A higher compared to 20C. I think I might have just tried 100A WFB on accident 
After I switched back from the loose setup to the double chubby setup for kartplanet, I noticed that the trucks are stiffening up on the edges the more I lean and the contrast from chubby / barrel was quite large.
Honestly the chubby chubby rear setup felt kinda like @TZDKB 's new setup on chubby / barrel in the rear, but there I think the reason for the progressiveness was from the ride height and lateral G pushback, vs on my board it came from bushing volume.
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I also wonder how playing around with fatcones would feel. I might need to get a set those. Just not many opportunities to ride now until March.
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When I canāt ride I keep brainstorming.
Since Stooge released pics about the WTF I was thinking about going that way instead of 7" BRPs. Looking into them more, they would definitely be a more suitable compound then my 9x3.5 which are designed for lawnmowers. But even these new tires arenāt a true racing compound. They are probably the closest thing to it under 10", and I have no doubt they perform well, donāt get me wrong. But unless I make the step to 10" I wonāt find a true racing compound.
So now I am considering trying 10" slim front gokart tires. For now I am looking at Mitas 10x3.60-5 SRB compound which is their soft-medium race compound. But I am open to other brandsā race compounds as well, given that I can find them in the EU in this size. This would increase ride height by 2 cm over my 9x3.5s (which measure somewhere between 210-215) which mightttt not feel that good. Similar width which is good. Softer compound which is also good. And a compound that was designed for racing. Thatās what Iām after. I just need to figure out how to mount gokart rims.
So how could I compensate for that ride height? Well again the WTF brings inspirations. Until it came out, I had no clue what getting the deck below the axle would feel like. But now Stooge does it. Apparently it feels like power steering. Given that I like very easily steerable setups, I am all for giving it a try.
So whatās the plan now? Given that I am on a mountainboard platform, making wheelbase extenders inherently drop my ride height. The best way to do it is to have this bracket above the deck - so that it doesnāt add itās own height which also needs to be removed by extra wheelbase. Since the deck is at 30 degrees, to drop 2cm ride height I need to move the trucks on the extension by 4cm. If I go all out and move a full baseplate bolt pattern length forward, which is about 63mm that could technically drop ride height by a whopping 4cm or so, because at that point the trucks can mount on just the extension bracket, they wonāt need to mount on the deck by 2 bolts. But that might be too much ānegative lateral G pushbackā or power steering. I have some scrap aluminium which should work for this. Going for an extension also means I need to do some carbon skinning - should be doable. And it of course means that I need to go up in angles as well - otherwise I loose steering. 40/15 should feel like a tiny bit more steering than I have right now. Given the super long wheelbase I must go higher angles than usual. I think 40/15 would feel nice.
Before committing to spending money on the gokart tires I would like to get the carbon skinning done, the extensions made, and the āpower steeringā behavior tested out on the current 9x3.5" tires. If I end up liking what I feel, Iād probably commit to the 10" gokart tires. This is all going to be a midterm project though.
First I need to get the flight pack ready for esk8con.
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Iām able to do plasma cutting + bending + welding on steel and aluminum. If you need really weird shaped brackets to control wheelbase and ride height simultaneously, i might be able to help.
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I might need to take you up on that offer once I know which way I want to go! Iāve got some wild ideas but to get the most of out some custom brackets I need to chop the deckā¦ I want to try the simple flat plate extender with a carbon skinned deck first to know if all this is even worth pursuing!
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Hereās what a 20S4P tabless pack could do at 75A per cell (which I think is totally reasonable pulsed load) on the 10" tires. Given that this takes off quite a bit from my total acceleration I can run less bias, this is calculated at a 67/33 bias.
70mph - 112kph top speed / 1340N - about 0.8G acceleration / 21.6kW - 29 hp.
Fun fact: I have previously accelerated quicker than 0.8G, so I am actually giving up some low end torque. But I will still have enough so no big deal. It wonāt be enough to place first in the drag race times though
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I was describing lining the truck back holes up with the front deck holes but thatās just what you said. Iāve done it on a longboard except using it as a drop through spacer simultaneously.
@kkim0228 did this.
Idea style brackets are an option but would stick into the enclosure. I made a 30/20 angled set and more drop at the back to make up for the angle. Iāve been meaning to post somewhere but I havenāt gotten around to belt sanding and polishing.
Iām even also skinning in cf to add stiffness lol.
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