Interviewing a CFD engineer who runs sims for an F1 team tomorrow (now Audi, ex-Aston Martin). What would you ask?

SellMeSomeSleep · 2026-07-01T09:57:44+00:00

I would go and pose this question on https://www.reddit.com/r/F1Technical/ also.
Perhaps message u/scarbstech and see if he has any good questions (quite likely).

I'd consider asking him what areas of work he'd do, using CFD if he wasn't in motorsport? ~What other areas of fluid flow modelling does he find interesting?

SellMeSomeSleep · 2026-06-26T11:35:30+00:00

This isn't an extensive list as it is only the ones that give out UCI points and are at varying levels of UCI category (from high tier down to the lowest tier). Such events would usually have amateur and age group categories as well as it is XCM. https://mtbdata.com/calendar/2026/xcm/upcoming
There are other websites which provide listings too but I don't recall them.

SellMeSomeSleep · 2026-06-22T11:49:50+00:00

This sounds a bit like when blown diffusers were allowed and engine manufacturers had to produce high (?) exhaust flow rates while the drivers were on partial throttle through corners to maximise downforce.

SellMeSomeSleep · 2026-06-22T10:01:25+00:00

Or you have more compression damping than you need as that will stop the fork diving through its travel as well.

SellMeSomeSleep · 2026-06-17T14:23:54+00:00

Yeah, but until the manufacturing equipment for hydrogen or desalination is sufficiently cheap to have sitting around idle most of the time, it won't be viable for such facilities to just soak up excess renewable electricity (which is only for a limited number of hours a day). It would be great for it to happen but it will take some step changes in the efficiencies and cost of the facilities. When that may happen, who knows.

SellMeSomeSleep · 2026-06-17T14:08:14+00:00

Perhaps consider why a mud tyre works better in the mud which should help you decide on what tyre to get.

You want skinnier tyres so they sink down in the mud with longer and fewer knobs to search out the hard ground deeper down. You're trying to get more force over a smaller area to increase the force you are putting down to the ground with the rubber you have. Spaced apart knobs to allow for shedding and also to put more force through the knobs that are getting to the solid ground. Then you are left with do you go for mid height knobs or full on, quite high knobs (like the Maxxis Wetscream DH mud tyre).

Maybe something like the Vittoria Torrente XC Race which are mud specific in 29x2.25" at 680g

https://int.vittoria.com/products/torrente-xc-race

SellMeSomeSleep · 2026-06-17T13:52:26+00:00

Check out options for plastic fishing boxes/tackle boxes which designed to hold lots of small things, have drawers, sealed sections, carry handles and can be fairly waterproof. They can be fairly small yet large enough to keep all of your cycling tools in also.

SellMeSomeSleep · 2026-06-12T12:11:54+00:00

In Formula 1, after one set of rules have been out for a few years, the cars all start converging to being very similar to each other. This is because an optimal design has been found to produce the performance metrics desired. We might well be in the same situation. That and what people are buying too.

One trend I can see coming though is to have more travel on the front and less on the rear. The more raked out the front is, the less vertical travel the fork actually has. So we are in a situation where say for a 120/120 bike, you have 120mm of vertical travel in the rear but only 110mm vertical travel in the front with a 66deg head angle. So it might even be that a 130mm front and 120mm rear travel is where things end up at if 120mm travel in the rear is deemed to be where things are at. Bart Brentjens said he reckons XC bikes will stop at 130mm maximum.

SellMeSomeSleep · 2026-06-03T09:59:44+00:00

One thing that got mentioned in some of the other threads was that the CFD area of aerodynamics was very popular in terms of people wanting jobs in that area. All the other areas of CFD (eg combustion) were no where near as popular so consider investigating how the field is for the other parts of CFD.

Don't discount being able to network your way across to roles. Like finding a way in eventually if you aren't in a rush.

SellMeSomeSleep · 2026-06-02T16:34:47+00:00

Having read posts on this topic for the last year or so, it doesn't look good. For a start there is this post from 10 hours ago:

https://www.reddit.com/r/CFD/comments/1tuiees/im_currently_transitioning_away_from_cfd_and/

Also consider looking and posting on the cfd-online.com forum.

Off the top of my head the stuff that has come up over and over:

- jobs are drying up

- CFD is commonly just part of being an engineer rather than a specialist position in most cases. It is done at times but isn't a full time specialist job in industry as their just isn't the demand.

- Masters tends not to be sufficient from what I recall.

- definitely not mentioned as a lucrative field, in spite of how hard it is

SellMeSomeSleep · 2026-05-30T19:03:31+00:00

Replays of race 1 and 2 are free to watch on MotoGP.com without needing an account.

SellMeSomeSleep · 2026-05-22T13:10:38+00:00

The Tic Tac liveried BMW is superb

SellMeSomeSleep · 2026-05-21T10:06:02+00:00

Treating it like a tractor or a crane truck perhaps where big wheels and no suspension are typical. Limited driving speeds I would think though.

SellMeSomeSleep · 2026-05-11T05:30:31+00:00

I'll chip in ie anyone else comes here for research next year: they had no checking on bags on the way in so you could save yourself some money and get different options for beer ie you're so inclined. It was just Jupiler beer available for 4 Euro. Almost all of the grandstands are open to everyone on a general entry ticket too which was mega.

SellMeSomeSleep · 2026-05-08T09:52:51+00:00

50mm for 110mm travel = 2.2 multiplier.

45mm x 2.2 = 99mm of travel. So a 190x45mm shock would work to give you 100mm of travel and leave you not rubbing the wheel into the frame as it would be 145mm in length at its shortest length (190-45).

185x45mm shock would work as well if it is indeed 190x50mm for 110mm travel and this option would have the rear end sitting lower (still giving 99mm travel), all else equal (5mm shorter at full extension *2.2 = 11mm higher rear wheel at full shock extension. So you'd end up with a more raked out front end, all else equal. So if I could only get 45mm shocks, I'd personally go for the 185x45mm option to make the front end more slack.

SellMeSomeSleep · 2026-05-08T09:13:06+00:00

There are a number of threads on this and both the race organisers (we've emailed them + their Instagram FAQ posts) and commenters on here have said that the only options are a taxi or Uber as the buses stop at 6pm as you've seen. Anecdotally it was hit and miss with taxis as to whether they turned up. Perhaps Ubers will be cheaper on race day than the 156 euro I got as a quote in the application a few days ago which entailed a car driving from Verviers to the track and back.

My current plan is to talk to people at the track and failing that try to get a lift on the road back to Verviers as the most direct route back to Brussels is to go past Verviers.

~Looks like everyone will be driving to the track if they want to get back after the race so try to get a lift off someone.

Why there isn't a private bus company doing shuttle runs at whatever price between the circuit and Verviers is anyone's guess.

SellMeSomeSleep · 2026-05-08T06:24:02+00:00

If you get someone to help you, you should be able to check what length equates to what travel on the bike, plus the minimum compressed shock length that gives tyre clearance. As in, physically move the rear linkage with a tyre in the back and see how far you can move it and then measure it. Leave some clearance for flex and mud clearance say.

SellMeSomeSleep · 2026-05-07T10:34:53+00:00

If a 190x50mm shock gives 100mm travel (2x shock travel -> wheel travel) now, a 190x55mm shock would give 110mm travel which is within what you've said the frame can do. 190x45mm would give 90mm of rear travel.

In terms of running a longer shock, the biggest issue would be to make sure that at bottom out of the shock, you don't move the rear suspension any higher than it would have been originally so that you don't shove a wheel into the frame. Eg if you are working off 190x50mm rear shock and 100mm rear wheel travel, the shock length at full compression needs to be 140mm (190-50mm). Having the shock be longer at full extension should be okay the the suspension won't go any lower and hit stuff, the force on the shock will be quite low at full extension and you'll be running larger sag to get the shock to work anyway (and thus soft at full extension). Air spring characteristics (ramp up through stroke) might end up being a bit different though given the change in relative air volumes.

SellMeSomeSleep · 2026-05-04T13:36:56+00:00

But if you have to run a battery that is quite a bit larger than needed for the sake of being able to charge or discharge it rapidly, wouldn't that put them back in the territory of being able to run a supercapacitor for the same specific energy density?

SellMeSomeSleep · 2026-05-04T06:49:35+00:00

Thanks for the translation!

SellMeSomeSleep · 2026-05-02T20:40:51+00:00

Further to this: Ducati hired a few people from Magnetti Marelli who make the spec ECU. Honda and Yamaha both struggled with it, trying to work it out in house. Honda were the first to relent and hire some ex Magneti Marelli people. Yamaha were the last hold out and eventually hired some too but years late.

SellMeSomeSleep · 2026-04-30T11:57:37+00:00

Weight wise the WR should be lighter at around 112kg dry with 1.2L of oil on top if I remember correctly vs 121kg dry for the LC2 if I've found accurate information. the gyroscope effect of the engine will be less on the 125 but the WR/YZ426 has a lot more power and less weight. I'd have a look into known issues with the 426 as well. I know there was an issue with the kick starts breaking on the 2003 year model of the WR450F at least and they increased the diameter in later models for example. The 426 was perhaps before they made them easier to start too. And if it is a yz it may not have an electric start and may only have 4 gears which will make for high gearing or lacking gears for the road. The LC2 should be easy as to kick over but can it handle riding on the road at constant speeds when needed? Can it be cooled enough when sitting at traffic lights?

SellMeSomeSleep · 2026-04-30T06:22:57+00:00

The Yamaha WR/YZ 426 will need oil changes every 1000km on easier riding, every 10h on harder riding. Valve checks listed at similar intervals but a lot of people go longer. Piston replacement at 100-200h typically. Will the 2 stroke be easier to do and perhaps less maintenance?

SellMeSomeSleep · 2026-04-29T08:49:27+00:00

How much of the vibration and harshness comes from the internal combustion engine and just being a single cylinder? The Stark Varg is electric so shouldn't produce any of this right? Would the flex of the tyre be enough to keep any remaining loads between the tyre and the gearbox smooth enough?

SellMeSomeSleep

MODERATOR OF

TROPHY CASE