Discussion: Bike change in Moto3

[adamysr]

Since there's there not much to do these days I figured I would start a thread about changing the bike in moto3. It's pointless and probably not relevant but who cares:laughing. I thought about this for a little while and I think it would be a good thing. Every since moto2 changed to 4 stroke I didn't like how moto3 bikes were so much much smaller in physical size and weight compared to the 600cc moto 2. Now moto2 switched to the 765 triple which makes the bike a little smaller but with more power (and motoGP electronics) to help adapt riders to motogp but widens the gap further from moto3 IMO.

My idea was they need to completely ditch the small current bikes and build a bigger chassis (similar size to the 2 stroke 250cc gp bikes) with a 450cc single production dirt bike motor (allow mods) with spec ecu. I think there would be more manufacture involvement if they could use a production based motor to help save costs. It would be nice to have more diversity in the lower class then just honda and ktm. The bigger chassis with a little more weight and a little more power might help adaptation to moto2 while still learning corner speed. There's a company in Spain called BeOn that has built one already. Here's a link http://beonautomotive.es/en/productos/catalogo/450gp/450gp/

What are your thoughts on this ?

 

[stangmx13]

someone proposes something like this every time they see a 450GP or Supermono bike. yes, more HP in Moto3 is likely the only way to increase the chassis size. the bikes are designs as small as possible that will still utilize the tires & HP while fitting the riders. so to force bigger chassis, you need larger tires. to force larger tires, you need more HP.

however, using a production-based engine is not the way to go (unless you make it a spec*), especially a dirt bike engine. a 450 production engine would hardly last a race weekend at Moto3 levels. maybe you get could away with a stronger crank, stronger cases, and a new cylinder head to deal with all the rpm. maybe not. but at that point, you arent really using a production engine anymore... so whats the point. on top of that, Moto3 uses 6 engines for 20 races. id be interested to know if SX teams use more or less engines than that. id bet more. SX 450 engines make comparable HP to Moto3 last I checked. this suggests you arent getting significantly more durability from that engine design.

*a spec engine would work just fine IMO using the Moto2 model... a massaged OEM engine in prototype chassis with whatever electronics. however, it needs to be a roadrace-able engine. that usually means a high-spec street engine. ideally you'd want something 2-3 cylinders in the 400-600cc range making 60-80HP stock. nothing exists, though an FZ-07 is almost there. I cant see this happening any time soon with no obvious choice for a Moto3 spec engine.

 

[stangmx13]

one idea that comes up every time when talking GP classes and capacities is chopping off cylinders. if Triumph removed one cylinder from their 765, ud get 510cc in a race-able package. tune it to make a reliable 80-90HP and spec the electronics however - you'd probably have an amazing Moto3 spec engine.

everyone would get a kick out of seeing GP racing at ~500cc, ~750cc, and 1000cc :laughing.

 

[budman]

I have a novel idea... how about clean 250 two smokeless bikes.

They have the tech to return to 2 strokes.

OK never happen.. but since this is a fantasy thread.. there ya go.

 

[Map8]

I think AFT's Singles class would be a better comparison than SX/MX racing when discussing longevity of MX-based 450 Singles. AFT singles are run WFO for extended periods of time and, though they have failures, its a lot more rare than you would think. AFT Singles don't do near the number kilometers that Moto3 does during a season so the six engine limit of Moto3 would have to be changed. I know the team that won the AFT Singles championship last season did not have a budget for multiple engine rebuilds during the season. Robby Bobby on the WERA BBS would have all that info as he was turning the wrenches and writing the checks.

On the other hand, the existing Moto3 formula provides excellent racing and doesn't seem to hinder the development of racers moving to the upper classes. Any change to the Moto3 formula might have negative impacts on the races and racers.

 

[stangmx13]

I think AFT's Singles class would be a better comparison than SX/MX racing when discussing longevity of MX-based 450 Singles. AFT singles are run WFO for extended periods of time and, though they have failures, its a lot more rare than you would think. AFT Singles don't do near the number kilometers that Moto3 does during a season so the six engine limit of Moto3 would have to be changed. I know the team that won the AFT Singles championship last season did not have a budget for multiple engine rebuilds during the season. Robby Bobby on the WERA BBS would have all that info as he was turning the wrenches and writing the checks.

On the other hand, the existing Moto3 formula provides excellent racing and doesn't seem to hinder the development of racers moving to the upper classes. Any change to the Moto3 formula might have negative impacts on the races and racers.

very good points. the proportion of WFO is way higher in a FT race than SX/MX. I do question if its still anywhere close to RR. even if we took best case scenario - mile vs the tightest road course? - I wonder how it comes out.

how long are ATF Single races these days?

im cool with changing Moto3 as I dont really like the races much these days. but thats personal and I dont think the class needs change.

 

[stangmx13]

I always thought the rider development issues were in Moto2, not Moto3. the lack of electronics tuning and fly-by-wire with the CBR engines was a big loss over 250GP bikes. the current Moto2 bikes havent brought all of that back just yet. but I think we'll c better rider development once the class stabilizes a bit.

on top of that, there isnt a real problem with rider development in all of GP. Zarco, Fabio, and other riders have made plenty of waves. we really just have a Marquez problem.

 

[Map8]

how long are ATF Single races these days?

AFT changed to "x minutes + 2 laps" format for 2020. Singles races should still be around 15 laps (previous format) but that lap distance/time varies depending on the track and surface.

A typical day is:
2 x 4 lap practices
2 x 4 lap qualifying sessions
1 x 4 lap heat
1 x 8 lap semi
1 x 15 lap main

As I said, nowhere near the same kilometers as Moto3 so its hard to make a direct comparison of wildly expensive factory Moto3 250cc to privately built AFT 450cc single for durability. 450cc could work for Moto3 but I'm not sure if there would be any benefit to switching. The noise would still be terrible. :laughing

 

[SFMCjohn]

would love to see (hear!) a Kawasaki 4 cyl/250cc spec engine in Moto3, but would hate to lose my KTM/Honda factory battle.

no accounting for taste, I suppose, wrt how entertaining this era of Moto3 is as a form of racing ...
draft passing, ftw! :laughing:angel

also: isn't making the transition from one class to another a part of our sport?
seem to recall folks having to adjust from F-II to the 500cc two strokes, and folks who wound up having a whole career in 80cc and 125cc classes back in the day?

 

[Shaggy]

Sounds like Moto3 needs some 450 cripples. :laughing

 

[SFMCjohn]

Sounds like Moto3 needs some 450 cripples. :laughing

:laughing:thumbup

should just cripple older gen MotoGP bikes down to one cylinder for teh new Moto3 class ... think of the savings! cheap international championship racing for everyone ... :toothless

 

[stangmx13]

AFT changed to "x minutes + 2 laps" format for 2020. Singles races should still be around 15 laps (previous format) but that lap distance/time varies depending on the track and surface.

A typical day is:
2 x 4 lap practices
2 x 4 lap qualifying sessions
1 x 4 lap heat
1 x 8 lap semi
1 x 15 lap main

As I said, nowhere near the same kilometers as Moto3 so its hard to make a direct comparison of wildly expensive factory Moto3 250cc to privately built AFT 450cc single for durability. 450cc could work for Moto3 but I'm not sure if there would be any benefit to switching. The noise would still be terrible. :laughing

I think that whole day might be less run time than a Moto3 race :laughing

if Moto3 does change engine designs, they need a minimum rev-limit rule. im tired of droning engine noises.

Sounds like Moto3 needs some 450 cripples. :laughing

a modern R6 engine with 80HP in a prototype chassis coming in around 250lbs would be an AMAZING track motorcycle.

 

[SFMCjohn]

BeOn 450GP from FB ... :ride

Engine: Yamaha YZ450F ´19.

Total Weight: 98 Kg (216 lbs)

Power: + 60 HP

Honda (well Leopard Racing) claims 60 hp and guess 84 kg (185 lbs) for their NSF 250RW Moto3 race bike ...

 

[Map8]

a modern R6 engine with 80HP in a prototype chassis coming in around 250lbs would be an AMAZING track motorcycle.

Back when I raced an FZR400, the FZR400 mail list group (I'm old :laughing ) always speculated that a 450cc triple in a GP chassis would be just about the perfect club race bike.

Then, as now, no value for manufacturers so it won't happen.

 

[adamysr]

I think the production 450 would be fine for RR. Didn’t people race the kit singles at club level like 10 years ago ? As far as Moto 3 using them I’m confident that’s teams or factories would figure it out reliably without to much trouble even if that means adding a couple engines per season, still probably cheaper then building purpose built motors. Also possibly some of the tech from RR *might* crossover to MX engines? All development and both RR and MX would be one motor, just seems cost effective to me. I got to think they can figure out how to produce a decent amount of power of the 450 as well.

 

[adamysr]

Also the idea of a spec motor wouldn’t be my first choice but the Aprilia sxv450 (or 550) motor would be a great spec motor

 

[scootergmc]

I don't like the idea of spec'ing Moto3 anymore than it already is. They're already bunched enough on track and I expect a flurry of more rules to address the problems that surfaced again at Qatar, in spite of the harsh pre-weekend warnings. If anything, I'd like to see a little more deregulation, but then you run into the high $ teams running away with the weekends... so what are we left with? If it ain't broken, don't fix it.

 

[stangmx13]

all this was discussed when Moto3 was first starting. people wondered why they didnt use 250MX engines like in the MD250H (CRF250X). besides being gutless, reliability was mentioned a bunch.

heres the service manual for the MD250H. inspection at 1000km means a pro race team would pull the engine apart every 2 rounds. this is for an engine making ~33HP. id bet a 450 in the low 60s will be worse.
http://www.tso.us.com/manuals/moriwaki/moriwaki_0250_md250h_2008_2service.pdf

I do know a guy that raced a Supermono in WERA and up Pikes Peak. I should ask him how often he rebuilds.

I think the production 450 would be fine for RR. Didn’t people race the kit singles at club level like 10 years ago ? As far as Moto 3 using them I’m confident that’s teams or factories would figure it out reliably without to much trouble even if that means adding a couple engines per season, still probably cheaper then building purpose built motors. Also possibly some of the tech from RR *might* crossover to MX engines? All development and both RR and MX would be one motor, just seems cost effective to me. I got to think they can figure out how to produce a decent amount of power of the 450 as well.

I bet there are more Moto2 bikes in the US than there are Supermonos. that idea never took off.

what makes you think 450 MX engines arent already optimized for their intended use? especially the ones for factory SX/MX teams? why do u think there would be any crossover in development?

 

[stangmx13]

I don't like the idea of spec'ing Moto3 anymore than it already is. They're already bunched enough on track and I expect a flurry of more rules to address the problems that surfaced again at Qatar, in spite of the harsh pre-weekend warnings. If anything, I'd like to see a little more deregulation, but then you run into the high $ teams running away with the weekends... so what are we left with? If it ain't broken, don't fix it.

IMO changing the formula would probably break up the super close packs for at least 1-2 years, even going to a spec engine. Moto2 wasn't that close its first year nor this last year with the new engine. but that style of racing would come right back as lesser teams sorted out the new bikes.

I suspect we'd have to return to racing haves vs have-nots to eliminate super close racing entirely. the parity and stability of the current ruleset has allowed so many teams to be in the front group because the draft is so powerful compared to max HP.

 

[adamysr]

all this was discussed when Moto3 was first starting. people wondered why they didnt use 250MX engines like in the MD250H (CRF250X). besides being gutless, reliability was mentioned a bunch.

heres the service manual for the MD250H. inspection at 1000km means a pro race team would pull the engine apart every 2 rounds. this is for an engine making ~33HP. id bet a 450 in the low 60s will be worse.
http://www.tso.us.com/manuals/moriwaki/moriwaki_0250_md250h_2008_2service.pdf

I do know a guy that raced a Supermono in WERA and up Pikes Peak. I should ask him how often he rebuilds.



I bet there are more Moto2 bikes in the US than there are Supermonos. that idea never took off.

what makes you think 450 MX engines arent already optimized for their intended use? especially the ones for factory SX/MX teams? why do u think there would be any crossover in development?

well i did use the word *might* for crossover development. Honestly i dont follow MX at all so i cant speak to anything related to it, but in general if the same base engine is used in different disciplines i would thing even a small part of the tech *could* crossover either way and help push the motor to be better.