Trials Bikes Of The Future

[Shenlong]

Imagine you're starting a new Trials company. You get to decide the direction that Trials bikes evolve. Or at the very least you will have a say in the direction that future Trials bike designs go.

What are some features that people want to see on Trials bikes of the future?

Some thoughts:

• Dual Disc 26" Comp/TGS frames
• Longer Wheelbase Street Trials bikes (e.g. Ashton Justice black/red MkII geo) + shorter stems (e.g. 55mm x 45* or 0mm x 0*) + taller headtubes (140mm, 150mm, 160mm), with low BB rise (0mm to +20mm)
• 142x12mm rear spacing with 1x6 gears
• One Piece BB Chainstay Yokes in 73mm width
• Full Suspension Trials bikes & Short Travel Hardtail Trials bikes
• Short travel suspension forks tuned for Trials
• Reba-A2 at 80mm travel = 460mm length-on-axis, 40mm offset (without sag)
• Lowered Pike DJ-A4 at 40mm travel = 422mm length-on-axis, 40mm offset (without sag)

 

What are your thoughts?

 

What would you do?

 

Thanks for any feedback. Any feedback and opinions welcomed!

Edited March 9 by Shenlong

[Canardweb]

I think the next step might be adding an electric motor to assist you. That would lead in some huge maneuvers!

[PLIW]

Intergrated HS33 mounts in a CNC’d yoke so it’s stiffer and less to fail. 
 

Stem length is a hard one as they does change the reach but maybe a slightly longer head tube isn’t a bad idea. 
 

Gears are done now rules have actually caught up. 
 

 

[La Bourde]

20 hours ago, PLIW said:

Intergrated HS33 mounts in a CNC’d yoke so it’s stiffer and less to fail.

Something like that:

 

 

Hoffmann bikes.

See http://www.t-t-h.de/Trial-Team-Hoffmann Home New Bike part4.html

 

 

 

 

Edited September 11, 2023 by La Bourde

[PLIW]

19 hours ago, La Bourde said:

Something like that:

 

 

Hoffmann bikes.

See http://www.t-t-h.de/Trial-Team-Hoffmann Home New Bike part4.html

 

 

 

 

Heheh nice find and yeah that. Clamps look way bigger and stiffer. 2 massive plates. 
 

I was going to say about the encentric dropouts as well but they done it 

[craigjames]

4 hours ago, PLIW said:

Heheh nice find and yeah that. Clamps look way bigger and stiffer. 2 massive plates. 
 

I was going to say about the eccentric dropouts as well but they done it 

The problem with eccentric dropouts is that they change the geometry as you tighten the chain. I think through axle rear ends and small sprung tensioners like Crewkerz and Clean use is the way forwards. Stiffer rear end, less faffing with brake set up etc.

I think through axle 135 or 142 rear ends would be a sensible standard to adopt for both mod and stock bikes, i don't see why 20" bikes have such narrow rear ends; surely a common size between mod and stock would make things easier for manufacturers and the end user?

[La Bourde]

I guess it makes sens to use the same width for both mods and stocks.

But I'll say both 135 and 142 are obsolete in MTB.

I did not double check, but I guess a lot of steel dirt frames use 135mm though.

 

I fully agree with you regarding the chain tensioner.

Eccentric can slip too, they can have a slightly different angle on both sides and the change in the chain tension will require to adjust them regularly.

 

[monkeyseemonkeydo]

Mike @ Phatworks was also working on a similar brake concept:

[Brettoll]

29 minutes ago, monkeyseemonkeydo said:

Mike @ Phatworks was also working on a similar brake concept:

Anyone ever know where this got to? Heard of a few prototypes with a mid-school geo and some cool bits.. but then disappeared?

[monkeyseemonkeydo]

Pretty much. I saw Mike made some prototypes for a few riders and wanted feedback etc. but everything seemed to stop after the pandemic and I've seen very little activity from Mike since then. He was also working on that single legged fork for trials for a long time but again all seems to have died a death.

[Shenlong]

On 9/9/2023 at 6:31 PM, Canardweb said:

I think the next step might be adding an electric motor to assist you. That would lead in some huge maneuvers!

Yes.

E-Bike Trials is most likely going to become a thing. Martyn Ashton did talk about it in The Shin Dig podcast.

Though I'm not a fan of E-Bikes in general, this could help Bike Trials re-connect with its Moto Trials roots. Less hoppy hoppy pogo & wannabe BMX, and instead more rolling dynamic Trials riding like how Chris Akrigg rides. Like in the the woods riding up muddy banks and up rocky streams. Can definitely imagine something similar to Moto Hard Enduro too. Maybe a hybrid style of riding between technical XC/MTB and some challenging Trials obstacles along the route. 

https://www.youtube.com/watch?v=evUP2bDDmNM

There is also the Bi-Motal. Would be interesting to see how well it'd work for Trials if someone got one and put it on their Hex!

https://bimotal.com/

https://www.trials-forum.co.uk/topic/206203-removable-e-bike-motor/

[Shenlong]

On 9/10/2023 at 4:20 PM, PLIW said:

Intergrated HS33 mounts in a CNC’d yoke so it’s stiffer and less to fail. 

Am curious, what's the appeal of still using HS33s these days? It's no secret that the backwards holding power isn't ideal. Screechy brakes, rims that need re-grinding every so often, poor modulation, only good for on-off braking. With how good disc brakes are all-round these days, I'm kinda baffled as to why it still hasn't really taken off for 26" Trials bikes outside of Street Trials models. 

The Hoffmann design reminds me of the seatstay yoke on the '06 Czar Ivan frames. The Czar Ivan's yoke/booster/integrated mounts looks better than the Hoffmann, imo. Though maybe the Hoffmann design enables superior backwards holding abilities?

What if the Czar Ivan's yoke was flipped upside down so HS33s mount onto the underside, kinda like that T-Rex prototype that Ali Clarkson won not too long ago.

[Shenlong]

On 9/10/2023 at 4:20 PM, PLIW said:

Stem length is a hard one as they does change the reach but maybe a slightly longer head tube isn’t a bad idea. 

Reach from the BB to Handlebar grips could be kept the same. 

Instead of having short frames and relying on long stems, wouldn't it be better to lengthen the front of the frame and use a mega short stem, along with a taller headtube, to achieve a similar BB-to-Handlebar Reach?

Some thoughts:

• More toe clearance relative to the front wheel
• Significantly reduced chance of bashing knees on stems.
• Longer wheelbases across the board:
• Can do bigger wedges and also be more stable overall.
• Also will allow bigger Up-To-Fronts, Taps, Hooks, etc.
• Shorter stems = hands closer to the steering axis
• Even High BB frames will be able to bunnyhop and manual better than they currently do.
• Long stems/Cantilever stems are pretty horrible to do Bunnyhops & Manuals with, and also are more prone to jackknifing:
• Imagine rolling at a slow pace, then suddenly the stem jolts sideways 90 degrees without warning and you go OTB and get tangled up with the bike - has happened to me, and I know it wouldn't have happened with a shorter stem.
• Long stems place too much weight on the hands too, so your hands/wrists/arms are more likely to go numb than if you were using a stubby stem with hands super close to the steering axis.

Edited September 19, 2023 by Shenlong

[Shenlong]

On 9/10/2023 at 4:20 PM, PLIW said:

Gears are done now rules have actually caught up. 

The thing with Singlespeed Trials bikes is that we're stuck with one spinny gear. Even though Comp rules no longer require gears, for the everyday Trials rider having gears could be a huge benefit?

Some benefits OTOH:

• Be able to pedal at higher speeds
• Ride to places more efficiently - less reliance on cars and trains
• Open up more possibilities like being better & safer for Dirt Jumps, Skateparks, Street BMX style riding due to having harder gears to choose from when you need that bit of extra speed for a run up or between jumps.
• Be good for riding in the woods like Moto Trials or Moto Hard Enduro style
• Have an ultra-light 1st gear that's even lighter than the normal SS ratio so you can ride up super steep muddy banks and other technical uphill lines in the woods.
• All of the above contributing to making Trials bikes good for stuff outside of just Trials riding.
• Attract more newcomers to the sport. Thinking MTB converts would be more open to the idea of getting a Trials bike if it has gears and resembles a normal bike a bit more, kinda like a modern version of what old school 90s Trials bikes were like
• Short cage derailleurs with tiny cassettes look sick
• Would help Trials bikes be taken more seriously and be more respected, because right now no-one outside of Trials can relate to a spinny-geared Singlespeed Pogo Stick. Current SS Trials bikes look like toys

The only downsides I can think of atm are:

• Bit more weight
• Bit more expensive
• Slightly more complex to set up & maintain than Singlespeed
• Derailleur & mech hanger are vulnerable to Sidehop damage & crashes in general (though this downside could be lessened just by keeping a spare mech hanger or two in your backpack)

Edited September 19, 2023 by Shenlong

[Ali C]

My 2 cents.

ebikes: I can’t see this being a thing for comp style trials, maybe better suited to oldschool hill climbs but the extra weight would hinder the size of moves more than the advantage of extra power would help them in my opinion.

 

disc brakes: never gonna happen for 26” comp trials, the extra weight, exposed fragile disc and spoke flex are way more of a handicap than the occasional rim grind.

 

geo: not too sure if we’ll see that much change here but I am curious to test a frame with a much steeper head angle than current bikes have and combined it with a short stem (kinda like your idea but keep the wheelbase the same). Longer wheelbases might help with a couple of moves but it would compromise others, current wheelbase measurements are a decent middle ground. I do think having a shorter stem could make things like hanging hooks easier though as there’s less leverage in the stem wanting to twist whilst your weight is on it. Current bikes with their long stems put the bars so far out in front the bikes effectively have a 90 degree head angle anyway.

 

tech: the biggest advancement I can see helping with comp trials is utilizing flex in frames to act like a spring and increasing height of moves. Frames are like pole vaulting with a stiff pole, imagine if you could preload the frame like you do with your tyre (and a pole in vaulting) and use that energy in a gap or sidehop…I’ve absolutely no doubt this will be the future but it’ll take a lot of cost and development to make it work

[Ross McArthur]

My 2 cents. 

I have tried the whole steep head angle short stem thing on a long WB 24" bike with a relatively high bb. It felt like an absolute barge and I didn't like it. 😂

I think the geo was 1060, 74, 50, 380. What did I do wrong? Not grow my limbs long enough?

[La Bourde]

19 hours ago, Ali C said:

tech: the biggest advancement I can see helping with comp trials is utilizing flex in frames to act like a spring and increasing height of moves. Frames are like pole vaulting with a stiff pole, imagine if you could preload the frame like you do with your tyre (and a pole in vaulting) and use that energy in a gap or sidehop…I’ve absolutely no doubt this will be the future but it’ll take a lot of cost and development to make it work

Exploziv, a french brand in the late nineties tried this concept:

https://www.lafabricavelo.fr/le-catalogue/nos/cadres-nos/

I still have a cracked zon'up frame from them in my basement...

 Only thing I recall riding it was the terrible amount of flex around the headtube.😄

 

[craigjames]

Didn't Crossbow try to do something similar not so long ago and then switched to normal frames as they couldn't get it to work?

[La Bourde]

On 9/19/2023 at 8:59 PM, Shenlong said:

Am curious, what's the appeal of still using HS33s these days? It's no secret that the backwards holding power isn't ideal. Screechy brakes, rims that need re-grinding every so often, poor modulation, only good for on-off braking. With how good disc brakes are all-round these days, I'm kinda baffled as to why it still hasn't really taken off for 26" Trials bikes outside of Street Trials models

 

The reason is the flex of the spokes.

There is nothing to do against this (or reinvent the wheel maybe😄)

When a rider is on his rear wheel on a round surface (like a sphere) for example, a disc brake won't be as good as a rim brake.

I tried my self with a comp bike and a street/trials and I noticed a difference too.

I don't know how to reduce the brakepads clearance too, so that there is no play when the rotor is hold.

 

I am a big fan of disc brakes too, but for a 26" comp bike, I am not sure it will be possible to use a rear disc.

 

[La Bourde]

On 9/19/2023 at 9:15 PM, Shenlong said:

Reach from the BB to Handlebar grips could be kept the same. 

Instead of having short frames and relying on long stems, wouldn't it be better to lengthen the front of the frame and use a mega short stem, along with a taller headtube, to achieve a similar BB-to-Handlebar Reach?

Some thoughts:

• More toe clearance relative to the front wheel
• Significantly reduced chance of bashing knees on stems.
• Longer wheelbases across the board:
• Can do bigger wedges and also be more stable overall.
• Also will allow bigger Up-To-Fronts, Taps, Hooks, etc.
• Shorter stems = hands closer to the steering axis
• Even High BB frames will be able to bunnyhop and manual better than they currently do.
• Long stems/Cantilever stems are pretty horrible to do Bunnyhops & Manuals with, and also are more prone to jackknifing:
• Imagine rolling at a slow pace, then suddenly the stem jolts sideways 90 degrees without warning and you go OTB and get tangled up with the bike - has happened to me, and I know it wouldn't have happened with a shorter stem.
• Long stems place too much weight on the hands too, so your hands/wrists/arms are more likely to go numb than if you were using a stubby stem with hands super close to the steering axis.

Are longer wheelbase better? Jack Cathy and Oliver Widmann ride a medium Crewkerz...

Does having hands closer to the steering axle help? It means also less feedback.

The problem with modern comp bike to manual or to bunny comes moslty from the weight distribution, which results from the high bb basically.

But, having the bottom bracket much higher than the rear axle 

makes the bike more difficult to control, it is too reactive.

It it quite easy to feel on a 29". Once in position, the manual feels very stable.

Edited September 21, 2023 by La Bourde

[La Bourde]

One thing I can think of: better freewheel based on the I9 approach: use the flex of the pawls to increase contact area. Maybe the freewheel will feel sluggish, don't know. But it may improve reliability.

 

Having standards shared between the different brand would be such a help too.

 

Carbon could be the next big thing, but trials companies are miles away to get the quintessence of this stuff...

 

[La Bourde]

On 9/19/2023 at 9:43 PM, Shenlong said:

The thing with Singlespeed Trials bikes is that we're stuck with one spinny gear. Even though Comp rules no longer require gears, for the everyday Trials rider having gears could be a huge benefit?

Some benefits OTOH:

• Be able to pedal at higher speeds
• Ride to places more efficiently - less reliance on cars and trains
• Open up more possibilities like being better & safer for Dirt Jumps, Skateparks, Street BMX style riding due to having harder gears to choose from when you need that bit of extra speed for a run up or between jumps.
• Be good for riding in the woods like Moto Trials or Moto Hard Enduro style
• Have an ultra-light 1st gear that's even lighter than the normal SS ratio so you can ride up super steep muddy banks and other technical uphill lines in the woods.
• All of the above contributing to making Trials bikes good for stuff outside of just Trials riding.
• Attract more newcomers to the sport. Thinking MTB converts would be more open to the idea of getting a Trials bike if it has gears and resembles a normal bike a bit more, kinda like a modern version of what old school 90s Trials bikes were like
• Short cage derailleurs with tiny cassettes look sick
• Would help Trials bikes be taken more seriously and be more respected, because right now no-one outside of Trials can relate to a spinny-geared Singlespeed Pogo Stick. Current SS Trials bikes look like toys

The only downsides I can think of atm are:

• Bit more weight
• Bit more expensive
• Slightly more complex to set up & maintain than Singlespeed
• Derailleur & mech hanger are vulnerable to Sidehop damage & crashes in general (though this downside could be lessened just by keeping a spare mech hanger or two in your backpack)

That is interesting.

Years ago I built an aluminum dirt jump with the goal to be able to do some trials moves with.

I had a Shimano Zee derailleur on it.

Somehow I wasn't really enjoying it much. The reliability with the Zee was good though.

 

My steel street/trials based on a steel park frame runs a single speed. I built the bike so that a derailleur fits, but the simplicity of single speed got me.

Having a light version of the Truvativ Hammerschmidt (was heavier than having 9 speeds) would be really nice.

Edited September 21, 2023 by La Bourde

[Canardweb]

On 9/19/2023 at 8:44 PM, Ali C said:

Tech: the biggest advancement I can see helping with comp trials is utilizing flex in frames to act like a spring and increasing height of moves. Frames are like pole vaulting with a stiff pole, imagine if you could preload the frame like you do with your tyre (and a pole in vaulting) and use that energy in a gap or sidehop…I’ve absolutely no doubt this will be the future but it’ll take a lot of cost and development to make it work

If the world in English is the same as in French then what you are referring to is resilience, it's the capacity of an object to get back to its original shape after being stressed. The higher the resilience, the faster it comes back in its original shape. And that's how the Jealousy was designed. And I have doubts you can make it better than that. You should see the test pics and how stressed it can get before coming back into shape. It's mindblowing.

10 hours ago, La Bourde said:

Are longer wheelbase better? Jack Cathy and Oliver Widmann ride a medium Crewkerz...

Jack does for certain types of sections where certain moves are required. But that guy could ride any bike and destroy an entire comp anyway.

 

10 hours ago, La Bourde said:

 

Carbon could be the next big thing, but trials companies are miles away to get the quintessence of this stuff...

 

Agreed. Although some years ago Crewkerz did. It's just way too expensive. Heck it's already pretty hard for trials companies only making alloy frames...

 

[Ali C]

56 minutes ago, Canardweb said:

If the world in English is the same as in French then what you are referring to is resilience, it's the capacity of an object to get back to its original shape after being stressed. The higher the resilience, the faster it comes back in its original shape. And that's how the Jealousy was designed. And I have doubts you can make it better than that. You should see the test pics and how stressed it can get before coming back into shape. It's mindblowing.

I’m talking about having the rear triangle acting like a spring when compressed, something along the lines of a leaf spring like the Lauf concepts (but obviously in a trials shape), you’d have it so stiff you wouldn’t notice it when hopping normally but when preloading it would be possible to compress it and use the rebound to hop higher.

  The Crewkerz looks like it has one of the stiffest rear triangles out there!

 

 

[Canardweb]

2 hours ago, Ali C said:

I’m talking about having the rear triangle acting like a spring when compressed, something along the lines of a leaf spring like the Lauf concepts (but obviously in a trials shape), you’d have it so stiff you wouldn’t notice it when hopping normally but when preloading it would be possible to compress it and use the rebound to hop higher.

  The Crewkerz looks like it has one of the stiffest rear triangles out there!

 

 

Ok, well that's kind of what the Jealousy does actually. I know it looks stiff but you can do insane things playing on tubes thickness, thermic treatment and hydroforming. Majority of its behaviour comes from the front triangle though as the rear one needs to be stiff for the power transfer.

You can feel it when you get stuck in between two straight obstacles. It will feel insanely soft when preloading it. But if you release weight the frame acts like a spring. That's also thanks to alloy that has good resilience.