Twmpa Cycles, Wood framed bikes

[chriswoody]

I came across this film today on youtube about an Ash framed bike. Now I'm not normally a great fan of a lot of GCN videos, but this one is a really interesting interview with the creator and a look into how the frame is produced. Si also rides the bike around and whilst you can play catchphrase bingo, it's not too full of hyperbole. As someone who has built a Bamboo frame, I found it a really interesting look at an alternative frame material and the craftsmanship is beautiful. The creator has set up a company called Twmpa cycles and the frames are retailing around 3000 pounds, I didn't think that was too bad for a bespoke piece of craftsmanship like this.


View: https://youtu.be/jd0vt5v37B0

 

[weareHKR]

Interesting concept, love the joints... 🌳

 

[Smokin Joe]

Very interesting. Mass production could lower that premium price to pocket money levels.

 

[Toshiba Boy]

Superb, one of those pieces of bespoke, high end, engineering that is also a stunning piece of art.

 

[chriswoody]

Just been perusing the Twmpa bikes website as well, here's a photo from them showcasing the Bottom Bracket joint, just how lovely are these frames?

 

[Tail End Charlie]

A friend of mine has been building, for a few years now, a wooden bike to break the world speed record. It currently stands at something like 12.5mph. No way I hear you say it must be much more than that. But absolutely everything has to be from a tree, so gears, chain etc must be fashioned from wood. Latex is allowed to make tyres as that's from a tree, but you can't have a woven straw seat as that's a grass. The rules are very strict as you'd expect I guess.
So far he has got close, but the gears break whenever too much pressure is put on them.

 

[johnnyb47]

Very nice indeed. A coat of creosote once a year will keep it in fine fettle for years to come

 

[IanSmithCSE]

Morning,

I generally find that one video every other week from GCN is interesting :-) and the rest just content to sell advertising, I've started to watch a few and the word AD was almost invisible. :-(

Some of their older videos when they had less need to keep advertisers/brands sweet were probably more interesting, especially the ones comparing cheap bikes to top of the range ones, if you get bored you can work forward from https://www.globalcyclingnetwork.com/archive/full/

At around 1,800g for the frame I was surprised by how light it was, but I was also left unsure about the durability of the frame in areas of frequent heavy compression/relaxation. I am thinking of where the rear ends join the stays, the bottom bracket and the headset.

The pictures showed a metal liner in the BB but I am unsure about the headtube and creaking BBs aren't exactly an unheard of problem, also the same picture shows the seat and chain stays without the aluminium ends.

I can't help but be impressed by the product but wonder if there are going to be complaints from customers who bought the frame expecting it to "just work" rather than it being interesting but possibly having some specific requirements.

From https://www.twmpacycles.co.uk/faq-1
Don't leave it wet and muddy.
Do store it in a dry space.
Do periodically check for damage to the varnish and repair before water can penetrate and cause damage.

Our frames have been tested to BS EN ISO 4210-2:2015 which test for impact and fatigue, simulating 10 years of use. We have also been riding our prototypes for nearly two years, clocking up thousands of kilometers of hard riding on trails we would normally reserve for a mountain bike.

Simulating the effects of time is really difficult and the retail market can be horribly hard on fitness for purpose requirements and what works for the owners and designers who take care and understand the limitations of a product often doesn't work when real customers buy and use the product.

Imagine going onto somewhere like Mumsnet, a large non cycling site and "I read a great review and bought one of those frames for my DH and it....,".

Bye

Ian

 

[chriswoody]

A friend of mine has been building, for a few years now, a wooden bike to break the world speed record. It currently stands at something like 12.5mph. No way I hear you say it must be much more than that. But absolutely everything has to be from a tree, so gears, chain etc must be fashioned from wood. Latex is allowed to make tyres as that's from a tree, but you can't have a woven straw seat as that's a grass. The rules are very strict as you'd expect I guess.
So far he has got close, but the gears break whenever too much pressure is put on them.

That really does sound impressive, have you any photos? I love hearing about design challenges like that.

Morning,

At around 1,800g for the frame I was surprised by how light it was, but I was also left unsure about the durability of the frame in areas of frequent heavy compression/relaxation. I am thinking of where the rear ends join the stays, the bottom bracket and the headset.

The pictures showed a metal liner in the BB but I am unsure about the headtube and creaking BBs aren't exactly an unheard of problem, also the same picture shows the seat and chain stays without the aluminium ends.

I can't help but be impressed by the product but wonder if there are going to be complaints from customers who bought the frame expecting it to "just work" rather than it being interesting but possibly having some specific requirements.

From https://www.twmpacycles.co.uk/faq-1
Don't leave it wet and muddy.
Do store it in a dry space.
Do periodically check for damage to the varnish and repair before water can penetrate and cause damage.

Our frames have been tested to BS EN ISO 4210-2:2015 which test for impact and fatigue, simulating 10 years of use. We have also been riding our prototypes for nearly two years, clocking up thousands of kilometers of hard riding on trails we would normally reserve for a mountain bike.

Simulating the effects of time is really difficult and the retail market can be horribly hard on fitness for purpose requirements and what works for the owners and designers who take care and understand the limitations of a product often doesn't work when real customers buy and use the product.

Imagine going onto somewhere like Mumsnet, a large non cycling site and "I read a great review and bought one of those frames for my DH and it....,".

Bye

Ian

Some interesting points, I suspect, like my Bamboo frame, that metal liners will be used for headtube and seat tube. As for durability, I suspect anyone spending the kind of money they're asking for a bike, would be looking after it very carefully. The demands of clean dry storage and occasional re-varnish are actually no different to the Bamboo frame and again, I think the kind of customer they will get will be happy with that.

Your points did make me think though of the comment that @Smokin Joe made and they could certainly be a barrier to more mass production and mass acceptance of wooden frames as an alternative to the materials commonly used today. Not only would the overall care and maintenance regime be more onerous, but as you say, would the frames survive 10 years of winter commuting?

I was also interested to note that in the film he mentions that some companies actually re-enforce their frames with carbon fibre, something that Twmpa don't do, would that be detrimental in the long term? Though carbon fibre inserts will negate some of the environmental benefits of using wood.

 

[IanSmithCSE]

Good Morning,

As someone who was really surprised to see carbon fibre forks appearing on non enthusiast bikes, things like the Halford's Carrera Vanquish (£425 today), I wouldn't trust my first impressions.

I expected to see lot a fork failures, after dropping the car boot down on the forks, banging the lawn mower against them or similar abuse handed out to an unloved tool bike kept in the garage rather than a pride and joy pampered inside the house.

This hasn't happened.

But looking at https://www.twmpacycles.co.uk/04-custom-dropouts and knowing that there is a 10 year frame guarantee just scares me for the company's sake. :-)

They look so beautiful but how can they stay screwed together for 10 years? :-)

Looking at https://www.twmpacycles.co.uk/gallery-1/aplkc7auovttr9csjpdcf6znoll52h-mld7a shows that there has been another design for the rear end.

Here's hoping that I am wrong again.

Edit: It's just dawned on me that they may be glued as well as just screwed.

Bye

Ian

 

[Tail End Charlie]

@chriswoody @Dogtrousers
Here are a couple from a few years ago now, not exactly sure how it's changed in the meantime. I'd agree a treddle system would make sense, but I'm not sure if that's allowed. By gears, I meant the teeth on the chainring and rear cog. It doesn't have to have a derailleur etc that would be even crazier!! As I understand the problem is the teeth on the chainring/ cogs keep shearing (even with a double set up).

 

[SkipdiverJohn]

At around 1,800g for the frame I was surprised by how light it was, but I was also left unsure about the durability of the frame in areas of frequent heavy compression/relaxation. I am thinking of where the rear ends join the stays, the bottom bracket and the headset.

Simulating the effects of time is really difficult and the retail market can be horribly hard on fitness for purpose requirements and what works for the owners and designers who take care and understand the limitations of a product often doesn't work when real customers buy and use the product.

They're a solution looking for a problem, have no advantage over any of the other common frame materials, but have a big maintenance disadvantage.
Frame weight is on a par with high end steel, and considerably more than carbon fibre. Cost is on a par with both high end steel and carbon fibre - except both of those can be happily left out in the rain and won't need preservative applying to them.
I can't see many people other than the usual more money than sense sustainability virtue-signalling type buying them.
Wood ceased to be used in the structures of road transport vehicles decades ago because other materials offered more utility at a lower cost, lower weight, and required less maintenance. Building bikes out of wood for use in a wet climate like ours is just not a sensible idea.

 

[chriswoody]

Thanks a lot @Tail End Charlie for posting those photos. That's absolutely brilliant, I can't believe he's made two chains out of wood, the craftsmanship on that is lovely. I really hope he makes it work and gets close to or beats, the record.

 

[Reynard]

Ash is a lovely wood to work with - I can see why it's being used, as it's got a lovely straight grain, is easy to split and has got a good bit of "boing" when load is applied to it. It's not such an alien material to make a bicycle out of, given that wood is essentially the natural version of fibre-reinforced plastics.

Jackdaws, who are one of the engineers of the avian world, build their nests almost exclusively out of ash twigs.

The issue I see with the completely wooden bicycle - and its drivetrain - is down to timber selection. I've experience with loads of different woods, and some are noticeably more brittle than others. Maybe the people who build these things could look into the gearing used for water-driven technology. Those medieval / tudor / georgian engineers certainly knew what they were doing...

 

[IanSmithCSE]

Good morning,

They're a solution looking for a problem, have no advantage over any of the other common frame materials, but have a big maintenance disadvantage.
Frame weight is on a par with high end steel, and considerably more than carbon fibre. Cost is on a par with both high end steel and carbon fibre - except both of those can be happily left out in the rain and won't need preservative applying to them.
I can't see many people other than the usual more money than sense sustainability virtue-signalling type buying them.
Wood ceased to be used in the structures of road transport vehicles decades ago because other materials offered more utility at a lower cost, lower weight, and required less maintenance. Building bikes out of wood for use in a wet climate like ours is just not a sensible idea.

At £2,300 without forks they are clearly not competition for a basic aluminium or steel frame but that doesn't stop them being something nice and as long as the price fits within purchasers' budget then they are a great product to have on the market.

If they can last 10 years then their life time is in excess of the requirements of many purchasers, yes it is true that there are many 1960s built bikes still in use today but I would hate to live in a world where you can't buy say a Grand Seiko Spring Drive watch.

Spring drive is a Seiko invention that is totally absurd and thoroughly wonderful. The movement has a spring that is connected to the hands, but the speed that the spring moves the hands is regulated by an electro magnet and a quartz oscillator powered by a electricity generator that is driven by the same spring that move the hands.

10 years does seem possible in a niche market, after all there are many wooden boats so the basic techniques needed to preserve wood in a wet environment are well established.

What is possibly less well established is the how to handle temperature variations especially if the bike is kept indoors and is rapidly heated to say 25-30 degrees centigrade in a house after being out in the cold and rain. This is the type of gotcha that gets businesses that have to release products with limited testing budgets, does many rapid cooling/warming cycles where the metal parts expand and contract put a load onto the wooden struct via the bonding material that causes failure or does the bonding material fail? The answer for CF is known, but is it the same for aluminim/wood?

For example was galvanic corrosion considered and discarded or not considered when carbon fibre frames started to appear in volume?

I live near Morgan cars which still use lots of wood in the construction of the body, not the chassis, but they are an niche market where all the "real cary (sic) bits" are made using current mass production bits, the wood is the marketing part of the car. :-0

Bye

Ian