Show us your bicycles!

[antcollinet]

My local runnabout:

View attachment 299996

View attachment 299997

I haven't had a bike with hub gears or a belt drive before when I saw this on Ebay and bought it try it out. I really like it, it's very smooth and quiet, low maintenance and you don't get oily trousers.

View attachment 299998

My last commuter was also a belt driven hub-geared hybrid. I still have it but don't commute anymore

 

[MRC01]

... I really like it, it's very smooth and quiet, low maintenance and you don't get oily trousers. ...

With my bike above, I avoided the oily pants leg issue by sizing the front & rear chainrings to get the gear ratios I wanted while having the front chainring smaller than the outer guard.

That said, I think internally geared hubs deserve to be more popular than they are. They're not quite as efficient as traditional gears, but that doesn't matter for casual riding and they are more compact, cleaner, lower maintenance, and easier to shift.

 

[Count Arthur]

With my bike above, I avoided the oily pants leg issue by sizing the front & rear chainrings to get the gear ratios I wanted while having the front chainring smaller than the outer guard.

That said, I think internally geared hubs deserve to be more popular than they are. They're not quite as efficient as traditional gears, but that doesn't matter for casual riding and they are more compact, cleaner, lower maintenance, and easier to shift.

I can't say I've ever noticed the efficiency loss. While chains and deraileurs can be very efficient when nice and clean, that will drop of a fair bit if they are not kept in tip-top condition.

Also, while the belt is significantly lighter than a chain, the hub itself is quite heavy, around 1.7kg, and you do notice the heavy rear end when you lift the bike up; although that is kind of balanced by my folding lock which weighs about the same.

 

[sq225917]

Carbon generally is not recommended for non professional bikers for any part of the bike like frame as wrong use can damage it and its failure (crack grow speed) is very rapid compared to for example aluminium increasing the danger for horrible accidents. An ex colleague of mine is one of the world's top bicycle researchers and involved in many regulatory organisations and also appraiser in such cases.

Rubbish.

 

[pseudoid]

Rubbish.

No, it is NOT

yet!

 

[somebodyelse]

No, it is NOT

Oh I'm sorry, is this a five minute argument, or the full half hour?

 

[Multicore]

David Tiemeier quit building bikes a few years after I got mine. This shot was taking during racing at USAC Nationals Masters 2013 at Major Taylor Velodrome in Indianapolis.

 

[Djsedaw]

BSA Javelin 5 speed

 

[JaccoW]

Oh I'm sorry, is this a five minute argument, or the full half hour?

Give me the feature length film please.

That being said, I'd love to ride a carbon bike for a longer period of time. Thin-walled steel can be susceptible to dings and crashes as well.
I do like how steel is less likely to break and shatter catastropically, but that's the same reason why I am very hesitant about aluminum in certain parts.

I have personally had way too many broken aluminium handlebars, forks, cranks and kickstands that just stopped working without warning. Luckily so far I've only had to deal with some bruises and walks home.

 

[MRC01]

Carbon generally is not recommended for non professional bikers for any part of the bike like frame as wrong use can damage it and its failure (crack grow speed) is very rapid compared to for example aluminium increasing the danger for horrible accidents. An ex colleague of mine is one of the world's top bicycle researchers and involved in many regulatory organisations and also appraiser in such cases.

A frame's engineering design and build quality determine its strength and durability far more than its materials.
For example, in this destructive frame test several of the steel frames failed, but carbon & aluminum frames did not.

12 High-End Frames in the EFBe Fatigue Test

The groundbreaking article describing scientific testing of the resistance of bicycle frames of different materials to fatigue failure

sheldonbrown.com

My dual suspension MTB is full carbon frame & wheels. I've put it through 10 years and thousands of miles of serious abuse on some of the toughest MTB rides in the country. So far, still performs like new.

 

[pseudoid]

BSA Javelin 5 speed

View attachment 300024

Picture shows your bike to be leaking oil...

BMW motorcycles intentionally use softer wheels which are more prone to bending than cracking.
I had a date with a "falling rock" on a mountain pass, which - of course - was aiming for my front wheel.
We kissed, nothing more...
With the exception of the bent wheel being shipped to some outfit in Minnesota, which repaired it for half the price of a new one.

 

[MRC01]

Picture shows your bike to be leaking oil...

Yeah, especially that tire oil

 

[thewas]

Rubbish.

Thank you very much for your qualified and well reasoned response, I will recommend you to replace my ex colleague who did his academic and professional carreer on the study of bicycle loads, fatigue and failure.

A frame's engineering design and build quality determine its strength and durability far more than its materials.
For example, in this destructive frame test several of the steel frames failed, but carbon & aluminum frames did not.

That is something different though, I am not talking about the maximum load, but the behaviour at overload where the carbon fibre collapses faster loosing its stiffness. By the way overload usually happens at non professional drivers who fatally also usually don't have the means for checking for initial damages.

 

[MRC01]

... That is something different though, I am not talking about the maximum load, but the behaviour at overload where the carbon fibre collapses faster loosing its stiffness. By the way overload usually happens at non professional drivers who also usually don't have the means for checking for initial damages.

I don't disagree with that. However, any frame or rim, made from any material, can fail and requires periodic safety inspection, especially after any crash.

My point is that there is nothing intrinsically limited about carbon. Well engineered and built carbon frames and wheels can last decades and many thousands of miles, maybe even a lifetime of riding, like steel or any other material.

FWIW, the only bike frame that ever failed on me was made of steel, and it failed catastrophically, breaking in half while I was riding it.

 

[BinkieHuckerback]

I had a Giant TCX aluminium frame that broke in half at the seat tube. No one was hurt. It was replaced. Still, not ideal.

 

[thewas]

However, any frame or rim, made from any material, can fail and requires periodic safety inspection, especially after any crash.

Sorry but I have to repeat the failure behaviour can be quite different and can significantly influence the course of an accident. Except of course cost this is also a reason carbon isn't typically used for example at important high safety parts for non professional use like for example automotive suspension while it is often used in professional applications like F1.

 

[Keith_W]

Oh I'm sorry, is this a five minute argument, or the full half hour?

He might be arguing with you in his own free time.

 

[JaccoW]

Well engineered and built carbon frames and wheels can last decades and many thousands of miles, maybe even a lifetime of riding, like steel or any other material.

As someone who mostly visits forums where people work on vintage bicycles, we just don't know yet.

In theory carbon frames can last forever when well taken care off but most early carbon was lugged or improperly designed. Early 80's and 90's carbon fibre bikes are currently death traps because we didn't know enough about how to use the material. Bikes with aluminum lugs especially are well-known to delaminate or separate. And they are virtually impossible to repair properly. One bit of contamination and the clock will be ticking again.
And improper sealing or UV protection from those early days mean some of those bikes are not as strong as they used to be.

We learned a hell of a lot in the meantime.

There is of course a survivorship bias going on with other materials. And because steel was the go to material for well over a century, most old bikes are steel.
Aluminum was rarely used in the 1800's but didn't become an affordable option until the 1970's.
And the first carbon fibre bikes came about in the 1980's.

We will see how they hold up.

 

[Pe8er]

I may be drinking the MTB industry koolaid and my personal experience is definitely anecdotal, but I can't shake off the impression that this discussion about carbon ignores the advancements made in the industry in the last dozen or so years.

Check out these 2 videos:

2017:

2023:

What do you think about how carbon frames react to stress in each video? @thewas any chance you can ask your colleague?

By the way the guy in 2nd video is Greg Minnaar, one of the most successful downhill riders in the history of the sport. Funnily enough, see what he managed to do to a carbon bike:

I guess one might ask a question - how often will I ride at such high speeds, go over the bars and hit a metal post?

My anecdotal experience / evidence - I've been riding a 2016 Santa Cruz Nomad with a carbon frame, handlebars, cranks and rims, in a substantially irresponsible manner. Too fast, hitting too many ruts and rocks, just general belligerence because the bike loves to go fast downhill, I'm heavy and lack skills, and I love to drive a rollercoaster. I've only cracked a rear rim once and the way it happened, I noticed it after I finished my ride:

 

[JaccoW]

I may be drinking the MTB industry koolaid and my personal experience is definitely anecdotal, but I can't shake off the impression that this discussion about carbon ignores the advancements made in the industry in the last dozen or so years.

Agreed, but that's exactly why I said we don't know yet.

I do believe we are much more capable of making carbon bikes and parts that make use of the advantages and durability of carbon. When properly designed for its intended usage. Carbon and its composites works great under tension, less so under compression, where it can be as little as 30-50% of its tensile strength.

With modern design tools and simulations we can build bikes and parts that are as strong and light as can be. It has been proven they are even stronger than their steel and alloy counterparts.

Long-term durability however is something that we can only find out in the long run, when the 20 year old bikes start becoming cheap and plentiful enough that people don't worry about using them as a commuter or cafe bike anymore. Maybe they won't do well with being out in the sun and rain all day. Maybe they are plenty protected and won't mind. We will see when the first well-designed ones become cheap enough.

For comparison, for the longest time you could expect a car engine to last 150,000 miles, nowadays that's easily 200,000 miles due to better designs, technology and better service standards. But that won't matter much if it is used in a badly maintained or abused fleet of vehicles like certain delivery vans. You won't want one of those second-hand.