seems like shaft drive with a hub gear is a better solution? both technologies tried & trusted no point reinventing the wheel

only if you want self contained though - chain isn't going anywhere

I don’t think it’s going to replace derailleur systems, at least not until there are more innovations in materials and engineering design. And while the engineering and materials challenges are significant, I think the real challenge is going to be convincing frame manufacturers to invest in the currently unproven design...

I think it’s a “solar roadways” sized fraud. It will attract funds because it looks so glamorous, like the Crown Jewels of drivetrains. It is front-and-square at bike shows as a lure for the journalists. They use every marketing trick in the book. Lately they have even been selling the concept on the aerodynamics. Like yeah, we are concerned about the surface area of our derailleur. My prediction is that the “investors” (if there are any, $1m is a conveniently round number) will lose their money. They are crowd funding now. The end product is 2 to 3 years away and always will be. Lol. Broker’s recommendation: avoid.

Not hep on it. Looks flashy but weak. CEOs letter said the same. I run a machine shop & ride Road & FAT bikes. My Road are chain & 10 speed (ubiquitous & flexible) + a Specialized Langster Fixed Gear (unbreakable & efficient). The Belt drive running an IGH is a 'dream item' in my Future + I believe the way forward for increased drivetrain reliability. I'm SUPER curious about Shimanos 13 Speed Gearbox development - what have you heard of late ? PS I know Rolloff & Pinion are FAB but they're $$$ still & Shimano seems to have all the right factors to bring Gearbox Bikes to the FOREFRONT of the marketplace.

I'll make a start up that sells solid rubber tires and advertise it as not needing any pumping

I used to live in an area where we had these really nasty weeds that grew these burs we called catheads, they would go straight through even those thickened puncture resistant tubes. I wound up putting stuff called green slime in them and the tyres would still pick them up and break most off again while riding but the ones that came out left tiny blobs of this green that had almost instantly sealed the punctures. There could literally be dozens of these little blobs of green and every 1 of them would have left me with a flat long before I got home. You will still lose a small amount of air and need to top them up semi regularly but at least I could go for a proper ride.

I'd recommend the Tannus Airless. They have tires with different "pressures" and different surfaces (slick/non slick/wet tires). Bit hard to get on, but ride very well and dont need swift replacement

@@GrafEnsker I must admit I'm not familiar with those tyres but, anything that can give a satisfactory ride and decent traction with low friction that DOESN'T contain air would be by far the best if you live in an area where punctures are a constant problem. I will look into them myself now too. Thanks for the information.I'm

Or rims that never go out of true.

Interesting! Thanks for the data point. 👍🏻

It's long been known that chain drives were more efficient - I remember reading through a book on the history of the Morgan Car company where they were saying the same thing about their Cyclecars (2 wheels at the front and one at the back- with a chain drive ) in the early 1900s What shaft drives bring are reliability. When I worked as a MC courier I'd generally get through a chain a sprocket set every 2 months (10k) - when I switched to a shaft drive bike I'd just have to change the oil in the shaft drive every few months and have the system serviced once a year. On a pedal bike you're probably going to want to optimize for power efficiency rather than high mileage reliability, so a shaft is never likely to catch on.

What about reliability

@@bev8200 no contest on reliability: shaft wins 10 times out of 10. As a source, just look at motorcycles applications

@@carlofasano4293 - the question is, is it really worth optimising for high mileage reliability, as opposed to optimising for power efficiency, on a pedal bike? How many riders are really doing enough miles to justify it and will want to sacrifice power efficiency to achieve it? especially considering the comparatively low cost of a replacement sprocket/cassette and chain. Shaft drives on motorbikes have always been pretty niche - mostly restricted to the big high mileage tourers from BMW and Honda and a few other corner cases - they're going to be an even smaller niche on pedal bikes.

In this environment also costs - beyond initial acquisition - for replacement parts and general maintenance are of no concern and a culture of over-provisioning guarantees availability and reliability.

That's true I have seen bicycles like that in the paper mills around here. Of course sadly and invariably they seem to want to switch over to golf carts or the industrial version of those things. Unfortunately I got a lot of Mill guys are fat and old

I've lost count of how many pant cuffs I've ripped on my bike!

true, lots of large facilities have mandatory work boots and long pants, so pants getting snagged by the chain would be a concern, and my guess is even the office staff won't like getting chain grease on their suits.

They seem to be common in bikeshare systems for the same reason.

@Bill while that is true of motorcycles, and while the power to weight ratio would be reduced due to efficiency on a bike and a motorcycle, I don't think the weight itself would be an issue with type of design on a bicycle. Assuming the shaft is made from fiberglass, carbon fiber, or the thin aluminum bike frame tubing, the weight would probably be similar to the front chain-ring parts, rear chain-ring parts, derailleur, and chain the system replaces. Definitely so if the gears are hollowed out to the minimum needed thickness and use lighter weight alloys. The system only needs to transfer between 250 and 1000 watts or so of total mechanical power continuously, so you can get away with much thinner and lighter materials than a 65+ kilowatt rated (500+ cc) motorcycle engine could.

This data comes from one example. Not really scientific is it?

@@joshnabours9102 you mention the power but forgot the torque, which as said in the video, is gonna be concentrated on a small area of gears, instead of whole lenght of chain that sits on a front sprocket. In motorcycles nowadays you can only get a shaft having like +1200cc engine (VFR1200, BMW K1600, FJR1300), with few exceptions, so there's a lot of torque and power to compensate the weight and still these are only heavy touring/offroad bikes or maybe cruisers. Not a sport ones.

The thing is in bicycle you have to pedal it by yourself while in motorcycle the engine do the work

@@Frost67915 The old Madura motorcycles had a 700cc and a 1200cc option, the 1200 ran a low 11 second 1/4 mile, not too shabby for a heavy cruiser with a driveshaft. I would NEVER put a driveshaft on a bicycle, lol. The only reason they're nice on motorcycles is they live forever with very low maintenance required.

Savage... but fair.

That is two very different things. Carbon is actually a difficult thing to produce to tight tolerances. Machining can be very precise

@@DaveCM some can't even machine aluminium for bb30 and pf30 .

Reminds me of a buddy who once told me cameras would max out at 8mp as the science at that time was where it was at. I told him just wait. Imagine how far science has taken us in the last 50 years and try to think forward.

@@davidstepro7486 the issue for the bike industry is cost effectiveness . Digital cameras are relatively easy to produce cheaper . Manufacturing a part like shaft drive , ensuring quality control at frame factories and producing the volume for such parts is hard for cycle manufacturers to get right . Case in point is the new cervelo with cracking head tubes , canyon with their seat posts .

Added weight.

*Rolls along on top of the bottom bracket gear because it's so big* 😂

@@keithwittman4741 SKELETONIZED gears.

Pedal assist seems like a far better solution.

wait till your ball sack gets caught in the gear

That's usually a QC or review related issue. Proper welds are generally stronger than the base metal they're joining, so if a weld breaks, it's usually just bad welding. It's only when base metal starts to break that you should really suspect a bad design.

Maybe that’s true of the hatchet, but I don’t think it’s true of the derailleur. For one, the derailleur is part of a complex machine that hasn’t stopped being reiterated from the start. For two, the hatchet is closer to a fixed gear bike, and the derailleur closer to a proper axe or saw. And while a hatchet can’t be improved on much, there are plenty of new axes and saws that benefit from innovation.

I would not say the attempts are not worth the effort. They add to our knowledge of ways not to do it. Possible there is no better way to do it but in the hunt to improve on it you need to know what has already been tried. Quite often inventions are overturned, but only after some serious effort, and every step along the way naysayers continued to say it could not be done. Powered flight is a good example.

Another is electric cars. They have been around for a really long time but only quite recently that they started to be mass produced as a genuine competitor to ICE cars.

Systems like the pinion gearbox paired with a gates belt are probably a better solution than a shaft drive.

Out of interest what percentage of mile vs transmission failure have you had? I do around 3k miles a year not loads but only ever had slipping derailleur once around 14 years ago, only 1 broken chain around 5 years ago both were simple trail side fixes. So 2 fixable transmission issues in over 45k of miles. Had one terminal issue of a pedal sheering off and stripping the thread. Cable tied my foot to the good pedal and cycled 19 miles to the closest bike shop.

Simple to have a guard included with the bike but that would cost $5.00 to the manufacturers... 🤣

@@golddiggerdave it all depends on the terrain. I ride in the Canadian rockies and I took out two in one summer season last year. Maybe put on 500km on my mtb.

Or if you have a little shit for a sibling that likes crashing into it

Was about to say the same!

@@Samonitari Ditto. I always use the unambiguous terms tight or close tolerances.

He kinda mixed high precision and low tolerances I guess.

Most of the time I've heard "high tolerances" being used in an engineering environment it's synonymous with "tight tolerances" or "high precision". With that said it's still pretty ambiguous which is why I prefer to use "tight" or "loose" tolerances.

It's not nitpicking it's being accurate.

I use closed Shimano Nexus 7speed. And the chain runs inside a cover. 4 salty rainy dirty winters and the chain looks like brand new 🙏

Ah, that checks out. I was wondering what the appeal of a closed up mechanism would be. Having fixed my (literally salvaged from a junkyard) chain many times on the road, I wasn’t thinking about the average person, who isn’t going to want to have to do that under any circumstances.

that's what i was thinking, especially office workers should appreciate not getting chain grease on their trousers and it's not like you're ever going to have to fight the reduced efficiency up hill in the netherlands. also one key disadvantage of derailleur drives not mentioned in this video is that, if you have a fall or get into any other situation where something bumps the derailleur, the whole thing will never work right ever again.

Didn't know they made these bikes

"Wow that's a neat idea, too bad it's worse"

@@thebirchwoodtree sad to admit but that's well said

The chain and derailleur system is beautifully simple, reliable and easy to maintain. The troubling bit is the cable levers mechanisms which seem to break on cheap bikes.

Sort of the opposite in many ways though. Rotaries are lighter, less reliable, more compact. Like shaft drives though they are less efficient.

If done correctly with crazy maintenance rotary engines are theoretically more efficient. Unfortunately they just aren't very practical or easy to maintain

@Giuliano Skywalker what about buying the tools and having proper assitnace from the seller?

@Giuliano Skywalker Someone who has been in automotive/mechanical engineering should be familiar with the concept of gear and shaft drives, but the tools and equipment appropriate for the drive is a different story.

What about the Alan Millyard built MTB? In very simple terms, he built an enclosed drive system, and the bike won some championship races in 2006. Very easy to mass produce from the look of it, but totally ignored. There is a few UKposts videos of it on his channel.

@@jerzywoking1699 Yes I saw that video, sealed drivetrain and gearbox. Amazing bike he built for his son to race.

@@brandywell44 here is the link of the MTB Alan built ukposts.info/have/v-deo/oYWSn2-qqICez4E.html

I heard those wear out the chain faster not sure if true

@@lyssanch3096 propably by a slight amount as it is tensioned a bit differently as you are pedalling

Actually, those eccentric chain rings were probably at the height of their popularity about 25 years ago. Even then, they weren't very common. I'm not sure but I think one problem with them might have been that they made it difficult to position the front derailleur properly as the chain would continually rise and fall with the rotation of the chain ring.

@@eyesuckle so its better suited for single speeds ?

@@lyssanch3096 Well, maybe not necessarily for one-gear bicycles, but at least bicycles without a front derailleur. An eccentric chain ring wouldn't be a problem for the operation of the rear derailleur. And from what I've seen, bikes with only a rear derailleur seem to be making a comeback!

Harley Davidson has been using belt drive since the 1980's.

I've been riding chain drive bicycles for almost 30 years. I got a belt drive about 6 months ago and I'll never switch back.

​@@john_barnettSame here. Just got a new bike with a belt. There's no going back

ye, I imagine in a city u wouldn't have any of the benefits of a shaft drive I would like to try a shaftdrive for a mountain bike tho

@Karl with a K you didn't even watch the video, or if you did you didn't comprehend it since he addressed most of what you said

@Karl with a K Pull up the data showing that claim is right then.

Somebody in this comment section literally used a “1-3% difference in efficiency” as a reason why shaft drives should be considered useless and completely ignored, and that’s just a sign of how out of touch the bike community is

@Karl with a K lmao you don’t even know what you’re talking about

They've all been tested thoroughly and the chain drive is the least friction, (something probably more important to a pushbike rider than most other applications) while belt drive was next best with shaft drive being the worst. If it was a motorbike operating in really dirty sandy type conditions I'd see the value in a shaft drive but for EVERYTHING else I'd stick with chain drive too. I've got 2 motorbikes now and seemingly only in recent years the chains somehow seem to have improved vastly compared to 15 years or so ago when I would be forever having to adjust them. On both bikes I've got I tightened them a tiny bit after about a thousand kilometers or so and keep checking but even 9,000 kilometers later on 1 it's still pretty perfect and same with the other after a few less but still not even looking like it's even changed at all since that first settling in and adjust. Admittedly 1 is only used on the road but the other gets a bit of dirt riding, not a lot these days but still, it has been in the mud and dust and is still excellent. So, I agree 100% without even watching a video once I saw that terrible high friction rear gearing arrangement in the thumbnail pic when you get to this video. I'm not going to waste my time watching the video of what looks clever(ish) but very high friction and wear and probably very easily jump teeth if you cranked hard which on a men's pushbike is a toe grinding and nutcracking nightmare, this coming from someone who grew up riding a pushbike with very second hand 3 speed hub gears that OFTEN found a sort of neutral and gave me those treatments. If it was an evil plan to stop me from breeding, it failed since I've got 3 kids lol.

Why is that?

@@brett7011 "Why is" what? Also, who are you asking? Any relevant reasons are already stated so if you've got a specific question, ask that specific question instead of just a general "why". EDIT: And specify WHO you're asking too.

@@lorditsprobingtime6668 interesting reply that matched my personal experiences. Part 2 for me is the bike industry is trying make a low power machine much too complex.

@@lorditsprobingtime6668 .95 Fpfpj

Yeah they'll be selling plastic chains in a few years. If they already dont

@MikMech -- that is what I have always thought too. A Rohloff hub with a shaft drive might be the ideal city bike set-up.

I agree. What excites me most are innovations around gearboxes like Pinion’s that happen at the crank. And, given the current technologies I like both chains and belts. I have both and they’re both great in different scenarios. I have a single speed with a chain, multiple bikes with chains and derailleurs, and a bike with a gates drive and shimano hub. They all have their place right now but an efficient, lightweight gearbox at the crank that can change gears under load seems to be the most realistic ideal. $.02

i prefer electric motors to pedaling. no sweat and no effort

@@Blox117 I commute to work using a Trek Aliant 8S - it is a pedal assist ebike that allows a 68 year old man to travel 40 miles back and forth to work. :) ...the bike makes me feel like a kid again.

@@kevingary7018 pedal assist sucks, throttle all the way

@@Blox117 Lol, change the input power supply would help that. Plus, bigger output motor.

No battery for me no motor or engine pedal power till the end

Good point they also need to make it a bit lighter for better bike control so that is doesn’t feel sluggish

I might be hard to make it work with mtb suspension but nothing is impossible.

maybe for cross country. anything with rear suspension is going to be impossible.

There's no way its more rugged than a chain drive. tolerances on the mesh have to be tight and in MTB the frame and rear triangle are constantly flexing. Not to mention dirt, mud, and debris on the drive solution is just going to wreck the bearings. Just because it is stiff does not make it reliable, in fact in many cases like this stiffness makes it less reliable.

@@corporalpunishment1133 It has worked for motorcycles, with a rear swing arm, for many decades.

There's also one system I've seen where it's rods pushing back and forth.

Pedal assist seems like a far better solution.

So... hipsters?

There's a reason these things haven't ever taken off. Motorcycles haven't even adopted the shaft drive. Shaft is is a solution to a problem that never existed.

@@untrainedprofessionals2374 Had Beemers for years. took them 6o years to get it right. Triumph of engineering over design.

@@whazzat8015 they still will be dumping a bunch of power into heating the oil around the driveshaft. When you've got to power the machine with your own meat sticks it's never going to be close. Transferring power thru 90 degrees not once but twice will always be a ball ache.

Good luck with that philosophy

I’m thinking you’re sarcastic but I’m sure there’s a ton of other people with his mindset

Its ALWAYS about astetics.

@@Bitterstone3849 You’re damn right

@@animalanimal7939 Thanks homie

Added to that is the shaft is angled away from the crank-angle!

Cool

coolest bike i ever seen was some crackhead who welded a bunch of 20 inch frames together untill the bike was like 18 ft high 😢

Hey, we want pictures!!

@@stevephillips8192 bump i love crack ideas

But a shaft drive wouldn't fail as often as a chain. Especially in a low power application as a bicycle it should last forever. That said, chain and sprocket are much cheaper and lighter. And if you are using hub gearbox you can completely enclose the chain, reducing wear from outside dirt.

@@JCGver until you break the gear teeth and are screwed

@@mass-cp6jf chain system also have teeth which grab on chain and in my experience it much more fragile.

@@RikkaYeet not even close to the same amount of stress being added. don't just say shit you know nothing about

You must have been buying low end bikes then

Internally geared hubs are a thing too.

Maybe next time you will take better care of your bikes.

Try adjusting the derailleur

To ignorant to figure out a bike? I wouldn't be bragging that up. I've got a 30 year old derailer that works just fine. But I know a thing or two about maintenance.

There's one thing that I have to wonder about though... I assume all these tests were done with fresh sprockets and chains. But if we assume that the user is not going to maniacally change these parts as soon as there are smallest signs of wear, the efficiency will drop, and chain system will likely start wearing much faster than shaft. Maybe on average the difference is not that critical? Motorbikes also have a separate gearbox instead of a derailleur, meaning they have much less chain/sprocket wear, too

Bike chain line efficiency has been studied to death. Bike chains can reach 98% under lab conditions with certain fixed large diameter sprocket combinations, think 30T+ on both ends. In reality a fresh and properly set up 9 speed drivetrain hits between 83% and 95% depending on sprocket combination and drops from there over time. The individual factor with the highest direct impact is chain tension. Any slack in the return (ie top) of the chain greatly impacts efficiency.

I have to ask: how do those percentages make sense? How can 95% and 80% of a group of people use something? Shouldn't it be 55% and 45%? Or so.

@@Hexmod369 Percent energy transferred, the higher the better. Remaining lost to noise and heat.

@@bytesandbikes Thank you.

Thanks Stan!

Just using a case protecting the gears and chain will be still cheaper than using a shaft. Bevel gears are also more expensive than a simple reliable chain.

Reliability is a factor

Buy a Fraser-Ńash car.

No point. They have transmission with a shaft drivetrain😂 derailleurs are just small size transmissions😂

@Karl with a K The video stated that they are less efficient than a chain drive…

@Karl with a K "zero maintenance" is a complete lie.

@Karl with a K Everything requires maintenance. You're just lying to make a point and it makes you sound stupid. Edit: So instead of adressing my point you try to insult me. You sir are a failure of the highest degree.

@Karl with a K you should be a shaft bike manufacturer for saying shaft are more efficient :D

There are patents and even mass produced shaft driven bicycles going back into the late 1800's. There is a reason they never succeeded.

@@tobyvision but hey intrusive market popping up maybe?

I agree. I've changes my chain on my 2x11 and bought a XT chain for $33. And jokey wheels for $14. Transmission has no sound except when i change gears. Easy to install a chain with a chain breaker.

And he did it by using a Shimano geared hub mounted inside the swing arm, with an enclosed final drive! Later versions even had single sided swing arms to speed up wheel/tyre changes. And he built it all at home in his shed! Also of note is the suspension shock/damper that Alan designed and built himself, basing his design on tank suspension!

Very good points!

more power equals more battery consumption. You've just killed your range.

eBikes actually have another point that makes then ideal for shaft drive; the motor can be mounted in alignment with the driveshaft for greater efficiency.

Yeah right

Much appreciated!

What's that last point? "I can also change gears while pedaling, which you can't do with chain/derailers." I'm pretty sure derailleurs can't change gears _unless_ you're pedaling. I'm right with you on everything else though. I especially like how shaft drive bikes don't need anything to be oiled or re-greased constantly, they can sit in storage for half the year when you can't ride and be taken right back for a ride without having to do any maintenance and it doesn't change how they ride at all. I used to ride bikes with chains and hated how if they sat for even a few weeks without being ridden the chain had to be cleaned and oiled or it would feel like I was towing a bus.

@@GremlinSciences Maybe it was the derailleur I used to have, but you couldn't apply any drive pressure when changing gears. With my shaft drive, I can be peddling with pressure and change gears. Might not be best for longevity but so far no problems in the 6 years I've had it.

Meanwhile ive been commuting by bike for the past 10 years, between 10 and 26km a day. Ive never had to replace the chain or even had it slip off the sprocket.

@@awellner3285 impressive!

@@awellner3285 Must take care of that bike.

Shafts are more reliable and durable. But less efficient. I would rather choose the chain ones. For comfortable cycling.

@@awellner3285 You're lucky.

That’s what I was thinking.

Keep velcro straps on your handlebars for your pant legs

@@DeAthWaGer Exactly 👍

I have trouble with my long skirts!

Fixed that with Truvativ Hammerschmidt a decade ago.

Thanks Nicolas, I appreciate that! 😊

Me too.

It might be easier to shield and clean.

concur + as saying goes : gimmicks can be defined by amount superfluous parts

I think the bike market needs some more alternatives for gear boxes. Because rohloff and pinion are just way too expensive to consider and most other options just don't have enough gear ratio. Right now the only gearbox i know that could be considered a solid value with enough gear ratio to be used on an allround (commuting/touring) bike is the alfine11.

@@jimihenrik11 I agree. Having said so, I have a Rohloff/chain combination on my about 40 kg 2-wheel cargo bicycle with the gear ratios optimized for hilly terrain. Even though I live in The Netherlands where it is mostly flat.

Ah

When you understand climate change, we don’t need cars

@@alohatigers1199 Lmao UKposts shadow banned your comment, even though you're pushing their views. Mechanical components are relevant to cars, even if you are concerned about the environmental impact of cars, it's a good reference point for mechanical components being used under load for extended periods of time. The environmental impact of cars is a seperate issue, not really relevant to my post.

Dont most E bikes have hub motors? Any sort of power transmission from motor to wheel would be inefficient in comparison

@@awellner3285 There's also mid-mount motors usually found with conversion kits, provided the bike has a spot to install the battery and electronic compartments, which changes the bike mass balance. Though a chain bike and trousers/ dress pants for work typically don't play nice. If transmission driveshaft ebikes convince commuters to use their cars less and shift more into the electrical grid, I would not mind. So long as people BOTHERED to know that Class 3 Ebikes and electric motorbikes are legally different classifications, and I am not too pleased with bikers not following road rules, which I have personally observed everytime I commute on foot. The car always beats the biker in the weight class, and bikers think a bike helmet is sufficient protection.

@@awellner3285 hub motors are easier to fit, but they have the same disadvantages as regular singlespeed bike.

Canada... get a heavy ccm with big tires and maybe chains... studs 100%

There are quite a few ways to implement them easily, problem is that most of them still try to implement the classic look of a normal bike frame which causes problems.

Motorcyclists have been doing off-road rallying with huge suspension travel for decades on shafties (especially Yamaha and BMW) - it can be done!

Not harder, but even more expensive, complex, heavy and more mechanical losses. Not worth a shot outside of some pretty specific use.

Bicycles aren't the only machines that use gears or chains, the efficiency advantages of chains and belts over gears (and especially bevel gears) have been well understood for a long time.

The cost, lack of efficiency, and lack of easy fix is still prevalent today. Keep in mind the bicycle is by far the biggest mode of transportation throughout the world for almost 2 centuries. Somebody keeps trying to revive the shaft drive like somebody keeps trying to make a better rotary engine. Its not happening.

Because all RnD was done in chain. I dont see many chain deraileur system in cars and machines

simplicity and durability of chains? in dirty condition? What? Chain is awful, always requires lube, frequent cleaning (unless you want to replace the whole drivetrain after a few thousand km), rear derailleur can be hit by some rock or literally ripped off, especially in mud. "the alternative systems would fail in dirty conditions" - why an interal geared hub with belt should fail in dirty condition? Dirt can't get into hub, and belt is like 10x times more durable than chain. For touring bikes belts are the best.

Chains are 200 years old, plenty of time to evolve. Back then chains weren't so efficient.

@@taufikabidin412 R&D was also done in gearboxes and shaft drives, that's why you can still buy them today. Shaft drives also has R&D in the motorcycle world (if you exclude automobiles), and the efficiency is even lower than bicycles shaft drives. Sometimes one design is just superior against another design.

@@ghoulbuster1 shaft drives existed for about the same amount of time. Sometimes one design is simply superior compared to another design for certain applications.

A convert to the church of the belt! I've heard that you have to cut through your seat stays to install the belt though. Are you up for that?

@@myfrequencies1912 Look at his video on belt drives.

@@jamesquigley8628 Yeah I have, that's why I'm asking you about cutting your seat stays!

@@myfrequencies1912 I don't care but the bikes I own now don't use disc brakes and that is a must for this project. YMMV

On a bicycle? warp 2, at most.

Isn't that pretty typical? Maintenance costs should be higher on a bike per km

There's a very common problem that affects gear adjustment in a "modern" bicycle chain-drive drivetrain: _Misalignment of the rear derailleur _*_hanger._* The hanger is intentionally made with a relatively soft metal so it will bend or break before your expensive rear derailleur or frame dropouts. That way, if you're in an accident, you just need to replace your cheap hanger and your drivetrain is back in action. However, since it's made with soft metal, the hanger is easily (and frequently) bent out of alignment through normal use, making it frustratingly impossible to achieve a good alignment between the rear derailleur and the cogs in the cassette. If you remember to always check and align the hanger *before* you attempt to adjust the rear derailleur, you'll avoid most problems and it will be a breeze. A rear derailleur hanger alignment tool/gauge costs as little as US$35 from Amazon. A professional tool like you'd see in most bike shops would be a Park Tool DAG-2.2 which costs about US$84. Or, if you're patient, you can pick up a used one for even less on eBay. I recommend checking the hanger alignment every time you need to replace a chain and/or every time you begin to have shifting problems.