How Fast Can A Brompton Go? | Ep 1 | A Newb's New Journey
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- เผยแพร่เมื่อ 9 ก.พ. 2025
- How Fast Can A Brompton Go is a TH-cam series uncovering That Brompton Guy's journey as he tests out different configurations and trains on his cycling fitness. If you're keen to explore a hybrid athlete's lifestyle, this is the series for you.
In this series, we aim to cover a newb's journey through training and testing optimised setups, inputs from professionals, cross-training from other sports, max speed tests, acceleration tests and many more. This series will see some collaboration with established Brompton-related TH-camrs. So stay tuned!
Episode 2:
• How Fast Can A Brompto...
Is the goal to beat a road bike? Hell no. Are we going to be riding at top speed non-stop? Eh, maybe, if your fitness is there. I just like the idea of experimenting and pushing things to its limits, like how I was really annoying to my parents when I was a child. I'm just kidding.
Curiosity always gets me, and therefore, you're going to see more interesting content!
My goal is to reduce my P-Line's weight, and also, showcase my 12-speed C-Line and push them both to its absolute limit.
Major credits to CycleOxygen for the assistance - @CycleOxygen on Instagram.
As a person from a country with a lot of people riding bikes (Denmark), I'm able to claim that in no way a brompton is as fast as an ordinary size wheel, bike! A strong and energetic person may be able to follow one of those for a short time, but the small wheels gives a Hell of a Lot more resistance when rolling (A nice mathematics lady here on TH-cam has a card giving the sad, Hard Facts about this!!!)! A brompton is a special tool for fun and easy transport and may ride nearly everywhere if wanted, as I do, also up and down very steep hills, but don't expect to be able to comped in a "Tour de France" on one 😁! Finn. Denmark
Absolutely agree. Hence why I put a disclaimer in my description that the goal was never to beat road bikes.
But you're going to have to be a bit more specific with "ordinary size" 20"? 26"? Pardon me, but my day job deals with specificity, and making broad claims without data, or physical evidence is kind of a flaccid statement to me. No offense.
Seems like you are referencing, 2Bikes4Adventure. They do a really great job diving into the detail and presenting their channel as an informational page.
But check out this Brompton versus Road Bike video if you'd like to see someone who actually been there/done that.
th-cam.com/video/CCAwg9OMa84/w-d-xo.html&ab_channel=GlobalCyclingNetwork
Overall, I think you're missing the point, bud. I did this video as an experiment. It's good to talk about things, I don't disagree. But personally, I would like to put myself out there and actually capture the data, and this video is about me... capturing the data. :)
Edit: I do like to add that I am NOT a Brompton fan boy, I'm just a boy who owns a pair of Bromptons, and I prefer it over a road bike as my apartment's small in Singapore. It's almost as though there's different bikes for a different use case. 🤣
@@thatbromptonguy2023Concerning the GCN video, we covered it here : Can a Brompton Climb? - GCN Challenge Explained
th-cam.com/video/VwRR3Ubp0DU/w-d-xo.html
It's not as fast, of course, but it's a lot quicker than most people think. The benefit you get for the compromise is well worth it IMHO.
The TERN VERGE X11. Is as fast and a full sized bike of the same weight. (23LBS). The 451 kinetix pro X wheel set is incredible..I've hit 28mph on the flat. And 37mph downhill. And no folder climbs better than an X11. With its incredible sram 10--42 gearing...
@@fender1000100 As a first I wondered for what use I had my low gears, of the 6 on my Brompton, till I met a steep hill and had to walk to continue up! So of course it is able to climb, but it feels a little "funny" when you are able to walk faster than riding the bike! And going down again at extreme speed from the top, as I frequently had to stop for the "cattle tubes" crossing road, so I was honestly afraid that my brakes became too hot during that, but my Brompton never let me down!
But I was also the owner of a 6,8 kilo LOOK top racing bike and its speed potential was classes above that of a small wheeled Brompton! You are able to do the same on a Brompton as an ordinary bike, but it takes much more effort to do it! Finn. Denmark
Let's talk about a cost-no-object Brompton T-Line electric build.
There are many ways to do this. The standard 4-speed T-Line weigh 17.5 lbs. One option is to buy the bike and leave as is. 4-speed gearing is too narrow and 12-speed gearing is a mess. Based upon what I've learned, 6-speed gearing on the Brompton T-Line is optimal. This means that the gearing on the T-Line would need to be replaced.
Websites like "Brompton Kitchen" sell many upgrades for the T-Line. Not only can you replace the cogs and chainring but upgrade many T-Line parts to bring the weight down to 15 lbs, which would make a minimum difference on ride quality but would make the bike more portable and easier to carry up and down stairs.
Let's talk about making the T-Line electric. The lightest option for the T-Line would be to add the Zehus 250 watt all-in-one hub at the rear, as used on the Hummingbird, single speed, 15.5 mph maximum. Based on my calculations, if parts on the T-Line are replaced to lower the weight to 15 lbs, the 7 lb. Zehus would hub would bring the weight to a featherweight 22 lbs., still super light for portability.
There are, of course, other options. You can use 6-speed cogs or 9-speed cogs and a 52T chainring. You can retrofit a Rohloff hub on the rear and you can use a 250 Swytch gear electric hub and battery on the front. With 9-speeds or a Rohloff hub, together with a 250 watt hub on the front, this would allow the bike to achieve 30 mph top speeds on the flats with little pedaling effort, perhaps with a weight not exceeding 25 lbs.
Of course, you can add a 500 watt front electric hub and large battery pack too which might defeat the purpose of buying the T-Line in the first place. If you were to electrify the T-Line, what would be your dream build and why? Thanks.
Great job making 40km/h. You'd do well to take off the mudguards. They act like parachutes. Also put your seat high and further back so you're in more of a prone position when riding.
You sir are an absolute legend 💪💪👍
i like how the HR shoots up when you shouted "I HIT FORTHY!" haha
It’s the cardiac arrest speaking, bro. 😂
You are a good and a likeable person ..great video
Hi @thatbromptonguy just stumbled upon your vids this morning 😅 love your crazy experiments 🤘🏼🤘🏼
By the way, quite interested with the 12 speed setup, do cycle oxygen sell the custom 12 speed cogs online?
Keep it up bro & happy experimenting 🤘🏼😎🤘🏼
Welcome aboard! You might want to ping @cycleoxygen on Instagram or Facebook, bud. They would probably be able to give you more details. I got mine in-house done. I believe there's some component that can only be acquired on-site. Which makes sense, they are running a business afterall.
When the Man, meet a Brompton, you get the Speed
Love to see the P-Line 12 speed review
Answered my queries that I have for 4 external speed. 58T is nice.
Stay tuned for the next video, brother. Got some pretty expensive upgrades done. Hint: Titanium crank and new carbon chainring. ;)
Kudo from South Korea 👍 and always be safe bro.
come on, next video, 20KM, flat, average speed test
Already done that for the recent OCBC race. Check out my TH-cam shorts. But that wasn't 100% flat. Tons of upslope, but it was fun.
Best!!! I'm on 60t CR bro. You can do 60t and definitely can do above 40kmph!
Wah bro, I’m honoured!!! I wanna see how fast I can go with the H-Bar first, then I’ll change to an S-bar setup and see what the main differences are.
It’s really fun to do these small tests as I swap some parts out to see the impact. 😂
@That Brompton Guy
Like some have mentioned, body position (assisted by the type of bar) tires (racing with 90 to 100 psi) & cleats will yield better top speed.
If u doing any tests let me know, I'm honoured to join and have fun.
I’ll ping you on Instagram, if you have one. Would be awesome to do a collab!
Awesome! What app do you use for the speed measurement?
For this video, I recorded my info on WorkOutDoors, exported the .csv file and upload it into a video maker that allows me to import footage and the stats into a dashboard.
@@thatbromptonguy2023 Thank you for your helpful answer
Why are you looking for speed? What difference does it make how FAST you go? Isn't the point of riding a Brompton the QUALITY of the journey, the things that the slower speed allows you to notice about the world around you? Just my personal preferences when I ride.
All very good questions. You are not wrong.
When I made this video for the very first time, my objectives were plain and simple, to see how fast I can go in one short burst. My goals now are to simply bump up my average speed over flat terrain, and that's really it.
Hence, why I stopped making new videos with regards to this series as I wanted to be of a certain level of cycling fitness before I continue posting again.
That's really it, to be honest.
Good stuff my man, when do you plan on continuing?
Average speed on a folder is reslly interesting to me
What do you care how fast a bike goes? Lots of people want to go fast all the time or just want to have fun.
can share how much is the chainring? thanks
I can't recall the exact value, probably around $200-ish? I say around because it could be less, or more.
You should reach out to CycleOxygen for more info, they'd know better, buddy.
I must of missed something ? How are you going to get a twelve speed on the P- line ?
CycleOxygen will do a better explanation because I’m probably going to butcher it. But TLDR; using a custom CNC’d 4-speed cassette that they sell will give you 12 variations or 12 speeds.
But just bear in mind, that just gives you more gear options for climbing, doesn’t benefit the flat road rider looking to maintain 40Kmph.
If you want, I can actually talk more about the 12-speed that I’ve done with my C-Line (completely different bike).
@@thatbromptonguy2023 Never heard of TLDR, they mad or cnc’d a four speed cassette ok , I have a six speed but I’m trying to see in in my minds eye yet can’t, I am new to the Brompton bike so excuse my lack of knowledge in regards to the subject, did you do a video on this so I can see it ? One question comes to mind why did you not just have the hub changed to accommodate 12 speed ?
@@KavanOBrien TLDR just stands for Too Long, Didn't Read, it's a colloquial term used online as a replacement to "in summary".
Your question contains 2 parts, let me answer them per part.
1) I have not done a video, but I am happy to touch on the 12-speed config. It's basically the same Sturmy Archer Wide Ratio x 4 sprockets (21-15-13-11), giving you 12 different configs. This is a great setup for touring, tbh. No hills are untouchable.
2) The 5-speed SA hub provided a mere 10% in gear ratio from the BWR, so it wasn't worth it. Alternative internal hubs such as the Alfine 11-speed, or the coveted 14-speed Rohloff required a change of the rear triangle, and that introduces it's whole set of problems. I use my P-Line quite heavily for commuting on top of long distance cycling as well, so I want to keep it light, and fast, with some ability to climb. Which is why I'm documenting my journey because there's no one answer to solve that problem.
@@thatbromptonguy2023 I think I got what you mean ? So really you’re just going to add the sturmy archer to the p line , or have I got that wrong ? If I’m right then I knew if one lives long enough one would be right at least once in a lifetime, if I’m wrong with my assumption then I will be right in the future with something.
Yup, that's right! But modifications are meant to be personal, there's no bike that can do everything. Let alone a Brompton.
So really, touring would benefit from a 12-speed config. If you are using it for leisure riding/commuting/workouts for predominantly flat or low angled hils, then a lighter config helps.
Ideally, cycling fitness determines everything but while I train concurrently, I like to optimise my bike concurrently and document the differences with each tiny change.
Des seems like a great guy and yes i would like to see how the P-Line can be upgraded to 12 speed. I have a P-Line while it accelerates a lot faster than a 6-speed C line the top speed seems to be faster on the C-Line. What would have been interesting is comparing the former 6-speed superlight with the current P-line. Btw love the colours on your video.
Thank you brother, that means a lot. You’re going to love my next video because you’re going to see what sort of pick up differences can be made just from a handlebar change.
I generally do my best to try and back my conclusions with data so stay tuned for the next one! Also, I’m sure there are wayyyy stronger climbers that can achieve the same stuff I did in this video with a way less decked out bike, but my videos are solely going to be documenting my journey and my crazy aspirations.
I’ll definitely be filming some stuff with the C-Line 12-speed very soon. Gonna be recording some top speed stuff with it.
Eventually, that will also be translated to the P-Line, just want to do it step by step so everyone can see how much impact each modification actually makes and they can infer from those videos.
Your helmet is too loose. Tighten it. Being loose, it offers no protection should you fall or get into an accident.
Yes dad.
It is meaningless for 40km/h in one second
Owl King Des Lim
He's the champ!
This is how you do it !
th-cam.com/users/shorts1phYFGMmTFk?feature=share
Haha, nah.