I came for something about Brompton gears. I found one of the best videos on KZfaq with graphics explaining gear ratios. Great job!

Its spring in Quebec and my favourite bicycle engineering professors are back at work!

You have a talent for storytelling. Excellent presentation of technical data.

hello, we, 2 of us who are considering foldings bikes, brompton, for activity similar to your channel, although for us, just starting, watched this video, and then several more. I KNEW Brompton offered multiple gear options, and methods. I KNEW could change the overall standard gear ratio by change a major gear. I KNEW about overall idea of gears being useful for hills, vs flat, of range of gears, of steps, ratio, between gears. YET, I DID NOT UNDERSTAND on any deep level, any of this. Just sort of that existed. Your VIDEO made all of this so clear, on not just Brompton, yet across ALL bikes. I have a bike, I know how to shift, I feel the impact of various gears, yet never really understood at level that I now do. All in under 9 minutes. Stunned. Upvoted, and subscribed!

This video was amazing, thank you for sharing!

Excellent video! Love the comparison at the end. Thx!

Well researched with great delivery. Thanks.

Accurately researched and superbly presented - thank you!

That’s an excellent and informative video. Thank you for making it.

Thank you again. Really appreciate the effort you put in to help us understand.

Extremely well presented summary. Thanks!

The clarity of presentation is just awesome. Great video!

I finally understand the different gearing configurations with this video. Thank you!

great video never have seen gear inch explained so well and elevations thanks for the video

Very clear explanation. Excellent.

Thank you so much for this explanation. I feel I can make a much more informed purchase.

Another really interesting, helpful and educational video about Brompton cycles and related issues. Many thanks.

Excellent video; thanks for taking the trouble to make it.

Awesome video & nice information , the only reason i'm getting brompton because of wide ratio 🔥🔥

I was hungry for data, and now I'm full. Thanks for giving me exactly what I was craving!

Thanks for this really helpful summary. You've enabled me to make my choice!

Thanks for the gear ratios, it's very useful for making a buying decision and I couldn't find it on the Brompton site

Thank you so much for this informative video! Very helpful indeed! I will definitely go for the C-Line and choose my favourite Cloud Blue Brompton! M6L 😊❤

This is really well done and super informative. Thank you for sharing your insight and explaining so clearly.

Love your channel 👍🏻

Everything I’m learning about Bromptons is from your videos! Thank you!

This has been EXTREMELY helpful - a huge thank you for this well-told brompton gear summary!

I think this is extremely helpful! Your thoughtful visuals, explanatory script and advice are simply a level above what I've seen elsewhere. Thank you so much!

Such an awesome video. I’m speechless, really. The simplicity belies much planning and effort, I suspect. Thanks Pam.

Pam and Gilbert Love the video. Fantastic comparison and very easy to see the difference on gearing. I had the opportunity to ride the new T line, it does lack gears for our touring purposes, but love the quick and staight response to pedal. Once more congrats, love it!

Hello Pam and Gilbert, so interesting like always!! I must definitively change with low gear for my next travel. Thank for your video precision!!

Perfect to choose the best Brompton ! Thanks😄

As an owner of the former Top, SuperlightM6LXBrompton, I have used it during vacations on our only Danish, Rocky Island of Bornholm, and it has a serpentine road going up to a former lighthouse. As an elderly, too heavy man in a bad shape I had to walk once in a while, going up and also to pass the several "cattle prevention bars", crossing the road at intervals, some with a self closing gate to the side. My 6 gears came in fine but wasn't even enough for the job! I do also own a 33 gears carbon MTB, with gears which are so low that I can't even start on a flat road in them, but going up an extreme hill in a wood, they are fine!! Finn. Denmark

Thanks so much!!

What a fabulously informative and well-explained video! I was almost ready to buy a 4-speed P-line Brompton for touring, but now think the 6-speed C-line will probably be better.

Probably the best presentation I've seen on all current Brompton gear ratios (including the new T line which was what I was looking for). Better than my spreadsheet and coming to the same conclusions on choice - i.e. 6 speed classic with standard/reduced chainring is best for touring/hilly terrain. I would however like more gears to reduce the jumps and to remove the compromise of having to either pedal furiously or with a slower less efficient cadence in order to maintain a particular speed, something which the new 4 speed doesn't address.

Great info! In Singapore and some Asian countries we have many different brands of ‘Brompton clone’ so call trifold bikes that comes with default 46 or 48T chainring running on the SFR3 internal hub and 2 or 3 external sprockets, giving a 6 or 9speed configurations.

Thank you - very useful! One update I notice on the Brompton support website, they show the 4-speed has a 56T option now which brings the top gear on the 6 speed closer to the normal 3-speed: 6.74m in the top gear.

amazing!!!

there is so much value in these videos it's ridiculous

Neat and well-explained. I recently upgraded my three speed to a 5xspeed just so that I would get a little bit more on the lower and higher end of the gear range. 256% as a whole lot better than the previous. But I can certainly see where others with the three speed have gone to the 44 tooth to get some of the same low-end gains.

Wonderfull!!

Thank you for this video! I have folding bike with 7 speed 👍🍀

Hi, wonderful and instructive videos. Could you please reveal how you make them? Or at least some essential hints for the animations? Keep on, I’m delighted!

I wish Brompton did a 39T chainring as I never use the 3 High gear. I had the thirdparty 39T but it did not fit the Shimano crank I installed to my M6 so I reverted to the 44T.

Ive got a p line and I love it! just wish I had a wider range of gears so I could keep up with my road bike friends if I wanted.

Awesome video. I like that you actually share how a gearing ratio could affect a climb. I wonder if one could do aftermarket modification from 44T chainring to a smaller 36T or 34T for better climbing experience? Many thanks.

Fab video thank you! Perhaps a further consideration if cycling in muddy or off-road conditions is that a hub gear system is less likely to get ‘stuck’ than derailleur, particularly when it’s so very close to the ground?

I put a 42 tooth Campy GS crankset on my 6 speed. Schweet!

Massively informative as usual.. Really going to have to look replacing the internal hub on my 3 speed as the weight to gearing ratio is the worst out of all of them. Unsure if I go for a aftermarket derailleur solution or go for a 6 speed hub. Really its naughty that brompton make two different internal hubs that weigh roughly the same but then force you to buy the BWR to get the two sprockets rather than just putting it on both models which gives you the chance to upgrade. Guess they need some incentive for people to go to the 6 speed as a default..

Thank you for your wonderful illustration! May I seek your advice: currently running a 54T 3speed SA for fitness riding (20-45km, x 2 per week, average 22km/hr over 1-2hrs) at relatively even terrain (parks & road) I am keen to get the P line to improve my performance (to cycle further & longer & perhaps fill the gap of a missing gear (betw 2nd & 3rd) when fatigue sets in. However, after watching your video & realise the 177% vs 164% gearing range, I am a tad hesitant about the earlier intention. Would love to hear your opinion with your vast experience! Thank you ;)

A nice explanation, particularly of the effect of varying power output on hill climbing - very good to relate this to gear choice as well. One question - am interested in your foot position on the pedals. We are normally taught to use the forefoot (or at least I was!), but you are using your mid foot on the pedal. It would be helpful to know why - perhaps I am doing it wrong?

Excellent video. When I was riding my Brompton M6R with 50T on the hill with 10%, I know it’s time to get a 44T. Just wonder what will the curve be at 6:31 when using 50T, how long does it takes for people to be exhausted with a 50T🤔🤔? And I guess also having a 55/34 traditional crankset for T-line probably will be an excellent option to turn it to an amazing bike with wider range, lightweight and performance. Thank you for your wonderful video again!

This video is Science. You have been Korea! I Love you. I am Korean 😊

Hi. Would you consider using a aftermarket 53T/33T chainring to give more gear ratios? I can’t wait to have one. It helps with touring and climbing.

@2Bikes4Adventure If I change the p line rear to 11-13-17-21 what would the gear range % be with either the 50 or 44 chainring? I’m thinking of improving it for climbing but not losing too much top end speed. Thanks.

What is your opinion on having one of those dual chainring (an extra small ring for climbing) for the 6-speed C line? I've read and seen some setups where there's no derailleur but they just use their hand/foot to swap rings.

Hi, I have recently discovered your videos and I was impressed by the knowledge and the way you explain things. I've just bought a Brompton P Line (because my first priority is the weight and couldn't find the t line anywhere) and I find that the gear range is too narrow for me. I often find myself frustrated when I can't take advantage of a downhill to reach full speed. I was thinking of the following options: 1. (ideal) Increase the number of sprockets (e.g. 5 or 6 total sprockets) to increase the range. I guess I would have to choose sprocket sizes that make sense, in order to cover the whole desired range (preferably similar to the 6 speed brompton). You think it would be possible? Would it require to make any modifications to the rear triangle (e.g. widen it) ? what would be the most lightweight way to do it? 2. (good) Keeping the number of sprockets the same (i.e. 4) but choose different sizes so as to increase the range. Would that be possible? and what kind of range do you think I could reach, keeping a satisfactory overlap between the four gears (as per your video) ? What would be the most lightweight option here? 3. (least preferable) If not possible to change the range without adding considerable weight or irreversibly altering the frame, perhaps I should shift its current range upwards? Would getting a 54T chainring mean that I could go faster downhill but would have to put more effort while climbing uphill? Thanks in advance!

I wish I could try, will need a bike to take me to and from work over the 59th street bridge. I'm 57. Would prefer the P line but not sure the 4 gears would work out for me...

Awesome, I wanted to look up your previous gearing video as my brompton tour in the hills did not go as planned and I was curious if I should go with 44t or maybe check for even smaller 3rd party options. Thanks for that perfect timing!

Do you have any advice in terms of gearing for riding through beach sand? Maybe wet sand. I know ocean spray isn't good for things like steel bikes, but it would be useful to me for certain activities where riding on the beach is necessary. I have thought about fat tires for this purpose but haven't tried yet.

for P line , will there be any difference changing the cog from 11-13-15-18sprocket 50T changing to 11-13-17-21 sprocket 54T chainring?

how do I know whcih C bike is 40T or 55T? edit: I couldnt find the info on bromptons website and I nerd the lower gear for the hills in my city

I got a C Line Urban for my commute to work. My commute is less than 3km, and there's only one hill of any significance; it's less than 250m, and depending on the stoplight at the beginning, I can generate enough momentum to fairly easily handle the first 1/3 of the hill. So for me, the C Line Urban was the perfect solution. That being said, I come from a road cycling background, and am used to covering distances on the road much faster; I tend to turn taller gears with relatively lower cadence. Do you think upgrading to a 56t chainring (I believe my bike came with a 54t ring) would make a noticeable difference?

Going to need a 12x video soon!

Was this at the Brompton Junction in NYC?

😍

I checked T line on Brompton's website, and the only 2 models available have gears… I'm looking for a model to carry on the bus daily, A line 3 gears seem interesting, despite the Dahon Marine D8 looking more attractive…

Hi , it’s really a great video i watched it nearly 10 times its really useful, but i hsve s question , how to know the meter of development of an internal hub lets say, because the gear ratio alone in percentage doesn’t give us a view if the hub offers less than 2 meter of development in order to be good for climbing . Let say im thinking to put a sturmy archer 5 or 7 speed on brompton how i know if its meter of development is less than 2 ?! In website they just talk about the gear ratio !

I’m surprised by the difference in overlapping between the 2-speed and the new 4-speed cassette. Don’t you think the new 4-speed could be easily and conveniently spread out so that it’s both faster and easier on hills? If not, why do you think they made it so “narrow”?

My advise for gear selection: 1. Do you climb hills, strong head winds and are you not as strong? Buy the 6 gear system. 2. Do you ride in the city, less then 5 km/ 3 miles? The 4 gear system will do if you are not so strong. The 2 or 1 gear if you are strong. The 3 gear is not useful, the gears are spaced too far apart. So the gear 3 you will seldom use. Unless you change the sprocket to a bigger sprocket or a smaller chain ring, so you can use gear 3 as well. 3. Do you use your Brompton for touring with luggage. Buy the 6 gear.

I have got a 6speed 44T equipped, but the two highest speeds are anyway too strong to push.... I hope Brompton would realize a 39T-40T in the future.....

Can you put a 44T on the p line?

6:06

Nice video. Current T line -stock 50 T chain ring can only be upgraded to a 56 T chain ring via Brompton i.e excluding 3rd party chain rings. I’ve notice I tend to spin out easily on the stock 50 T so upgrading to 56 T.

The P line’s gearing is disappointing.

Makes no sense to me who knows nothing about bike gears.