edwong3

You know, I've been eyeing the Brompton A-Line as a possible purchase. Birthday is coming up in October and am finnishing an online degree, so I thought that would make a perfect "excuse" to splurge a bit. One concern I have is that there is this hill that you have to go up in order to get to my street. It's not really steep, but it is nearly 1/4 mile long and since I am now in my 60s and not as strong as I used to be, I wonder if I will be able to make it up that hill when going home. It would suck and be a bit embarrassing if I have to walk the bike up the hill. Imagine me, and my fancy new $1,200 bicycle doing just that.

I have read elsewhere that it is a bit of a challenge getting up even moderate hills with the stock gearing the three speeder comes with. I watched a video on YouTube made by a guy who bought a new Brompton A-Line, and he switched out the rear cog to a 15 tooth. I could be wrong, but it seems like he mentioned it was an 11-tooth stock.

Has anyone done this modification to their 3-speed Brompton, and is there anything I need to be aware of?

Thanks in advance for any information. Have a great day and ride safe!

Edward

P.S. Alternatively, I thought about maybe spending a bit more (Actually $1,000 more!) and will also consider the C-Line Archive edition which comes with the roller rack, front carry block, fenders, and dynamo lighting, and since it too is a 3-speed, the same modification applies. Thanks again.

tcs

The Brompton A uses a Sturmey-Archer 3-speed with a 13T sprocket and a 44T chainwheel. This gives 42, 56 and 75 gear inches in the three gears. I don't know you or your hill, so I can't speculate if this will meet your needs.

You can play with this gear calculator to see the effects of changes:

https://www.gear-calculator.com/?GR=...26,34&UF2=2220

IIRC, you can go up to ~19T 17T* sprockets and down to 39T chainwheels. These are commonly available, inexpensive aftermarket parts from many sources. Fitting a larger sprocket will require a longer chain; a smaller chainwheel will require shortening the chain.

Lowering your low gear will also lower your high gear.

Walking up a hill is no big deal.



PS - the Brompton C-Line Explore 6-speed is le$$ than the 3-speed Archive. Just sayin'.


*18T with a minor modification

Winfried

It's simple and cheap (clamp + derailleur + shifter + double crankset ~$100) to add a double chainring.

It ships with a 44T chainring and a 13T cog, giving 42.2-74.9"/3.36-5.98m.

Adding a 28T chainring (16 teeth difference) would provide a first speed of 26.8"/2.14m.

edwong3

Thanks for the reply TCS. I also appreciate that you included the gear inches for the Sturmey Archer hub. With the lowest stock ratio of 42, I think that might be low enough to get up that hill for me. I am terrible at guessing grades on inclines, but I would say it is not more than 5%. That is nowhere near the 20% grade in the photo you posted. If push came to shove, it should be no big deal to have the local bike shop change out the rear cog for one that is 3 or 4 teeth larger. Probably relatively cheap to do and either add links to the chain or just have them install a brand new one that is longer. Easy Peezy.

As for the alternative that I was considering to the A-Line, the C-Line Archive, I was attracted to it because of the fact that it is a "special edition" of sorts and thought to myself that should I want or need to sell it in the future, I might get close to what I paid for it. It is also nicely equipped but you are right about the 6-speed (C-Line Explore), it is about $400 less with the same accessories. The only downside is that I don't like the available color for that configuration (House Red). We'll see.

Thank you kindly.

.

edwong3

Hello Winfried. Thank you for taking the time to post a reply. I now have a clearer picture or what I am going to do should I decide to pull the trigger and get the Brommie. I would not touch the chainring and go instead with just having a bike shop change out the rear cog for a larger one. I might find that even that might not be necessary if I am able to handle that hill to get home. I will find out I guess by trying it.

Thanks again for your reply.

Jipe

Brompton is making easy money with many "special editions" that actually do not have any advantage wrt. the standard models.

And several "special editions" became permanent special edition lasting forever like the black edition or the CHPT3 that repeat with some differences every year.

edwong3

Well, Brompton is a money printing machine as you know. Just like Rolex, Louis Vuitton and other "luxury" brands that offer no extraordinary advantages over their more common counterparts.

I think since this would be my first Brompton, I should just stick to getting an A-Line. At just $1,150 shipped, it will take me to all the places I normally go to that a $3,000 one could. Just some advice to myself.

Joe Remi

I agree that you'll probably be fine with the stock gearing. If not I found the 3-speed to be WAY overgeared on the top end, I don't think you'll mind much if it gets dropped a bit.

edwong3

Hey Joe. Thanks for chiming in. Just today, I went for a short ride on my e-bike and as I was going back up Livingston Street (that's the hill), I couldn't help but think to myself what a huge difference in pedaling effort between the bike I was riding (which is effortless) and something like a three-speed Brompton. Now I am really curious.

Yes, a top gear ratio like a 75 inch is quite high since I don't ride fast. I like to cruise at 10 or maybe on a good day, at 12 mph, it seems almost redundant. As stated in previous posts, I could have a bike shop change out the hub's cog to say something like a 16 tooth, and maybe that could prove to be the "sweet spot:" for me.

I still have yet to pull the trigger, so we'll see.

edwong3

When I first started this thread, I had posted my concerns of whether the first gear on the Sturmey Archer would be low enough for climbing the hill to get to my street where I live and found out just yesterday that the A-Line comes stock with a 44 tooth chainring instead of the more common 50 tooth one. This represents a 12% reduction ratio by default. I know that people pay extra to get that done to their bikes to have better hill climbing but Brompton took care of that. I think that the A-Line is looking better all the time. I am not looking for either a "speed machine" or a "touring machine", just something to get me around my little universe, (shopping, restaurants, dollar stores, fun pleasure rides, etc.) That unmatched folding is perfect for what I need.

jfouellette

My Dahon Glide is in the shop for maintenance and I decided to get the rear sprocket replaced with a larger one to improve the hill climbing abilities. Since in has an eight speed Nexus hub, this is the easiest way to lower all the gears. I prefer having a better time going up than going fast downhill. I did the same thing with my trifold with a three speed Sturmey Archer hub but replaced the chainring with a smaller one.

edwong3

Thanks for chiming in "j". Good looking Dahon by the way. As a male, I have always had a soft spot for step-thru bikes long before they stopped being identified exclusively for women.

Good move in deciding to lower the gearing as it will prove to be better for the knees. I don't know your age, but I am now 62 and no longer "invincible". Yes, the years going by teaches you that we are after all just human.

Please come back and let us know how you like the modification. It is good to see the other perspective to those who feel that box stock, bikes are too "under-geared". If they have the legs and good joints, more power to them. Me, I love to tootle around pedaling easy gears without trying to break speed records.

jfouellette

Here is the update. The original sprocket was 16, the new one is 20. From my perspective I’ve gained one to two lower speeds and lost the same at higher speed. In other words I can now go up hill more easily. This was a good decision. We are close to age. I ride in the city so I’m regularly stopped at red lights. There is not much use in going fast to get to the next red light. It’s just like driving a car in the city. BTW, urban bikes need to be different from road bikes. They are used for different reasons and need certain functionalities that are not offered much in North America.

edwong3

Hi Jfouelettette, Thanks for the update. Sorry it took so long to respond but I had a lot going on with finishing a degree program. Now that I am finished, I can go back to my "normal" life what-ever that means.

Good to hear that you like the mod. To me, a bike that is easy to pedal is more fun to ride. Just my personal opinion.

Thanks again for stopping by. Happy riding.

GoodShipRuffles

Just my opinion. Three gears is best for a Brompton. Never found a hill I can't get up.
And for a bike you'll use all the time keep it standard and the maintenance will be easier. Standard chain and cog.
Also, they really ride best with weight on the front. Otherwise it's a bit like a BMX!

edwong3

Thanks for your input. I haven't decided to buy the bike yet as I am trying to justify making the investment. Funny that you did mention the three speed version as on the US Brompton website, the "Archive Edition" that I mentioned at the start of the thread comes with the 3-speed hub in addition to the rack and dynamo lighting. It is the best accessorized model out-of-the-box but quite pricey at $2,150 USD. I can handle the payment, but do I want to? interesting thought. As to the last part of your comment, I never had a problem with the handling of a BMX bike, but I get your point. They're fun.