chagzuki

I would consider a CSS rim on a Brompton... not tried one before and some say the don't brake well in the wet, so perhaps not a perfect solution. Plus they're a bit heavier.

Tsuru

I looked around at other rim brands for sure. They have some lovely ones out there you can get made for you. But I think for me, when I thought about the extra friction a small wheel goes through to stop the same distance, disc brakes really seemed to make the most sense to me. I'm very very curious how the E-Brompton rims are going to hold up, assuming you get extra speed out of them vs. normal casual riding.

Honestly, I really just wish Brompton took inspiration from some of the amazing mods out there. People have been making discs and higher speed versions of the Brompton. Would be great to see them work on that.

Tsuru

Thanks! Sounds like you and I are of the same ilk in this case. I really hope it will last. I'm about to move to Hong Kong and I'll be taking the Tern with me to hit those mountain side (I hope), so we'll see how it holds up!

tmesis

Hi Aaron,
I've read and enjoyed your previous articles on riding your Brompton. As you say in your new article, I think Bromptons make the most sense for multimodal commuters, so I'm glad you found a bike that better fits your needs.

Tsuru

I love my Brompton, but I do think some stock parts are pretty cheap. Some of this may have improved on the 2018? Not sure, but on my 2016 S2L, the handbar grips were that cheap foam. that and the seat were the first to go (but that's because I have my Aliante that fits my bootie perfectly). I do think the little plastic derailleur with plastic gears spinning on plastic is also an odd cheap choice. Taking that apart and cleaning it was a mess, lol, and I wish it spun with less friction. I looked into a better one, but the NOV and other 3rd party derailleurs were just too expensive. That's where the 3spd internal shines, you just have the tensioner. The spring suspension is nice, but got squeeky a lot. And obviously, I wasn't a huge fan of the rim material, but that is mostly my problem, not Bromptons...

As for hammering the Tern, the Verge series I think is designed for "road cycling". But we'll see... maybe 2 years in the bike will be laying in my apartment in 2 pieces? *fingers crossed*

Tsuru

Thanks! That's the goal! To help people find the right bike for them. Cheers and happy riding!

Joe Remi

Ah, good point about grips and saddle..I change mine on every bike to Ergons and Brooks B17 immediately so I didn't think of that. The 2017-and-later models have nicer lock-on grips.

The bolt inside the shock needs to be greased occasionally, especially in the weather conditions you ride in.

tds101 

I still don't think I'll get a Brompton now,...meh,...

bmac.to

This is what I moved to - I got sick of rebuilding my Brompton wheels (7 new rims in 6 years - avg of 3000km per year in all conditions - used as my commuter so no maintenance, just new pads regularly). Both the CSS rims now have over 2000km and I cannot see any signs of rim wear. I have been using Koolstop's CSS specific pads which seem to need replacing every 1000km or so. Braking in dry is the same as before - wet braking is totally fine except you need to squeeze a bit harder than expected (your heart misses a beat the first few times you ride in the rain).

2_i 

To throw in a piece of data, when I bought my Trek 730, top hybrid in Trek line-up, I paid for it about $400 new. It came in with, in looking back, pretty low level components. In commuting on it practically every workday over 4 seasons, and loading it heavily, I had to change the wheels every 2 years and brake pads every 6 months when going with similar level components as original. In scaling it up to a Brompton it is plausible to end up with the price for which Brompton sells, life of wheels at 1 year and life of pads of less than 6 months, given the wheel size reduced by about two. I stabilized the Trek situation by investing in quality wheels that last 10 years on the bike and better quality brakes where pads last about 2 years. I use the Brompton primarily for travel now but if were to commute on it loaded day in day out, I would expect to invest in the sturdiness, though presumably I would wait to see what yields too often to tolerate.

dahoneezz

Joe Remi

I'm not trying to sell you a Brompton. People who want Bromptons should buy them, other people should not.

Kabuto

Just occurred to me that Tern's logo is ... <drumroll>.... a tsuru!. One that folds, obviously.
Best of luck for the move to HK!!

Tsuru

I know!!! Oh man, but I didn't notice it until I got it and was gobsmacked. The fates brought us together.

Tsuru

CSS is a coating, if I remember right, that you can get on some wheels. Ah, found one - https://www.sjscycles.co.uk/rims-tap...illed/?geoc=US

I don't know if the stock Brompton wheels were single or double wall.

Tsuru

That's awesome! Where did you get the rims? Sounds like a great solution.

tds101 

LOL!!! I know you're not trying to sell me a Brompton,...I'm just sayin' is all. Chill my friend,...

With all the $$$ required to do repairs when there's issues, and with me there will be, I'm turned off by it. I'd rather deal with my Dahon, Tern, or even Origami folders. Repairs are much less expensive, and way less proprietary. It's good for some, but I now realize it's off my plate.

berlinonaut

Brompton was using single-wall rims until the end of 2012. Over the years they changed the rim model several times. With older Bromptons before the MK4 of 2004 rim wear was more of a common issue than with later ones. Since about 2007 or one or two years earlier they were using rims with a wear indicator. Since 2013 they are using double-wall rims on all models (same rims no matter if x-light model or not). Front and rear-wheel rim are since then differently drilled and no longer exchangable with each other due to the way the spokes are built into the wheel (which makes a difference on double wall rims). The rims do no longer have a wear indicator.

Regarding the problem of the op it would be intersting to know which rims wore (front or rear wheel) and if they wore through or what was the indicator to change the rims.

The (inner) circumference of a Brompton wheel is Pi*349mm which equals 1096mm = 1,01m.
A 20" wheel has Pi*406mm, equals 1275mm = 1,27m
A 28" wheel has ETRO 622, thus equals 1954mm = 1,95m

So in theory rim wear on a Brompton wheel should be roughly 20% more than on a 20" wheel and roughly almost double of a 28". It may be a bit more due to more dirt on the rear wheel. Brake pad wear should in my opinion not be different as it does not really depend from the wheel size if the speed to kill is the same.

With 28" wheels rim wear is not a big topic as far as I know - 40.000 km and more are common. So if someone wears through a Brompton rim every 3000km or so like bmac.to or the op it would be interesting how the situation is/has been for them with bigger wheeled bikes.

From experience: Typically on a Brompton the rear wheel is more prone to wear due to road dirt in combination with dirt from the drivetrain. Personally I never managed to wear through one of my Bromptons' rims in many years but I have the unfair advantage to have several Bromptons to choose from plus several other bikes. Still my Bromptons all have at minimum several 1000kms on them and the one I used the most over the years should clearly have more than 10.000 kms.

Regarding the Brakepads: My 2008 model had Fibrax pads that lasted about 8000 km (on the single wall rims) before I exchanged them. Again Brompton made several changes of the pads over the years and the ones on my newer Brompton definitively do not last as long. But as the Pads are Shimano compatible there should be not really a difference to other bikes if you use the same pads.

Regarding the drivetrain the stock chain seems not to be of the highest quality but any 8-speed chain will do - plenty of brands, models and quality levels to choose from. The sprockets on the 2-speed are the weak point - especially the 12t does wear relatively fast, especially in comparison to the wider and bigger 15-t one on the 3 speed.

I am curious how wear will develop for the op on his tern - rims will obviously no longer be an issue and break-pads (knock on wood) less than before. But the drivetrain and especially the chain would be of interest - I'd be curious if he could share his future experience in that regard.

Tsuru

Great post! It was back failure, then front, then back. The first time it happened, I was not aware of rim indicator, so I chalk that one up to me being stupid and lazy (for not staying more vigilant). As the front (and later the 2nd back one) started to fade, I was cleaning and trying different braking methods, (pumping, doing front, then back, etc, anything to keep them "cool", different pads, the works) I saw the rim wear coming, but the bust through still would surprise me. There's a pic of the wheel in the review about a 1/4th the way down. https://medium.com/off-the-verge/i-t...o-dc501057755c

Joe Remi

Maybe this wouldn't make any difference, but it might be good to work on some "pre-braking" techniques so you're not loading all the heat in there in one big grab of the levers. There's no way to ease up on acceleration and pedaling without screwing up your riding style, but I suspect you're going to go through pads and rotors pretty quick. Even in my car I've perfected the idea of getting some braking done to about half speed, ease up for a couple beats to let the rotors "breath", then back at it to finish the stop. I could be wrong, but I suspect you're going like hell to the bottom of the hill, then grabbing a big handful and praying!

Abu Mahendra

The basic issue regarding rims is not framed correctly. The amount of energy generated in braking is a function of momentum, mass x velocity. For a given mass and velocity, the energy to be dissipated in braking is the same regardless of the wheel size. In smaller wheels, however, the energy dissipated and the mevhanical abrasion is spread out over a smaller surface. That's the rub.

The author does himself no favors when he declares plainly that small wheels generate twice as much heat. That was a point in reading the article that immediately gave me pause. That point is conceptually flawed. He didn't want to do the math; now we know why. Again, the energy to be dissipated in braking is dependant on the mass and velocity. Once we understand this, a question that naturally emerges, germane to the issue of rim durability, is - how much does the rider weigh? Tsuru, how much do you weigh?


* Mass/weight is fundamental to the earlier issue of tire pressure, and now to rim durability. Tourers understand this better than most because touring involves loading the bike, and this has implications for the choice of wheel and for braking. For example, a touring rim is not a touring rim because of its load capacity only, but also because of its beefier sidewalls. Hopefully Tsuru, unlike another, will be forthcoming with his weight so we can ground the discussion on quantitative indicators, rather than spurious suppositions, subjective perceptions and beliefs.

2_i 

It should be twice the heat per rim length - that is presumably what the author meant. This further leads to twice the temperature difference compared to surroundings. There is also twice the abrasion per rim length if the temperature and everything else stayed the same. With increased temp, a twice as small wheel should wear more than twice as fast. On the other hand, a smaller wheel is more rigid, so maybe there is some compensation there.

Abu Mahendra

Even the factor is off. 622/349 = 1.78. 559/349 = 1.6. But again, let's not get distracted by this. The take-awats are:
1. The energy to be dissipated in braking is given by mass x velocity
2. Mass/weight will have an impact on rim durability

The mass of the system is of fundamental importance.

Joe Remi

Frankly I think all the math about rim size is a diversion from braking technique. Replacing a 16-inch rim with a 180mm rotor isn't going to solve the diameter issue, so a rider is going to have to learn to either take care of the brakes better, or spend a lot of money on brakes. This is true for cars and motorcycles, too.

Abu Mahendra

braking technique can help, but it does not undo the underlying physics. It's not either/or. If you truly understsnd the physics, you will understand that a disk rotor can provide a much larger surface area on which heat and abrasion can be dissipated. And a worn down, abraded rotor can be replaced, and has no bearing on rim condition.

Braking technique - i grew up in NYC, and cycle 9ften in dense urban areas. In these environments, there's lityle chance for feathering. It's hard breaking, or you're plowing into things or people. That's the nature of the city.