GlowBoy

I just started a thread asking for help choosing a folder with disc brakes for daily commuting. There were a number of responses questioning my "need' for discs; I'd like to keep the other thread confined to the original topic, so I'm opening a discussion here to debate the actual merits of different braking systems on folders. I got a lot of interesting responses, and I do want to respond to them because although my experiences give me a pretty solid belief in discs for wet weather, I do think it's a conversation worth having.

So is there something about 20" wheels, or folding bikes generally, that makes rim brakes work better than on bigger-wheeled bikes?

A little background on my experiences and how in the past I have not found rim brakes to be acceptable for my commute. In the early 2000s I used to ride a cyclocross bike; but I upgraded it to V brakes (with 287v levers) when I found the Avid Shortys just weren't up to the job. Big improvement, and they worked great in the rain -- as long as the rims were clean and the pads weren't glazed. Problem is, after a week or two of riding in the rain my braking performance would diminish. A LOT. In a panic stop I'd grab a handful of brake and have to wait a second or two -- a couple of wheel revolutions -- before I'd have enough braking power to lock the wheels. When I'm rocketing down a hill at 50 ft/sec, or cruising downtown and panic stopping from 25 ft/sec for some idiot who pulls out in front of me, that is unacceptable. I could restore full braking performance by scrubbing down and cleaning the rims and pads, but having to do that once every few days is not acceptable either.

The other problem was pad glazing. Even with the ridiculous maintenance task of regular rim cleaning, after a few weeks of riding down 1000' hills I'd find the pads glazing up, and to restore full braking I would have to attack the pads with a file to remove the crud. And that was with red or blue Ritchey pads -- the problem was even worse with harder pads.

I converted to discs for commuting more than 6 years ago, and I haven't looked back. They solved all of my problems: maximum braking is instantly available in any conditions with a single finger on the lever. Disc brakes have become standard equipment on nearly every dedicated commuter bike above the $1000 price point or so, and that price cutoff is dropping steadily; that's been particularly true in this bike-crazy town where discs have particular advantages. While the bike industry is highly susceptible to profit-generating fads, I've been pretty well convinced by my own experiences that this particular trend is functionally justified.

To those of you who are commuting in rainy, hilly urban environments with rim brakes: what's your magic bullet? How do you keep rim brakes working well enough for optimal safety? Or is there something about the physics small wheels that makes rim brakes work better? Or are caliper brakes such as on the Brompton that much better than Vs? Or is it just that disc brakes another thing like the Internet or smart phones or quality beer -- if you've never experienced it you don't really know what you're missing, but once you have had it you'll never go back?

GlowBoy

Wow, that's quite a testimonial. Are the Brompton's calipers just that much better than V-brakes? I haven't ridden a road bike with calipers in many, many years, but I've definitely heard from roadies who think they're a lot better. I will also check in with Clever Cycles in town, who no doubt field the same question on a daily basis, and see what they have to say about Bromptons in our conditions.

Even if the rims are dirty and the pads are glazed? Instantly? I sure tried to make rim brakes work for me and with the day-in/day-out grime I just couldn't. I'm honestly not trying to be hostile or defensive, I'm just trying to learn about others' experiences. Maybe I was doing something wrong.

fietsbob

add that I've seen a re machined Drum Brake that Greenspeed the Australian
recumbent trike manufacturer and Brompton Distributor down there
It fits in the 74 wide fork of the folding bike.

[Greenspeed cuts an X-FDD hub in half , drills spoke holes
in the side face of the drum] so it's then quite narrow.

example:
https://www.wrhpv.com/small_stuff/hub...eel/index.html

that cures the front rim wear .. then there is just the rear hub to go, Sturmey has IG hubs with drum brakes

may require some Mods to get in the 8 speed version into the rear section, but is certainly possible.
A Glasgow UK dealer has been doing a brisk sales of Modified 8 speed hub and small sized cranks in Brommys.
[33t as, other than the low direct ratio, all the other gears are overdrive.]

bendembroski

I'm sure some of the more technically astute members are about to chime in here, but I'm pretty sure that rim brakes are actually at minor disadvantage on smaller wheels.

For a a given speed, the wheel is making more revolutions, so more wear, heat build-up, etc on the pads / rim.

Any particular reason you aren't considering the 3rd option, drum brakes? No performance drop-off in the wet. Nice and tidy package on a folder. Practically maintenance free. I personally haven't experienced any fade on big descents, but I've heard stories of it being a concern (sorry, can't remember where.).

fietsbob

the current brake on Bromptons is a dual pivot. I put Salmon compound Kool Stop Continental shoes
on my 94 made Brommy , that helped .. and mine is fitted with CLB made for Brompton, single pivot brakes

Standalone 

I ride a 26" folder. Dahon Espresso. Commuting beats up wheels anyway, so by the time a new rim from brake wear would be in order-- well-- the rim has taken enough hits otherwise that it might as well be replaced.

My dahon cost me $190 used. 2 years commuting, 10-33 miles/day 2-3 days/week. Rims are still ok. A new front will be $100 or so. NBD.

bendembroski

Kinetics. No affiliation, just a happy customer. He set-up my Swift with a front / rear drum & IGH. I talked to Ben (Owner of Kinetics) about setting up a Brompton similarly, and in addition to respacing the rear for the IGH, the fork would also need to be spread a bit to fit a drum brake up front.

Russcoles11

Modern rim brakes work well and should be perfectly satisfactory for most peoples needs. The only real issue is they wear out and need adjusting etc which is a chore and some people just have trouble with them. Rim brakes are less effective on smaller wheels as the rims are rotating faster to do the same speed as a larger wheel.
I have a Fold-it with front and rear drum brakes, these are amazing. Early drum brakes had a bad reputation but modern ones are exceptionally good. Like disc brakes these work better on smaller wheels. Drum brakes add a bit of weight but almost never need any maintenance. Sturmey archer make drum brakes with 3, 5 or 8 gear hubs or for single speed, there are even versions for cassette hubs.
I have never used disk brakes but I imagine the performance is similar to drum brakes with less weight and more maintenance issues (still less than rim brakes).

GlowBoy

OK, so I hadn't really considered drums. I've heard a lot of complaints about them, but mostly from (1) mountain bikers who've used them and (2) riders of cargo bikes. The latter are exceedingly popular in Portland now, but many of their owners are finding their expensive drum-braked Bakfiets from the Netherlands to be frighteningly inadequate for our conditions. It's not the rain, obviously, because drums are impervious to that. But unlike Amsterdam, Portland has a lot of hills, and American conditions involve higher speed riding and sharing the roads with MUCH less conscientious drivers. Many are finding drum brakes simply not up to the task of panic stopping 300-400 pounds of bike, rider, cargo and child down from American street speeds when some SUV pulls out in front of them, and are having to ride much more conservatively than otherwise necessarily simply due to the long stopping distances. My neighbor, a serious bike geek employed in the industry, has gone to the (considerable) effort of upgrading his Bakfiets to discs as a result.

But again, mountain biking and cargo hauling are a lot more demanding of brakes than commuting. Maybe drums are up to the job for commuting? That would enable a much wider choice of bikes, not to mention dovetail nicely with the addition of an internally geared hub (not a necessity, but something I might consider).

About the "all hub brakes work better with small wheels" ... OK, as a longtime rider of 29" wheeled mountain bikes I have observed and participated in a LOT of "discussions" (you know, the Internet kind, which sometimes get a bit heated) about the effect of wheel size on hub braking systems (which are now used on nearly all mountain bikes). One camp points out that a hub brake on a 29"er will need to exert additional rotational force to achieve the same braking effect against the larger wheels' additional leverage. The argument goes that a larger rotor is thus needed, and many 29" owners (including myself) have therefore opted for 7" rotors instead the 6" standard on 26" XC bikes; and some heavier or more aggressive riders already on 7" rotors have gone to 8" when they switched to the bigger wheels.

But the other camp makes a good point too: although less force is needed at the hub to slow down a smaller wheel from a given rotational velocity, the fact is that smaller wheels rotate a lot faster at a given bike speed, negating that advantage. Although I was in the first camp for many years, I have ultimately become convinced of the latter point of view: that wheelsize effectively cancels itself out of the equation, and is irrelevant.

But my opinion is based on lengthy discussions based on everyone's (variable) knowledge of physics, NOT truly on actual experience. The difference between the two mountain bike wheelsizes is only 10%, and most people would be hard pressed to discern a 10% difference in braking (or lack thereof) between two different -- and usually differently equipped -- bikes.

On the other hand, a typical 700c bike's rotating stock is a full 33% bigger than that of a typical 406mm bike. If wheelsize does make a difference in the effectiveness of hub (or, for that matter, rim) brakes, it would be much more apparent. I'm open to the possibility that drum brakes might just be capable of locking up the wheels from high speeds when the rider is <200 pounds and not subjecting the bike to the kind of repeated braking that you seen when mountain biking.

GlowBoy

That's a concern for me too, as my armchair physics knowledge would tell me that rim brakes would be a few percent less effective on small wheels than on big wheels. And I did NOT find rim brakes to be satisfactory for my needs even on 700c wheels, at least for extended use in grimy conditions.
Chalk up another testimonial for drums!
No real maintenance issues to speak of: turn the knobs every couple hundred miles to adjust for the pads' thinning as they wear, and replace the pads every 1000-2000 miles. Unlike with rim brakes, replacing the pads only takes a few seconds, and doesn't require any readjustment other than backing the knobs out a few turns to compensate for pad thickness. That's it. I would think that drum brakes would have more maintenance issues than discs, due to the necessary repacking if the grease overheats. (We mountain bikers all know how Repack Road got its name!)

BruceMetras

You won't be happy unless you have disc brakes.. so narrow your search to bikes that can accommodate disc brakes, folds decently, rides well, sturdy, doesn't cost a fortune.. You're in Oregon, so it just seems a no brainer.. BF customer support is legendary and they build to suit.. call them up and tell them what you want..

bendembroski

Re: Less conscientious drivers: You should come hang out in Glasgow some time

I've ridden a bike with mechanical discs before, so I can make a couple of observations based soley on my experiences. I'm no mountain biker. I only ride with my kid(s) in tow on the local MUP, and a mix of mostly urban commute type riding and the occasional jaunt into the hilly countryside. There are a couple of bits in town where there I can easily see about 30 MPH bombing down a hill, and there's always somebody pulling out / doing an impromptu U-turn or something right in front of me.

Me + bike + bag on rack weigh something in the 'hood of 230-ish lbs. I have never had a problem with the drums stopping me well enough. If anything, the issue is always the tyres losing grip in the wet. However, I do have to grip the handles HARD when I do a panic stop. The brakes feel really progressive, so one of the things l like about them is they are easy to modulate in slippy bits.

I've done 600 ft descents with no perceptible fade or overheating. Then again, I am not an aggressive rider. As with all things, your mileage will inevitably vary.

They are relatively heavy though.

However, the thing I like the most about them is that I never have to think about them. I've adjusted them once in the 500 odd miles I've run them. On trains, in and out of the back of the car, whatever, I never worry about things breaking. Although I wasn't thrilled with the perfomance of rim brakes in the wet, the biggest reason I switched to drums and and IGH was I was spending too much time futzing and cleaning stuff. As much as I like getting my hands dirty, I really need my bike to just be ready whenever I need it with minimal fuss. This setup does that for me.

badrad

although not a folder, but it's a really cool 20 inch with disk brakes:

https://www.cannondale.com/usa/usaeng...HL3-Hooligan-3
nice ride.

chucky

There are many different kinds of drum brakes. The good designs don't use grease, but pads. I also suspect that people having difficulty with drum brakes on their Bakfiets have traditional steel vs modern aluminum hub shells. If so then I'm not the least bit surprised with their dissatisfaction because we all know how well steel rims work as a braking surface.

As far as maintenance for drums...there really isn't any. You adjust the cable when it stretches and replace the pads probably as often as you'd replace your disc rotors.

I also doubt there's any weight penalty for using a drum vs disc if you use a normal fork vs a disc fork. Besides, on an odd bike like a folder you might not have many fork choices anyway.

Bacciagalupe

I hate to break your stipulation, but...

As far as I know, disc brakes aren't available on folders.

And you don't need them. Just get some good pads, quickly hose off your bike once a week and you'll be fine. I'd guess that most of your problems were due to dirty rims.

You also don't really need to lock the wheel. Unless you actually enjoy endos.

If you need the convenience of a folder, then just get one and don't worry about it. People have successfully and happily used rim brakes on folders for over a decade, in all sorts of weather and for all kinds of uses.

One last thing; you should call Bike Friday and see if they are wiling to do a build with disc brakes for you. They may decline, but they do lots of custom work so they might actually do it. If they won't, they can tell you why not.

Problem Solved.

GlowBoy

In the thread that originated this discussion, I am deciding between a Downtube, a Swift folder (both of which ARE available with discs) or a Bike Friday (see below).

Unfortunately I have to shut off my outdoor spigot for the winter, which is exactly when cleaning the rims is an issue. So not really a solution, unless I hire a plumber to come out and install a frostproof spigot. Which I may eventually do, but having that decision driven by inadequate bike equipment seems perverse.

And as I've already experienced, hosing off alone won't do it. You've got to scrub down the rims and pads, which is a bigger hassle than the mere act of hosing down the bike. All you're proving to me right now is all the downsides of rim brakes that I remember from big-wheel bikes apply to folders too.

I assume you're being facetious, because any experienced rider would have a deeper understanding of riding in traffic. No, I don't need to actually lock the wheel -- but I need to have enough braking power to do that so that I can modulate the brakes up to just short of locking the wheel. I want it instantly, and not have to get by with only half (or less) of maximum braking for the first second or two. The limiting factor needs to be my tires' grip, not my outmoded 19th century braking system.

People got successfully and happily without the internet for decades too, but I'm not giving it up. I got along just fine without my iPhone until two years ago, but I'm not giving that up either. If you haven't commuted on discs you may well not know what you're missing. But I'm do, and I'm not giving that up unless someone can convince me that somehow rim brakes on a folder can magically work as well in lousy conditions as discs. "Other people are happy with it" is not going to convince me. I'm looking for some tangible argument about rim brakes' actual physical performance on folders, and so far I'm not hearing it.

Now (as you will see in the other thread) I just need to weigh the pros and cons of Bike Friday (after confirming that they will do discs, which sounds likely) vs. Downtube vs. Swift. Three very different bikes, all of which meet my stated "must-have" needs.

invisiblehand

I've seen Bike Fridays with disk brakes. I don't think it is an issue.

bendembroski

I think it's pretty safe to say that if you weren't happy with rim brakes on a larger wheel, you won't be on a 20" wheel either.

GlowBoy

Thank you for the comparison! I've been really hoping that someone who's actually ridden a disc-equipped bike in wet conditions would chime in at some point. It's one thing to say you're "happy with" non-disc brakes when you don't know what discs are like; it's another to have experience with discs and other system and say the alternative (drums in this case) works just as well for your needs.
I'm obviously pretty ignorant of what modern drum brakes are like. Thanks for helping catch me up.

So drums might well be an option for me IF there was a particular folder I wanted that isn't available with discs. So far the only such bike mentioned has been the Brompton. Presumably because of its extremely compact fold -- and while that is amazingly cool, it's not really one of my requirements. I'd probably be satisfied with the folded size of almost any 20" folder. If I could get a Brompton for under $1k I might consider this route, but given that they are MORE expensive than a Friday or a disc Swift, at this point I'm still leaning towards sticking with discs.

chucky

This is being gone over in the other thread. The Birdy has em, some Dahon's have em, Downtube has everything except the rotors/calipers, Bike Friday has equipped them on occasion, and various users have also modified/upgraded their bikes with em.

Of course the problem is dirty rims. That's the problem hub brakes solve, they move the braking surface to a place where it doesn't get dirty so easily.

Also hosing off the bike isn't as easy as it sounds when the pipes are turned off to prevent freezing/bursting. Naturally, this also occurs at the time of year when the roads are dirties and slipperiest.

That's news to me. I thought rim brakes have been the bane of folding bike riders for over a decade. Longer cables, accelerated rim wear, additional rim curvature, and wheel geometry combined with the usual rim brake issues all conspire to create piss poor caliper brake performance for folding bike riders.

GlowBoy

Although I'm definitely still considering Downtube and Swift as well, I will definitely call them up. Eugene (home of both BF and CAT/HPM, which makes the Swift) is only 100 miles away, so I may need to go down there soon for some test rides.
I'm now even more convinced of that than I was yesterday!
Ahhhh ... and there it is! Call it confirmation bias if you will, but THAT's the information I've been fishing for!

jur

Yep forget rim brakes. I commute in all weathers, but lately I am trying to avoid actually riding in the wet due to chain and rim wear.

Rim wear: I effectively stopped using rear brakes, as road grime in the wet accelerates rim and pad wear enormously, while not giving much stopping power from the rear wheel. If used regularly in all weather, rear rims will only give you a few 1000km. Since I stopped using rear brakes except in real emergencies or extremely steep descents, my rear rims have stopped wearing (now on 12,000km on my Birdy and of course the rear rim is literally like new (once I wash it! ), while the front rim is up for replacement.

I would use front discs if I could get them.

Regarding stopping power from the rear wheel, that isn't much, see Sheldon Brown on this topic. So strictly speaking, address the front wheel for which conversion kits exist.

rnorris

Another vote for disc brakes here in the Pacific Northwest. Only speaking for myself, and I can't comment on brakes for smaller wheels, but my experience with rim brakes on 26" or 700c wheels here in the Pacific Northwest echo Glow Boy's. I discovered disc brakes after 30 years of riding here with rim brakes and I wouldn't go back either, except on a road bike that doesn't get much time in the rain.

vik 

If you want discs go for it.

I have used my Tikit as my goto snow and rain bike for 3 yrs. Just replaced a worn out derailleur and cassette. The rims are going strong and should last another 3 yrs without issue. By the time they wear out I'll be ready to upgrade them to some wheel bling!



I live in the PNW and most of my bikes use v-brakes...a few use discs. I don't really see any practical difference in terms of my riding. When it's raining I don't reach for disc brake bikes usually and I don't have any issue stopping nor do I wear out rims or brake pads usually fast.



Most people around here use rim brakes and are fine in the rain. I'm building my GF a new commuter rig that will be her goto bike and it's got v-brakes.

Ultimately do what makes you happy - both systems work.

mtalinm

if you are thinking about getting drum brakes, let me talk you out of it ... at least if you are considering the Shimano nexave. I have these on my Trek Soho and they suck rocks. sure, they work equally well wet or dry, but I would say they work equally poorly wet or dry. they are generally slow to respond and heaven help you if you are storming downhill and need to stop in a hurry.

i think my Swift's rim brakes are better in the rain than the Soho drum brakes. really, they suck. and yes, I have had them adjusted by a reputable Trek dealer