So what elements are custom (or nonstandard) on the Brompton?

EDIT: that wasn't a rhetorical comment. I'm genuinely interested. Here's the ones I know of (besides the frame): the rear hub, chain tensioner, and/or derailleur; cables and the cable gatherer; the pac-man hinge; handlebars and stem, brake assembly, crank, chainring, brake levers, gear shifter, suspension assembly, and various hinges. Did I miss anything? Pedals maybe? Clicky lock-together things?

I think you misread him. He wasn't making that argument... he was showing mulleady that his similar argument in support of the Brompton was bad. Just sayin'.

As for me... I would GLADLY add a Brompton to my stable. Not sure if it would replace my Tikit, but I like both bikes for the various reasons that have already been noted above.
--sam

This discussion will not be the first, nor the last for many more months to come. Sigh!

That is right. Plus any other tool you have to remember to lug along with you. I rather concentrate on the trip, rather than focusing on the bike.

Actually I am more likely not to carry tools with me. While I have done some emergency repairs in the past, more often than not nothing happens. And if it does, when my father was alive and healthy, he would pick me up in the truck and the regular road bike or the old English 3 speed I had at that time went in the vehicle's back. Now that my father is dead and the truck is long ago sold, I have my little folding bikes that can go anywhere like on a bus or train, cab, friend's or sister car, rental car, whatever. Or I have the option to drop it off at one of several bike shops that I patronize and recommend in the Southern California area. I practice a strict following of bike trouble prevention (riding more carefully on the road, buying quality Kelvar tires, no curb jumping, and checking out the bike before I ride anywhere) is the way I prevent almost any problem. The last time I had a flat was almost 10 years ago with my old English 3 speed. The only time I stop now for a bike problem is with one of the Dahons. They always seem to need a little extra tweaking or tightening of the QR latches and levers.

I use my own "credit card" or "emergency fund" when I am out and about, rather than carrying tools. I can avoid any explaining or excuses of being late to an appointment as the bike might be dropped off at one of my selected shops if anything major happens-very rare, if ever-on the way or it is simply left at home as it might prove to be too much trouble to take it with me at that particular time. People are not very tolerant of bikes here in Southern California.

several dealers sell Dahon but, get this, if a Dahon custom part breaks, the Dealers aren't permitted to repair it; in fact they can't even get parts from the company. Instead they are required to ship the bike back to Dahon


A FLAT OUT LIE

Using caps-lock and no punctuation does not make your assertion any less ridiculous.

I discovered this unfortunate fact about Dahons in Italy (or Rome at any rate) when I needed a crucial part for my Helios and went hunting for Dahon dealers: specifically Lazzaretti and Olmo. Instead, I'll be buying it from Thor when I get back to the US.

I thought that one could use a standard crank and BB on a Brompton. I believe standard brake levers and shifters will work too. Although now that I think twice about the rear derailer shifter. Presummably a bunch of different friction shifters would work; but I don't know for sure.

From my standpoint, both the Brompton and tikit have nonstandard front hubs. Although a gentleman recently showed his tikit with 100mm front fork spacing -- I believe it was a special order to fit a Shimano dynamo hub.

I never checked, but I assume that the super long seatpost for a Brompton is Brompton specific.

Oh right, I forgot about the Tikit's front fork width, the same as the Brompton's I think, 74mm. Also used on Birdy and Dahon and Moulton, so nonstandard I agree, but not *that* nonstandard.

Apparently so. Looking it up I found an archived Bike Forums message from "Raxel" which listed it among others:

does a tikit have any sort of suspension, full, front or rear suspension?

No, the Tikit does not currently have suspension. While the Brompton has a rear suspension, I found it made the ride a bit bouncy. Others on this board have suggested that replacing the elastomer on the Brompton would relieve this.

The best suspended folding bike is probably the R+M Birdy.

quite the opposite for me on my brommie...not enough bouncy for me. and i have the regular suspension block and not the firm block suspension. how much do u weight?

I find mine to be a bit bouncy,but not real bad.Standard block.I weigh 170.

and right in the middle of these compromisers/choices is the Mezzo.

slightly bigger folded, but larger to ride than the Brompton.
More adjustable fit than the the Brompton, but not available in different frame sizes like the bike friday. or as easily customised to fit as the tikit.The Mezzo does not have extending seatpost option as standard haowever. Although it fits people up to about 6 foot 3 ish.
About the same weight as a Brompton. Heavier than the tikit
Half Folds on to rack unlike the tikit ,but is unable to hold a front QR bag like the brompton can.
Folds faster than the brompton,but slower than the tikit.
Can be wheeled easier than the tikit but not as well as the Brompton.(2rack wheels not 4)
Is faster than the brompton but slower in standard form than the tikit.
Price is about the same as a 6 speed racked brompton.
In the uk parts need to be ordered for the mezzo ,but they arrive quickly. Alot of brompton bits are held in stock by Brompton dealers. However not sure how many Bike friday dealers there are in the UK.
Mezzo can take more standard parts than a Brompton but less than a tikit. This is due to spefic stem, chain retainers.

Anyway back to the debate........................

Four. Bath, Cambridge, Edinburgh, and Tadcaster.

Great! Tadcaster is just down the road from me.

230 lbs. I'm definitely on the top end with regard to rider weight on any folding bike.

--sam

I weigh almost half that and still find the Brompton mushy in the rear (and the tikit flexy in the handlebar stem). I know everyone praises these two bikes as being the best riding bikes in their class, but I don't share the same sentiment and actually prefer the ride of the Dahon Curve to both (maybe it's cause I'm shortish?).

but compared to the Brompton S type I tried the mezzo is flexy with a fatbloke in the saddle. As for BF, dunno, but given it is available in different sizes would think it is a peach for the like of.

I don't really notice the flex unless I'm up on the pedals riding hard or going uphill. But now that I live on a hill... I notice it a lot more. It's definitely my least favorite aspect of this, or any, folding bike. My Giant Halfway was a little sturdier in the handlepost, but it still flexed. I think it's just a problem with any bike where the handlepost folds down.

I never tested the Curve... it looked to small for me when I saw it in the store. I did try the 20" Mu which I thought was a pretty good bike all around. The super fast folding is what sold me on the Tikit though... nothing I've seen compares to it. Oh... and I got mine at a great price used, that definitely helped my decision. I saved about $400 off a new, similarly equipped Tikit by going through Craigslist.

--sam

I used to notice the stem flex on the Tikit. But I lowered the handlebars for a more aero riding position and it's not as noticeable anymore. Part of it is that I've just gotten used to it.

On the Brompton M class, the riding position is pretty upright and I'm rarely riding it aggressively, so I don't notice stem flex at at all. As for "bounce", I weigh 190lbs and I don't feel much of it at all. Maybe I got a bike with a stiff elastomer already.

Some notes about stem flex in the tikit.

1. If you have a 2007 tikit with the two-cable hyperfold system, get it upgraded. It will significantly improve the flex.
   
2. If the stem seems not only flexy but actually slightly wobbly, there are two main causes of this:
   
   1. Your pac-man clamp isn't on tight enough. You can fix this by tightening the hyperfold cable. Be careful not to tighten too much: you'll put stress on the headset if the headset is loose. You'll also put stress on the hyperfold cable guide (underneath the fork), and it'll eventually start resisting rotation. Note that Bike Friday has guidelines for maximal tension (I know, they talked to me about it. :-) Which brings up...
      
   2. Your headset is loose, which creates a similar effect. Make sure your headset is tightened down (the two screws underneath and the screw above).
3. Stem flex in medium and small tikits is worse than in large tikits because the stem riser (the silver part) is made of 1/3 thinner tubing in the medium and smalls. Ask Bike Friday for a size-large riser cut to a size-Medium or size-Small height. This has a *very* significant impact on the stem flex.
   
4. A shorter stem will flex quite a bit less. I know BF is assuming size-Mediums and size-Smalls are ridden by smaller people, hence shorter stems and need for thinner tubing. But it's a bad assumption IMHO.

In truth, I don't even notice. But there's no doubt that the Brompton flexes far less (because its stem doesn't telescope) and the Dahons flex about 2/3 of the tikit with the same force (because they have a more solid -- but less fun -- stem hinge).

Flex in the seatpost= yes. Flex in the frame ,handlebar stem or frame= no. Sorry I have had one of each of these running simultaneously. Flex in the Mezzo anywhere in the frame or stem is greatly reduced compared to a Brompton S Type. There can be a little "slack" in the folding stem if the pivot tightness is not adjusted correctly on the mezzo.

A Brompton rider rode my dahon Curve the other day and asked if it was suppose to flex as much at the stem! He initially thought there was a problem with headset play.

Neither Dahon curves or Bromptoms are very rigid in the stem aspect. However both improve with straight bars in a low position. I have cut the stem down slightly on my Curve.

I wonder how BF and Brompton riders that have fitted drops/bullbars feel about the affect on stem flex ? My bullbared mezzo seems fine, abit of flex, but OK.

A tricky aspect of the discussion is, "what does 'standard' mean?" Clearly, we all understand what the word means, but where is this theoretical line when there are varying degrees of weirdness.

I think it is safe to say that most folder frame parts or things with the folding mechanism are nonstandard. Whether weirdo Brompton frame/folding parts are more standard than weirdo Bike Friday frame/folding parts is not a particularly interesting question, IMO. Although how robust those parts are, the quality of customer support, and the future viability of the companies is an important question in this context.

The tandem market supports long square taper axle BBs. Old bikes seem to use long axle BBs too. Although the old bikes tend to have cup and cone BBs instead of the more modern disposable BBs. We have a few shops here that service both markets so consequently, I could get a 120+ mm Shimano BB today. Although I would spend some time on the phone doing so and this might not be the case for many people.

I don't think that I could find a 74 mm front hub today. But there are a few shops carrying folding bikes in the area. So perhaps it is simply the case that I have not looked for a 74 mm front hub that creates a bias. However, I am confident that I can find a 100 mm front hub. I do recall that some high end manufacturers are making hubs with the reduced width. Just from my fuzzy memory, Hope, Phil Wood and American Classic come to mind. And SON and Dahon makes a hub generator in the narrow width.

I forgot about the chainring. But a replacement crank and BB would not be hard to get. So perhaps the chainring/crank belongs in the same bin as the front hub as something nonstandard but pretty far from a deal-breaker.

I recall seeing 31.8 seatpost here and there. I still think that it is not the diameter that makes it nonstandard but the length. Nevertheless, I think we agree that it is nonstandard.

Clearly the brakes have always annoyed me. I could never find an adequate reason for sticking with looooooong caliper brakes other than to guarantee themselves a small revenue stream with aftermarket components.

The rear dropout spacing -- I should have mentioned this, but we have talked about it so much that I just don't bring it up anymore -- annoys the hell out of me to given that the extra width that you gain by using a standard OLD is approximately half the increase in OLD. I can't remember whether the OLD is actually 115 instead of 120, but either way we are talking about an extra cm in width to accomodate widely available rear hubs.

Brake: There are plenty of standard reach brakes nowadays. Tektro and Shimano both have them, although it may still be an issue since the mounting and clamping points for the Brompton are reversed.

Rear wheel: It's actually 110 mm. But yes, that's a bugger if you want a Chris King replacement.

Seatpost diameter: There are 31.8 mm seatposts around. Thomson makes one. But good luck finding such a long one! :)

Saddle clamp: The Pentaclip is actually a very fancy aluminum version of the steel saddle clamp that we have all along for as long as I can remember; I had one on my BMX bike in the 80's. They're $5 at your LBS, more typically used on older or cheaper bikes.

Chain tensioner: Yup. And there's no rear derailleur hanger to use an aftermarket one either.

Chainring BCD: The stock Brompton crank has a non-detachable chainring. BCD is really N/A.

BB size: The Brompton BB shell is standard 68mm English. It'll fit any standard English BB cup. And of course we all know that the spindle length is dependent on the crank used...

Other custom parts: Fender, all the miscellaneous small frame parts, rack (front and rear) and those short spokes.

Other parts replaceable by standard parts: pedals (crank dependent), headset (1.125" threaded), chain, handlebar (standard 25.4 mm), BB, crank, cables, brake levers, grips and saddles.

But for me, these discussions are moot. Despite the existence of many custom parts on a Brompton, it is relatively easy to replace broken ones simply because the parts are readily available. I'm lucky in that I live close to C.M.Wasson Co., one of the US west coast Brompton dealers. But even if I didn't, I can always get parts within a week if I order from the UK.

Regardless, Bromptons are quite reliable; I commuted on mine almost every workday for the past year and didn't break anything. Bromptons are also fairly optimized from the factory if you choose the appropriate configuration from the wide range offered; since new, I only had to change out the saddle for a Brooks (yes, I got the Pentaclip), the rear sprocket to a 14T from the stock 13T because of a $#%& 12%+ hill on my route to work, the brake pads to Koolstop salmons (OMG, standard Shimano pad refills! :)), and the elastomer suspension bung to a higher durometer version (because the stock one appears to be for a 100-pounder). It's pretty good for its intended use as delivered.

Yes, tinkers will be more challenged if they want something different or more suited to their taste. But I'm guessing that for most people, a Brompton is a tool more than an interest/toy.