Originally Posted by 14R
If you really feel the need of adding disk brakes to it, you are in Portland! You can always find a frame builder to add them to your Brompton. Best folding size, more than decent bike once unfolded, with the braking powers you want. Last time I quoted, it would cost 100 bucks of labor, 20 for the parts to be welded to the frame (I was adding V-Brakes though) and another 50 for the repainting.
Good point! A decade ago all my mountain bike buds were spending $100-ish to have disc tabs welded to their bikes. Since the Brompton is steel, that would be an option. There is a Brompton dealer here in Portland (and lots of people who can do the welding), so I'll check it out. There would of course be the matter of acquiring an additional wheelset (I'm assuming the Brompton's stock wheels do not include disc hubs) and a new fork (I'm not going to have disc tabs welded onto a fork not designed for the forces of disc braking). Also would need to make sure that discs wouldn't interfere with the Brompton's fold.
Originally Posted by chucky
I'm sure you could get disc brakes on a Bike Friday and if you're picky about geometry that'll be your only choice. Also, I wouldn't discount Dahon offhand: they make some nice bikes and I believe some have disc brakes.
Otherwise I'd definitely go with the Downtube because:
-There may be rack issues with the Swift due to the way it folds.
-Downtube already has the disc tabs.
-You're a discerning rider that puts in the miles. Save the $500 to upgrade the Downtube as you wear it out.
-The front suspension will be perfect for moderate offroading.
You can get some geometry measurements here:
http://downtube.com/Bike_Measurements/
The stem riser has adjustable height and the stem is adjustable around a circle.
Thanks for all the great words! Very helpful and informative. I will contact Bike Friday and ask them about discs. I can't find any mention of discs on their site, but of course they're a full-custom shop so maybe they can still do it. And (as with the steel Swift) if I'm going to be spending $1200+ it's nice to have a chunk of that going to local industry.
I agree with you about the upgrade path on the Downtube, and I'd expect to replace and upgrade quite a few of the parts. I'm used to building my bikes up from the frame with my choice of parts anyway, so I'm mostly concerned with the quality of the frame as opposed to the parts. And THANK YOU for the link to Downtube's geometry page. I didn't seem to find it from their home page. Biggest surprise to me is the ETT and wheelbase aren't really "shortened" at all compared to typical larger-wheeled bikes. Surprisingly "normal", really. No mention of the STA though: I might contact Downtube and ask them since that's such a critical measurement for me.
As for the Swift, it doesn't look like a rack would create any folding issues, since the front folds
away from the rear triangle. Looks like clear sailing to me.
Originally Posted by cpach
It seems that Dahon makes a bike with stock hydraulic disc brakes, as well as a 8 speed IGH, front dynohub, lights, and a phone charger battery thing.
http://us.dahon.com/bikes/1677/ios-xl Maybe a little steep in price, not sure about the standard rear rack. Anyhow another bike for you to check out.
Unfortunately the Ios XL has 24" wheels. If it weren't for TriMet's 20" rule that could be a good compromise.
Originally Posted by jur
The Dahon Jetstream EX has disc brakes IIRC.
Sure enough. Unfortunately that bike is $2500 and full suspension. Thanks for the suggestion though.
Originally Posted by Chop!
Steve Parry does a conversion :- Disc brake Brompton
Nice! So it's been done. Interesting fork.
Originally Posted by ShinyBiker
I have a DT and I rarely fold it. However, when I have, it's kinda gangly. Not a neat tidy process. There could a danger of something striking your rotors and perhaps damaging them esp. if you're in a hurry.
Good to know. It
looks like a clean fold (if not the smallest -- not that I'm too concerned with that). Is there more to it than just (1) dropping the saddle, (2) folding the stem and (3) pulling a pin or lever and flipping the front end around? Or is the awkwardness in dealing with the folded package?