sjanzeir

So... Yeah. I did it again.




I hopped on my Mu this afternoon and, perhaps emboldened by a wicked - and rare - southerly tailwind, I decided to haul ass over to the sporting goods store where I buy my Dahons to see what they've got now that things are easing off post-COVID-19 (a second wave hasn't been in the making over here yet.)

To my complete lack of surprise, they still had that other Mu from last year on the shop floor.

And they had this Hemingway, which they said had just landed in the store yesterday, complete with its own 55 percent sale. So instead of paying the SAR3,998 (US$1,065.95)list price, they said I could have it for SAR1,799 (US$479.65.)

Mind you, this was my last money for the rest of the month. And yet somehow I said, "oh, eff it."

I brought it home, did all the basic checks and adjustments and took it on its maiden shakedown ride. Right off the bat, and even with my almost complete lack of experience with disk brakes, I couldn't help but notice just how terrible those Dahon-branded disk brakes are. Though the levers and calipers seemed to be properly mounted and adjusted, I'd have to pull on the levers real hard - with at least three fingers - for any meaningful braking to start happening. They did seem to get a little better the more I used them, but whether
that's them getting bedded in or me just getting used to them I couldn't really tell. I just can't trust them - or at least not yet.

With that being said, it's a nice handler. Though it feels a little more neutral than the Mu - and a little more tossable for that matter - I can't really say that it's any better or worse than the Mu with regard to its handling; it's just different. The Dahon-branded 20x2.00 tires are nice and plush at R60/F55 psi, but they don't have the positive feedback of the 2.00 Big Apple hoops I had put on the Mu (on the stock 15mm rims, mind you) a couple of months ago and running the same pressures.

Of course, I did to the Hemingway this evening what I did to the Mu last night: rode straight to the Trek dealership near our house and changed out the mickey mouse OE resin grips that were all too happy to work themselves off of the handlebars on any hot day for Bontrager Elite lock-ons. The difference is night and day.

CargoDane

It looks very cute (it's a good thing). Congratulation on your new bike.

3speedslow

Interesting choice for a model name. I wonder if the “man” himself would have rode it?

It does look like a good machine! So, what’s on the meal menu for the rest of the month!?

sjanzeir

Oh, we got stuff! We got chicken! We got fish and some mutton, and we got plenty of rice! Cheese, butter, veggies, about a third of a watermelon left... we're gonna make it!

I think this same bike is called Horize in Asian markets, probably because "Hemingway" won't resonate as much. I, too, wondered why they chose to call it after The Man - whoulda preferred that they called it Steinbeck myself...

And I hate disk brakes!

Schwinnsta

For whom the Heimingway Resonates.

sjanzeir

I know, I know... It's poor netiquette to be quoting my own posts and all, but seriously, these disk brakes, entry-level-quality as they may be, are starting to get under my skin. The more they get bedded in with use, the better the feel and stopping power of them. As excellent as the rim brakes of my Mu and the two 7.6 FXs are, I'm finding it harder and harder to want to get back on the older bikes - maybe ya'll "disk brake people" were on to something all along!

sjanzeir

... Should I start thinking about upgrading my Hemingway's brakes?

I've been checking out the brakes that I've got and reading up on cable-actuated disk brakes; there seems to be a definite consensus that the TRP Spyke/Spyre are the **** when it comes to cable disk brakes.
Besides, as a non-engineer with great interest in mechanical engineering and considerable training by my engineer father (may he rest in peace,) I really don't care for this single-side actuation method. The least whoever built these calipers could've done was to design a sliding caliper system (which, I know, could be more prone to contamination and eventual seizing, but still!)

So, what do you think?

CargoDane

If you're not going to fold it (much), maybe go hydraulic?

sjanzeir

Actually, I do fold it more often now that I've been driving an old station wagon that I bought just for this purpose. I've never really warmed to the idea of exterior bike racks. Besides, going hydraulic might prove both too expensive and too messy of an upgrade; I'm just not inclined to go that route for now.

CargoDane

Fair enough

sjanzeir

I'm sorry, I'm just stating some facts

CargoDane

LOL, yes, I know. I thought your reasoning for not going hydraulic was perfectly adequate. Hnnce my "fair enough" comment with a smiley at the end.

Kabuto

Other than folding being an issue (it isn't) that was my first thought too. Mechanical disc is maybe marginally better than V-brakes, but hydraulic... wow. I have hydraulic disc brakes on my Tern X11 and the stopping power is next level. Especially in the rain. Folding isn't an issue either. Never going back to calipers or V-brakes. Ever.

sjanzeir

Okay everyone, the dreaded thing is here: my front disk brake is already squealing like crazy and I've barely ridden the thing three or four times. Now what do I do about it?

There is an upside, though: the squealing front brake has proven to be a great attention grabber; all I have to do is feather the lefthand lever a little and drivers and pedestrians will stop for me! Especially now that the weather is nice and most motorists have their windows down.

tcs

Consider TRP HY/RD.

I heard the machine was named after Mariel.

Nyah

I'm guessing that the problem might be caused by disc-brakes being used with quick-release skewers. If you replaced the fork with one that has a thru-axle, that brake might work as intended. In the scenario of a disc-brake in a slotted dropout (which I suspect is the case, here), the brake is powerful enough to move the axle around in the slot, resulting in the disc rotor moving around in the caliper. The thru-axle system keeps the hub from doing anything other than rotating.

tds101 

See about upgrading to Avid brakes. I had BB5's and they were quiet. The BB7's are said to be an even better brake. Quick release skewers shouldn't matter in the least, unless they're so weak the wheel would be out of alignment.

vanngoh

Both brake pads are in the way of the discs?
roll it and see thru the small little gap and adjast the brake tension. Disc brake maintainence is a pain in the arse. Very difficult to tune to perfection..

sjanzeir

I've spun both wheels while the bike is upside down. While the front rotor (the one that's making all the ruckus) seems perfectly true, it's the rear one that's very slightly bent, but enough to stop the wheel after as few as three turns. Still not sure about the actual alignment of the calipers, though. I'm going to look into that next.

tds101 

If the rotor is bent, just take a set of pliers and bend it straight. Simple fix,

Pinigis 

I recommend an adjustable wrench instead. Since you get a larger flat surface in contact with the disc, you have less chance of creating a local deformation in the surface that could cause you problems. ParkTool makes a tool specifically for this task, but its narrow and no better than an adjustable wrench. It really isn't difficult to straighten out a warped rotor, just be patient and pay attention.

sjanzeir

I got one of these! A big one (a 12-incher, I believe 🤔 )
And I used it to strengthen out the disks on my brother-in-law's MTB a couple of years ago 😇

sjanzeir

So I spent a couple of hours working this out. I looked at those brakes and thought: hey, how hard could this be? I racked every brain cell I had - all two of them - for about 30 seconds and had me a eureka moment; it all made simple, elegant sense! If I could rebuild the entire braking system of my Peugeot station wagon, surely I could chase the demons out of a bicycle's brakes, right? Right?

First, I undid the cables, loosened the stud bolts, and used the thinnest piece of plastic packaging I could find around the house to set an air gap between the stationary brake pads and the rotors. Then I tightened the calipers down in this position (I could've used the feeler gauge I normally use to adjust valve clearance on my old Peugeot... if I had remembered that I had one. Could be getting old or something.)

Then I listened for rubbing, straightening the rear rotor out with a 12" adjustable wrench where needed. The front one - the one that squealed - turned out to be just fine.

Next I used two pieces of the same plastic packaging to set the air gap between the active pads and the rotors, pulling on the actuators just enough to hold the piece of plastic between pad and rotor, and tightened the cables down to the actuators in this position. Turns out the gap was too big, leaving way too much dead travel in the levers. I readjusted the cables with a single piece of plastic (i.e. leaving equal air gaps on both sides of the rotors) and voila! Perfect lever action and travel for my liking, no more noises and perfectly predictable, reliable braking!

Still, though, I'm still not crazy about this kind of half-assed, built-to-a-price engineering of acting/stationary pads. The option to go all-out hydraulic notwithstanding, I would totally love me a pair of TRP Spyke/Spyre calipers (not exactly sure which one would work best with my existing levers.)

Geepig

One day they may create the equivalent of the dual pivot on side pull calliper rim brakes.