Messages

1

Urban Cycling / Re: Walmart Electric Bicycle Affordable To The Masses

« on: July 28, 2010, 11:22:20 am »

I'm thinking about getting one next year when I start my work placement for college. Either that electric bike, or an electric scooter.

Have you guys ever considered building your own electric bike? I have, it seems like it'd be a fun little project!

2

Urban Cycling / Re: commuting by bike

« on: July 28, 2010, 11:20:50 am »

I bike commute everyday. Portland, Oregon is a great city for this. My one-way distance home to work is 13 miles. However, in the winter, if its windy i'll pedal to the bus stop and take my bike on the bus and shorten the 13 miles to 3 miles.

Work to Eat
Eat to Live
Live to Bike
Bike to Work

Must be a great ride, I bike to work, it is only 4 miles away from home though, I live in Fort Lauderdale, Florida; suprisingly, the roads are pretty friendly, many roads have a bike lane dedicated to bikers. 

3

Gear Talk / Re: Which pedal?

« on: July 27, 2010, 09:26:03 pm »

Have you thought about "CRANK brothers" pedals?  They are the eggbeater type.  They are excellent for clearing mud, which means you can always get your feet in even in the muddiest conditions (no clogging).  They come in a range of pedal sizes.  You can have just the "eggbeater" mechanism  They're brilliant and I wouldn't use anything else now.  I have much experience of pedals having spent many years with both Look and SPD type pedals.  If I was road racing again I wouldn't use them, but for touring, especially off-road, I can highly recommend them.   This is their web-site  www.crankbrothers.com

Totally agree.  I've been using them exclusively (albeit without the platforms) for all my road riding for 7 years.  I like the recessed cleats, and when with a group we had to walk throught mud for awhile, I was the only one to hop back on and ride.  Everyone else had to take off shoes and work the mud out.

Glad someone else agrees with me.  They are definitely the most versatile pedal I have ever used.  I'm suprised no-one else has mentioned them, especially as they are in the USA.  I'm in the UK, but they have a very good name here.

I am in the USA, and a few guys I ride with have these pedals and swear by them. I actually just placed an order on Sunday for them .

4

Gear Talk / Re: TIRES - 700c vs 26 inch for long tours AND S&S Couplers

« on: July 27, 2010, 09:24:28 pm »

He blamed the wheel breakages on a combination of rim brakes and over tensioning of spokes.   He also said that if he was doing something like this again, he'd use disc brakes.

Unlikely.  If the stresses from rim brakes were the cause of broken spokes - the front ones would break also (most of the braking in extreme stops is on the front)

+1.  Disc brakes put a lot more stress on spokes.

About the spoke-bracing angle though-- that makes the wheel a lot stronger, and is why tandem wheels are so much stronger, and famous wheel builder Peter White insists that 36 spokes are virtually always enough for a tandem when the wheel is built right.  I found out about him on the tandem forum where everyone raved about his trouble-free 36-spoke tandem wheels, including for loaded touring.  To get that wider spoke bracing angle though, tandem wheels use 145mm or 160mm dropout spacing, not 130 like road bikes'; so you can't just put a tandem rear wheel in a single road bike or even a touring bike.  Decades ago when tandems' rear dropout spacing was 135 or less, they had a lot more wheel trouble even with 40 or 48 spokes.  To further press the point about bracing angle:  For the last 9 years, Santana has been selling 16-spoke tandem wheels which have proven to be very reliable.  The dropout spacing is 160mm, and the spokes from the right flange go to the left side of the rim, and vice-versa, to improve the spoke bracing angle.

The inertial weight advantage [of the smaller 26" wheel] will be very slight as the smaller diameter wheel also has accelerate faster to reach the same road speed.

No, it's the same number of feet per second.  RPM itself is not the issue.  The myth of rotational weight is exploded in this wheel-science web page though.  You can see for example in the middle of the first table that the wattage savings in the uphill portion of a training ride if you cut the front wheel's rotational inertia in half (an absolutely huge reduction!) is only 0.004%.  IOW, it doesn't matter.

The very low hub rolling resistance will be slightly higher for the smaller wheel at any given speed

very low, yes-- totally negligible.

and the smooth surface rolling resistance of the tires (assuming identical construction) should be identical.

It's a hair higher with the smaller tire, due to more energy being wasted by the slightly sharper bend at edges of the contact patch; but yes, the difference is too small to matter.

Great informative post, what is your thoughts on mags compared to spokes regarding momentum?

5

Gear Talk / Re: Trek 520

« on: July 27, 2010, 09:23:03 pm »

You are half correct - 73/55 is a very low trail design, but low trail means that the handlebars have to turn a lot to make the bike turn - not good handling.  You can have the bars "twitch" all over the place and nothing happens.

With a high trail design, the bike steers significantly with every "twitch" of the bars.

If you look at a criterium racing bicycle it will have very little fork offset, because the trail is already diminished by the steep angle.  By cutting down on the offset - the designer is actually adding some trail back in to keep the steering quick.  

Take a look at a frame design book if you don't believe me.  I have changed a nasty slow steering "pig" of a sports tourer into a responsive enjoyable ride that carves turns great by replacing the 55mm fork with a 38mm.  (Truth is, I would have prefered a 42, but I still haven't found an affordable one.)

Road touring is great at 72/45.

Replacing the fork can have tremendous benefits, I have a buddy who recently completed this install and loves his bike more than ever. He use to call it "sluggish", and wanted a new bike, now he is happy, and so is his bank account!!

6

Gear Talk / Re: which bike to buy?

« on: July 27, 2010, 09:21:13 pm »

If you like the feel of the Sojourn over the LHT and 520, then that is the steed that was made for you!

Disclaimer: I love disc brakes.  They are, in so many ways, the perfect brake system for my do-everything bicycle.  Now, with that out of the way...

Don't get disc brakes unless they are the right system for your needs.  Disc brakes are for you if: you ride in the rain somewhat frequently; ever ride in snow and ice; don't want to do rim cleaning; or might want to experiment with different wheel sizes.  If the aforementioned conditions don't apply, then you don't have to subject yourself to the weight penalty of disc brakes.

If you're still set on disc brakes, for the love of all that is brake-y, change your pads from the stock Avid pads to an aftermarket sintered pad.  Right now, I am using Aztec and am very pleased with them.  Previously, I used Gator sintered pads and was also very happy with them.  Avid pads wear out too quickly, glaze too easily, and are overpriced to boot!

You mention a good point regarding when you should have disc brakes, I've been riding for about 2 years now and live in Florida. Hence the importance of disc brakes, it literally rains on one side of the road, and not the other.


Happy Riding,