Messages

76

Gear Talk / Re: Belt drives?

« on: November 21, 2011, 10:29:11 am »

*Outboard bearing bottom brackets already wear more quickly than an internal cartridge BB.**

Uh, where did you get that?  Outboard-bearing BBs last far longer, for two reasons.  One is that there's room for more and bigger ball bearings.  The other is that there's less force on them since they're father apart.  The wider stance on them results in less leverage up & down with pedaling, and less forward & back with chain tension.  In fact, with a triple, the right-side bearing is almost in the plane of the middle ring.  I'm on my outboard-bearing BB, and it has 27,000 miles on it and it feels and acts brand new, totally smooth and with no slop.  I've never had any inboard-bearing BB last anywhere near that long.

Oh, I know about the physics of outboard BB, but the reality of their longevity is a different matter. I'll start with the bikes that come through my shop with outboard bottom brackets. I frequently get bikes less than a year old needing new bearings (three in past month alone). I see this as a potential combination of two factors: shoddy facing or a complete lack thereof, or bearings hanging out in the Portland elements with about 9 months of dousing. While the need for more diligent facing is not explicitly a fault of the outboard BB, it becomes a problem with the system since the outboard BB requires installation attention that it is not usually getting.

I have gotten a couple years out of my outboard BB before needing replacement, but haven't yet replaced the square taper on my do-everything bike in the same period with about triple the miles. I attribute this difference to nearly constant road spray on the bottom bracket. The square taper is Shimano UN-54; do a search, the longevity of these things is legendary. And when it comes time to replace, it will only cost about $25.

I still prefer outboard BBs when possible, if only for their ease of installation and replacement. But I am firmly unconvinced it is a durable technology. Amongst people who wrench regularly, the stories of sub-5000 mile bearing replacement are legion.

77

Gear Talk / Re: Belt drives?

« on: November 20, 2011, 01:25:25 pm »

Waynemyer's note that belt drives put higher loads on the hub and bottom bracket bearings and that these loads are asymetric puzzles me.  Is it because the belt pulleys are wider and the loads are cantilevered further outboard?  I've never seen this as a problem before. 

The belts have to maintained under high tension. The constant tension causes drive-side bearings to wear faster, just like it does in motorcycles (I used to own a belt-drive motor pickle). Strict attentiveness to chainline reduces bearing wear, but the increased loading is still there.

Because of the high tensions required for Gates' current design and the ratcheting (slippage) issues, they have redesigned their system a few times, including the upcoming CenterTrack belt. They also increased the cog/ring sizes to help reduce the amount of tension required to prevent ratcheting. The increased ring size means on some frames that the ring and cog have to be even further outboard, providing a longer moment arm by which the belt can stress the bearings. Even with Gates' changes, reports of early bearing failure with even heavy-duty bottom brackets are still floating around, although anecdotal*. If the system was anything near ideal, Gates would not keep changing its design and specs so much. These are not cosmetic or model-year changes we're talking about, but deep, serious design shifts, including the necessary changes to the bicycle frame, e.g. chainstays need to be beefed up to handing the longitudinal loading from the belt.


*Outboard bearing bottom brackets already wear more quickly than an internal cartridge BB.**
**If there weren't so many issues, Gates wouldn't keep making so many changes.

78

Gear Talk / Re: Burley Travoy trailer

« on: November 19, 2011, 12:00:11 pm »

I have a Travoy. I have used it on a couple S24O trips, but I don't think it is well-suited to touring. My main complaint with the Travoy is the polymer sheet that covers the frame. It makes for a great commuting and in-town trailer, but that sheet acts as a serious parachute. One would think that the trailer is mostly in the draft, so it shouldn't matter. But it adds up.

Also, the Travoy has a capacity of 60 pounds. Above 35 - 40 pounds, the trailer really makes itself known. The frame starts to flex and it just doesn't feel "right." I can't quantify it better than that, but I wouldn't want to do 100 miles with the trailer loaded for touring. I will say that the trailer still remained stable at ~50 pounds and cornered like a champ, even at "speed." It is definitely the best handling trailer I ever owned.

If it was the only trailer I had and I insisted on touring with a trailer, the Travoy certainly would work. But there are better touring trailers out there.

79

Gear Talk / Re: Belt drives?

« on: November 19, 2011, 11:48:14 am »

Deraileurs may be at their pinacle but personally I find them a pain for touring in terms of maintenance, vulnerability to the elements and whatever might get in their way. Roloff have a good reputation although they are costly and heavier and make taking out the wheel more complex. Can't have it all.

Definitely can't have it all; again, it's a matter of mitigating all of the compromises.

I don't know what you're thinking about with regards to maintenance and vulnerability with derailleurs. Yes, the drivetrain is all hanging out there like a nadsack waiting for a kick, but it's a pretty hardened sack. Anecdotally, my Deore LX derailleur has about 60,000 miles. I have replaced the pulleys a handful of times. I'm still using the original cage bolts, but they are about completely cammed-out now. I clean this thing maybe once a year or so. I live in wet Portland OR, but used to live in salty, sandy, snowy Vermont. My front derailleur is a trashy C101 (it came stock) and it's just a science experiment in equipment abuse.

Bear in mind that an IGH does require maintenance, specifically oil changes. And in the case of some hubs, it is a proprietary oil. I think you're on the right track: the recent round-the-world record was set using a Rohloff/Gates drivetrain. The guy is an experienced tourer and he claimed that he would not have been able to pull off the record using a standard drivetrain. As it was, he still went through two (three?) belts. Then again, if I recall correctly he was sponsored by Gates and Rohloff, so take that as you will.

Both derailleur and internally geared hub have a shift cable that has to be kept in adjustment (only when it's new and is still stretching, or, as some would argue, only has that effect)

With Rohloff hubs, the indexing is internal to the hub, so cable bed-in is much less of an issue, if at all.

80

Gear Talk / Re: Fargo 2 vs Fargo 3

« on: November 18, 2011, 02:32:43 pm »

I should have offered more context: I can readily spin over 180 on rollers (the cadence meter doesn't read any higher than 180). On the road, I can't get this bike over 42MPH on my regular descents whereas I can hit 52MPH with my other bikes. Any way you slice it, the top end is too low.

81

Gear Talk / Re: Fargo 2 vs Fargo 3

« on: November 18, 2011, 12:30:19 pm »

I took delivery on a 2012 Fargo 2 two weeks ago and have been shaking it out with S24O trips. If the crankset on the Fargo 2 is the FSA comet, I say go with the Fargo 3.

There is just a rash of not-quite-enough-range coupled with proprietary lock-in with the 10-speed, 2-ring drivetrain. The SRAM Apex shifters are plenty good and the wide range/close ratios of the 11-36 cassette are pleasant. But the FSA Comet crankset makes for a low that is not low enough (for fully loaded touring) and a high that is definitely not high enough. I can spin 180+ and I regularly run out of high end. Replacing the chainrings is a pain because there are almost no worthwhile variations on the 86mm BCD chainrings. Changing out this crankset with something compatible presents a bit of a challenge. It's doable, but not optimal.

The advantage of the front derailleur on the Fargo 2 is its capacity (22T with a 44T max ring). You can conceivably use a 64/104mm BCD crankset with  24T and 40T rings to get range. But you're looking at another $100+.

Oh, and I find the Thudbuster seatpost to be entirely unnecessary and excessive.

I beat up on the Fargo 2 component spec because I am really finicky. But in truth, it's plenty good. I changed out a bunch of parts already to dial it in to my preferences. If I was going to do it again, I would have bought the Fargo 3, though.

82

Gear Talk / Re: Belt drives?

« on: November 18, 2011, 12:11:17 pm »

You have to have hub gearing too - which I'm contemplating, and lower weight and maintenance are advantages.  However, if they're so good how come they're not more popular? Any thoughts or experience ?

• Requires a special frame design (split in the rear to accommodate the belt).
• A hub transmission of equivalent gear range will weigh much more than a similar derailleur and cassette combination.
• The hub transmission costs a lot more.
• Replacement parts are not as ubiquitous as for chain and derailleur drivetrains.
• Belt drives place a lot of load on the bearings for the rear wheel and bottom bracket. Bearing life is markedly reduced and wear is asymmetric, side to side.
• In order to get the gear range of a chain and derailleur, e.g. a triple with a 11-34 cassette, a front planetary transmission would be required, e.g. Schlumpf, Hammerschmidt, Patterson. Large expense, high weight, and, with the exception of the Patterson, requires a special frame or special facing of the bottom bracket shell.

That said, I think IGH/belt drivetrains are great. The durability of the drivetrains is legendary. They are perfectly suited to commuter bicycles (the mainstay of IGH/belt bikes) and the durability is well-suited to mountain biking (where IGH bikes are catching on, the last time I was paying attention).

All engineering is mitigating compromises. The modern chain/derailleur drivetrain is the pinnacle of a century of engineering balance between all of the compromises. What we have is plenty good enough and cheap enough that gyrating to upgrade for the sake of upgrade is chasing diminishing returns or attempting to put a square peg in a round hole.  I am sure that, once IGH/belt drivetrains have a couple decades of similar engineering prowess, the popularity will be closer to what you expect.

83

Gear Talk / Re: Anyone been touring on the Salsa Vaya yet?

« on: November 14, 2011, 12:01:39 am »

I  dont like  the  ergo drop in the  handlebars & cannot  use  the  drops comfortably, can you  get  the  MOTO ace  bars  without the  stupid dent  in them?  anyone ?

If you like Salsa otherwise, the Cowbell, Short and Shallow, and Pro Road don't have the dramatic ergo bend of the Bell Lap. I'm partial to the Cowbell, but it's probably too short and shallow for many people.

I  find  the  bike  a  bit  wobbly  for  my  liking but  it  must  be  me   as  no  one  else  seems  to .
There is  a  lot  of  flex  in  the  forks when (front disk) braking  hard  what  this will  do  to  the bearings  in  the  steering  tube  time  will  tell , otherwise  I  love  my  Vaya.

If the headset isn't clunking under braking load, then there will be no premature bearing wear. The Salsa touring forks are a little flexy in the longitude, but that's for soaking up road noise. I've borrowed my friend's Vaya and I have experienced the wobbliness you described when I loaded my panniers badly. Some load rejiggering helped immensely.

84

Gear Talk / Re: Preferred method of terminating handlebar tape ?

« on: November 10, 2011, 07:04:00 pm »

Another voice for electrical tape. I recently found this generic tape with an adhesive that doesn't smear. The trouble I have is getting the terminating cut angle of the tape just right so that everything lines up square and even.

85

Gear Talk / Re: Panniers and Lightweight System Bags

« on: November 09, 2011, 09:48:25 am »

Your inquiry is very poorly stated, and I'm accustomed to confusing requests. I had to read it about five times just to get the grammar and flow, yet I still have no clue about what you are asking.

Do you want two front panniers and the rest rackless bags?
Do you want to avoid rackless bags entirely?
Is a transverse saddlebag acceptable?

Help us help you. More context and complete sentences will go a long way.

86

General Discussion / Re: Edinburgh - Lisbon (Winter) Possible?

« on: November 03, 2011, 09:38:57 am »

Riding your bike through the Channel might also be a bit of a challenge. 

87

Gear Talk / Re: Rear hubs - Phil Wood and Chris King

« on: October 31, 2011, 02:56:51 pm »

Really noisy? Chris King. It's a very distinctive sound.

88

Gear Talk / Re: SRAM Apex?

« on: October 31, 2011, 02:55:25 pm »

I was delighted to give up the double road rings on my Canondale cross-racer--which I bought for commuting, a delightful bike--for the triple mountain rings on my recumbent. Huge advance in efficiency and comfort.

But that's just my story, not necessarily relavant.

Entirely relevant. I have a 2012 Salsa Fargo awaiting pickup. Based on my test ride, I think that compact doubles provide a semblance of range, but still don't come anywhere near triples for range and steps. No double crankset is going to provide 17 to 108 gear inches with pleasant steps all throughout. I was reticent to make the jump to 10-speed for a touring bike (off-road, no less), but time will tell. I really put the screws to the bike during my test ride and it seems like a respectable group. I'm curious how it will hold up through year-round commuting abuse and pounding around in the mountains. Hopefully I can get to the shop this week and I will tell you more after a few days of abuse.

89

Gear Talk / Re: Building up a LHT frame

« on: October 28, 2011, 12:36:08 am »

I am a huge fan of disc brakes, but I really bristle whenever I read any person talking about the great braking power of one system or another, regardless of design. Pretty much all modern, quality brake systems have the same braking power: once the wheel is locked up, there is no additional braking power to be had. Just about every decent system out there can do this. And locking up the wheel is indicative of a loss of friction with the pavement.

The tradeoffs are in modulation (this is the implicit biggie for most people), ease of maintenance, weight, foul-weather performance, and longevity of any given aspect of the system.

Peter White is a great wheelbuilder, but he's no Gerd Schraner or Jobst Brandt; one measurement is worth 1000 opinions, even if the opinion is Peter White's. The forces involved for loaded touring with disc brakes are easily addressed with conventional wheelbuilding techniques. If you're feeling the disc love, find a wheelbuilder that thinks as you do; avoid the wheelbuilder that is mired in baseless biases. Whatever you do, read both Schraner's and Brandt's books on wheels and don't let wheelbuilders make you think that there is any kind of voodoo or obscure knowledge in wheelbuilding. The science and engineering of the bicycle wheel is quite simple (although maybe not easy) and accessible.

90

General Discussion / Re: Camp Coffee That Doesn't Suck

« on: October 28, 2011, 12:04:15 am »

Hm, I have one of those! I will have to try it for some coffee.