Archive for July, 2008

An Experiment In Front End Geometry: Fork #1

July 31, 2008

Now moving on to the first fork I used on the Blackbuck other than the baseline On One Carbon fork, which is the Blackbuck fork that is offered along with the frame from OS Bikes.

Blackbuck frame/fork

The Blackbuck fork is a radical departure from conventional thinking. Paired up with the Blackbuck frame you get these numbers:

Head Angle: 74 degrees
Axle to Crown: 440mm
Offset: 51mm
Wheelbase: 42 7/8ths
Bottom Bracket Drop Range (EBB) 74mm-85mm
Approximate Trail*: 55mm

Changes Made: The necessary changes made to accomodate my saddle to bottom bracket relationship and my saddle to bar relationship were as follows:
-Moved saddle backwards approximately 20mm.
-Used a total of 50mm of spacers and cut the steer tube longer than normal
-Changed to a 20mm shorter stem

Handling Characteristics: By the numbers, a lot of folks would say this should be scary! In reality, it was an eye opener for me. I was not thrown by the handling at all. It was a bit quicker than it had been, but not twitchy, nervous, or anywhere close to unrideable. Quite the contrary. I found it to be a bit challenging in slow speed manuevers, and descending steeps made me feel as though I really needed to get back over the saddle. The front end felt lower and pinned to the trail. Curves were carved with no feeling of washing out. Initiating a turn was was a subtle act. Strong arming this set up was not a wise thing to do. Lines were switched telepathically. In fact, it was a bit nervous in longer descends and I would venture a guess that it would be a mentally taxing thing to descend at speed for very long with this set up.

Two things that bear mentioning about this fork and frame combination. #1: It rides fantastically smooth with this fork. Something about the frame comes alive with the Blackbuck fork on board. The whole bike feels even more like a steel bike than it did before. Almost an amplification of that “steel feel”, if I can put it that way. #2: It struck me as I was riding it that those with fine motor skills would probably get along just fine with this combination. You really needed to be still on the bike. Weight shifts and hand pressures were minimal but would yeild big dividends in turns, climbs, and manuevers. The only thing that was harder to do was to get the front end up. I think the lower front end and steeper head angle were to blame here.

Close up of the fork

A Note On The Forks Ride: The Blackbuck fork is a pretty smooth steel fork. Even at 440mm axle to crown, it doesn’t rattle your teeth out too badly. Hey! It is still a rigid fork though, so don’t get any ideas! My only beef is that it seemed to flex a tad laterally. Enough so that I could get the rotor to rub my pads at times. A bolt on hub or one of those fancy new locking skewers may take a bit of that away. The big thing for me was the combination of this fork and the frame. Together they make a great pairing in terms of ride feel.

Final Thoughts: This should have been an unrideable combination, if you listen to conventional wisdom. In fact, it is a very fun, albeit quite quick, handling package. As an example, I loaned it out to a friend as we rode the trails one day. He really enjoyed the bike and noted the quick handling, but got along just fine with it. We are pretty adaptable as mountain bikers. Just looking at numbers and making judgements isn’t a good way to analyze a bikes ride. This Blackbuck fork was a testament to that. It was a fun combination, and I’ll be revisiting it someday after this test is complete.

Next: I go to the other end of the spectrum with a Bontrager Race X Lite Switchblade fork.

*The trail charts I used all gave slightly different answers and of course, your tire selection will also affect the trail figure slightly. Take my trail figures with a grain of salt. Your mileage may vary!

YiPsan Winter Bike: Preview

July 30, 2008

This past weekend 650b.com took delivery of a randoneering bike to give the 650b road riding a try.  The bike is Renold YiPsan of YiPsan Bicycles personal steed.  Tagged as a “winter/rando” bike this thing seems to be bomb proof and perfect for winter riding.

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An Experiment In Front End Geometry: The Baseline

July 29, 2008

In this post I will detail the “baseline” for the handling characteristics that all other comparisons will be measured against. Keep in mind that this is my opinion. Your “baseline” for handling may differ from mine, but we all need a reference point here, so this is it.

OS Bikes Blackbuck/On One Carbon Superlight fork

The OS Bikes Blackuck has been set up like this with the On One Carbon Superlight fork for most of the year so far. Here are the pertinent numbers for you to crunch on:

Head Angle- 72 degrees
Axle to Crown- 470mm
Offset- 47mm
Wheelbase- 42.8″
Bottom Bracket Drop Range (EBB) 53.4mm-63.4mm
Approximate Trail*– 76mm

Handling Characteristics: The On One fork and Blackbuck bike are like an old friend to me, reminiscent of the sort of handling I had with this same fork and the On One Inbred. That being quick, but not twitchy. Corners are carved with no drama. Slow speed maneuverings are perhaps a bit nervous, but imminently manageable. I find it best for medium to fast singletrack riding where carving a precise line all the way through a corner is important. Mid corner corrections are easy to initiate and complete without losing control.

A Note On The Forks Ride I have reiewed this fork on Twenty Nine Inches, (Please check in the Search box at the upper right of the page for more.), so I will not go into too much detail here other than to say that this fork rides very nicely, is tough, and gives your brakes a slight boost in performance due to the excellently designed drop outs.

OS Bikes Blackbuck/Blackbuck rigid fork

Next I will detail the changes made and the ride characteristics that resulted from switching out to the Blackbuck rigid steel fork with 440mm axle to crown and 51mm offset. Stay tuned….

*The trail charts I used all gave slightly different answers and of course, your tire selection will also affect the trail figure slightly. Take my trail figures with a grain of salt. Your mileage may vary!

Stans ZTR 355 : Long Term

July 28, 2008

For roughly 2.5 months I’ve been throwing all that I can at the Stans ZTR 355 that came to my door step for a review. Check out my Out of the Box article for the spec and weight of these wheels.  As a wheelset they have always had a NeoMoto in the front and a QuasiMoto in the back mounted up.  They have spent most their time on my single speed machine, that was then turned into a 1×9 geared rig.  There hasn’t been too much carnage and in all these wheels/rims have treated me very well to date.

The Ride:
As the wheels were built up for a racey feel, they are stiff and light.  It is how I prefer my every day wheels.  I would rather have something burly for longer or mountainous that I can easily put on, and something quick/stiff for my local beatings.  It is what I find more comfortable under me and what suits my riding style.  This might not be your bag, but its mine.    This set is tuned perfectly for what I had asked for.  The guys at Stans make a living out of their rims and wheels.  Knowing how to build suitable wheels per rider is part of what they do really well.

Going Tubeless:
After the first month I turned the tires that were mounted up (NeoMoto in the front, QuasiMoto in the rear) tubeless with some help from the Stans sealant.  The rims hooked the tires that are NOT UST approved wonderfully.  I rarely have an issue turning tires tubeless with the Stans system and this wasn’t anything new.   Pour in sealant, inflate with compressor, make sure bead is seated, inflate to close to max PSI of tire, spin wheel in truing stand or bike for a few minutes, and wah-lah sealed and ready to rock.  Only once did I get a flat that the sealant couldn’t clog up and this was due to the large gash in the side wall that I could barely boot with a gel pack.  Going tubeless with a lighter weight rim like this (compared to an all mountain) sometimes is like rolling the dice.  I run my pressure super low.  Between 22-18 lbs often.   Yes, I have burped a tire here and there but in race situations I’ll add a bit more air for when I’m pushing it through the corners.  Running this low of pressure also means you can smack your rim pretty hard.  Instead of the air pressure taking some of the beating, your rims are now physically hitting things.  It isn’t too often this happens, maybe once every 5-6 rides.  Thankfully I am a light rider, around 140lbs (I won’t lie, I SHOULD be at 140 lbs) and I don’t “plow” into things too often.  Only twice have I thought “Oh S&^t”  and only once has it left physically damage to the rim.  Yes, the rim has a slight bend in it but it has not affected the tire sealing with the rim and bead.

Changes:
So far, the only changes I would of made to this set up is:

  • Maybe a different hub set.  This is a lightweight hub which is good, but the lightweight freehub body is taking a licking.  I don’t torque out a lot of watts and there already is a few good cuts in the body.
  • A wider version of this rim.  This isn’t directly pointed to this wheelset but instead towards Stans to come out with a more all mountain rim for bikes like the Ventana El Bastardo. If I could be running tubeless, safetly, on that bike I would be delighted.

Stans ZTR & Fatty Rumpkin

Other notes:
The wheelset has now been taken off the Fast Boy due to the frame needing to go back to the builder for some TLC and now they are on a Yipsan touring/road bike that will be featured here soon.  They are doing wonderfully on the road/cyclocross arena and I think the light weightness has been a huge help.  Also, 41.5mm Fatty Rumpkins mount up wonderfully on them!

An Experiment In Front End Geometry

July 27, 2008

Introduction: As the geometry evolves for 29″ers, riders have been getting increasingly more aware of front end geometry, especially as it pertains to forks. Offset and axle to crown measuremens are topics du jour, while head angle charts are consulted like the newspapers latest astrological section. What does it really all mean? Does this stuff matter all that much. (Actually, that is a totally valid question) What happens when fork “A” gets mated to frame “B”? Will my bicycle become a wheelbarrow or a twitchy track bike? Hopefully the following posts concerning my forays into this nebulous world of front end geometry will help to clear some things up for some of you.

On One Carbon Superlight fork

The Set Up: I decided that in order to figure out what might result from swapping out forks that I would use one bike. This bike would get several fork swaps throughout the summer and I would report on each forks effects on said “one bike”. That bike is the OS Bikes Blackbuck. I also decided that for the most part I would stick with rigid forks, since there will be less variables with rigid forks versus suspended forks. (Although I will use a couple suspended forks as well) Along with the different forks, I will also detail out the different equipment and fit changes I needed to make to keep my relative seated posistion correct. All forks will be fitted with the same Avid BB-7 disc caliper with a 185mm rotor. I will also be using a Titec H-Bar, Avid levers, and Ergon grips throughout the test with various Salsa CroMoto stems to help achieve proper fit. The head set will be a Chris King No-Thread head set.

OS Bikes Blackbuck

I will periodically update the test with new posts. The first in this series will be on the initial set up. Then we will get into the following fork swaps afterwards. I will also touch upon my past experimenting with an On One 29″er where I swapped out the stock fork for a Bontrager Switchblade. Stay tuned for the first part in this series coming soon.

In the meantime, please leave any questions or comments in the comment section. I’ll be sure to address each one if I can.

New Tire: Schwalbe Marathon 650b x 40

July 26, 2008

Our Diggers@650b.com email received word from Grant of Rivendell about a new Schwalbe 650b pavement tire that became available this weekend over at Rivbike.com.  Schwalbe’s claimed 650b x 40mm with directional tread is perfect for commuters, long hauling, long wearing, riding.

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El Bastardo : 1st Impressions

July 25, 2008

650b.com took delivery of a new Ventana El Bastardo frame about a month ago.  With the help of Kirk Pacenti with the loan of a XFusion Velvet R fork I was able to build up this fine steed.

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A 29″er UST Standard: An Update

July 23, 2008

A little over a year ago, I wrote a post here about the coming of UST standard approved tires and rims. I recently got a question regarding this subject:

Is there any word on when we will get more choice in tire(s)? This article is over a year old and still only one tire is available.

Well, while this is true, there have been several developments since then that bear looking into. Let’s see where we are and where we might be going.

Hutchinson Python tubeless ready tires

The “tire” in question that has a UST certification for use with sealant is the Hutchinson Python. Huthinson has also introduced a Toro model in 29″er size that should become available soon. This would make two 29″er tires available with the much ballyhooed UST certification seal. That doesn’t quite seem to be cutting it for some folks. The feeling I get perusing the various forums and talking to folks is something that isn’t congruent with what tire manufacturers are doing, and really, is incongruent with riders own expectations.

Right now there is a group of folks waiting for a “true UST” tire in 29″er size. My opinion is that you will probably never get it. What is “true UST”? It is the idea some folks have based from the earliest 26″er UST tires that all tubeless UST tires need no sealant. In many riders minds, there isn’t any other UST type tire out there. But there is. It is the UST tire that requires sealant to work, most commonly known as “tubeless ready”. These tires meet UST certifications and are compatible with UST certified rims. Yet some riders do not recognize this as UST.

Bontrager XDX tires

Why won’t you see a UST tire that requires no sealant in 29″er size? Because of weight. A UST tire requiring no sealant adds extra butyl rubber to the casing making it air tight. Some may see this as a cool thing for sharp rocks or more abusive riding, but for mere tubeless uses, it is a deal killer for 29″er freaks and the manufacturers know it. I’m not saying it will never happen, but I wouldn’t hold my breath.

Why don’t we see more UST certified tubeless ready tires? I think manufacturers are finding out they can do rims and tire manufacturers are finding out they can do tires that will work together tubeless without spending the money for the UST certifications. Bontrager’s Tubeless Ready tires and wheels are an excellent example- no UST certification needed. However; in my mind the real underlying reason for the lack of tubeless ready UST tires and rims is Stan’s NoTubes and the efforts of individual riders all over the world who have turned to making tubeless work on their own terms. If you, as a manufacturer, see what is going on out there, why would you spend the money on a certification when you can make an end around on the whole thing. Think about Panaracer, who when introducing the Rampage more or less gave its blessing on using it tubeless. Continental has essentially done the same thing, declaring all their mountain bike tires safe to use with any of the mountain bike tire sealants commercially available. Doesn’t sound as though either of those manufacturers is interested in doing a UST 29″er tire anytime soon, does it?

Stan's NoTubes Flow rim diagram

Then you have the various rim manufacturers who are doing a lot of refinements to rim bead seat designs on 29″er rims, not saying they are “tubeless compatible”, but making it a lot easier to do just that. WTB, Sun, and Salsa are three that I saw at Interbike that were doing new rim bead seat designs, but not going so far as to say they were tubeless compatible.

What of Geax and Michelin? I have seen that Geax has gone their own route with the “TnT” concept and Michelin is also rumored to be doing their own tubeless ready type designs without seeking UST certification. At one time it was rumored that these companies would do a UST 29″er tire, but this seems to be not the case now.

So, revisting that article of over a year ago makes me say that I was wrong. There still is “that” argument against 29″ers. However; you can choose to stick with looking for a UST 29″er tire, but the rest of your riding buddies and competitors at the races are already doing something about it. Tubeless ready type tires are here now and there are rims that work as well. Some will scoff and say the risk isn’t worth it, but it’s something that isn’t going away anytime soon. Advantage or disadvantage for 29″ers? You’ll have to make that call.

Scwalbe Racing Ralph 2.4": Final Review

July 20, 2008

With our time spent on the Schwalbe Racing Ralph’s, we feel safe in posting this “Final Review” on the tires. We have put them through snow, ice, mud, dry dirt, and gravel throughout our testing period. This will be a combined review from Captain Bob and myself.

Pofahl  with Racing Ralph rear tire

We experienced a long, icy, and snowy winter. Both Captain Bob and myself were using the Racing Ralph in winter riding conditions. I found that the racing Ralph was an incredible tire for ice and snow. The casing seemed to wrap itself around anything it could get a grip on. Traction was phenomenal for me. Captain Bob concurs saying, “I use them most of the winter riding gravel roads that were not gravel very often. The gravel roads were complete ice that was at least one inch think all winter, or completely covered with several inches of snow. What I do know for sure is that these tires will grip to ice better than any non-studded tire than I have ridden. I was amazed at how well that they grip ice. Snow? These treads roll over many inches of snow with ease. Very little washing out was experienced. I am guessing that the width of the tire is adding to their stability. I could ride almost as fast on 4 inches of snow racing down the gravel roads as I could with just gravel.”

Racing Ralph

Moving into the spring and summer saw a lot of wet, muddy, and tacky trail conditions. The Racing ralph’s are no match for true mud, especially sticky dirt or clay conditions. I found that the tread packed up rather quickly and that the tire would continue to collect mud, losing all ability to grip the trail surface until it cleared out its tread. If the trails started to firm up, things got much better. I felt that the Racing Ralph really started to shine on tacky to hardpack trails. Captain Bob thought similar things here. He says, “Hardpack singletrack was another area where the RR’s shine. If the trails were too smooth though, or on any trail that felt like pavement, I noticed some drag from them. Nothing too much. Just more than I expected.”

On really hard trails or on rides to the trail head on pavement, both Captain Bob and I thought that the Racing Ralph showed it’s width and tread compound as higher rolling resistance. Not too surprisingly, we also didn’t find as much to love on hard trails with any loose dirt over the top. Captain Bob explains, “I feel like I am not getting the tires to dig in. They seem to float over everything. Almost too much. I have a little trouble getting the cornering bite that I want, and it’s making it difficult to rail in the turns. I have tried lowering the psi but that just seems to make the bike steer too slow. It feels as though there is too much contact which causes everything to slow down. Straight lines are fine but anything involving turns is where I notice this.”

Conversely we found this “float” to be a great attribute in sandy situations. Captain Bob says, ” I know they float over sand better than other tires I have.” I’d have to agree, and since they did so well in the snow, this shouldn’t be a surprise. Captain Bob calls the Racing Ralphs, “The best sand tire out there.”

Final Thoughts: We like the Racing Ralph as a front tire on a rigid bike because of its volume. The Racing Ralph has an uncanny ability to “float” over trail obstacles and sand/snow as well. Although it is claimed to have a low rolling resistance in hardpack and fast trail conditions, we didn’t notice anything noteworthy there. The casing seems very flexible and it may not hold up to sharp rocks and abusive trail conditions because of this. We have not ridden in these sorts of conditions, but we have heard reports of such instances. The tire comes highly recommended if your trails are buff, tacky to dry with little loose debris over the top. In these conditions the Ralph rails turns and has great stopping abilities. Anything beyond tacky makes the performance fall off dramatically. We do not recommend the Racing Ralph for anything resembling mud.

This ends our look at the Schwalbe Racing Ralph 2.4 inch tires. Thanks for reading!

Marin Bikes To Introduce New 29"ers For '09

July 17, 2008

In a recently posted story on Bicycle Retailer and Industry News website, it has been revealed that Marin Bikes will offer two new 29″er models for the 2009 model year.

Added to Marin’s two existing 29″er models, (the two urban models that accept 29″er tires not with standing) will be the Nail Trail and Pallisades models. The Nail Trail will retail for approximately $1965.00 and the Palisades for $1395.00.

Look for coverage on these two new models as we are able to get more information. Certainly, we will be checking into these bikes and more during our annual trip to Interbike………in only a little over two months!