What do you think about the Velocity 27.5 rim on a 26er?

[kbteachme]

What do you think about the Velocity Blunt 27.5 rims on a 26er?

* With 650B wheels (which measure 27.5" in diameter, half-way between 26- and 29-inch wheels), full-suspension bikes can be produced with four to six inches of travel and throughout a wide range of frame sizes without abandoning proven 26-inch wheel frame geometry.

* 650B wheel bikes can be designed for a wide variety of uses from XC racing to 4X and DH racing.

* 650B wheel bikes can accommodate riders 5' 3" to 6' 4" tall or more.

* 650B wheels offer great obstacle roll-over capabilities for a smoother ride.

* Consumers are already demanding 650B bikes and bike designers are producing the bikes.

"What I believe 650B wheeled mountain bikes will allow builders to do, is to utilize proven 26-inch wheeled geometries, coupled with the largest wheel possible in a bike with little or no geometry compromises," Pacenti said. "As 140mm travel bikes become the norm (even for XC bikes) the 650B wheel size is going to make even more sense."

Hard to argue with Pacenti, but what about the effort it'll take to get the big tire makers on board? Pacenti has already covered that rocky ground. A Pacenti-designed and branded Panaracer-made 650B tire - the Neo-Moto - is currently in production and will be available by mid-September for $54.95US each. Current handmade samples weigh approximately 740g, according to Pacenti. In addition, White Brothers is producing suspension forks for the new wheel size, and Velocity USA, which has built 650B rims for the bicycle touring market for years, is already in production of their new Blunt, all-mountain MTB rim.

Because the 650B wheel size is compatible with many 26-inch wheel components numerous parts are already available. For instance, Maverick forks can be easily optimized for 650B wheels with a travel reduction kit, and some current 26-inch and all current 29-inch disk specific suspension forks will work with the 650B wheel size.

"Kirk's forward thinking vision is correct in that 29'er wheels don't work well for frames with more than 100mm of rear travel," adds Noel Buckley of Knolly Bikes. "While working on the design of a 29er version of our new Endorphin frame, we started realizing that serious compromises would need to be made to the frame geometry due to undesirable forward wheel paths, chain stay lengths, and BB height all caused by the large 29" wheel diameter.

"Kirk knows what he's talking about," Buckley added. "The 650B wheel size makes more sense for a company looking to produce big wheeled bikes in the 100 - 150mm travel category because they get the rolling benefits of the larger tire, but don't have to modify frame geometries much, or have to contend with the design compromises imposed by 29 inch wheels."

"I am fully committed to the 650B wheel mountain bike," says Pacenti. "I have been receiving daily inquiries from custom builders and even consumers who are very interested in the wheel size. Support for this project has been overwhelming. I truly believe 650B wheel bikes have a bright future in mountain biking."

http://blackmountaincycles.blogspot....onversion.html

[tkblazer]

my buddy has been loving his 650b front wheel on the front of his ironhorse... he tried a 29er front end on the same bike and liked it, but didn't like how flexy the reba fork was. After swapping to a 650b and going back to his old 32 van, he loved it

[strobelite]

im down to try it.

[soul rider]

Warning Against Unapproved Use Of Fox Forks

FOX 32, 36, and 40 suspension forks (with the exception of model F29) are engineered and tested for use with 26 inch Mountain Bike tires. These models meet CEN and AST M testing standards based on use with 26 inch tires. Use of FOX forks with any tire larger than 26 inches, such as a 650b tire, will subject the FOX fork to loads and forces it has not been designed or certified to meet. FOX 32, 36, and 40 suspension forks are not recommended or approved by FOX Factory, Inc. for use with tires larger than 26 inches, either as original equipment or aftermarket. Unauthorized and unapproved use of these forks with tires larger than 26 inches may result accidents, causing serious bodily injury or death.
Thank you,

FOX Racing Shox

FOX FACTORY, INC
130 HANGAR WAY
WATSONVILLE, CA 95076
TOLL FREE 1-800.FOX.SHOX

[autoduel]

Covering their donkeys from lawsuits, but they didn't mention anything about voiding warranties. What's the difference between fitting a 650B under the crown and a 2.5" tire? 10mm of diameter.

[2wheel_lee]

I'm with soul rider on playing it safe. A few years ago, back when Rock Shox didn't really do any engineering or testing prior to bringing their products to market (before they were purchased by SRAM), I had a Panaracer FirePro 2.1 hit the bottom of the crown when I landed from a jump. Although I was able to save myself from falling, you don't forget the feeling of your tire hitting the crown and stopping the front of the bike. With fork companies doing their best to keep the axle-to-crown heights to a minimum for a given travel, they're not leaving a whole lot of room up there. I think it's foolish to try and fit one of these 650B wheels on a normal 26" fork.

[tbowren]

I will definitely be having the Path build me a 650B wheelset later in the year.

I'm actually interested to see how they work on a 29er bike as well as using a 29er up front and 650B in the back.

I was especially excited to read that Kenda is releasing a Nevegal in the 650B format as well. This is my most favorite front tire and might be cheaper than the Neomoto.

[kbteachme]

Keep us updated on the wheelbuilt.

Originally Posted by tbowren

I will definitely be having the Path build me a 650B wheelset later in the year.

I'm actually interested to see how they work on a 29er bike as well as using a 29er up front and 650B in the back.

I was especially excited to read that Kenda is releasing a Nevegal in the 650B format as well. This is my most favorite front tire and might be cheaper than the Neomoto.

[tbowren]

FYI. Got my front 650B wheel on Friday. Took it for a quick test spin and I love it. Anybody who has a 26er fox fork should be able to run this tire. It has some of the more stable characteristics of my 29er tire but much faster to spin up and slow down. Also, the Neo-moto is as nice or nicer than the Nevegal as a front tire. I've always felt the tread pattern if the Nevegal is more rear tire oriented (ie. paddlewheel ) but it had such great grip I dealt with its slow rolling style.

[kbteachme]

Originally Posted by tbowren

FYI. Got my front 650B wheel on Friday. Took it for a quick test spin and I love it. Anybody who has a 26er fox fork should be able to run this tire. It has some of the more stable characteristics of my 29er tire but much faster to spin up and slow down. Also, the Neo-moto is as nice or nicer than the Nevegal as a front tire. I've always felt the tread pattern if the Nevegal is more rear tire oriented (ie. paddlewheel ) but it had such great grip I dealt with its slow rolling style.

Great! Do you have any pictures of your new setup?

[2wheel_lee]

Originally Posted by tbowren

Anybody who has a 26er fox fork should be able to run this tire.

So Fox issued the memo not to use 650b wheels with their forks for no apparent reason? If you ride hard, make sure to post the pictures of the carnage.

You've been warned.

[tbowren]

Originally Posted by 2wheel_lee

So Fox issued the memo not to use 650b wheels with their forks for no apparent reason? If you ride hard, make sure to post the pictures of the carnage.

You've been warned.

Well I am running it in a 29er fox so I won't have any issues. However, I have slipped that wheel into 2 other fox forks and there is ample clearance. They issued that warning because they probably HAVEN"T tested them. That doesn't mean you are any unsafer. I'm sure in 2009 or 2010 they will come out with a 650b approved fork thats is even more expensive but not necessarily any safer.

Believe me I worry about a lot of things on the trail, but this will not be one of them.

[tbowren]

Originally Posted by kbteachme

Great! Do you have any pictures of your new setup?

Yes I will try to take a pic tomorrow morning. I have been slammed with work all weekend.

According to my inclinometer the head angle is 69 and the seat angle is 71. Normally that 71 would be a bit too slack for me, but since putting on the gravity dropper I lost the setback seatpost so my saddle is an inch closer, thus making up for the angle change.

I rode the bike again today to work, at lunch, and home again. I wish I could afford a rear wheel now, I think it will work great. It just seems wrong to tear apart a perfectly good Chris King rear 29er wheel just to save money on an "experiment".

[2wheel_lee]

Ah...you'll be just fine running the 650B in a 29er fork.

Running it in a 26er is a bad call, though. Unless you remove the spring and bottom-out system from the fork and account for tire expansion on impacts, it'll be hard to tell how much clearance you have.

[tbowren]

So I decided further investigate the 650B in a fox 26er fork situation.

Upon letting all of the air out of a 2007 F100RL the crown DOES hit the tire.

I suppose I need to investigate how possible it is to put an extra 5mm stopper inside the fork to fix this.

The only way for the crown to rub would be a total failure of the air pressure system. Normally I would think this could rarely happen, but it has happened on my Reba. I realize the internals are different between those 2 forks, but if one should happen to have a total fork failure, the last thing they need would be their front wheel getting stuck as well. Not a good combo.

I wonder if a coil fork would have the same issues since you cant lose pressure in that, and the spring would be its own stopper.

[2wheel_lee]

I'm glad you found that out the easy way (the hard way can be ugly). It's perfectly normal for your fork to be able to fully bottom out during a ride. In fact, a common recommendation is to set up the suspension so that it does complete bottom out at least once during a ride.

A coil spring fork will bottom out in the same manner.

Important note:
There are often rubber bottom out bumpers inside the fork that you could never fully compress, even without air or a coil in the fork. These are in place so that you don't have hard metal-to-metal contact when the fork does fully bottom out. You can easily see these bumpers on coil spring rear shocks. You can completely remove the spring, and you still can't fully compress the bumper. However, when landing a jump or drop, or hitting a hard square-edged object, you can sometimes easily fully compress the spring and the bumper. That is the bottom out bumper doing its job.

And as I mentioned above, even if you do remove the spring (air or coil), AND the bottom out bumper, you still have tire expansion from impact that you can't replicate.

[tbowren]

Originally Posted by 2wheel_lee

There are often rubber bottom out bumpers inside the fork that you could never fully compress, even without air or a coil in the fork.

So the question is, can I insert Another bumper or spacer of some sort to limit where the fork bottoms out?

So it doesn't go ALL the way through the travel.

[2wheel_lee]

I don't know your specific fork design, but it does seem possible to add a hard spacer next to the rubber spacer.

[tbowren]

Finally got some time to take a pic.

Took this bike up Blackstar to Beeks place today in 1:07:00 (close to my best time ever) and kept rolling on the main divide to Pleasants Peak. The ride back down was amazing. As much cornering traction as my 29er Nevegal (i.e. as much as I'm willing to push it) but much faster to spin up, slow down, and lean side to side.

It's so crazy that after 2 years of fighting with this bike's geometry to get it to work for me, THIS would be what is making me happy. I just wish it had more travel and the frame was stiffer overall.

I have been thinking of trying the fork / tire combo on a Turner 5 spot, but today I realized maybe what I want is just the 4 in version of the Leviathan.