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· Mtbr Founder
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Discussion Starter · #1 ·
Le'ts start building one.

What are the most frequently asked questions on 650b. What are the answers?

Let's start building one here. Post the questions and then the answers.

Who wants to own this article. It will be a great resource and it will prevent the same questions getting asked over and over in this forum.

fc
 

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Q: How does the bike geometry change if I convert a 26" bike to 650b wheels?
A: It does not. The BB height will be raised by 1/2", but the bike geometry stays the same if both wheels are replaced with 650b ones.

Q: If I convert to 650b, how will my bike feel?
A: Awesome! ;)
 

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Increasing wheel size will increase trail numbers.
EX..... I went from 75mm w/26" wheelset and installed 27.5"s and ended up at 82mm. I felt the difference.
I then installed a X-fusion velvet. Longer axle to crown which changed HT angle,ST angle and BB height. Velvet has less offset at 41mm then the fork I had on. Which also increased the trial numbers. I ended up at 91mm of trail. Too much.
I ended up building another frame with a steeper HT angle with 12.125" BB height it's much better....FOR ME riding rooted trails in NY.

650B..........I agree is awesome.
 

· www.derbyrims.com
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650b front-wheel-only convertion for a 26" bike

Q: How does the bike geometry change if I convert a 26" bike to have a 650b front wheel and leaving the 26" rear wheel?
A: The frame becomes 1/2 degree slacker. And the 1/2 inch higher axle (on average, depending on tire size difference) gives added steering-trail to feel like the bike handles much like a 26" bike having a 1 degree slacker head and fork angle. The BB is raised also by 3/16 inch when going to 650b front-only, giving improved pedal clearance, which riders prefer for more difficult trails having many obstacles.

Q: After swapping to a 650b front only with 26" rear wheel, my seated position is changed to be too far back and my bars are too high, I can't climb as easily. However, downhill bump compliance and front wheel cornering traction is much improved. What can I do to return to my familiar climbing position?
A: There are a couple options. 1) If the fork design allows, you could lower the fork travel 1/2 inch to return to the bike's original frame geometry and rider fit over the wheels and crank.... or, 2) Do not reduce fork travel, instead, lower the handlebars 1/2 inch by swapping stem spacers or using a bar with less rise, and move the seat forward on the rails about 1/4 inch and raise it about 1/8 inch to maintain the same leg reach and rider center over the wheels and cranks as was familiar before swapping the 650b front wheel with 26" rear wheel. The second option maintains the familiar climbing position, and 650b in front-only improves downhill and fast corner traction balance compared to the same bike previously with 26" wheels.
 

· Mtbr Founder
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Discussion Starter · #6 ·
Nice ones so far!!

Some questions:

1) What exactly is the benefit of 650b? How does it improve a stock 26er bike converted to 650b? Who is the ideal user?


2) Given that 650b is only 39% of the way from 26er to 29er, isn't it too close to 26er to make a difference? Why not just go 29er?


3) What tires and forks are available today? What will be available next year?


4) Where is 650b derived? What is the proper designation, 650b or 27.5?


5) Do bike/fork manufacturers approve of their product used with 650b wheels? Are the warranties still honored when something breaks?

fc
 

· J:
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good questions comparing 27.5" to 26" tires

- What are popular 26" equivalent tires that have the same characteristics as the current 27.5" offerings?

Talking about likelyness to pinch flat, cush/ volume, handling, tubes or not etc. would help people get an idea of what to expect

example... is 27.5" 2.1 Neo Moto closer in volume to a 26" 2.3 Nevegal, a 2.3 Maxxis DHF Minion, or a 2.1" Panaracer Fire XC pro?
 

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Nice ones so far!!

Some questions:

1) What exactly is the benefit of 650b? How does it improve a stock 26er bike converted to 650b? Who is the ideal user?

Ideal User? I think the range of people who could enjoy 650b mountain bikes is extensive and the wheelsize will work well in various disciplines from XC to AM/Freeride

2) Given that 650b is only 39% of the way from 26er to 29er, isn't it too close to 26er to make a difference? Why not just go 29er?

Ride one and decide for yourself with regard to these two questions. The difference has to be felt on the bike out on the trails. Only then will you truly know if it is for you.

3) What tires and forks are available today? What will be available next year?

Tires - Pacenti Neomoto (2.1, 2.3), Pacenti Quasi-moto (2.0), Kenda Nevegal (2.1, 2.3), Schwalbe Racing Ralph, IRD FireXC Pros, WTB Wolverines (hard to find though)

Next year - A whole slew of choices!

4) Where is 650b derived? What is the proper designation, 650b or 27.5?

Metric or Imperial measurements. Designation is still being sorted out - but either way -it is a great new mtb wheelsize option

5) Do bike/fork manufacturers approve of their product used with 650b wheels? Are the warranties still honored when something breaks?

Well Fox doesn't officially approve, not sure on Hayes with their Nixons and Minutes, and not sure on Rockshox with their Pikes and Revelations and others - but hey that's never stopped people from trying before right!? :)

fc
See my answers in Red

How's that for my shot at those questions?
 

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On the 27.5 versus 650b....

I think of it akin to the 29er versus 700c...

Same thing, but, if you say 700c, you think road bike, if you say 29er, you think MTB....

27.5 could be the MTB name, whereas 650b can be the touring-bike name.

650b is a far older name, but, marketing at the big companies wouldn't care to roll over tradition in order to make an extra buck... small companies might not, but, corporations....
 

· Mtbr Founder
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Discussion Starter · #11 ·
See my answers in Red

How's that for my shot at those questions?
Good answers for me. But we need more detail as I'm not the target reader for this.

The target reader is the 650b noob that is really curious about the subject, doesn't know what to ask but is willing to learn and try.

fc
 

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Good answers for me. But we need more detail as I'm not the target reader for this.

The target reader is the 650b noob that is really curious about the subject, doesn't know what to ask but is willing to learn and try.

fc
Those answers are good for anyone (aside from the little bit about you being an ideal candidate for the wheelsize). Feel free to edit that out, or I can do it. :thumbsup:
 

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To the above Q/A..........

With the given clearances of 355-360mm, are you referring to the length of the stays necessary?

If one were to measure the clearance between the bottom bracket the center tread of 26x2.1 tire, how much more room would one need to account for to know if the frame would be compatible?
 

· www.derbyrims.com
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To the above Q/A..........

With the given clearances of 355-360mm, are you referring to the length of the stays necessary?

If one were to measure the clearance between the bottom bracket the center tread of 26x2.1 tire, how much more room would one need to account for to know if the frame would be compatible?
355-360mm (about 14 inches) from the axle center to seat stay stay bridge and chain stay yoke for the about 350 (13.5inch) 650b wheel with tire clearance.

A 650b wheel and tire is 1/2 inch larger radius using the same height tires on each. Some 26 inch frames and swingarms easily clear 650b already, some barely clear, some don't.

IMO, going forward, frame designers should design to accommodate both wheel sizes with minimal to no increase in chain stay length beyond current 26" stay lengths. Allowing riders to decide for themselves which wheel size on the same bike works better for their interests. On currently convertible 26" bikes this works very well already.
 

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355-360mm (about 14 inches) from the axle center to seat stay stay bridge and chain stay yoke for the about 350 (13.5inch) 650b wheel with tire clearance.

A 650b wheel and tire is 1/2 inch larger radius using the same height tires on each. Some 26 inch frames and swingarms easily clear 650b already, some barely clear, some don't.

IMO, going forward, frame designers should design to accommodate both wheel sizes with minimal to no increase in chain stay length beyond current 26" stay lengths. Allowing riders to decide for themselves which wheel size on the same bike works better for their interests. On currently convertible 26" bikes this works very well already.
How do you propose they account for change in bottom bracket height? Some type of swap-able/adjustable dropouts?
 

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couple

Nice ones so far!!

Some questions:

1) What exactly is the benefit of 650b? Rolls notably better over chop than 26" How does it improve a stock 26er bike converted to 650b? Tough call, the BB goes up so much that handling deteriorates, 650 specific designs are the way to go. Who is the ideal user?Those that tried 29 and understood the benefits but did not want the drawbacks, so stuck with 26.

2) Given that 650b is only 39% of the way from 26er to 29er, isn't it too close to 26er to make a difference? Uhhh, no. whatever the tire choice there is still a notable difference, even when comparing huge '26' to smallish 650. I have ridden 650 a lot recently but last weekend took a 26" wheeled bike to a 55 mile ride with over 8k feet of climbing. Needless to say I had lots of time to ponder the differences, and they are vast. Why not just go 29er? The difference between 26 and 29 are huge, and of course many are more than happy to ride 29 and always will. But the moment of inertia differences are so notable between the 3 sizes that riders can make a choice based on what they like, not % on paper.

3) What tires and forks are available today? What will be available next year? Plenty of options by the end of summer 2012.

4) Where is 650b derived? What is the proper designation, 650b or 27.5? 26" does not measure 26, 650 does not measure 650 and 29 is well over 29. i.e. a '650' with a 2.35 designation is actually 712mm diameter. When is proper anything applicable to the bike industry. If it looks good, ride it.

5) Do bike/fork manufacturers approve of their product used with 650b wheels? Are the warranties still honored when something breaks? The 5 Spot and the Sultan both take 650 wheels with various tires and predictable geometry changes, but they are still warranted whatever tire you run.

Thanks for the catalyst Francois

DT
 

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Nice ones so far!!

Some questions:

1) What exactly is the benefit of 650b? How does it improve a stock 26er bike converted to 650b? Who is the ideal user?

2) Given that 650b is only 39% of the way from 26er to 29er, isn't it too close to 26er to make a difference? Why not just go 29er?

3) What tires and forks are available today? What will be available next year?

4) Where is 650b derived? What is the proper designation, 650b or 27.5?

5) Do bike/fork manufacturers approve of their product used with 650b wheels? Are the warranties still honored when something breaks?

fc
1) What exactly is the benefit of 650b?
vs. a 26er, you get improved roll-over in chop as mentioned, plus slightly more stability, and improved grip due to the longer contact patch of the larger diameter wheel. The higher tire volume allows for slightly lower pressures too.....basically, the same benefits of a 29er but in smaller measure. Personally I find the cornering feel to be noticeably more "confident", and the overall ride to be faster, smoother, and more efficient rolling.
vs. a 29er, you get some of the rollover, cornering, and traction benefits that people love about 29ers, but in a lighter, faster accelerating wheel, a bike that feels more familiar and "flickable" to 26 riders, and a bike that can do things that 29er's stuggle with such as long travel applications (140mm+) and shorter chainstays for easier manuals, drops, and switchbacks.

How does it improve a stock 26er bike converted to 650b?
re-read "vs 26er" above. If you have a bike with a low bb then the increased height MAY be seen as a benefit. The Ibis Mojo SL and Santa Cruz Blur TRc are notable examples that have bb heights on the low side of average for 5" bikes (13-13.3"), and so they play better as a conversion bike than something with a 14" bb height.

Who is the ideal user?
For conversions.... Are you 29er curious but can't afford a new bike? Do you love your existing bike but would like to try out the benefits of bigger wheels? Do you have lots of pedal strikes on rocky trails or struggle scaling ledges or clearing tall obstacles? Do you like to tinker and invest time in optimizing your bike for you?
In general.... Anybody wanting big wheel benefits in a bike that can have travel up to 160mm...and maybe beyond...only time will tell there. Anybody wanting big wheel benefits in a bike that handles more like a 26er, with shorter chainstays and more "snap" and agility than most 29ers have. Any riders of shorter stature who want big wheels in a bike that's sized more proportionately to them than a 29er. Racers looking to balance the advantages of big wheels with the desire for lowest possible weight and fastest possible acceleration.

2) Given that 650b is only 39% of the way from 26er to 29er, isn't it too close to 26er to make a difference? NO. Ride it and you'll see. Ski's don't come in just 2 lengths....neither do surf boards, shoes, or anything else where the human body interfaces with a "tool".

5) Do bike/fork manufacturers approve of their product used with 650b wheels? Generally, no. They take the safe route and say "not approved". The Mojo HD140 is a notable exception as a product that was originally intended for 26" wheels, but adapts to 650b without requiring modification so Ibis approved it for use.
 
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