My 650b long term experiment (long post)- Mtbr.com
Results 1 to 9 of 9
  1. #1
    bump and grind
    Reputation: cobym2's Avatar
    Join Date
    Apr 2005
    Posts
    707

    My 650b long term experiment (long post)

    Having a frame and a few parts lying around and nothing to do, I decided to dabble in something totally unknown to my cycling brethren (at least where Im from) in 2009.
    I decided to do a 650 b experiment back with a Voodoo Wanga hard tail, with Stans 355 650b rims and Pacenti neo moto 2.35 up front and a Quasi in the back. The fork was a Fox Vanilla. Clearance was excellent with the Quasi and Neo, and even with the WTB Wolverine 2.2s.



    After several months of riding, I really couldnt discern a major change in handling from when the bike when it was still with 26 inch wheels. Perhaps a little better roll-over and traction, but all in all it was a bit underwhelming. The bike was still quick and handled well, however, despite the slightly higher bb height. Anyway, I was stuck with the wheels and it was still good for getting quizzical looks from other bikers ("Is that a 29er?", "What brand are those tires?")

    I later changed the fork to a Fox F100 (again excellent clearance) and put my old XTR 8 speed drivetrain, and a slightly longer 90mm stem, narrow flat bars with bar ends. The bike was now my daily drive/commuter, long distance and occasional race bike.



    I wore through 3 rear tires with this configuration - The quasi (which became a slick in no time), and 2 wolverines. The neo-up front is still in good shape, however. Somehow, the changes made the bike an absolute pleasure for long distance xc rides. I was very comfortable on this bike. Also, despite the narrow bars, I was able to decently keep up with many full susses with 26 inch tires on many not-so-gnarly descents. Was that the advantage of 650b tires? Maybe.

    In 2010, due to some insane episode and the lure of a titanium frame, I sold my Voodoo frame and fork and now had an idle pair of 650 wheels and tires lying around again. Having two 29ers (a Lynskey and a TNT Sultan), I figured - why not? Thus, the experiment continues, this time with 29 frames and forks.

    First, the Lynskey Ridgeline 29er with a Manitou MInute 29 fork with 200mm (more or less 510mm A-C length).
    Impressions - Really light, very quick, almost twitchy steering, BB was toooo loooow and pedal strikes on many things was a problem.


    After 3 rides, i decided to move the 650 wheels over to the Sultan, same fork


    and later with a RS Sektor 26er fork.
    Clearance on the RS Sektor coil fork with 2.35 neomoto - good!
    . Overall, one of the best forks I've used 26er or 650b, especially for the price.

    Impressions - The Sultan with 29 wheels was a great xc and trail bike, was very stable, but like many 29ers, it was a handful to control in tight, swoopy turns at speed. Of course, the 29er wheels were also a bit plodding at takeoff. The 650 wheels changed this - the bike was quicker, snappier on the take off, and steering was razor sharp, but not twitchy. But again, the ultra low BB reared its ugly head. On stock configuration, 650b wheels on the Sultan simply would not do.

    Attempted solution - raise the bb up by getting (a) offset shock bushings; or (b) a longer shock, and (c) a longer fork.

    a) offset shock bushings - Ordered and changed the bb height a fraction of an inch. Not really helpful.

    b) Longer shock - the sultan uses a 6.5" x 1.5" shock. I was able to find a 6.75" long shock for dirt cheap (a dirt cheap DNM coil shock), so I slapped it on. The bb height went higher to around 13+ and pedal strikes were quite reduced, but still more than if it had 29 wheels.


    The only problem was that now, the head angle was steeper and on steep descents, it became scary. Part of the problem was that the Sektor 140mm 26er fork and the 100mm Minute 29er fork had A-C lengths of around 510-512mm. I needed something longer to slack out the head angle a bit.


    The solution....

    c) Longer fork - I jumped on a Jenson sale for a Manitou Tower Pro 120mm fork with 20mm axles. A-C of around 540mm. The head angle eased up to 69.5 deg or so and the 20mm axle helped stabilize the steering also.

    With this configuration (longer shock and fork, 650b), the Sultan was a joy to ride. Quicker, snappier and more flickable than the 29er, albeit less of the monster truck roll over capability. It was a happy medium. The bike actually felt more like a 26er, but with better roll-over and traction. Not bad at all. It made me want to go faster, downhill, around turns, over jumps, etc. It was, in a way, scary.

    The bike stayed this way for several months, with a lot miles logged. One recent ride involved a 7 hour climb and a 1 hour descent in unfamiliar and very rocky, high speed terrain that required quick reflexes and instant direction changes.


    I figured at the end of the ride that I would have been more tired and worn out with my 26er bike uphill, and I wouldnt have been as gung ho and fast if I was on a 29er on the downhill. Talk about a good compromise.
    The only thing holding me back was the thought that I had superlight rims that may just suddenly buckle and throw me off a cliff in the middle of nowhere. If I had wide 650B all mountain rims with 650 minions, WOW.
    But to their credit, the ZTR 355 rims have held up to the abuse I've given them.

    By the way, I also tried the 650bs on my Turner RFX, but clearance wasnt good enough for my mud, and it resulted in a really sky high BB. With the mud I encounter daily, I never even tried to ride it.

    My impressions after nearly 3 years on various 650b frankenbikes?

    Major issue in converting from a 26er is tire clearance, but really nothing much else.
    Major issue in 29er converted to 650b is BB height. Pedal strikes have become tiring. Resolving the issue was a pain (slightly longer shock? I just got lucky). Looking back, I would rather convert a 26er to 650b than a 29er.

    The tire size has a future. A light racer with light rims and a low profile tire, or an all mountain do it all with wider, stronger rims and a full knobby 2.35 tire or larger. It just takes needs dedicated equipment to make it all come together better. Frankenbiking has gotten me quite far, but currently the product choices are still woefully little. Tires are limited to a few, and are $$$$$, forks and shocks have to be shimmed, etc.

    I can just imagine how a purpose built 650b bike designed with care from the ground up would be absolutely shine.

    What to do now? That Intense Tracer/Carbine 27.5 looks good.
    Last edited by cobym2; 11-11-2012 at 12:49 AM.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    847
    Great write-up!
    The 7 hour climb, where is that?

  3. #3
    650b me
    Reputation: golden boy's Avatar
    Join Date
    Oct 2008
    Posts
    1,483
    I commend you on your extensive experimentation. You sound like a restless tinkerer.

    I was glad to see that you came to the conclusion that a 650b-specific frame is really the way to go. And they're coming quickly now! I have been riding a 650b-specific hardtail that I built at UBI in February. No, it's not a big change from 26". But over time, I have really come to appreciate this wheel size. I can tell the difference. It's much more evolutionary than revolutionary, but hey, every little bit counts, right? I'm sold on the wheel size enough to say with confidence that my next bike will be a 650b full-suspension model. I'm not in a position to buy right now, or I'd consider the Ventana Zeus. I really like what the company stands for, and by all accounts they build quality frames. But by the time I'm ready to buy, I'm hoping Pivot will have a 650b model out. I have a Mach 4 now and after three-plus years it still impresses the hell out of me.

  4. #4
    mtbr member
    Reputation:
    Join Date
    May 2005
    Posts
    2,192
    Very nice writeup and good on you for all the tinkering vs just throwing in the towel

    7 hour climb Yeah, where is that???

    Lots of nice dedicated 650B bikes now compared to just even 6 months ago. Jamis, KHS, Ventana, Rocky, Norco, Scott, Intense, Turner, Banshee, Nicolai, KTM, and other Euro brands I'm not quite up on. Hopefully Pivot soon and a birdie told me mid 2013 a Spec. EVO 650B.

    Plenty to pick from now IMO except sub 4" models but I think that will happen in good time.
    2016 Trek Remedy 8 29er
    2013 Banshee Spitfire V2 650b SOLD

  5. #5
    mtbr member
    Reputation:
    Join Date
    Jul 2011
    Posts
    187
    Quote Originally Posted by cobym2 View Post
    If I had wide 650B all mountain rims with 650 minions, WOW.
    second that~!
    actually the upcoming High Roller 2,4 and ardent will be fine, if not minion I will stick with those I think.

  6. #6
    Stubby-legged
    Reputation:
    Join Date
    Jun 2006
    Posts
    1,263
    I really noticed the difference in my 1x1 when I changed back to 26. I had a set of 26 wheels "incase" 650b did not work out.
    One ride on the 26er's and that was it. Off with them and back went the current 650 set.
    The 26ers hang in the garage next to the 29ers I tried before. Lonely and gathering dust.

  7. #7
    bump and grind
    Reputation: cobym2's Avatar
    Join Date
    Apr 2005
    Posts
    707
    Thanks all, just wanted to share my views.

    @steelbike @skidad - The 7 hour climb (lots of hike a bike, rests, and dismounts) is in Bataan, Philippines. We were taking our time a bit though. It was an adventure ride to some beautiful waterfalls and we had some not so fast riders with us. If pushed we could have probably gotten up in around 5 hours. Our camelbaks were empty around the 2/3 mark and we had to refill from a mountain spring. A real epic. The return trip downhill was the most fun I had in years.

    @goldenboy - The tinkering continues. Im eyeing some generic Carbon frames which seem to have good tire clearance (unbranded whippet?) and watching out for a Ti hardtail with sliding dropouts on ebay. Im missing my 650b HT.

  8. #8
    Baby Bear is in the house
    Reputation: r1Gel's Avatar
    Join Date
    Jan 2004
    Posts
    2,030
    Quote Originally Posted by cobym2 View Post
    Having a frame and a few parts lying around and nothing to do, I decided to dabble in something totally unknown to my cycling brethren (at least where Im from) in 2009.
    I decided to do a 650 b experiment...
    Nice writeup dude
    Still looking forward to when we cross trails.

    Alas, I don't get much ride time nowadays...

    I hope to bring by BB Ruth to Morong when I attend a friend's wedding at the end of December
    Better to have and not need it, than to need it and not have it.

  9. #9
    bump and grind
    Reputation: cobym2's Avatar
    Join Date
    Apr 2005
    Posts
    707
    Quote Originally Posted by r1Gel View Post
    Nice writeup dude
    Still looking forward to when we cross trails.

    Alas, I don't get much ride time nowadays...

    I hope to bring by BB Ruth to Morong when I attend a friend's wedding at the end of December
    We should do a 650b ride. That would be a bit lonely though, with just two or three of us. Hehe.
    Next epic, Ill let you know.

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.