Share

How-To Convert 26″ to 27,5″ / 650b MTB wheel size

Want to convert your 26 inch MTB to a 27.6 inch? That’s a job you can easily do yourself. Converting your 26” mountainbike to a 27.5” or 650b wheelset isn’t as hard as you might think. Kees walks you through the steps.

Why are there so many different wheel sizes out there anyway? The image below illustrates the difference between the various sizes. The angle a 29 inch-wheel needs to overcome in order to get over an obstacle is smaller than the angle required by its 26 inch counterpart.

Convert 26 to 27,5 inch
A bigger wheel size makes a small onstacle less of a nuisance then a smaller wheel size. Converting a 26″ wheel to 27″ can mak a ride more smoother.

A 29’er then rolls over obstacles more easily. The larger the obstacle, the larger the advantage of a 29 inch wheel gets. Now though, there’s the 27.5” wheel, which for some is the best of both worlds.

There is a snag though: your bike needs to be able to fit the larger wheels. A lot of bikes are being converted to 27.5” and there’s a lot to be said for doing so, but it doesn’t use the full potential to be had from a 27.5” wheel.

The conversion of a standard 26” can come with a range of problems, such as inadequate frame clearance or geometry trouble.

Create enough clearance to convert your 26″ to 27,5″

So how do you know whether you’ll have enough clearance, both at the front and back? Ask yourself the following questions.

  1. Will the rear wheel fit my MTB frame?

Not all 26 inch frames are compatible with a 27.5” wheel, as it can easily rub on the stays or bottom bracket. There’s a number of lists out there, with all the frames suitable for a conversion to 27.5”. 650b Palace has one of those lists on their blog.

  1. Will the front wheel fit my fork?

Fox forks are the only forks compatible with 27.5 inch wheels. Rock Shox and Magura forks aren’t, as the tyre will make contact with the arch of the fork. These two brands have made 650b-specific forks however.

  1. What happens to the geometry of my MTB?

As the wheels are 1.5 inch larger than before, your bike will stand 0.75 inch taller. This will make the bike feel slightly less nimble through the corners. This is easily compensated however by the extra grip provided by the tyres.

Share
Kees Neijenhuis

Kees Neijenhuis

Enthusiastic trail runner and mountain biker. I love being outdoors! I also have a weak spot for beautiful products and true craftsmanship. Rides a Trek Top Fuel 9.7 SL 2018.

Leave a Reply

Your email address will not be published. Required fields are marked *

121 thoughts on “How-To Convert 26″ to 27,5″ / 650b MTB wheel size”

  1. I have an older Specialized Rockhopper Comp FS with Fox Float forks. I do not recall the exact year of the bike, but think around a 2004 (been in storage for years). Curious if I can convert it to 27.5″ rims. Has anyone done this on such an old bike?

    1. I have a 2010 specialized Enduro that has 26 wheels and would be so much better on some 27.5s but I don’t really know how to go about the swap

    2. I have a 2009 Hars Rock and front is close but back brace above wheel is tight!! No way to go much bigger

  2. “Kees walks you through the steps”.
    Is there another article where these steps are discussed in more detail?
    “Create enough clearance…”
    If a 27.5 rim and tire won’t fit in the rear, are there extensions available to get the clearance needed?
    I understand the concept of upgrading forks, but as I’m just getting into the sport recreationally, I’m ignorant when it comes to doing such a modification.
    I came across a 2009 Trek 4300 for a pretty good deal ($20) that needs some tlc and was curious if doing this conversion is difficult and is it worth doing so.

  3. I have a 2014 26 in Trek Session 88
    already converted front fork to a 27.5 203mm but was wondering if I purchased a 27.5 rear triangle and evo link, will the geometry line up or will I snap my frame

  4. Hi all, I recently was given a 2004 Ellsworth isis (I know different times) and love how it rides but am looking to upgrade the forks. I was looking to also move from a 26″ to a 27.5″ and do not know if it is possible. I am new to the sport and still am learning about how I can make my bike better and feel that the larger tires are a good start. Thanks.

    1. Hey Alvin,

      I have the same bike. Did you find out if its possible to fit 27,5 inch weels? It will be nice upgrade. What fork you have at the moment? Please let me know ;)

      1. I have a 2008 epiphany Ellsworth and recently moved to flat land with lots of paved trails
        I would like to Slo move to a 27.5 I am experimenting with some 1.25 front and 1.5 panaracer gravel king I mounted the one on the front tire and it looks pretty funny yet I think it will ride ok I get the 1.5 in the mail Tuesday
        I am concerned with my xtr rims
        Any thought

  5. Hello, I am a Cannondale Scalpel 27,5” from Portugal. My Scalpel used to be a 26”, 80mm from 2012. Turned into a 27,5” 2018 bike.
    To achieve this the carbon was worked on the carbon bridge so as to leave enough clearance.
    Then the whole frame was painted a dark gray with the appropriate lettering.
    This year I installed a SRAM XX1..36X46.
    I think I have a bike with the best of both worlds; agile to overcome obstacles, rolling, light and extremely maneuverable.
    Pleased? No. Much more than that and for a very affordable price.

    1. I have a small specialized stumpy fsr 2013, 26er.. lovely bike but wanted to update it..I bought a rear 27.5 wheel with bolt thru hub, and had a set of 29er forks and front wheel. Put a 2.6 tire upfront and a 2.25 on the rear.. the bb is to high but most of the angles appear very similar to my 2015 kona hard tail..seat angle, top tube head tube all appear nearly the same.. my gosh it feels great. The fork head tube angle has changed and its a bit twitchy, i changed stem for a shorter 30mm one, but going downhill with dropper feels awesome..looking at my old cannondale 04 jekyl might have to convert this..

  6. Question ! Cube AMS 26″ wheels , can I convert to 27.5 , do they do Mavic rims in that size or can I change forks and rear suss arms to fit this model and make up to a 29 we ???

  7. Hi, I have a 2011 Giant Trance X2 large frame. its a 26″ wheel set and I would like to modify it to a 27.5″ wheel set. Has anyone done this before? Im wondering if its possible with the Frame. Thanks.

  8. Hi I have a voodoo hoodoo mountain bike and have 26 inch wheels can I put 27 inch wheels in my frame and forks thanks

    1. I have 2006 Specialized Stumpjumper FSR Expert. Can I convert from a 26″ to 27.5″?

  9. “Fox forks are the only forks compatible with 27.5 inch wheels. Rock Shox and Magura forks aren’t”

    Rock Shox Totem from 08 fits 27,5 easily

  10. Hola, tengo una Spec Stumpjumper FSR Comp 2008 de 26″. La horquilla es una Fox. Es posible la conversión a 27,5″?

    1. Also I know this is different but how do i know weather to get a straight or tapered steerer for my bike, do they all fit any bike?

  11. Hi, I have V-break in the rear. Are there V-break with longer arms to support to conversion from 26″ to 27.5″?

    1. I don’t know if there are v-brakes with longer arms. But I do know that you can convert from v-brakes to disc brakes in the rear. There are some cheap rotors, and brake calipers out there. There are also some adapters to fit on your frame. (Rear)

      1. Hi there, you can only convert to disc if your frame is already suited for disc brake. Furthermore avoid adapter sets for this purpose as they can come off in worst case scenarios. Be safe!

  12. Hi,

    I have a 2014 Giant XTC frame (26er) with a Suntour Epicon RLO fork.

    I am planning to change my present wheelset which is fitted for a 26er to a 27.5 rimset. Is this possible?

    Thanks

    1. I have carrera vengeance 26” wheel. Is that possible to upgrade 27.5 on it.
      Please if you have any idea.
      Thanks

  13. What is wrong with you people. Don;t follow the latest fad. There is still plenty of 26″ tire availability. I’d challenge anyone to notice a significant difference in your speed from making this switch. The only thing you will accomplish is wasting $$.

    1. Totally agree. For extended trips abroad 26 inch wheels and tyres are readily available if required, along with 8 or 9 speed cassette s, I’m using XT thumb shifters and butterfly bars on my thorn, square taper sks BB. Five years in still smooth.
      I’m still using 26 inch wheels built by merlin cycles when they where in Ormskirk lancs, XT hubs mavic 230 SBP rims.
      I’ve a voodoo Bantu I’ve turned into more of an adventure bike, running the original wheel set with schwalbe land cruiser tyres.
      Pannier rack, frame bags and butterfly bars.
      Microshift sl9 thumbies. The sun tour forks need to go that’s the next upgrade rigid forks.

      1. Pedro, if you’re going rigid on the fork, Soma have a nice one, curved, tapered blades and disc mount (made by Tange). Or, there are plenty of more heavy-duty options from Surly and others. I like the Soma as it rides nice and supple like the old Tange 9 series. (Ritchey Logic, Cannondale) Would like to go tubeless on my bike (I bought two NOS no-name titanium frames, from a local shop. Mid-90s type from the look of ’em, super cheap) but I’m having trouble justifying the cost.

  14. I have a 2013 Specialized Enduro Evo (26er) I know the newer versions of this bike come standard with 27.5 or 29ers, but I am not sure if that was a frame modification from the factory, or if there is enough room on my model year to make the conversion.

  15. I am new to doing this and i need some help i just bought a montana mongoose with stock everything it has 26 inch rims and tires so can i convert it to a 27 inch rim and tire

  16. I have a 2012 Fuji Nevada 1.0 , this has 26” wheels, can this be converted to 27’s ??

  17. I have a 26 in huffy durasport.
    I but 27 in wheels for it. That fit the frame but the side pull hand brake don’t reach the rim.
    Is there hand brakes out there that I can buy to to replace the ones I have now so i can us the 27 in wheels ?

      1. Does your frame still have cantilever/V-brake bosses on it? If so, you can run Paul Motolite V-brakes and they will allow you plenty of adjustment for the height of the pads. They will cost you a pretty penny though.

    1. Hi Gan,
      Many thanks for your question.
      26 inch wheels is biggest size that will fit on frame size 17.5, so unfortunately you can’t upgrade to 27.5 or 29 inch.
      Kind regards,
      Robin

  18. Wondering if possible on a Gary fisher Joshua f1 frame from 1999.
    I can get forks, but not sure of rear.
    Where do I measure from to see if fits.

  19. I Don’t see the point in doing this to be honest, even if you have a 26er frame/fork that can clear a 27.5 wheel you are going to be restricted on the width of tyre you can cram in (on the rear at least) and it screws up the geometry. You will get better results from simply fitting the fattest 26″ tyre you can get away with and maybe converting your rims to tubeless. Its not like you can’t buy 26″ tyres in the latest designs Maxxis’s entire range still comes in 26″.

  20. I have a 2013/14 Rocky Mountain Flatline Pro WC DH Bike, it currently has 26in wheels on them, am I able to put 27.5’s on my bike?

  21. Wondering what is the smallest size, good quality road tire available for 27.5/650b? I want to run 27.5s on my old Salsa ti frame. (mid-90s) Mainly for delivery work. Looking for something of the quality of Hemisphere kevlar tires but with a smaller cross section to cut rolling weight. Are there 27.5 x 1.0″ tires out there? Frame clearance shouldn’t be a problem as the Salsa frame has no chainstay bridge. Using it with a Tsunami 27.5 rigid fork.

    1. Hi Patrick, thank you for your message. Unfortunately, Mantel does not offer the tyres that suit your bike. Continental or Michelin could have the ones you are looking for.

      Regards,
      Simone | Mantel.com

      1. Hi Simone,
        I didn’t see the one I have on the list. Giant xtc 1, hardtail disc brakes (2009). I wonder if a 27.5 can fit. It has a lot of space in the rear. Rock Shocks in the front.
        If it’s not I’ll stick to my “26. Not going to invest in forks drop extensions. I’ll rather invest in upgrading it.
        Please let me know and thanks in advance

  22. I have a 2006 Iron Horse Maverick, is it possible to convert to modern components and 27.5″ wheel set?

    1. Hi Kyle, thank you for your question. It is not possible to convert a 2006 Iron Horse Maverick to modern components and a 27.5″ wheel set.
      – Simone

  23. Hello, I have a 1991 trek 7000. She has 26″ wheels. Can I change them for 29ners? or 27.5ers? Need to change the forks also. ANy suggestions on who might sell them?

  24. Hello, I have a 2009 Norco Bigfoot. Comes with 26×2.35 wheels and I’d like to convert the wheels to 27”. Has anyone ever done a wheel conversion on this MTB. What was needed to do so, Please let me know

  25. Hi. Like the others here, I’d like to know if I can convert to a larger wheel set. I have a 1986 stump jumper with 26″ wheels . Thanks for your time.

  26. I have a Cannondale f800 with headshok that would make an excellent commuter. I didn’t see it on the list but any thoughts on 26 to 650b conversion?
    The numbers seem to work out where my 2.25″ tire on the 26″ rim is 673mm diameter vs my desired conversion is 45mm on 650b rim is 674mm.
    Thanks

    1. Hi Chris,
      This should be possible. As long as you don’t pick tyres that are all too wide, there should be no problem.
      Any questions on the matter? Contact our English customer support for assistance.

  27. I have a 26” MTB with a cheep rock shock fork that is frozen up so my plan is to replace it with a rigid fork and 27.5” tires I think They will fit on the rear because the chain stays aren’t straight they bow out up near the bottom bracket.
    Freddie Strong

    1. Hi Freddie,
      It may well be possible, but it is hard to say based on this information alone. If you could contact us through our customer service and provide us with a few more details and/or images, we may be able to help you even better.

    1. Hi Jessie,
      Different manufacturers use different standards for their measurements. While one manufacturer measures the product on the inside and ends up with 26×1.95, it may well turn out to be 26×2.25 when measured on the outside. However, this is not the displayed value.
      A different manufacturer which measures its products on the outside may at the same time end up with 26×2.15. Based on numbers alone, this would seem bigger than the 26×1.95 , but because they were measured differently, this may not actually be the case.
      If you have other questions on the topic, feel free to ask our customer support.

  28. I have a 2008 Trek Fuel 5.5 with 26″ wheels. I am replacing the front fork and was wondering if I should upgrade from a 26″ fork and tire to 27.5″ front fork and tire. Would that work on this bike? I would leave the 26″ tire on the rear. Any thoughts, suggestions or just stay with a 26″ set-up, thanks…

    1. Hi BM,

      You can sure do so. Permitting you select a fork that has the clearance.
      It will lead to more stability during cornering but you’ll corners will be a bit less sharp!

      Good luck with the remodeling!

  29. This not rocket science. The tiny potential difference in the frame geometry is well within the variation seen by using different tires, tire pressures, weight, maybe types of headsets, or the real terrain you will see in the real world. Measure how much space you have when you have your 26 inch tires on. For the same type of tire, you need .5 – .75 inches for the extra radius. If you can fit your thumb in sideways, you’re fine. Biggest issue is at the top of the seat stays where the gap narrows. .
    make sure you have enough side clearance with the tire sitting slightly higher.

    Bikes are simple machines. Stop the flipping pseudo science already!

  30. Will a 700c or a 27.5 wheel fit my bike? Trek Navigator 2012 16.5″

    Alloy hubs; Bontrager 550 36-hole alloy rims

    Tires

    Bontrager H5, 26×2.0″

    Drivetrain
    Shifters

    SRAM 3.0 Comp, 7-speed twist

    Front derailleur

    Shimano Altus

    Rear derailleur

    Shimano Tourney

    Crank

    Shimano M131, 48/38/28 w/chainguard

    Cassette

    Shimano TZ31 14-34, 7 speed

    Pedals

    Nylon platform

    Components
    Saddle

    Bontrager Suburbia FIT w/super-soft padding

    Seatpost

    Alloy, adjustable suspension

    Handlebar

    Steel, 80mm rise

    Stem

    Alloy, adjustable rise

    Headset

    Threaded, semi-cartridge bearings, sealed

    Brakeset

    Tektro linear-pull brakes w/Tektro levers, Kraton inserts

    Colors

    Charcoal Metallic

    Matte Lavender Grey

  31. Cool article.

    I have a 2010 888 rc3, mounted on an intense 951.

    Im trying to see if a 27.5 wheel would fit in the fork.

    I need that extra speed so my fat ass can keep up with the 29ers .

    Thanks gang

    1. Hi Michel,

      Thank you for the cool compliment! (you also have a cool bike, btw)
      I’m afraid that a 27.5 wheel won’t fit, but if you want to be really sure you could measure the space left between the fork and the tyre you have now.
      If you have any further questions, feel free to send us an email.

      Kind regards, and happy holidays!

    1. Hi Heath,
      Thank you for your question.
      Unfortunately this will not fit – I’m sorry!
      Kind regards, and happy (almost) new year!

  32. Hello everyone!!
    I have a 2012 26” Scott Scale 80, does anyone knows if the convention works well in this bike?

    1. Hi Giosser,
      Thank you for your question. Unfortunately this will definitely not fit with your front fork – for the back, it depends on your frame size.
      Kind regards, and happy (almost) new year!

    1. Hello Liam, because I am not familiar with the Mondraker frame geometry I can not asure you that this will fit.
      You also need to take in consideration how much space there is left for tire clearance. Maybe you have a cycling friend with some 27,5 wheels?
      That would be the best way to try if it fits your bike ?

      Antoine I Mantel

  33. Hi,

    I have bought a Marin Attack Trail 2008.
    Few questions if anyone can help

    I would like to update the tyres on the bike too 27.5 from 26 ” .. is this possible? And also would I have to change front forks etc..?

    Rear shock is in need of changing. At the moment it is a Fox RP23.. where would I pick on up?

    1. Hi Ryan, You will have to change the front fork to a 27.5″ one. Considering the rear tire clearance and the rear shock it is best to hop in a local bike shop if it is possible. If you have any other questions please send us an email to service.uk@mantel.com
      Paul|Mantel

  34. Hi, I have 26er Mtb Kona Stuff Model year like 2000 to 2003 and the fork shock is Marzocchi Bomber M seires.my question..Is it possible to accomodate the size wheel of 27.5er?

    1. Hi Jason,
      The best way to find out if it will be possible, is to hop in a local bike shop. The frame is quite old so i doubt it will be possible unfortunately.
      I hope it will be possible!
      Kind regards,
      Paul|Mantel

    1. Hi Charlie,

      Thank you for your question. Since your bike is a bit older, I woudl advise you to check with a local bike shop!
      I hope it is possible!

      Kind regards,

      Rose | Mantel

  35. I have a Santa Cruz blurt 2015 with 26 wheels and wanted to convert to 27.5 just wondering is it possible

    1. Hi Finn,
      I believe your frame should be okay, but I’m not too sure if your fork is compatible. My advice is to visit your local bike shop for advice, as they’ll be able to take a better look at your bike.
      Pelle|Mantel

  36. I have a 2010 rocky mountain altitude full.sus carbon frame 26. Will it be converted to a 27.5 wheel and a fork? Many thanks for a reply.

    1. Hi Frederick,
      For what I can find about your bike, it seems that both the frame and the front fork are not suited for a conversion. You can swap the fork for a 27.5 one, but then you’d still be stuck with a 26 on the rear.
      If you’d like to know for sure though, I’d advise swinging by your local bike shop.
      Kind regards.
      Pelle|Mantel

  37. I have a 2000 Gary Fisher Wahoo 26er. I wanna convert either to 6560b or 27in. I don’t know if this is the right place to ask or if I’m asking the right questions but the local shops near me have been very unhelpful. Basically “buy a new bike (preferably from us)” is what I get out of them. I like this bike, I have sentimental attachment to this bike. I don’t want a new bike, I want to upgrade this one lol. I dunno if it’s possible but I’m hoping someone may have some advice.

    1. Hi Ian,

      Good question! But unfortunately, I think the local bike shops were right. The 27.5 inch option is only possible for mountainbikes with a fork of Fox. The 650B option does only work for the Gary Fisher Fat Possom edition, not the Wahoo. There will not be enough clearance for the convertion in your current frame.
      To keep the sentimental attachment, only 26 inch wheels are an option.
      Hope this clarifies things!
      Kind regards,
      Babette | Mantel

  38. i have a devinci wilson 2014 carbon, i love that bike i wondering if the rear triangle of wilson 27.5 will fit on it ?

    1. Hi Gabriel,

      No it that won’t work unfortunately. I wouldn’t do that on a carbon frame but I wouldn’t recommend it even if it were a steel frame. Swapping rear triangles is practically impossible between different models of bikes (with the exception of availability of kits from some bike manufacturers).

      Christine|Mantel

  39. Hello , i have a Specialized s works Enduro sl 2008 or 9 i don’t really know now,. with a Future Shock E150 fork , please if you can tell me or anyone, am I able to convert the bike to 27,5″ with , i that fork ?
    Personally I don’t think so ,..
    So if you guys more known in these cases ,could help me to get an idea , i would appreciate you.
    Thanks !
    Take care ya’ll .

    1. Hi Miguel, it al depends on how much space there is left between your tire and the arch of the fork.
      You need to leave some save clearance as well, mud and dirt can be a problem if there is not enough space.
      It is tricky to confirm if it will fit or not, maybe you can try it with a 27,5 wheel setup of a friend ?

      Antoine I Mantel

  40. I have a Gary Fisher Marlin approx 2001 or 2002 and need new wheels. Having some trouble locating 26 inch replacements and converting to 27 inch. Any idea if the frame will accommodate?

    1. Hi Aaron, it’s not possible to say for certain without physically seeing the bike, so to sure it is best to speak to someone at your local bike shop, but the main considerations if you want to convert from 26″ to 27.5″/650B are as this: You´ll need to measure to check if there’ll be sufficient clearance between the wheel + tyre and the arch of the front fork. The same goes for the rear – there needs to be sufficient height clearance in the rear triangle for the wheels to spin freely.
      Christine | Mantel

Related posts


Most viewed