Can you fit 27.5s on 26inch frames?

[baldyonabike]

Hi folks, I don't have any 27.5 wheels lying around or I'd check myself, but has anyone tried putting them on a frame/fork designed for 26 inch wheels?
In this case, a 99 Marin B17

BOAB

 

[Siish]

It can be done with some frames, but not all, biggest issue ive heard of is with the 650b (27.5) wheels being slightly larger in diameter its issues with tyre width on rear chain stays. ( although ive never tried so what do o know )

 

[M_Chavez]

I don't think conversions are that uncommon. Depends on the frame and what tyres you're planning to run?

Assuming you are running rim brakes, you encounter 2 problems:
1) Calipers might run out of upwards adjustment (might have to buy different calipers)
2) Pads move further away from the stud, decreasing mechanical advantage. Braking might become spongy.

With disk brakes I'm pretty sure you can fit 700cx25 into some 26er frames.
Don't know why anyone would do that, but hey, I don't judge. What happens behind closed bike shed doors is not my business.

 

[clubby]

Pretty sure with that frame design that the tyre would physically fit but I agree with M_Chavez that the brakes would not work unless you also do a disc conversion. Not many 27.5 rims designed for rim brakes either.
Other more important issue is the bigger wheel/tyre would likely run into the seat tube before the shock bottomed out. Last thing you want is jamming solid on a bit hit.

 

[robfinger]

With disk brakes I'm pretty sure you can fit 700cx25 into some 26er frames.

I'm running a 2000 Bomber Z5 with x32 Marathon tire on 700c wheel, there's literally 1mm clearance between the arch and the tire. I'd imagine a more modern fork will have more space in that area, good chance that applies to frames as well.

 

[tintin40]

Here is a picture of a 1994 26er Trimble with 700C wheels. Fitted a Pauls rear brake. if this helps?

 

[velomaniac]

I have a set of 27.5s that can use rim brakes on and they do indeed fit many different 26er frames. I use modern bmx v brakes with extended pad mounting slots that allow bmx riders to use 451mm and 406mm 20" wheels on same frame. These brakes work well on 26 and 27.5 frames. However I tend to find only frames with loads of clearance allow tyres greater than 27.5 x 2.0 circumference /width.
As for fitting to a full sus, some designs will be fine such as a Trek Y frame but others such as a Marin B17 might not as Clubby suggests although there was a guy who converted a Marin possibly a B17 into a fat bike with 26 x 4.0 tyres which are greater in diameter than a 27.5. The conversion did involve cutting and welding so might have involved swing arm lengthening as well

 

[Siish]

@legrandefromage concoction when i gifted him a set of 'vision team 30' 700 c wheels and he put the pn a 26er

 

[baldyonabike]

Cheers for the advice folks, the bike is running disks front and back which may help. Tyre width clearance and the rear tyre hitting the frame seem to be the biggest caveats. I have a Fox Vanilla 35 fork kicking about which by the looks of the clearance will take a 27.5 happily whereas the Manitou currently on the bike. looks like it might be a little tight.

 

[M_Chavez]

I presume that you want to go 650B to make use of the "gravel" tyre selection in 37-47 sizes, so clearance should be OK? Otherwise what's the point, just stick with 26ers. They are better anyway