650 B conversion

[BogusOne]

You should be fine with 27.5 wheel and 2.1 tyre. I managed to get a 29er wheel with a 2.0 tyre in that exact Raleigh RM4.0 frame with extremely minimal manipulation of the frame.

[Azza]

You should be fine with 27.5 wheel and 2.1 tyre. I managed to get a 29er wheel with a 2.0 tyre in that exact Raleigh RM4.0 frame with extremely minimal manipulation of the frame.

Oh awesome ! But if i fit a 27.5 wheel, according to your memory of when you fitted the wheel, will their be a sufficient amount of clearence so it wont clog up with mud on rainy days... Thanks

[Ceres]

Go for it, should fit. Also keep your old 26inch wheels so if its a muddy day just use those.

[BogusOne]

Oh awesome ! But if i fit a 27.5 wheel, according to your memory of when you fitted the wheel, will their be a sufficient amount of clearence so it wont clog up with mud on rainy days... Thanks

 

 

Shouldn't be a problem if you stick to a tyre that is not too wide. The 29er tyres I ran was kenda karma 2.0's and they were fine with clearance. Keeping in mind the Karma's isnt a very high volume tyre. I would still if I was you just pop around to your LBS and try some different options as some of the other hubbers have mentioned before you spend the dosh on the conversion. But you should be fine.

[Azza]

Now Im abit confused.. Would their be a point of going for 27.5 wheels with skinny tyres as it seems like if I run high profile 2.4/2.3 26 inch tyres it would be the same as 27.5 wheels with skinny tyres..

[King_Crispy]

Now Im abit confused.. Would their be a point of going for 27.5 wheels with skinny tyres as it seems like if I run high profile 2.4/2.3 26 inch tyres it would be the same as 27.5 wheels with skinny tyres..

Yes, but then you won't have 650b wheels :-P

[Lone_Ranger]

Now Im abit confused.. Would their be a point of going for 27.5 wheels with skinny tyres as it seems like if I run high profile 2.4/2.3 26 inch tyres it would be the same as 27.5 wheels with skinny tyres..

 

This is exactly why I'm thinking twice about going 27.5. A high volume 26 inch tyre can give u the same circumference as many 27.5 tyres, as the difference in the wheel size is so small.

[Sephton]

In my opinion it is of no use to go for 650b wheels if you can't fit a 2.25 tyre at least. My 2.25 R Ralphs measure about 27.5" but the 2.1 would barely be 27".

[nolipoli]

If you have to fit a tiny tyre on your bike in order to make 650b work, then rather don't bother.

 

You won't benefit from the advantages of a larger wheel size:

You won't have a bigger contact patch - no better traction.

It won't be more more comfortable - actually probably less comfortable because of a lower air volume in the tyres.

It won't roll over the rocks any better, because the outside diameter won't be much different.

[kosmonooit]

Even with a 2.1 there is a higher rotational mass with 650b, which is one of the benefits of large wheels, how much exactly I would have dig out my Mech Eng notes and calculate but I guestimate in the region of 10-15%.

 

I have 2.1 on my the back of my Scalpel, its a noticeable difference although I can rule out the placebo factor.

[Kiwi]

Hi Azza,

 

Measure 350mm from the axel forward along the chain stays (average diameter of a 650b tyre is around 700mm), check the same along the seat stays as well. Then measure the width between the chain stays and the seat stays at 335mm from the axel, this is the widest point of a 650b tyre on average. Here's an old table of 650b tyre data that will help:

http://mtbtires.com/...275q-tire-specs

Edited March 3, 2014 by Kiwi

[Azza]

Hi Azza,

 

Measure 350mm from the axel forward along the chain stays (average diameter of a 650b tyre is around 700mm), check the same along the seat stays as well. Then measure the width between the chain stays and the seat stays at 335mm from the axel, this is the widest point of a 650b tyre on average. Here's an old table of 650b tyre data that will help:

http://mtbtires.com/...275q-tire-specs

 

Thank you ! Ill have a look. But now I am just thinking of getting some high prfile 2.4 26er tyres. And ill get more grip with the wider tyres. But ill think about... Thanks for all the help

[Lone_Ranger]

Thank you ! Ill have a look. But now I am just thinking of getting some high prfile 2.4 26er tyres. And ill get more grip with the wider tyres. But ill think about... Thanks for all the help

 

I decided to go the same route. Far cheaper than either buying a 650B specific frame or trying to fit 650B wheels with thin tires on a 26 inch frame.

 

And you get almost the same effect.