Ok so bare with me on this one..

Got an on one whippet and I currently have a rigid carbon (exotic) fork on it that replaced a rockshox sid. It’s currently running mavic crossmax sl 26 wheels.

I’ve read and seen a few people put 650b wheels in these frames and really rated them.

I’m considering puting a 650b wheel on the rear with an xc type race tyre prob a 2.25 ralph. Then on the front as I’ve got the rigid fork a 650b+ tyre to act like a little bit of suspension.

Q1) any Weird cornering characteristics likely to occur (standard stw will I die question)?

Q2) can anyone recommend a light wheel set that will be ok with a 2.25 ralph and give a decent profile but still wide enough to run a 2.8 out front? Would like to avoid mismatching rims if possible.

Cheers for inputs in advance

Sort of like what this guy has done?

facebook linky

I had a quick spin on that bike, it feels fast. Very fast.

Around an XC course the tyre combo worked well and I didn’t even give those weird forks a thought, they just worked. Sort of surprised me how good it all felt.

The problem you may encounter is that you are raising the BB

Cant open the link 🙁

Sorry, probably a closed group or something. It’s a Travers RussTi frame with 35mm Nextie rims and a 2.25 Thunder Burt on the rear but a 2.6 Rocket Ron on the front. Not very suitable for rocky terrain I’d guess but worked a treat for an XC race bike.

How about going 26+ front with the 27.5 rear. That way you minimise the bb height change and roughly keep the same HA.

Shirley it would be odd having softer tyre and more grip up front?

Is that any more odd than having only front suspension? Tractors and dragsters tend to prioritise rear grip over steering but they have specific reasons

Would love to be able to see that Traver Trus ti. Can anyone scrren grab it?

Rubber_Buccaneer – Member

Is that any more odd than having only front suspension?

The levels of grip will be different.

Generally people run a grippier tyre on the front though don’t they.

For example on my big bike I run a magic Mary up front and I’m now on a Rock Razor on the rear.

Suspension increases grip too and I’ve ditched the sus fork.

Question is I guess… how different?

The levels of grip will be different.

Like chilled76 says it’s not uncommon for people to put a big soft compound tyre up front and a harder compound faster rolling tyre on the rear. It looks a bit strange but felt fine, in fact rather good, around an XC course.

Since no one can see the link I should probably mention the forks are the Lauf leaf spring suspension forks. It’s a different discussion but I thought they would be a horrible pogo stick affair. In reality I didn’t really notice them, they just did their job. I need to keep stressing though that my little demo ride was around an XC race course.

Yeh this bike never gets used for big terrain, I’ve got a trail bike I take if I go peak district/lakes etc.

This one is more for local woods etc. Fast xc type riding

I have an inbred with a 26 rear and 27×2.8 front, rides fine. Used to run it as a 69er but this is better as more cush and the diameter of the 27.5×2.8 is quite a bit less than a 29×2.4 so steering is better.

Every off road bike I have had for the last 20 years atleast has had a bigger more aggressive tyre up front, including my CX.