I recently re-read Steve Worland’s excellent article from WMB (May 2010) about his custom Pacenti frame. After much experimentation he arrived at a favourite combo of 650b rear & 29er front end. It got me wondering about the Soul 27.5 & its potential do the same thing.
In 2010, 650 wheels were a rarity and even today Pacenti frames are rare and expensive things. However the Soul 275 is 853 Steel, pretty light, can take a longish fork, and is pretty cheap compared with a Pacenti frame. It occurs to me that the Soul 275 might make a great platform for a fat(ish) rigid bike that’s been on a diet. Has anyone on here experimented with a rigid 29er front end on their Soul 275? Also what are the largest 650b tyres you’ve fitted into a Soul 275 frame?
Regards, Timmy 😀

I did something similar but more bodgy with a Genesis iO 26″ around that time. The bike wasn’t designed for it though. The higher front end added a lot of trail – not just from the higher and now slacker head tube but also the larger dia front wheel. BB was raised also. It was sort of fun, hoppy and carvy feeling, but handled badly in some ways.
A couple of years ago I had some ’69er’ converter forks made to account for all that and they were fitted to a friends 26″ bike, worked well.
With a 27.5 bike the front end differences will be less than with a 26 but you’ll need a short-ish fork ideally with more than the standard ~45mm offset to help keep it all in balance. 29″ wheels will fit into most 440-450mm rigids.

I used to run a 2.4 29″ tyre in On-One carbon forks on the front of my 26″. Not sure on the A-C measurement on the forks, but think they were 26″ suspension corrected.
Not sure on 27.5″ tyres in a Soul, but just put 2.8″ Nobby Nics successfully onto my 29″ Solaris. Looking forward to trying it out properly tomorrow.

but just put 2.8″ Nobby Nics successfully onto my 29″ Solaris.

any pics of the clearance?

I’ve seen piccies with plumpish tyres on the rear end of Soul 275s but I don’t know details. The front end is not a problem as loads of rigid fork will take bigger tyres. On the geometry thing, I think Steve Worland used a 425mm rigid fork. I guess if you were using a bigger tyre, you’d want to minimise the fork length as much as possible.

any pics of the clearance?

4mm at chainstays, but plenty to seatstays.
We don’t get sticky mud here and if I was riding that I’d stick a 29″ mud tyre on anyway.

Been thinking of doing something similar with my 26 Soul. I have a 29Reba and a front wheel but was hoping to use a 440 rigid I have. Drawback at the moment is that the wheel is 15mm only and the fork is q/r Anybody done this and what were the results?

If you use a 29er sus fork & a 29er wheel it’ll make the front end way too high. A 29er wheel & rigid fork is the way to go