falling off bikes since 1975

Last time I left you on the 29er front I was just off into the shed to fetch out a 26″ front wheel.

It had been suggested that the 29er handled so ponderously because the fork offset was designed for use with 26″ wheels. I figured that fitting a 26″ wheel in there, coincidentally steepening the angles a little, might help.

So I pulled out a 26″ front wheel and tried it. The worlds second 69er.

Instead of looking like a Chopper or a Stingray it looked odd, but definitely no worse than any 96ers out there. Indeed, from the seattube forward it looked a whole lot better. My wife suggested I try two 26″ wheels in there. Not a bad idea. I could ride the bike with the same geometry and angles and the only difference would be bottom-bracket height and fork trail.

I would have liked to ride it’s 26″ incarnation with the same tyres as the 29er, so that the only difference between the bikes was the metalwork in the wheels. But I didn’t have 60 quid to spare and the shops were shut. So I picked some tyres with the same carcass width and had done.

A quick rubber change later, and the wheels were in. Hey! It looked like a well-proportioned bike again. Maybe the bottom bracket height was a bit low compared to what you expect, but it certainly didn’t look that odd.

So I threw the bike and the 29″ wheels in the car and headed off to reride Saturdays trails.

First of all I rode them in it’s 26″ incarnation.

At the front end it was noticeably quicker steering, like my old Spot or the Rocky Mountain Hammer when fitted with Pace RC-30s. Sharp then, but not twitchy.

The rear end was likewise transformed. It had some life, some snap, some feeling! Unsurprisingly, it didn’t smooth the trail out as much as the 29er wheel. It was also less smooth than my wife’s regular 26″ wheeled Spot which runs the exact same chainstay length. Which only tells us that frame material makes a difference. Tell us something we didn’t know!

yes, that is 26″ in 29er forks

On the rocky uphills it suffered no loss in traction. On the final climb, I not only rode it past the point where it had stalled on 29″ wheels, it made it clean to the top. Why? Because I could now choose where I wanted the bike to go.

Now I was faced with the downhills, and I wondered briefly about the low bottom bracket height. I’d not had an pedal strikes on the way up, would it ground on the way down? Well, not on the steps it didn’t, so off to the more technical downhill I headed - the Ice Cream Run for those who care about such things. It’s not World Cup DH course technical, but it’ll do. It just felt more manoeuvrable underneath me, I could change lines, I could unweight or lift the front end better, and in the air I could make tiny corrections. With only 80mm of travel the forks had a busier time of it with the small front wheel but the lower unstrung weight and fatter rubber than my normal tyres meant things didn’t get out of hand. A pair of Fox Vanillas on there and I’ve have been laughing. The rear end bounced around a bit, but followed eagerly enough, and the fatter rubber than I normally run made things better than my regular hardtail.

Back at the car, I checked no-one was around to point and laugh, swapped the rear wheel for the 29er version, and headed back out on the same trails.

At the front the steering was now bang on. If the regular 29er steered like this I’d have been a whole lot happier with it from the start.

At the back that old sluggish feeling was, um, back. Over whoops, where I wanted to maintain momentum down one side to get me up the next the 29″ rear wheel definitely helped.

At the top of one climb I looked back and I could see where my two trails rode side by side. The 26″ rear wheel trail showed marked treads where the tyre had dug in as my power had pulsed through the transmission. The 29er trail quite clearly showed how these power lumps had been smoothed out. Again I cleaned the final climb.

Only the downhill remained. Now here I have to say that of all three 26/29/69er incarnations this was the one that rocked! The forks could still have done with more travel, some of the manoeuvrability was gone due to the gyroscope effect of the bigger rear wheel, but at least I could pick lines and unweight the front. And the rear end did an excellent job of smoothing the trail. Not 2.75″ of rear travel smoothness, but definitely better than a pure 26er hardtail.

Ideally I would have now tried the bike in a 96er incarnation, but I was running short of time and needed to get home. I may get round to this, but right now it seems a little pointless.

Conclusions?

I’m more convinced than ever that if there’s a benefit to be had from 29″ wheels they’re best at the rear. Slap some longer travel forks on the front with a 26″ wheel for manoeuvrability, wheel strength, lack of toe overlap, proper length headtubes, and gain the 29er smoothness at the rear on the downs.

Of course, you could just use a slightly longer chainstay on your steel 26″ hardtail to get mostly the same effect.