There’s currently a lot of attention on reduced offset forks on long travel 29ers. Anyone would think that manufacturers are about to release their new stock and flood the Internet with marketing bollocks. With that said, I’m a mug, and the additional trail seems to make a lot of sense. So, what I’m trying to say is………..does anyone know of a manufacturer that produces a 150mm travel 29 for with 42mm offset for sale to general public? Or, will they, ever?

I thought that it was going the other way and more 29ers were now coming with 51mm offset forks the same as Gary Fisher was using years ago . However it’s about a lot more than just fork offset and the recommendation would always be to ride before you buy .

I thought that it was going the other way and more 29ers were now coming with 51mm offset forks the same as Gary Fisher was using years ago .

For XC with steeper head angles yes. Now trail bikes are running 65 degrees and long travel they are going the other way and reducing it towards ~40mm

Is it boll*cks or not – I have a 46mm on one bike & 51 on the other (steeper XC bike) but I bet if I swapped them and changed the travel, I probably couldn’t tell the difference…

They were all something like 46mm when 29ers first came out. Then we were told that more offset was better, so they went to 51mm. Now we are being told that less offset is better and we should go to 42mm. Anyone would think that there wasn’t really a better and they just want to sell more stuff.

It seems that industry has been experimenting with different offsets on larger frames. Gary Fishers geo was based around trying to give same characteristics (trail figures) as that of a 26″ ride. Have a look at the write up on the Whyte S150 on pinkbike. It explains it far better.

Now trail bikes are running 65 degrees

Just for my sake, Trail bikes are running 65 degrees, what are enduro bikes running?

Now trail bikes are running 65 degrees and long travel they are going the other way and reducing it towards ~40mm

I don’t get that. If the head angle gets slacker doesn’t the trail increase anyway? So, surely you’d want more offset with a slacker head angle rather than less, or am I missing something (as usual)?

As RM says, its not a new thing. RockShox have offered 46 and 51mm forks for a long time on 29ers, no special orders or custom forks, just pick your offset (as an OE that is).

For 2018 however the new ranges only run 51mm. Thats no doubt a reflection of a marked decline in 46mm sales. I can’t tell you which is better, I can tell you Ive run 41, 42, 44 and 46mm offset 27.5s and I can’t say I have ever really been able to pin down a major ride difference. Just when I think I can tell, I’ll ride something else and be less sure again.

Who knows what is the right one, pros and cons to both I reckon. Whats more likely is that anyone building bikes last year for sale this year probably got caught out by the lack of 2018 46mm option and so had to go to SRAM to get some made, is now marketing it as the next best thing 😉

I completely get the selling conspiracy. Totally agree 90% of the time. Then you read something that piques your interest and it seems to make sense. Think as head angles have got slacker and reach longer it may have altered other ride characteristics. Anyway, I’m not looking to buy a new bike (yet!). Just wanna try a reduced fork offset in my current frame.

Would it not be easy enough for fork manufacturers to have a flip chip on the dropouts as to where the thru axle sits so one fork could be set to give either offset?

Gary Fishers geo was based around trying to give same characteristics (trail figures) as that of a 26″ ride.

I achieve this by simply riding a 26 er

Another year another load of bollocks to sell shit to the new golfers

When 29ers first kicked in offsets for forks were 38mm, then into the 40’s and now low 50s (unless its a jones in which case they’ve had huge offset for years well ahead of the herd)

Small fork offset is one of the reasons why early 29ers got slated for funky steering.

Seems most odd to have super slack head angles and a low offset, as that used to be a recipe for dog handling, unless its being pared up with super short stems and huuuge bars to try and wrestle it all back into control

Anyone would think that there wasn’t really a better and they just want to sell more stuff.

I think that there’s definitely an element of this, here.

So many ways to balance out trail, ‘flop factor’, front centre, weighting the front etc, this is just one of them.

Early on, they added offset to reduce trail as there was this idea that you needed to make a 29er handle like a 26″, that was probably wrong where trail is concerned since wheel size affects how trail is felt as ‘flop’ or slackness – bigger wheels can have more trail before they feel floppy in the steering. Slack HAs and long reach mean front centres are getting very long already. Slack feeling steering is linked to stability (not always rightly but generally) so this all makes some sense, as ever though, depends what you want a bike to be good at.
To me, not much feels worse on some trails than excessive trail and the bike oversteering into corners (ie the flop means too much positive influence in the steering) but that same handling response feels pretty good when it’s steep and rough with bar + stem to suit.

Any excuse for the bike industry to make a new ‘standard’ 🙄

Another year another load of bollocks to sell shit to the new golfers

Or, geometry takes time to develop. Habits and muscle memory and to-fro comparisons, seperating out what does what when it’s all so interlinked etc, can’t be done that fast.

This is mainly coming from Mojo, Transition & Whyte so far, yeah?

You can hardly accuse them of being marketing-led rip-off merchants.

Or, geometry takes time to develop. Habits and muscle memory and to-fro comparisons, seperating out what does what when it’s all so interlinked etc, can’t be done that fast.

Or there is a game of manufactures trying to provide the market with what they want and at the same time trying to lead the market and provide them with products they think the consumers should want. It’s a difficult balance to strike and the 650b vs 29er thing is a classic example. Manufactures were pushing 29ers because that is where they thought the industry’s future was, the consumers rejected that, and the manufactures eventually gave up and provided the consumers what they wanted with 650b’s. Now things are coming back round to 29ers again.

It’s a fickle industry where bike manufacturers think they know best and consumers think it is they who know best.

One thing is for certain – the geometry you want for a 29er is going to be different than the geometry you want for a 650b or 26er. 29ers to date have really just taken 26er and 650b geometry and squeezed in larger wheels and tweaked things like head angle and fork offset to try to address some of the negative affects of larger wheels. Of course there are going to be some downsides to the end result as its a compromise. But this latest concept is designed specifically for 29ers so bound to be a big departure from the norm. Lets wait to see some independent reviews of how the ‘new’ geometry performs.

Some interesting reading here on this subject:
https://www.pinkbike.com/news/whyte-s-150-carbon-rs-review.html

Like everything in the bike world, the real world and often poorly understood formulas on a piece of paper are very different.

For example, physics tells us, it would be better to be hit by a car doing 50mph than a truck doing 50mph (F=MA) however, in most cases, you’re dead in either case, so it’s irrelevant.

Same case here imo. Tiny differences in geometery change the “Feel” of a bike to those riders sensitive enough to notice it, but most riders aren’t sensitive enough and the final nail, is that as humans we are extremely good at adapting. Get on a new bike and it feels different to your old one, ride it for a bit, get back on the old bike and yup, now that one feels different.

Of course, many small changes can add up to a big one. A modern geo bike rides very different to a 10 year old one, as each change makes a difference, but i wouldn’t get too excited about tiny individual changes myself, certainly not enough to make me buy or not buy any particular brand.

Bike designers like to bamboosle readers and journos, but often, they fail to grasp the true significance of what they are saying. For example, in that PB article, the designer talks about mounting the brake caliper behind the fork to minimise it’s rotational inertia. Now, that’s totally true. The closer to the centre of rotation a given mass is located, the smaller the rotational inertia of that mass.
But what they fail to say, (and given this is rather important you wonder why) is that Inertia = Mass x Radius ^ 2 So given you have a 29″ wheel, with a big heavy tyre right at the outside of it, exactly what contribution to the total rotational inertia do you think the brake caliper on a mountain bike plays?

In fact, you can do an easy test:

1) put your frame in a stand with the front wheel fitted, rotate the handlebars backwards and forwards rapidly, get a feel for the inertia.

2) take off the brake caliper and repeat the exercise!

Ive just tried this and even with the front wheel fitted i can’t feel any difference (because the handlebars also have heavy objects right at their ends!.

(a 700g 29″ tyre as an inertia of approx 0.041 kgm^2 and a 160g brake caliper 50mm off axis around 0.00018 kgm^2. ie the tyre alone is around 220 x more inertia when referenced to the steering axis than the brake caliper) Add in wheel, handlebars, grips, brake levers, and shifters and i suspect the brake caliper itself will be something like 1:500 of the total inertia. ie irelevant in the real world.)

I’ve just checked and the valve cap on the air valve actually has a similar rotational inertia to the brake caliper when referenced to the steering axis when that cap is at the front or back! So as the wheel rotates, the change in rotational inerta of the system is the same as fitting or not fitted the brake caliper!

So hands up who can feel the steering feel change as the wheel rotates if they take the valve cap off??? 😆

negatively effects the neutrality and influences the restoring and correcting forces of the steering kinematics in rectilinear motion,

So, what I’m trying to say is………..does anyone know of a manufacturer that produces a 150mm travel 29 for with 42mm offset for sale to general public? Or, will they, ever?

I’ll let you know in a few weeks as I’m changing forks on a slack-ish 650b+/29 hardtail. I suspect there will be a difference (as I’ve been geeking up on the numbers) but equally I don’t expect it to be earth-shattering. My guess is it will be slightly better* but I’m predicting subtle evolution as opposed to ground-breaking, game-changing advances.

*which is obviously tenuous and in the eye of the beholder.

I thought he was saying that the calipers were positioned behind the fork legs to balance out the mass created by the steering axis? I really do get the whole ‘not another standard’ thing but am with jamesco, chakaping, and wobbliscott in my views about progressive geometry for 29 bikes. It’s just not there yet. Bikes getting better and better (all wheel sizes). Manufacturers are starting to recognise the differences and how we want to ride them. Above all, bikes are awesome!

For example, physics tells us, it would be better to be hit by a car doing 50mph than a truck doing 50mph (F=MA) however, in most cases, you’re dead in either case, so it’s irrelevant.

You have more chance of surviving if you are hit by a car so it’s not irrelevant .

Castoration…