Would you notice any difference in bike handling if you moved from a 51mm offset fork to a 42m, assuming it was the same 140mm fork & hardtail bike and you were not told which was which ? Is there any real noticeable change, or is it mostly just marketing guff ?

I ride a Ragley Big Al – Frame size XL, at 6:2ft it feels good but slightly compact in reach, currently running a 51mm offset Recon Silver 140mm, just purchased a Rockshox Revelation 140mm and slightly concerned the 42mm offset may affect the feel of the bike and make it feel “smaller”. I believe the offset would have no effect on reach, is this correct ?
thanks

No effect on reach, its all below the headset. You might feel the bike handles a little better, but most likely you won’t notice, and having the newer/better/stiffer fork will be the majority of the difference you’re feeling

It will calm down the steering a little. Some notice it, some don’t. It doesn’t affect reach. Only way changing a fork could change reach (along with other metrics) is if the two forks had massively different A-C lengths or you changed your sag very dramatically.

Thought so, thanks for the responses. So it might have a very slight effect on the steering ?

I defy you to notice any difference

is this the £270 revelation fork of wiggle 140 29er boost(2019)? mines due in the next few days, from seeing what rivals are selling i was half expecting it to be 51mm rake, 42mm.

I’ve just gone from a 140 Pike to a 150 Lyrik (interestingly the A-C was only 5mm more). The Pike was a 51mm and Lyrik is 42mm.

In theory it should ‘slow’ the steering, in practice it rides better – but whether that’s because it’s a stiffer fork, or a better fork, or the offset etc. No idea but the PR’s are there on Strava 🙂

I do though ride very steep stuff with a fair bit of fast rocky/rooty too – so slowing the steering a tad won’t do any harm.

is this the £270 revelation fork of wiggle 140 29er boost(2019)?

It certainly is, purchased one on Sunday, should turn up this morning. I have only ever ridden Rockshox Recon’s, this will be my first “fork upgrade”.

should be a good upgrade, 35mm stanchions should make the fork far stiffer,
i managed to grab the last one the other morning. didnt really need a new fork, but not seen many fork deals in the last few years, especially on 29er forks.

i’m now a dropper, bars and frame short of a new bike :0)

I can’t swear I’d tell the difference blind, but on going from 51mm to 42mm offset I found the steering felt more composed at speed and less floppy in tight, steep trails.

No downsides for me. If your bike is particularly short then there might be though?

I can’t comment on the steering effect, but it will make the wheelbase almost 1cm shorter.

chakaping

I can’t swear I’d tell the difference blind, but on going from 51mm to 42mm offset I found the steering felt more composed at speed and less floppy in tight, steep trails.

Same fork? I went from a 51 offset 130 34 to a 150 42 offset Lyrik and it turned a bike I liked into a bike I love, everything was better, including cornering, but really hard to know what effect if any was down to the offset. Suspect the OP will have a similar experience.

Same fork?

Same chassis and amount of travel (170mm Lyrik) on the same frame, but the new fork did have a better damper. That brought other benefits.

Yeah – it’s hard to know. I did get a mangled 27.5 Kashima stanchion replaced on an old fork with a 26er(short offset) one, and again, it felt better in the corners, but again hard to separate the better grip and tracking of a newly serviced fork from the old.

From personal experience of doing pretty much the same, you might notice on day one but it’s very unlikely that you will by day 3.

got the revelation fork through 42mm offset, great news

I’m sure it makes a difference but I’m also sure that most people who’re totally convinced they can feel a positive change, couldn’t repeat it in a blind test. You always get differences in feel even between two identical forks after all.

(guilty as charged here- I had a Pike and a G3 Fox 34 and I totally thought I could feel the difference in that fancy Trek offset. Then it turned out that it was a couple of years old and so the Pike had exactly the same offset)

Yes, offset will affect reach slightly. Becuase… Trigonometry.
44 to 51 offset will increase reach around 1.5mm (depending on starting geometry). The longer offset drops the front end slightly, (also dropping the bb by 1+mm) which pushes the reach out slightly. Draw it on a piece of paper and it will make sense. But I doubt you would notice 1.5mm reach.

I’ve recenly gone the other way (51 offset to 44 offset) and cant say I notice much of a difference.

After reading a lot of reviews on this topic, it seems a lot of riders prefer the longer offset for steeper HA bikes (e.g. steeper that around 65.5) and the shorter offset for slacker bikes.

More importantly how is the sizing on the XL big Al? I’m 191cm and am tossing up between the L & XL – I’ve generally ridden 19″ or 20″ hardtails in the past but I’m guessing this will feel a bit smaller than an old school frame if you swapped out the Large for an XL?

Hi – I am 6:2 ft (189cm)… you 100% need the XL Ragley frame, the XL frame is only 20inch and feels pretty small. I originally purchased a large (18inch) complete, after a few weeks I realised it was too small, bought the XL frame only and swapped the parts over. The XL feels spot on and is a really nippy and playful bike. I fitted a 175mm dropper, tubeless and changed the chain ring to 32T, perfect bike for me. The Big Al is loads of fun and really playful. Definitely change the chainring from the standard 30T, the ratio on the 32T just feels better.

This is pretty much what I did,10 years ago, when I built my 29er.
I test-ride the top model of the Trek Marlin, and loved the way that it rode, but didn’t fancy having to get used to SRAM shifters, as I have Shimano on all of my bikes.
So, I bought the lowest spec model (same frame, lower spec components) and installed better brakes, drivetrain and fork (for about £100 less than the top model)
The fork was a 51mm offset boat anchor (that stopped my shed being blown away, in storm Eunice) and was replaced by a 42mm offset Manitou Tower Pro model.

It’s been absolutely fine, for all these years.

To be fair, I only did that one test ride with 51mm, so can’t really say that I can compare the two.

Still a great bike, though.

Thanks Coconut – I read the Big Al review in WideOpen and the reviewer had downsized! Didn’t really make any sense after all I’d read about it being a fairly compact frame.
Just ordered a set of Marzocchi Z2s to go on it (with a 51mm offset) as I couldn’t find any Revelations at a sensible price.

i reckon youll prefer the z2 over the revelation anyway. that moco damper is average.

i recently changed from 51 to 44 offset fork on my dually. don’t notice it. 64.5 degree head angle.

But what i did notice is when i went briefly from 42 to 51 offset on my 27.5″ bike (its a long story!). Felt VERY tucky. Front wheel just wanted to jack knife under all the time.

Probably a dumb question – does fork offset have any impact at all on height of the front end?

“Probably a dumb question – does fork offset have any impact at all on height of the front end?”

About 3mm between 51 and 42mm offset – such a tiny amount that you won’t be able to feel it. (Might be possible if you’re a very sensitive rider on a track bike with a rigid fork and tyres at 100+ psi but not on a MTB with big squishy tyres let alone a fork with 100mm+ of travel).