TrekAudi

Hey all,

Wasn't sure what thread to ask this in but I have a Ti road bike that I am needing to change the fork on due to delamination and cracking of the carbon and figured I'd change to a fork that will allow 28c tires.

My current fork has a offset of 43mm with a Axle to Crown Length of 368mm.

The replacement fork I've found is a Columbus Futura with a offset of 45mm and a Axle to Crown Length of 367mm.

Is this enough to make a big difference or will the be essentially the same? I want to change the handling as little as possible as I currently like the way the bike fits and feels.

Any help is appreciated.

13ollocks

it’ll theoretically reduce your trail, making the steering a little “twitchier”, but I doubt you’d even notice. Furthermore, I think installing a slightly taller tire will increase trail again, so I think it’ll be a wash

TrekAudi

That's exactly what I'm looking for thanks.

PeteHski

Nothing in it there. It will feel the same in terms of geometry.

TrekAudi

I found a alternative fork that I really like but it's got a slightly longer Axel to Crown. It's specs are 45mm offset and Axle to Crown of 370mm. Will I notice 3mm height or am I good?

TiHabanero

I have found that frame geometry is not that sensitive to minor changes. 2-3mm rake is a minor change, 2-3mm is a minor change.

TrekAudi

That's what I was hoping but wanted to be sure.. 😀

soyabean

You'll get the same 2-3mm change just from swapping tyres of different brands that all share the same nominal size.

I have some 26x1.50 Bontragers H5 and they are race thin as expected, then I have some 26x1.50 Vittorias that I swear look more like 2.00 and they made an error in the factory as they stamped their nominal size.

Steel Charlie

Tell everyone that there is a fantastic improvement in handling to make the expense worthwhile

unterhausen

I offer a service where you tell me the results you want from a geometry change, and I'll convince you that's what you'll get.

Koyote

Leland Sklar and his "producer's switch."

wheelreason

p-hacking is the new black...

Groasters

I've recently made precisely the same change, on my straight-steerer (43mm rake) Easton EC90 fork on my Ti bike. This was discarded in good condition because I wanted to fit 28c tyres (the rear triangle was fine but the Easton fork was tight even for 25C) and I always felt, subjectively, that the Easton fork was a bit harsh.

So I fittted a Columbus Futura with 45mm rake. The 28c fits with plenty of room to spare on a rim with 25 external width. I've ridden this bike for thousands of miles and I noticed immediately two changes.

1. Improved comfort from a 28c GP5000 vs the old 25c GP5000 and
2. Way better vibration damping on rough tarmac roads.

Any change in geometry (both in the increased rake and the increased axle to crown dimension) definitely had no negative impact and may even be responsible for the better road "feel" I've tried to describe. If anything it feels more stable on fast descents, which may be due to the better vibration damping or maybe due to a miniscule change in trail is the reason, who knows?

What I do know is that it was a good modification as it's measurably improved the ride feel of the bike!

rosefarts

Id be way more willing to jump to 45 than to 41. If I were offered both sides of the coin.