...if a 700c 1-1/8"up to 28mm with guards, caliper brake, 52mm rake, carbon fork exists?

[nomm]

Because I don't think it does...

[SimonCelsa]

SPA cycles Audax must be pretty close, not sure about the 52mm rake, but what's a few mm anyway!!

[nomm]

SPA cycles Audax must be pretty close, not sure about the 52mm rake, but what's a few mm anyway!!

45mm offset/rake

[leftpoole]

Possibly a Kinesis DC07?

[nomm]

Possibly a Kinesis DC07?

Rake: 43

[531colin]

Because I don't think it does...

52mm offset will go with 71 deg head angle to give relaxed "touring" steering.
Most bikes with carbon forks will be of the brighter steering sort, ie about 45mm offset and 72 deg head.
Fit a 45mm offset fork in a frame with 71 deg head and the steering will be a bit ponderous, even for me.....that assumes, of course, that the "new" fork length won't alter the head angle much.
(20mm longer fork equates to about 1 deg. slacker head angle, with an "average" wheelbase.....1 deg on the head angle equates to about 5mm offset.
Once upon a time wasn't there a "Tusk" fork ? Columbus carbon fork for touring geo?
just googled it and drawn a blank
i think some gravel bikes have more offset than 45mm, but you won't get caliper brake.....

[slowster]

It used to exist, but no longer. Seven Cycles offered different offsets for its 5E fork by using different drop outs which varied the offset in 3mm increments. Needless to say, what with bespoke manufacture by a premium US brand plus import duties etc., they were very expensive.

Its successor offers the same, but has a tapered steerer:

https://sevencycles.com/accessories/forks.php

https://sevencycles.com/accessories/pur ... k-data.php

[Norman H]

As Colin points out it's not just about fork offset, axle to crown height will alter head tube angle.

Would a front disc brake be acceptable? Disc brake forks intended for so called Gravel Bikes are often a little taller to allow for fatter tyres.

SJS for instance have this carbon disc fork with clearance for 40mm tyres (45mm offset and 390mm axle to crown.)

[531colin]

As Colin points out it's not just about fork offset, axle to crown height will alter head tube angle.

Would a front disc brake be acceptable? Disc brake forks intended for so called Gravel Bikes are often a little taller to allow for fatter tyres.

SJS for instance have this carbon disc fork with clearance for 40mm tyres (45mm offset and 390mm axle to crown.)

Yebbut a taller fork gives a slacker angle so you want more offset to get the trail back where you started from. ...ie more offset than 52mm

[nomm]

Because I don't think it does...

52mm offset will go with 71 deg head angle to give relaxed "touring" steering.
Most bikes with carbon forks will be of the brighter steering sort, ie about 45mm offset and 72 deg head.
Fit a 45mm offset fork in a frame with 71 deg head and the steering will be a bit ponderous, even for me.....that assumes, of course, that the "new" fork length won't alter the head angle much.
(20mm longer fork equates to about 1 deg. slacker head angle, with an "average" wheelbase.....1 deg on the head angle equates to about 5mm offset.
Once upon a time wasn't there a "Tusk" fork ? Columbus carbon fork for touring geo?
just googled it and drawn a blank
i think some gravel bikes have more offset than 45mm, but you won't get caliper brake.....

Urgh, I had a feeling it was a little more complicated than initially thought. I had seen a genesis gravel fork with ability to put a caliper brake on, it also had a lot of mounts. Tbh it might be cheaper and easier to braze the 853 already on the bike... But respray will never match the original colour

[Norman H]

As Colin points out it's not just about fork offset, axle to crown height will alter head tube angle.

Would a front disc brake be acceptable? Disc brake forks intended for so called Gravel Bikes are often a little taller to allow for fatter tyres.

SJS for instance have this carbon disc fork with clearance for 40mm tyres (45mm offset and 390mm axle to crown.)

Yebbut a taller fork gives a slacker angle so you want more offset to get the trail back where you started from. ...ie more offset than 52mm

Oops! I should have thought that through.

[531colin]

Because I don't think it does...

52mm offset will go with 71 deg head angle to give relaxed "touring" steering.
Most bikes with carbon forks will be of the brighter steering sort, ie about 45mm offset and 72 deg head.
Fit a 45mm offset fork in a frame with 71 deg head and the steering will be a bit ponderous, even for me.....that assumes, of course, that the "new" fork length won't alter the head angle much.
(20mm longer fork equates to about 1 deg. slacker head angle, with an "average" wheelbase.....1 deg on the head angle equates to about 5mm offset.
Once upon a time wasn't there a "Tusk" fork ? Columbus carbon fork for touring geo?
just googled it and drawn a blank
i think some gravel bikes have more offset than 45mm, but you won't get caliper brake.....

Urgh, I had a feeling it was a little more complicated than initially thought. I had seen a genesis gravel fork with ability to put a caliper brake on, it also had a lot of mounts. Tbh it might be cheaper and easier to braze the 853 already on the bike... But respray will never match the original colour

Its not terribly, terribly complicated.......50-odd millimetres offset is pretty common on "touring" type forks, but these will be steel rather than carbon, and usually relatively heavy gauge....I think 853 is probably fairly thin wall. All you have to do is match the offset and fork length reasonably closely. ...eg Spa's tourer fork is 54mm offset and 385mm axle to crown race seat. That will come with mounts for (mini) Vee brakes, and the crown will be drilled for at least a 5mm mudguard bolt; its a big strong crown, no reason to be frightened of drilling it to take a caliper brake.

And my rule of thumb figures are wrong.....1 deg on the angle counts about the same as 10mm off the offset, not 5mm as above!
....so a 45mm offset fork will need to be an impossible 20mm shorter to have similar steering!

[nomm]

52mm offset will go with 71 deg head angle to give relaxed "touring" steering.
Most bikes with carbon forks will be of the brighter steering sort, ie about 45mm offset and 72 deg head.
Fit a 45mm offset fork in a frame with 71 deg head and the steering will be a bit ponderous, even for me.....that assumes, of course, that the "new" fork length won't alter the head angle much.
(20mm longer fork equates to about 1 deg. slacker head angle, with an "average" wheelbase.....1 deg on the head angle equates to about 5mm offset.
Once upon a time wasn't there a "Tusk" fork ? Columbus carbon fork for touring geo?
just googled it and drawn a blank
i think some gravel bikes have more offset than 45mm, but you won't get caliper brake.....

Urgh, I had a feeling it was a little more complicated than initially thought. I had seen a genesis gravel fork with ability to put a caliper brake on, it also had a lot of mounts. Tbh it might be cheaper and easier to braze the 853 already on the bike... But respray will never match the original colour

Its not terribly, terribly complicated.......50-odd millimetres offset is pretty common on "touring" type forks, but these will be steel rather than carbon, and usually relatively heavy gauge....I think 853 is probably fairly thin wall. All you have to do is match the offset and fork length reasonably closely. ...eg Spa's tourer fork is 54mm offset and 385mm axle to crown race seat. That will come with mounts for (mini) Vee brakes, and the crown will be drilled for at least a 5mm mudguard bolt; its a big strong crown, no reason to be frightened of drilling it to take a caliper brake.

And my rule of thumb figures are wrong.....1 deg on the angle counts about the same as 10mm off the offset, not 5mm as above!
....so a 45mm offset fork will need to be an impossible 20mm shorter to have similar steering!

No not terribly, but my dilemma remains - your wisdom and knowledge Colin is very useful

A carbon option would have cut a bit of weight and remained a permanent feature - especially something like the Genesis CGR1 QR (although who am I to spend 350 on a fork!)

Brazes on the 853 would have added carrying options and remained a permanent feature

Having a separate fork isn't something I am keen on at this stage

[531colin]

Might be least stress to have mounting points brazed on the existing 853 fork and paint it black....just like a carbon fork.
Or is there a repair required?

[nomm]

Might be least stress to have mounting points brazed on the existing 853 fork and paint it black....just like a carbon fork.
Or is there a repair required?

No repair needed... I'll have a think. It's a thorn audax 853 and the metallic red frame and fork are perhaps too lovely to mess with