Fork change: how will geo change?

[Lewis Moon]

I just put a Seven fork on my Mr Pink. Its 8mm longer crown to axle and has 2mm more rake. So... Longer wheelbase and shallower head angle. What might be the change in ride?

[weisan]

What might be the change in ride?

lewis pal, wouldn't riding it and see for yourself be better than anyone could have done by looking into their crystal balls, even with an informed opinion?

[Lewis Moon]

lewis pal, wouldn't riding it and see for yourself be better than anyone could have done by looking into their crystal balls, even with an informed opinion?

Yeah.. But for the most part, it just feels different. Can't really quantify it.

[kramnnim]

Slacker HTA/STA, so more stable/sluggish?

I kind of want to put a tapered fork on my Alchemy, but it would require using an external lower headset cup, which would basically add to the axle-to-crown length...

[David Tollefson]

Likely what you're feeling more than anything else is the handlebars being 8mm higher.

The slacker HTA but 2mm more rake (which would reduce trail) kind of cancel each other, though the slacker HTA is larger in relation.

[tv_vt]

Hi Lewis,

The extra 8mm height will raise the front of the bike and reduce the head angle a bit, maybe 0.5 degrees. That by itself will slow the steering a little (increase the trail). And the extra 2mm rake will quicken the steering a little, by lowering the trail a tad.

So one feature somewhat offsets the other, but it probably will be a change one way or another, either a little quicker steering or a little slower.

As others have mentioned, first try to replicate your HB height from the old fork setup and see how that feels (measure distance from center of front axle up to center of HB).

Cheers,

TV

[unterhausen]

without bothering using a trail calculator, I figure the rake increase isn't enough to cancel the head angle decrease. So you're probably feeling the effects of more flop.

My All City has horrible flop. It's a pain to stand on it if I have been riding a bike with a more reasonable geometry. Making a new fork with more rake is high on the list.

[e-RICHIE]

Maybe lower your stem 1/3" or less and neutralize the change.
That's all it is, at most.

ps

arrange disorder

:):):rolleyes:
:):):p
;);):cool:

[kramnnim]

It's so confusing to me how increasing rake will quicken the steering... How much more rake would be needed to cancel out 8-10mm of increased axle-to-crown?

[charliedid]

I just put a Seven fork on my Mr Pink. Its 8mm longer crown to axle and has 2mm more rake. So... Longer wheelbase and shallower head angle. What might be the change in ride?



Slightly easier to do a wheelie!


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[Brian Smith]

I just put a Seven fork on my Mr Pink. Its 8mm longer crown to axle and has 2mm more rake. So... Longer wheelbase and shallower head angle. What might be the change in ride?

Do your differences in axle to crown length and offset come from printed specs or from measurements taken of the actual parts? If by measurements, are you sure that the measurements are accurate enough to rely upon?

Can you fit a 15mm larger diameter rear tire in the frame?

[skouri1]

Maybe you should trade it for my whisky road + . I should have bought tvt*'s as my bike was designed for that exact fork . Got a +5 baseplate on the whisky which is close enough ...

[smead]

It's so confusing to me how increasing rake will quicken the steering... How much more rake would be needed to cancel out 8-10mm of increased axle-to-crown?

This always helps me .. -

http://yojimg.net/bike/web_tools/trailcalc.php

Doesn't answer your specific question, but I'd guess the 2mm increase in offset counters the 8 mm increase in length such that your overall trail change is minimal.