Road Bike, Cycling Forums banner
1 - 8 of 8 Posts

·
done
Joined
·
3,293 Posts
Discussion Starter · #1 ·
I'm considering replacing the fork on one of my rides. The stock fork is 371mm from axle to crown. It's tough finding anything to match this. Just about any fork I can find isn't available in stock anywhere.

IRD has a couple forks that I think will work.

One matches the rake (45mm) and tire size + fender dimensions of the current fork. It's 378mm vs 371mm axle to crown, however. How much is that going to throw off my steering geometry? They also have a 43mm rake version. I figure this would help get the trail back to the original design?

The other fork has no fender eyelets. But it does have a A-to-C length of 368mm, so it's a better match in that regard. Would this be a better fit? Rake options are 45 and 43, though I imagine I'd want to stick with the 45 in this case.

Thanks for any help.
 

·
Registered
Joined
·
359 Posts
The 378 would decrease the HT angle by about .6 degrees. Assuming a 73 degree HT angle (even if it does not the relative changes are the same even if the numbers are not) the stock bike would have 56mm of trail. With a 7mm increase at a rake of 45mm you’d have a new trail of 58, which a 2mm difference is generally not perceptible. Decreasing the rake to 43 would give you 61mm, and that would give you noticeably slower handling. I think you have the idea backwards; you want more rake with an increase in A-C length as more rake results in quicker handling, and 47mm would put you back at 56mm of trail. The other fork at 45 would give a 2mm reduction in trail, 43 would be almost the same as stock.
 

·
done
Joined
·
3,293 Posts
Discussion Starter · #3 ·
Gotcha. I had to draw it out after reading your post. Yeah, I had it totally backward. Looks like the 43/368mm fork it is. Thank you, dcl10.
 

·
Registered
Joined
·
151 Posts
Love Commander said:
I'm considering replacing the fork on one of my rides. The stock fork is 371mm from axle to crown. It's tough finding anything to match this. Just about any fork I can find isn't available in stock anywhere.

IRD has a couple forks that I think will work.

.
Hiya,

doing something similar but it's becuase I want to fit a disc to the roadie.

Do you have a link to where you are getting the IRD forks from please ?

Cheers

Michael B
 

·
done
Joined
·
3,293 Posts
Discussion Starter · #5 ·
MichaelB said:
Hiya,

doing something similar but it's becuase I want to fit a disc to the roadie.

Do you have a link to where you are getting the IRD forks from please ?

Cheers

Michael B
From IRD's website. All the disc forks are steel. Not sure if that's what you're looking for or not.
 

·
Slow but not so steady
Joined
·
598 Posts
Go for it. If you go from a 371 to 378, you will not know the difference after 3 miles on bike.

I went from 372 to 384. The handling was a little sluggish but forgot about it after a few miles. I kept the rake at 45.

If I had gotten a 50 rake on the 384 Axle to Crown fork, the handling would have matched up perfectly with the 372 A to C/45 rake.
 

·
Registered
Joined
·
151 Posts
acckids said:
Go for it. If you go from a 371 to 378, you will not know the difference after 3 miles on bike.

I went from 372 to 384. The handling was a little sluggish but forgot about it after a few miles. I kept the rake at 45.

If I had gotten a 50 rake on the 384 Axle to Crown fork, the handling would have matched up perfectly with the 372 A to C/45 rake.
Hi acckids,

Thanks for the feedback. I'm in the process (waiting for the last of the parts) of putting a disc on the road bike, and will be going from 374 to 403mm using a Mosso fork just to see the effect.

If it's too much, will then go to a custom fork from Woundup (bloody expensive, but best option found so far) to get the correct axle-crown length.

Have found one that is 384mm from Traitor, but it weighs 1000g, which is a bit heavy.

TThe Mosso fork was only A$65 delieverd, so is a good starting point.

Cheers

Michael B
 
1 - 8 of 8 Posts
Top