Advice on forks,rake, headset, stem

[vl1016]

I will say this maybe an elementary question, so here goes: how does fork rake effect the ride? I have a 2000 Bianchi Campione with a cromoly fork that has a 42mm rake. It also has a quill stem, and one inch steerer tube. Recently the drop-outs on the fork were damaged (unfortunate stem mount transport incident). They were fixed by my local bike shop, but with the warning to watch for lateral movement. I also discussed the matter of tighter steering with a threadless headset/stem combo, rather than with the quill. I have noticed on descents the steering can be kind of iffy with the current set-up, with some flexing from the fork as well. So, I'm kind of sold on the idea of getting a threadless headset, stem, and carbon fork (eventually anyways). I have yet to see, however, a fork with 42mm of rake. What would happen if I got one with 45mm rake, or 40mm rake? Any suggestions on headsets and stems? Seems there are quite a few reasonable deals out there, especially on headsets and stems. My local bike shops have no prices that are even competitive with any online shops (for instance Profile 1" threaded carbon fork with aluminum dropout for $350). Hence, I am not asking them. Anyone have any experience with Weyless/Performance/other store brands? I do not want to change my ride characteristics too much, aside from maybe lessening some vibration and tightening up the steering. Any advice would be appreciated. Here's the link to my bike. http://www.sheldonbrown.com/harris/bianchi00/campione.html

 

[serenaslu]

I will say this maybe an elementary question, so here goes: how does fork rake effect the ride? I have a 2000 Bianchi Campione with a cromoly fork that has a 42mm rake. It also has a quill stem, and one inch steerer tube. Recently the drop-outs on the fork were damaged (unfortunate stem mount transport incident). They were fixed by my local bike shop, but with the warning to watch for lateral movement. I also discussed the matter of tighter steering with a threadless headset/stem combo, rather than with the quill. I have noticed on descents the steering can be kind of iffy with the current set-up, with some flexing from the fork as well. So, I'm kind of sold on the idea of getting a threadless headset, stem, and carbon fork (eventually anyways). I have yet to see, however, a fork with 42mm of rake. What would happen if I got one with 45mm rake, or 40mm rake? Any suggestions on headsets and stems? Seems there are quite a few reasonable deals out there, especially on headsets and stems. My local bike shops have no prices that are even competitive with any online shops (for instance Profile 1" threaded carbon fork with aluminum dropout for $350). Hence, I am not asking them. Anyone have any experience with Weyless/Performance/other store brands? I do not want to change my ride characteristics too much, aside from maybe lessening some vibration and tightening up the steering. Any advice would be appreciated. Here's the link to my bike. http://www.sheldonbrown.com/harris/bianchi00/campione.html

This link has a pretty good discussion of the effect of rake on trail and it's relationship to handling. Other minor issues such as wheelbase extension, etc. are ignored though.

http://www.phred.org/~josh/bike/trail.html

( link excerpted from http://www.sheldonbrown.com/gloss_tp-z.html#trail )

 

[vl1016]

Thanks for the reply. Any other suggestions. the head tube angle is 73 degrees, by the way.

 

[boudreaux]

Thanks for the reply. Any other suggestions. the head tube angle is 73 degrees, by the way.

That's perfectly normal.Don't mess with it.

 

[Fat Hack]

From my experience, 2.5 or 5mm difference in rake alters the handling of a frame very little compared to the other characteristics of a fork, such as the material, flex..whatever, and maybe shape. I had a very twitchy frame (light steering) that I hated, but before selling it I tried a variety of forks with different rakes, but it made no difference. I stopped short of buying a 50mm rake Reynolds Ouzo Pro -- maybe that would've done something; I don't know.
The differnet forks did handle slightly differently, but it wasn't the rake, it seemed to be more the material that made the difference.

By the way, I own forks with 42.5mm rake, so there's some out there.

$350 is not such a great price these days. Check out the new prices of the new Columbus Carve forks, Columbus Tusk (alu steerer), and Columbus Tusk (carbon steerer)

 

[dhk]

From my experience, 2.5 or 5mm difference in rake alters the handling of a frame very little compared to the other characteristics of a fork, such as the material, flex..whatever, and maybe shape. I had a very twitchy frame (light steering) that I hated, but before selling it I tried a variety of forks with different rakes, but it made no difference. I stopped short of buying a 50mm rake Reynolds Ouzo Pro -- maybe that would've done something; I don't know.
The differnet forks did handle slightly differently, but it wasn't the rake, it seemed to be more the material that made the difference.

By the way, I own forks with 42.5mm rake, so there's some out there.

$350 is not such a great price these days. Check out the new prices of the new Columbus Carve forks, Columbus Tusk (alu steerer), and Columbus Tusk (carbon steerer)

Care to mention what your old frame was? Were you getting speed wobbles on fast descents, or just whippy steering? Do you think the problem was a too-light frame for your size, geometry, or your fit on the bike?

You said you considered a 50mm rake Reynolds fork. But, that would reduce the trail, and make the handling even more twitchy. Perhaps you thinking that lighter steering from the 50mm fork would reduce the flex in the frame? Believe the Ouzo Pro, at 420 grams is about as stiff and strong as they come, but putting a stiff fork on a wimpy frame might not be the best either....could make the frame flex more apparent?

I'm just throwing out questions and thoughts, since I've got no direct experience with handling problems like you have.

 

[Fat Hack]

Care to mention what your old frame was? Were you getting speed wobbles on fast descents, or just whippy steering? Do you think the problem was a too-light frame for your size, geometry, or your fit on the bike? .

It was a strange Scapin that I'd never seen before. It had normal sized tubing (no oversized tubes), curved seat stays, and vertical drop-outs. It was about 1660g, and was supposed to be Columbus Genius.

The guy at the shop was vague when I kept asking what year and model it was -- he just kept saying that it was "old stock", whatever that means. I was stupid to buy a frame with no fork, then expect any old fork to work with it, but it was cheap for a Scapin. I contacted the company, and they said it might've been a "KSE".

It was twitchy at all speeds, and felt unstable on the slightest of bumpy roads. I was not comfortable taken one hand off the bars. I had speed wobbles riding no hands over 18 to 20mph.

I've read on these forums about guys having speed wobbles, then another guy gets on the same bike, and no wobbles! I dunno.....after about 6 weeks of changing forks and stems, I was sick of it. I was so ****** off. In the end I was just happy to get it out of my sight

 

[dhk]

It was a strange Scapin that I'd never seen before. It had normal sized tubing (no oversized tubes), curved seat stays, and vertical drop-outs. It was about 1660g, and was supposed to be Columbus Genius.

The guy at the shop was vague when I kept asking what year and model it was -- he just kept saying that it was "old stock", whatever that means. I was stupid to buy a frame with no fork, then expect any old fork to work with it, but it was cheap for a Scapin. I contacted the company, and they said it might've been a "KSE".

It was twitchy at all speeds, and felt unstable on the slightest of bumpy roads. I was not comfortable taken one hand off the bars. I had speed wobbles riding no hands over 18 to 20mph.

I was so ****** off. In the end I was just happy to get it out of my sight

Not familar with this brand, but it sounds pretty light for a steel Genius frame, depending on the size of course. I'll bet the frame was just too light and whippy for you. You were smart to get rid of it.

 

[Fat Hack]

Not familar with this brand, but it sounds pretty light for a steel Genius frame, depending on the size of course. I'll bet the frame was just too light and whippy for you. You were smart to get rid of it.

coulda been: I'm about 190lbs, and the frame was a 58 x 57

 

[dhk]

coulda been: I'm about 190lbs, and the frame was a 58 x 57

Yep, that's a big frame. I'm 175, and also ride a 58cm with 57.5cm top tube. It's Zonal AL, with the megatube-shaped TT and downtubes. When I asked the builder if a thinner tubeset would be better for ride qualities, he said not in the big 58cm.....you need a bike that will be stable at 55 mph down twisty descents. Frame weight came out just under 1300 grams which isn't that bad for a size 58.

With the "heavy" Ouzo Pro fork, I'm very happy with the solid high-speed ride and handling. Also like the stiffness and response when jumping out of the saddle.

I mention all this because I think ultralight frames are overrated. Believe too many are sold to people who really need something else.

 

[Fat Hack]

I agree about the light weight stuff. I've got a theory that most of the light gear going around these days is meant for 130lb Euro Pro roadies, not lardos like me. However, in my opinion, your 1300g frame is quite light for a 58cm Zonal.

 

[SDL]

I will say this maybe an elementary question, so here goes: how does fork rake effect the ride? I have a 2000 Bianchi Campione with a cromoly fork that has a 42mm rake. It also has a quill stem, and one inch steerer tube. Recently the drop-outs on the fork were damaged (unfortunate stem mount transport incident). They were fixed by my local bike shop, but with the warning to watch for lateral movement. I also discussed the matter of tighter steering with a threadless headset/stem combo, rather than with the quill. I have noticed on descents the steering can be kind of iffy with the current set-up, with some flexing from the fork as well. So, I'm kind of sold on the idea of getting a threadless headset, stem, and carbon fork (eventually anyways). I have yet to see, however, a fork with 42mm of rake. What would happen if I got one with 45mm rake, or 40mm rake? Any suggestions on headsets and stems? Seems there are quite a few reasonable deals out there, especially on headsets and stems. My local bike shops have no prices that are even competitive with any online shops (for instance Profile 1" threaded carbon fork with aluminum dropout for $350). Hence, I am not asking them. Anyone have any experience with Weyless/Performance/other store brands? I do not want to change my ride characteristics too much, aside from maybe lessening some vibration and tightening up the steering. Any advice would be appreciated. Here's the link to my bike. http://www.sheldonbrown.com/harris/bianchi00/campione.html

Here is a link to a trail calculator just enter you head tube angle, fork rake and wheel diameter and it will calculate the trail. Generally you want anywhere from 56-60mm of trail. Higher trail value = more stable steering. If you are using metric calculations your wheel diameter is 66.8 cm.

Hope this helps