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passive/aggressive
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Discussion Starter · #1 ·
If you happen to be of the unlucky few that have litespeeds from the era of the HP designs forks and feel like your bike is sketchy or just vague occasionally do not spend time searching out the solution: it is your fork.

Quick back story: Got a Siena, loved it a lot, rode it mostly as a fast commuter and on weekend rides. Finally took it up Mt Lemmon and on the way back down as the speed popped over 34mph, boom, massive speed wobble. Deathly huge and terrifying. Now initially after regaining my composure I check the obvious culprits on my bike: the QR's. The rear seemed loose but I took it easy descending the rest of the way.

That night I researched the shimmy and determined that perhaps the super light real ultraspheres my bike came with might be too light for me so I swapped them out with a set of 14g 32 3x CX/Commuting wheels I have. Gave the light ultraspheres to my wife and set a date to try to do it again. Just popping over 30mph gave me the willies so I just shut it down and coast back home.

I swapped out my handlebar for a stiffer CF one and checked the headset and the dish of the wheels. Everything check out fine so I headed out again hoping, magically that it was solved. Wasn't.

It was then that I noticed that under power and out of the saddle the magnet on my wheel would touch the sensor of my computer at its location at the top of the fork. I began moving the sensor and magnet down the fork towards the drop out. Eventually when it got near the spoke crossing it wouldn't hit anymore.

Now I was sure it was the fork but after call to Litespeed they had me take my frame to a local builder to check the alignment, just in case, so I wouldn't spend dollars on a fork and still have the problem. The frame and fork check out aligned.

So I finally went to the shop I bought it at and borrowed a fork. A new uncut steerer and 47mm offset vs the 45mm offset of the HP Designs. I mounted it on my frame using the same headset and everything else except a 4" tall stack of spacers on top. For safety sake I threw the wheels in the jig and check their roundness and trueness and dish. A little hop but otherwise good.

I headed off to Mt. Lemmon on a very blustery windy day. Thoughts of doom in my head "it is too windy to do this today" " what if I get blown sideways and it induces a speed wobble". 6 miles up to an area in a valley where the winds were minimal and the road was straight.

I steeled myself for a few seconds, wipe the sweat off my brow and glasses and then hurled down the mountain. I slowly picked up speed, snicking off gears and just tried to sense the bike. I didn't look down, just tried to sense the bike and it demeanor. No wandering or vagueness. No odd hunting or weird behaviors. Just singing along, occasional buffeting of wind but otherwise pretty normal behavior for a speedy bike with a a too much rake fork.

I finally looked down at my computer and was astonished to see I was about to crack 40mph. Previously I would feel that at any moment I was about to be dashed against the rocks or plummet off the cliffs at 30mph but here I was almost 10mph over that speed and never noticed the difference on the way there or at that moment.

Ultimately this freaked me out, along with the 4" of steerer waiting make my junks acquaintance, so I slowed down. A lot. I glided along at this slow speed until I hit the esses and then slowly and guardedly I let off the brakes again.

Still felt great even on the bumpy corners. It was like riding a new bike. I was euphoric and excited and disappointed at the fact that something so banal as a fork could have so affected my feelings towards my "forever dream bike" for such a long time (have had it over a year now).

So...the HP designs fork, I looked it over, twisted it, squeezed it, could not find any readily obvious or salient reason why it would be so different from the loaner but in defiance I ordered a new fork for my bike with the correct offset (a ritchey pro ud) and am ready to restart my relationship with my litespeed, sully in the past but no more (hopefully). If you have one get rid of it you won't regret it.
 

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haole from the mainland
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5,962 Posts
The HP fork on my Merlin Atreus came with 45mm of rake (49cm size frame). Almost all the forks I've been considering as a replacement have a rake of 43mm. Will that be a significant change?
 

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I wouldn't expect the changed rake to be a problem. I replaced the RealDesign fork on my Firenze with a slightly different raked Reynolds Ouzo and my wobble problem went away (low speed wobble, like if I put a slight jolt in the handlebars, the bike did wobbly esses for too long - high speed performance was OK).

I think the LS Real Design forks tend to kind of "walk", where one leg gets out in front to the other, leading to a wobble, though I can't prove it.

I do know that the Reynolds was a vast improvement.
 

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haole from the mainland
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5,962 Posts
Good to know. The Reynolds Ouzo Pro, along with Easton's EC90 SL and possibly Alpha Q constitute my list.

I see a new fork in my future.
 

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Expert Crasher
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jorgy said:
Good to know. The Reynolds Ouzo Pro, along with Easton's EC90 SL and possibly Alpha Q constitute my list.

I see a new fork in my future.
Nice fork - though it's my first carbon road fork so I wouldn't know what the other's feel like. :D

 

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Scott CR Fork Replacment

Wow! I had the same problem with my HP Real Design fork on my Merlin. I ended up replacing it with a Scott CR1 Fork, fixed my problem as well. The cool thing is my Merlin is a CR Works and the Scott fork is a CR as well, so it kind of looks like a factory Merlin fork, kinda.
 

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I have a Litespeed from 2006 with a real design fork. I've never experienced the speed wobble you're describing. I don't have descents long enough to get much faster than 40mph, and I've never attempted anything close to those extreme aero positions.

I'm only ca. 140/145lbs, and not particulary powerful, so I probably don't have the same issues with flex that a larger, more powerful rider would.
 

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Man, I'm glad I found this ancient thread.

I have a 2005 Tuscany that has the HP Pro Design fork and I have always thought it felt unstable at high speed 40mph+. This is only my second bike so I never knew it was me or the bike. However, I long suspected it was the fork and think I even posted on here about it several years ago. After reading this thread I think I'm giong to start savign my pennies to get a new fork.

My bike is a 57cm and is listed as having a rake of 4cm. Any recommendation on which fork I should try?
 

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I am also glad as I am shopping for a fork for a works cr that I have incoming. Mines a large so I need a 40mm rake which makes shopping tough.
the real forks are still out there but sound like they might be best left alone.
I am actually thinking of vicious cycles or gunnar steel. I have no love for carbon anyways.
 
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