Is there a relationship between the forks offset, or the stems lenght/angle and the riding feel?

Question

After I got a bike fit for my road bicycle it feels like the stearing has a "nervous/wobbly" ride. I could shorten the stem about 1 inch (2/3 cm) from the original 4,5 inch (11 cm) and/or lower the stem angle from todays 20 degrees. Would it help? Is it maybe something else? (The stearing isn´t loose)
Thanks!!!

Answer 1

step 1. ride your bike for a while and see if you get used to the way it feels...if you still don't like it...read on.

the overall handling characteristic of your bike is rather complex, and the overall stability is primarily dependent on wheel base (longer = more stable at speed). however--stem length, fork length, and fork offset or "rake" factor in as well.

...starting with the headtube tube angle (of your frame). the "steeper" (closer to 90°) it is--the faster the steering will feel in general, and consequently, less stable. obviously you can't change this, without replacing the frame.

a longer fork (with a lager axle to crown measurement) on the same bike will slow steering a bit because it will effectively reduce your head tube angle, and increase your wheelbase. the same is true for a fork (of the same length) with less rake.

a stem will affect steering feel as well. a longer stem will slow steering input, but overall feel will also have something to do with where that longer stem locates your weight--over the front hub = stable, in front of it = not as stable, behind it = "twitchy". a rule of thumb for this is, when in position on your bike, the handlebars where they meet the stem, should "hide" your front hub from your line of sight. stem angle is pretty simple, lower is more stable--until it puts your weight in front of the front hub. stem angle will only make a very slight feel difference.

so, if you are generally pretty comfortable on your bike--i'd recommend a shorter stem first (cheapest and simplest option)--but nothing drastic 10 or 20mm at most. the more expensive option, that preserves your riding position is an appropriate fork (similar to what you have)--with a somewhat smaller "rake" (a couple of mm's makes a big feel difference).

hope this helps!

Answer 2

The twichiness has to do with frame (head tube) angles, wheelbase and most importantly fork rake. You don't say if you're new to road bikes or if this is the 1st "race" geometry bike for you. But a few decades ago the fork rake got smaller and this really added to the twitchiness. I had 2 bikes with the same seat and head tube angles the fork rake was the only difference - it made a huge difference in the feel as you noted. The head tube angle will affect this a lot too.

Your stem shouldn't change this to any great degree, but if you need to a shorter stem than get one. 110 isn't that long but I use a 90 and like the feel more than longer stems. As I did and many others, putting on miles will make it all feel natural to you.

Answer 3

If you got a pro fitting, you might just give it time.....you'll get used to it. If they did it right, then it *should* be pretty comfy for you over the long haul.....but everyone's body is different. Ride it for awhile and see what you think after you've put some miles on it.

But to answer your question, yes, a shorter stem will slow the steering input slightly and make it feel a little less twitchy. Keep in mind that road bikes are usually pretty twitchy to begin with, some more than others due to frame geometry. The shop should be happy to let you borrow one of their fitting stems if you want to give it a try to see how a shorter one feels. I'm honestly not sure how much different it would feel when you start mixing in stem angles, though....I've fitted and ridden probably 20 stems in my riding years but most of them have been in that common 5°-7° range.

Fork offset and design DO make a huge difference in the feel of the bike. The amount of offset changes where your weight distribution is on the contact patch where the tire meets the road, and that directly affects handling. You don't see much in the way of rake on forks nowadays, but that affects feel and comfort as well. Stems are easier to play with, and unless it's going to affect your fit/comfort too much, I'd say just do that before you look into the expense of a different fork.

Good luck!

Answer 4

You've got some good answers so far. Let me add that you probably need to take it out for a good thrash to get a feel for the new and different handling.

My time trial bike feels awkward at low speeds, but take it over 20mph and its steady as a rock.

If this is a bike you've had for a while, but just got a pro fitting, yes, putting more weight farther in front will change steering response.

A caveat: If this bike was too small for you to begin with, and the shop mechanic had to go with a long stem to give you enough room, then you may have sacrificed some control for comfort.

Answer 5

I guess this is the first time I disagree with Ride Urban and M R... On most of their post their right on, but unless road bikes are completely different than mtb, shorter stems tend to be more twitchy. Just my opinion.

Answer 6

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