Patmanified

So I'm a road rider with 3 decades of riding and racing experience behind me. I just got an aluminum Jamis Comet (fixed gear conversion) and started riding it. I don't seem to be able to ride hands-free with it. I don't know if chain tension has anything to do with it or not, as my chain tension is probably a bit tight. I can't reposition this particular rear wheel in the dropouts. Would adding a link or two help solve the stability issue?

I love the direct drive and all, but sometimes the direct drive seems to make my bike follow lines that I would not have chosen on my own. Im concerned about safety in a group environment as a result. Is this just what comes with the the territory, or do I have some mechanical tweakings to make? Thanks.

Nagrom_

The drive train has no effect on how the bike handles.

Is your fork bent?

Patmanified

I'll check, but I don't think the fork is bent. It's an aluminum kinesis air foil fork. I remember my track bike back in the 80s was not so easy to ride hands-free on the velodrome, so perhaps it's just the geometry, etc. Thanks for your reply.

Velognome 

Don't worry, it'll come with time and miles. Fixed gear vs. freewheel bike handling is very different, your 3 decades count for some skill but not all. Ya gotta put your time in..

carleton

It's probably a rake/trail thing.

I also find it more difficult to ride no hands on my track bike which has a 74.5 deg head tube with a 30mm rake fork. My road bike (from memory) is more like 73 degree head tube with 43mm rake fork.

carleton

And, as always, Sheldon has the answer:


https://sheldonbrown.com/gloss_tp-z.html

FixedDriveJess

I notice a difference between riding hands free on fixed and free. It might be in our heads, but I feel really uncomfortable riding hands free on a freewheel.

ThermionicScott 

I bet/think it's the constant input to and feedback from the pedals -- I'm way more comfortable riding hands-free on my fixed-gear as well. Although it does also have a bunch of trail.

hairnet

Is it simply difficult or does the bike predictably veer to one side when you try? Before checking the frame see that the front wheel is straight in the fork and that the headset is not too tight or too loose.

Patmanified

Thanks guys. The Kinesis AirFoil fork (as pictured on a Jamis Comet):
https://1mg.me/?w=300&h=300&filename=...t.jpg&f=Photos
is pretty much straight, so there is very little rake or trail to it at all. I suppose that explains a lot.
My headset adjustment is good / proper and there is no "pitting" in the bearings. It does not veer in any particular direction, but is an equal opportunity potential wipeout. I suspect (as was suggested) that I'll develop a "feel" for how this bike rides and I'll eventually be able to anticipate where my front wheel goes when I use different levels of pedal pressure. I think I'm just very used to the "feel" of a road bike.

sinikl

I cannot ride no-hands on my Kilo TT... the front wheel hunts from side to side and it feels VERY sketchy. However, a guy i ride with has a KHS Flite 100 (basically the identical frame and fork) and can ride no handed for miles without a wobble. I've had my bike 4 months, he's had his for 3 years. I think that may have something to do with it.

The headshake coupled with the fixed gear and the clipless pedals mean i'm in no hurry to learn handsfree anytime soon --potential for eating it is high.

RoyIII

tighten up your headset - just kidding...

prathmann

If your fork actually had no rake at all it would result in a geometry with lots of trail. But looking at your picture it appears to actually have a decent amount of rake (which reduces trail). Just because the fork blades are straight is not an indication of no rake. Extend a line through the head tube down to the front dropout and note that this line passes some distance behind the front axle - that's the amount of rake. Now extend that same line all the way down to the ground and note that it lands some distance in front of the tire contact point - that distance is the trail.

Jaytron

I feel more stable riding no hands on my track bike. I am a weird man.

IthaDan 

Jam your knee into your top tube to start.

I built up a bike with effectively no trail (going to weld a parcel shelf on the forks, kind of a poor man's truck bike) this past week. It was really odd to ride- as you leaned, the steering just STAYED put, aimed where you'd left it when you took your hands off.

hairnet

For a given head tube angle, rake and trail are inversely related. How long is that fork compared to the original?

IthaDan 

Longer. Trail on the top one would be more, but I set the horizon line to the rims (flat tires ++), not the tires.

Real quick, real dirty. <3 photoshop.



vs:

Patmanified

So I just went out and rode it. On my past road bikes, I could lean slightly and control the steering. Need to go left? Lean a bit to the left. The steering simply responded. On this bike, I have to lean way too far to make the change I need (in a safe manner). I don't think it's just an issue of learning the subtleties of the bike. It's either the geometry... or perhaps the headset is too tight? My gut says that the bike should just go where I want it to go.

I think my bike handling skills are solid enough that I would have adapted already. I've looked at the trail closely and it is not out of the norm of any existing road bike. Something has to be wrong. I don't feel any significant resistance with the steering when the wheel is off the ground. I'm stumped.

Nagrom_

I just looked up what a Jamis Comet is.

It's a goddam time trial bike. That's why you're having issues. Time Trial bikes have really crappy handling, compared to road bikes.

Patmanified

Current Jamis Comets are indeed TT bikes. But mine was not sold with aero bars or anything like that:


Mine was sold with a standard Ultegra gruppo. Road bars, etc. I'll have to do a geometry check.

IthaDan 

you might be on to something with the headset.

McRussellPants

I can ride no hands on my track bike pretty easy. My road bike feels super sketch.


I'm way more in tune with my TK3 than Allez though. I really only get on the allez if it's over 50-60 miles or hill hunting.