kevrider

i have beautiful roadie machine, a 2010 Orbea Onix, purchased as a new frameset and built with cannibalized Ultegra and Mavic parts into a sweet bike that i love to ride, it's both fast and quick. unfortunately, it has suddenly become too fast and quick. i have recently begun to have a problem with long, curvy descents. i have other dropbar bikes which i ride more frequently and i am not adapting as quickly as i used to when i hop onto the Orbea.

i took a short ride on the Orbea yesterday, a five mile loop with appx a 1.6 mile climb and similar length descent, fairly steep and curvy, this was an unfamiliar road. the climb was (a bear) great, but the descent... i have never braked so much. even on familiar descents i have been braking more than usual. the bike has quick handling, which was never a problem before, but now it feels unstable and twitchy, my confidence is low. this bothers me because i am really good at road descents. i was a sport riding motorcyclist for years before i started road biking and the techniques are similar. when i lived in GA, i spent a lot of time in the NGa mountains training for a century and i railed those descents. of course, that was on a different bike....

i have a dropbar city bike, which looks a lot like a gravel bike, that i use for commuting and errands. i recently put wider, treaded tires on it and have increasingly used to joyrides. this bike gets out of the barn more often that any other.

i also have a dropbar mtn bike, built up about one year ago, and this bike gets a lot of joy rides, as mtn biking is my thing. the original justification for the roadie was to increase my stamina on the trail. coincidentally, the difficulty adapting to the Orbea has become a problem only in recent months, after this mtn bike build.

here are the head tube angles // offsets (not listed on the Orbea geo chart) // wheelbases for the bikes in question.
Orbea Onix: 72.1 / (43?) / 970
Novara Road Buzz: 71.5 / 50 / 1037
Salsa Fargo: 70 / 45 / 1064
Schwinn Fastback: 73 / 43 / 995 ... this was my road bike when riding the mountains in GA days

i have considered replacing the Orbea with something more endurance-oriented or even a gravel bike, as i am a chronic n+1 guy. but i'm trying to rehab and contain the bike purchases, so it would help if i could somehow adjust the Orbea to suit my apparent/developing preference for stable vs reactive bikes. my question is... would a wider bar calm the handling of the Orbea? i have a 42cm bar with an 80mm stem. if i go to a 44cm bar, would i need a shorter stem? on the one hand, the leverage would increase with a wider bar, which would be counterproductive... on the other hand, a given horizontal displacement of the bar would cause a smaller angular rotation, slowing the steering. i'm not sure which effect predominates. i'm not sure a 1cm longer lever really matters.

is this happening because i'm closing in on age 50???
any insight would be appreciated.

kevrider

wow, lots of words. thanks for reading.

andr0id

I think you are thinking about fixing your problem in the wrong way...

HB width is meant to be about as wide as your shoulders regardless of stem length.
Too wide and your arms are too spread likely resulting in hand fatigue.
Too narrow and your chest is compressed resulting in breathing restrictions.

Yes, there is a tiller effect based on stem length. However, the frame builder/design should account for a reasonable range of stem sizes based on the frame size.

Most bikes will take 80-120 without affect the steering adversely. Taller bikes will take a bit on the longer side, 100-140 perhaps, and smaller bikes might allow a bit smaller. You will likely get weird steering with a 140 stem on a 50cm from or 60mm stem on a 61cm frame.

HB width and stem length are both very important with regards to proper fit. I think that messing up your fit to attempt to change the handling of the bike will just be expensive and have disappointing results. The frame design (HTA/rake/trail) is a much larger part of the handling equation than tiller effect. (which I think you had already surmised)

Maybe you need a descending refresher? Remember you need to be looking up the road AS FAR AS POSSIBLE and planning turns before you get to them. As you come out of one turn, you should be immediately positioning yourself on the road for what comes next.

But, I tend to use the brakes more now that I'm 56 than I did 10 years ago too.

trailangel

970mm wheelbase is really short, short bike.

IK_biker

H/bar width won't influence twitchiness at all.

Are you sure that your headset is properly adjusted (preload)?
Are you sure your tires were at the right pressures?
Were you dragging (any of the) brakes or just "burst" braking every now and then?
Any recent part changes on the bike (like a new crankset/cassette/seatpost or even seatbag) or cleat position change on the shoes?
Was the wind blowing in a different way (speed or direction) compared to your more comfortable descents with the same bike?
All of the above affect the handling (and could potentially induce shimmy).

Also, I suggest a very thorough inspection of your fork and frame for any suspect scratch which could be a micro-crack.

Retro Grouch 

[QUOTE=IK_biker;19459964]Are you sure that your headset is properly adjusted (preload)?[QUOTE]

That's what I was thinking. A too tight headset will handle funny. It won't center itself so you'll be constantly correcting. If the front wheel doesn't flop side-to-side by itself when you lean the frame over, the headset is too tight.

corrado33

[QUOTE=Retro Grouch;19460084][QUOTE=IK_biker;19459964]Are you sure that your headset is properly adjusted (preload)?A too loose headset is also bad though (likely resulting in wobbles!) I had a small crash a few weeks ago (bars got turned on the steerer tube) and recently I noticed the bike was more wobbly than normal. It would wobble instantly when I took my hands off of the bars. After THOROUGHLY inspecting the fork/wheel/and headtube I noticed that the stem bolt had gotten turned a bit (it lines up straight with the decals on it.) After retightening the headset, the bike was back to normal!

3alarmer 

.
...as stated, check your headset. In terms of things that can change the feel of your steering, wheel alignment in the frame can also affect steering. It's pretty hard to diagnose on the internet.

fietsbob

You need to get the actual Trail measurement , on the ground..

that is what rake + head tube angle really do not give you.. incomplete measurement.

the line down from the axle crosses the HTA, above the Ground plane.

Andrew R Stewart 

I agree with the above comments about bar and stems being about fit and not steering. It's different on a mountain bike as fit is far less an issue what with one's body moving all over the place to maintain balance over rough trails.


I pushed some simple math with the assumptions of tire widths. The Orbea with 25mm tires has about a 65mm trail figure. The Novara with 35mm tires about 64mm of trail. The Schwinn with 25 tires about 59mm trail. The Salsa I deleted as it's not really a road bike and therefore has different design goals.


The trail amounts are all pretty close to each other so not much difference here. But the only other known (as we don't know seat set back, front or rear center dimensions, BB drops and more we can't speak to them even though they do effect stability) dimension we have is wheel base. 60+ mm of difference is a lot of change. A huge amount when dealing with the ride's perception of handling. This indirectly speaks to the weight balance between the two wheels and the leverage the steering has on the rest of the bike/rider system.


It would be surprising if the OP didn't feel the bikes were handling differently WRT stability perception. Note that I use that word a few times, perception, as measuring stability is not a well understood calculation to make easily. And this goes to my biggest point. The rider is the largest factor in stability. How their mechanical connection to the bike changes (with fit, equipment and contact points placement shifting) and how the rider's control (of both their body and the bike) change over time and can 'learn" a bike over time yet then forget this memory is far greater a range of difference then any frame geometry ones. Andy.


I'll also agree with the chance of a too tight or high friction headset. Always check what is free to do so first. Andy

70sSanO

I didn't ride my short wb/steep ha road bike for a few years, put on a few lbs and was riding fewer miles, and when I got back on it, it wasn't that stable and I was wondering if I could adapt back to what I had ridden for a long time. It really didn't take long for me to get used to the quick steering and now it feels rock solid. You may just have to get used to it.

Also, you are spending more time riding stable bikes that will only make the Orbea seem even less stable.

It would be possible, I believe, to swap out the fork to add a bit more ATC, and maybe change up the rake/offset. You would need to find someone astute in this area. In some ways it is not that much different than swapping out a mountain bike suspension fork for a slightly longer one. If done correctly you can slow down the steering a bit so-to-speak.

John

kevrider

thanks for responses gents. the front wheel does flop freely from side-to-side when i lean the bike left and right, so i don't think the headset is too tight. there are no clunks when riding over bumps in the road or dropping of off curbs, so i don't think the headset is too loose. the bike does not have wobble or shimmy, i don't think it is a mechanical problem. it does nothing that i don't ask of it, it just does so more quickly than i anticipate and to a larger degree than i desire. there are too many course corrections, my lines are sloppy.

i will heed the good advice regarding fit and refrain from changing the bars or stem. this is the only bike for which i've had a profit, so it would be silly to screw that up. sounds like i need to increase the saddle time and get myself recalibrated for smoother, more deliberate inputs. if that doesn't sort it, maybe it'll be n-1+1. i hope it doesn't come to that.

cheers!

Bandera

You routinely Drop off of Curbs on a Orbea Onix CF road bike and complain about it's Handling?
Never mind...

-Bandera

kevrider

funny. you don't know what i do routinely, but the place where i am staying this month (away for work) has a fairly steep curb at the end of the driveway. it is not square-edged, but it's steeper than 45 degrees. i "dropped" off on my ride yesterday at leaving-the-driveway speed. i am not a clyde and it was not dramatic, though the bike really isn't so delicate. anyway, if the headset were loose, there would have been a clunk or clang or something.

Bandera

The Test for proper HS adjustment is not in using even moderate curbs for an audible "clunk or clang" much less a "something".

Try this instead :


-Bandera

bradtx

kevrider, I think you just need more saddle time on the Orbea. My reasoning is two fold, first I have a bike with similar numbers, but with a steeper HT angle which allows for quicker transition into a turn. My bike's geo. is: HTA=74.25d, WB=977 mm, fork offset (rake)=38.1 mm, and trail=58.44 mm. The bike is stable well into the 40 MPH range. Second reason is that the Orbea is possibly different enough from your other bikes to seem unstable. Take a good ride on the Orbea and then ride one of the other bikes. If the other bike is rather sloth-like, you have your answer.

I also ride sport bikes and I don't find cornering stratagies very similar at all. You need to weight the outside pedal on a bicycle.

Brad

1Coopgt

Wondering if it has to do with the Rake & trail numbers you have in this bike . Bicycle Trail Calculator | yojimg.net You said you road sportbikes usually they are more twitchy (quick steering) compare to a cruiser because of shorter rake and trail numbers by design . Also a short wheel base can cause twitchyness as mentioned . Also Wider bars would give yo more leverage while counter steering . Bicycles steer just like motorcycles once you build up some speed .Food for thought .

Andrew R Stewart 

Less rake equals more trail, all else staying the same. Also race bikes currently have a fair amount of trail, typically 55-65mm.That the head angle, the rotating weight and the weight distribution are so vastly different between a sport bike and a cruiser's is a lot of the reason why they steer so differently. The rake has little to do with it. Andy

Andrew R Stewart 

Again I'll take issue here. While some of the mathematic equations of balance and steering are the same there's a vast (love that word) difference in inertia and weight location/transfers between a motorcycle and a bike. A motorcycle (and it's wheel/tires) are a much larger % of the vehicle weight with a rider then with a bike. So the dynamics of rotational inertia and momentum are rather different and how one works the body WRT to this is also different. Then there's the bike's side to side weight transfers with each pedal stroke that don't happen on a motorcycle. A motorcycle's center of gravity is much lower that a bike's. I think why many say what 1coopgt does is that the rider's skill set transfers well between the two single track machines. This is different then saying the two handle much the same. Andy

1Coopgt

Have you ever ridden a motorcycle? Also do you know about counter steering and what it is ? You do it every time you ride your bicycle. You are right a motorcycle weighs a lot more but depending on the motorcycle the CG may not be as low as you think. But I'll stick with Motorcycles and Bicycles steer exactly the same way. One is just a lot more subtle.

The head angle witch partially determines the Rake and Trail geometry make a big difference on how a bike steers. Compare a chopper to a sportbike or your bicycle . The chopper is slow steering with the turning radius of a truck . Your bicycle is even twitchier than my Sportbike due to its Rake and Trail numbers . Also mentioned by someone the longer ,I think its called the chain stay ( Swingarm on a motorcycle) the more stable and slow turning the bike becomes .

Honestly I'm not sure what you were trying to explain to me . But I do know motorcycles ( been riding them for 30yrs) and bicycles even though I took a 30yr hiatus from them . Bicycles still work the same way they did as when I was a teen.

Andrew R Stewart 

I got my MC endorsement back in 1977 and made sure as I move from state to state that I retained it (and more then one state didn't transfer it without prodding). While the miles I've motored are far less then pedaled I have gone past the limits on both. The first time I locked up a front wheel on a 750 was eye opening to say the least. That it came after doing so on my bike made it less stressful


What I was trying to get across is while the math behind steering and balance between motos and bikes are the same the large differences of weight, traction, CG, and more make direct comparisons challenging at best. These differences push the results (of math) to realities where handling situations do differ in how they are dealt with. My personal experiences riding both machines prove this to my comfort. That the geometries of the two machines tend to be so different reinforce my views, IMO.


And that bicycles are so much the same, so simple, yet so strong at bring out basic joy and conectiveness with the rider is why I've studied them for so long. Andy

andr0id

Countersteering is much more subtle on a bicycle. On a MC, you very deliberately begin a turn by pushing fwd on the turn side grip.

I only do that on a bicycle to initiate a very aggressive turn. There is one turn coming into my neighborhood where I have to take a tight right and then avoid a pothole for example.

kevrider

thinking more about reading the turn radius, brake point, trail braking, entry point, line selection.... yes, operating the machine is not the same, but what to do and when to do it is a familiar process. well, corner exit... that's pretty different. i noticed when doing that event in the mountains that a lot of cyclists are not well-versed in cornering techniques, it was evident on the descents... there was a lot of coasting, poor lane positioning, questionable lines.

@Bandera, thanks for the vid, i have been thru that procedure on a another bike. i learned the hard way to tighten the star nut before the stem pinch bolts. i'm confident this headset is good to go, especially since i haven't changed anything beyond bartape in ages.

i will work on the saddle time issue and get myself recalibrated. i think you guys are right, that should cure me.

sunburst

You're giving this advice to a motorcyclist. I had to laugh, because I learned this on a motorcycle a few years ago, after cycling for three plus decades. I brought a few lessons from motorbikes to descending on a bicycle.

Edit: Oops, I skipped most of this thread, after I saw this advice early on. Didn't realize they was a longer discussion of motorcycles. I believe I'm a better cyclist because of my recent motorcycle experience. I rode when young based on someone showing me the clutch and how to shift gears, nothing else. Then didn't ride for three decades and change. When I started back I took it very seriously indeed and tried to learn how to ride safely.

miamijim

+1 to that. Don't take this the wrong way but your riding skills aren't up to the abilities of the bike.

I've ridden a few in my time that were beyond my skills/confidence level....trek y foil 77 was scary on descents. Back in my 20's the Madone 6.9 Pro was probably equal to my confidence levels but in my late 40's not so much.