Loving the fixed but two problems...

spasypaddy

Problem one is me, i cant go over 110rpm wthout getting all bouncy. I've only been riding fixed a few months and not done a huge amount of miles on it. Will it come with time and is it just because im not flexible enough or used to the speed yet?

Problem two is a bike one, rebuilt my bike on monday after transporting it last week and when im stopping at lights and turning the wheel to get the pedals in the right place my chain keeps coming slightly detached why is this?

A third question, what are chain lugs?

meagain

"turning the wheel to get the pedals in the right place my chain keeps coming slightly detached why is this?"

Not quite sure what you mean by "detached" but rather sounds as if chain too slack?

"A third question, what are chain lugs?"

Chain Tugs, possibly? A means of helping prevent axle-creep i.e. once chain tension set doesn't slip (so quickly!).

As to rpm, never known what I reach - but probably less than that! But then I'm old and a well-known coward!

spasypaddy

when i say slightly detached, its as if its peeling off the cog (and i dont mean in the good way because its rotating!)

tomorrow i shall add some chain tugs, will pop to evans and pick them up in my lunch break.

meagain

tomorrow i shall add some chain tugs, will pop to evans and pick them up in my lunch break.

Tugs won't really GET the tension right - simply help keep it that way.

"Peeling off". Is the chainline OK?

spasypaddy

i thought the chainline was ok, the backwheel is on straight and its a purpose built fixie/ss and there have been no problems whilst ive been riding its only when ive been rotating at lights to get the right position

GarethPJ

As to the bounce issue; things do get better with practice, but I find seat height is more critical at high RPM on a fixed. It's a process of trial and error, try raising a lowering the seat fractionally to see if it improves matters. I think mainly though it's a matter of not allowing the pedals to control you, try to match your cadence to the speed of the bike rather than letting the pedals push and pull on your feet. All that stuff about being "one with the machine".

Quite apart from bouncing in the saddle allowing the bike to push you will actually make your spinning technique worse if you should return to a freewheel. Learn to match you cadence to the speed of the bike and it will actually improve your pedalling. There is a popular myth that riding fixed will automatically improve your pedalling, however if you don't pedal right when riding fixed it will have the oposite effect. On a fixed wheel bike the pedals will carry your feet through the "dead spots" at TDC & BDC, get into the habit of allowing that to happen and if you return to a freewheel you may find your pedalling becoming jerky especially on climbs.

As to the chain issue; You say it's a purpose built fixie, but what exactly is it. I have heard of one or two off the shelf fixies whith chainline issues. The Genesis Flyer springs to mind.

spasypaddy

Its a pearson for all intents and purposes but it is differently branded (from my LBS in north london that have the same frame suppliers), and probably different wheels/components

GarethPJ

Is the rear hub a fixed/freewheel unit? If so take a careful look at it, some of these units have been oddly machined. The spacing on the hub body itself is threaded symetrically so the "bottom" of the thread is the same distance from the centre line on both sides. The reverse thread for the lock ring is then added on the fixed side. This means that in order to get the chainline right on both sides the hub has to be assembled with more spacers on one side. IIRC it's 4mm more on the freewheel side. Some bikes with hubs like this have them assembled symetrically and the chainline on the fixed side is usually the one that suffers. IIRC this is what affected early Genesis Flyers.

Maybe this also affects your bike?

flashes

I've reduced my bouncing by raising the gear. I'm with the others on chainline, have a look to make sure the sprockets on the right way...........

spasypaddy

it is a flip flop hub but this problem has only started occuring since i rebuilt it at the weekend after coming back from a trip. The cog is on correctly that im sure of. I shall just keep on riding it until the weekend and take it in to my LBS where i got it. Although this is the first time ive ridden it heavily as a fixed beast.

There are no problems with the actual riding and the chain hasn't come off yet so its not too much of an issue

dreamlx10

it is a flip flop hub

Not to be too pedantic, but what you mean is a fixed/gear hub.

gtitim

bouncing on the saddle is normally due to gearing - the gear is too easy for you, as such you don't have proper control over the entire peddle stroke.

GarethPJ

dreamlx10 wrote:

it is a flip flop hub

Not to be too pedantic, but what you mean is a fixed/gear hub.

I don't recall anybody using the phrase "fixed/gear hub".

spasypaddy

GarethPJ wrote:

dreamlx10 wrote:

it is a flip flop hub

Not to be too pedantic, but what you mean is a fixed/gear hub.

I don't recall anybody using the phrase "fixed/gear hub".

no i mean i have a flip flop hub.
http://en.wikipedia.org/wiki/Flip-flop_hub

thank you gareth

meagain

"no i mean i have a flip flop hub."

A strange, new, modish term.

More properly, indeed a "fixed/gear hub" or "fixed/free".

GarethPJ

Never heard it called a fixed/gear hub in all my years of cycling, although I know I don't have as many years in as you Dave. I've heard them called flip flop hubs and fixed/free hubs for as long as I've been aware of the concept. I supposed to some people the late seventies would qualify as new modish.

meagain

That's me told! It is, after all, a long time since I werra lad....

Monty Dog

Regarding the 'bounce' whilst pedalling - everyone has a point at a certain RPM that bounce is more noticeable , but actually if you pedal at a higher RPM it often calms down - my 'bounce' is at about 150rpm but actually if I keep the pedal load on I can continue smoothly all the way beyond 200rpm when practised enough - my spinning drills used to go 120/130/140/160 etc to avoid it. Seat height and crank length will have a bearing too. Just make sure the cadence isn't within your normal 'working' range - either gear-up or down to try and avoid it

spasypaddy

the bounce only reall happens on downhills, its probably because i relax too much. Its become less noticeable with more riding this week but i now know what sort of RPM im doing by my speed which is nice

mackdaddy

I found on my fixed that once I get above a certain cadence, around 150 then I used to bounce because the pedals were pushing me. I also felt a bit unstable as well, so started on the brake.
Recently I have kept on top of the pedals and trained myself on the turbo to push much higher and so I keep pushing the pedal rather than letting the pedal get carried away on it's own. This has cured both the bounce and the instability.
Hope this helps.

spasypaddy

Thats exactly what ive started doing, push through it. Was happily spinning at 130rpm today without any bounce