Author Topic: Geared vs Fixed Bike Fit  (Read 4392 times)

Chris N

Re: Geared vs Fixed Bike Fit
« Reply #25 on: 30 December, 2020, 05:28:31 pm »
Dunno.  IME you just have to get on with it or slow down.  If you're insisting on riding fixed you might as well try to offset some of the risk by using shorter cranks and/or a higher BB.  I use 170mm cranks with a fairly wide Q on frames with a 290-ish mm BB height (60mm BB drop).

Re: Geared vs Fixed Bike Fit
« Reply #26 on: 31 December, 2020, 01:08:43 pm »
I've only had it a couple of times, resulting in a sideways hop of the back wheel.  The only danger on fixed is if you haven't enough road to straighten up on, though of course you will have scrubbed off a bit of speed. 

Re: Geared vs Fixed Bike Fit
« Reply #27 on: 31 December, 2020, 02:14:59 pm »
FWIW if your setup is a bit crap (low BB, long cranks, high Q and sticky-out pedals) then you won't be leant over very far when you get pedal strike and if the strike  is not too hard you may well be in a recoverable situation, with just a hop.  However if you have a setup which provides more cornering  clearance you are that much closer to the limit of grip when you get pedal strike and you are therefore more likely to come off, lowside.  The rear wheel hops, and then slides when it lands instead of regaining traction.

Reatively small changes in bike setup/geometry can make for in excess of ten degrees more (or less) cornering clearance.

With fixed gear setups, you can usefully gain a bit more clearance if you lean whilst pedalling, much as tricyclists must do when cornering. However it is neither comfortable nor terribly efficient to do this.

cheers

Re: Geared vs Fixed Bike Fit
« Reply #28 on: 31 December, 2020, 02:23:03 pm »
The usual practice is to take a wider line or slower speed around corners, but raised kerbs at chicanes, mini-roundabouts and adverse cambers can still be a problem.

Riding in a group with geared riders must annoy them: you are faster up the hills, slower down the hills and you can't take the same line around corners.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Re: Geared vs Fixed Bike Fit
« Reply #29 on: 01 January, 2021, 07:08:49 am »
Out of interest, how high? I find 10 3/4" is good enough with 165mm cranks but I'd want more than 11" with 175mm cranks. I tried my singlespeed as a fixie but it was scary - 170mm cranks and a 10.5" BB meant a couple of pedal grazes on mini-roundabouts before I put the freewheel back on!

(Apols for mixed units)

Erhh..standard track frame height, whatever that was. I still have the drawing somewhere from when I had the frame built..I'll see if I can find them.
High enough that I had no clearance issues at the local velodrome, with 47 degree of banking.

Re: Geared vs Fixed Bike Fit
« Reply #30 on: 16 January, 2021, 10:50:10 am »
I always seem to be the odd one out... My fixie has a slightly lower saddle height compared to my road bike. I think this is mostly because my feet are at often times used as a brake... I'm still kinda new to this pixie thang...
I dunno why anybody's doing this!

citoyen

  • Occasionally rides a bike
Re: Geared vs Fixed Bike Fit
« Reply #31 on: 16 January, 2021, 11:09:25 am »
My geared and fixed road bikes have very similar fits. The fixed has the handlebars slightly closer but that is mostly because it is mainly used as a commuter and I rarely ride on the tops in traffic.

This is part of the reason I have crosstop levers on the fixed bike. I do think it probably needs a shorter stem as well though - I built it to the same fit as my fast road bike but I mostly use it for commuting so a more relaxed fit would make some sense.
"The future's all yours, you lousy bicycles."

Re: Geared vs Fixed Bike Fit
« Reply #32 on: 16 January, 2021, 08:06:01 pm »
I always seem to be the odd one out... My fixie has a slightly lower saddle height compared to my road bike. I think this is mostly because my feet are at often times used as a brake... I'm still kinda new to this pixie thang...

You can use the brakes, just like with gears.

Re: Geared vs Fixed Bike Fit
« Reply #33 on: 17 January, 2021, 05:50:33 pm »
I always seem to be the odd one out... My fixie has a slightly lower saddle height compared to my road bike. I think this is mostly because my feet are at often times used as a brake... I'm still kinda new to this pixie thang...

No, it's quite normal. It's easier to spin faster with a slightly lower saddle as well. It's just that this forum is odd :)

Re: Geared vs Fixed Bike Fit
« Reply #34 on: 18 January, 2021, 12:49:12 pm »
Slightly lower here too. I tend to use the fixed geared bike around town and for shorter rides where I will need to put my foot down. The road bike is for longer rides where I don't often have to stop. I also have a geared bike that I ride around town on and its saddle is at the same height as the fix.


Pedal Castro

  • so talented I can run with scissors - ouch!
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Re: Geared vs Fixed Bike Fit
« Reply #35 on: 18 January, 2021, 03:23:06 pm »
The shorter cranks on track bikes was to avoid right pedal strike when going slowly on the banking. Also a higher BB. I think my vintage track iron has 6.5" cranks.