Saturday, May 14, 2011

Just when you thought it was safe....

Just when you thought it was safe to revisit this blog and not see something that dissappears up its own black hole about gear ratios: i'm going to talk gear ratios.



Lets say that following on from a pretty bumpy 12 hour race you have another bumpy 12 hour race coming up. You might have a history of doing ok in that race and it may be the one race you look forward to (in the uk at least) more than any other. Buuut the last time you did it you were nearly reduced to tears by back and arm pain due to riding on the baked hard course on an uncompromisingly rigid forked bike with narrow tyres at high pressure. Something has to give, right?

This is where i am.

At Newcastleton i used high volume Conti race kings at 20psi. This was a good thing. The Jones was pretty comfy for the most part, just a little jangly on some of the washboard sections. It was awesome to ride through the singletrack...but lets say i want to race a bike with a suspension fork at Bristol Bike Fest....especially if it is as baked hard under-tyre as last year.



However, the Vertigo frame has no chain tensioning bits. Fortunately. FixMeUp! provides a way to calculate what cog and chainring combos might work for a given chainstay length....

Once all this goes into the melting pot i'm left with several options that will potentially allow me to 'magic gear' the Vertigo for Bristol.....35x19, 39x23, and 34x20. These all fall at very slightly different chainstay lengths, so one or the other should fit, especially if i try combos with new or used chains...

Other things to look at:

Entries open for SSUK 11.

As is SSUSA.

New Black Owls visuals.



Issue 3 of Privateer is out. If you want a more cerebral mtb magazine, get it.

11 comments:

davechopoptions said...

Leave the gears on dumbass.
;-)

or 35-19.

Anonymous said...

So you have a singlespeed Jones, a singlespeed Indy Fab, a singlespeed Voodoo, a singlespeed Kelly, and out of all that lot you still feel the need to singlespeed your Vertigo?

dRjON said...

no voodoo, no kelly.
jones isnt suspension corrected.
vertigo has suspension forks.
new vertigo will be able to too...
it all makes perfect sense.
:-)~

dRjON said...

*and* i should add - its for one race only....

Anonymous said...

Every Jones is suspension corrected.


Anonymous said...

Why not play with the big guns, rather than some self selecting bunch of gearless try hards?

dRjON said...

i think i have my first blog troll!

:-)~

Tom Levell said...

He's got a point though...

:0)

Oh and more wibbling about gear ratios please but I'm with Nick on the don't multiply by Pi.

Nick said...

Just rediscovered 32:16 after two years of 34:18. Ouch.

AdamM said...

I'm forcing myself to TTFU and ride 34-19 on the Pegasus after it being 34-22 since riding at Napa... it is going to hurt!

Nick said...

WTF are you doing on 20psi? I just rode 1/4 mile on 20psi as a result of a slow puncture and it's horrid. Sidewalls flex too much, steering is shite as rim turns by tyres doesn't. Sure the contact area is great and it was comfy over bumps but at helluva risk of pinch punctures. Even if I eliminated that risk with tubeless it would still feel rancid. Don't see the point of making everything on the bike nice and stiff only to spoil it with flexy sidewalls. Tom RItchey said back in 96 or so that you need to consider a bike as a system not a collection of independent components.