biopace chain ring - fixie conversion
 

Can I convert my road bike with Shimano Biopace to a fixie? My intuition tells me that I won't be able to set a consistent chain tension if the front chain ring is not round?

Am I over thinking this?

GG

biopace aren't round?
are they square?

Check a few weeks back, some guy did it on his fixie and posted how he did it and how it felt. Sounds like he liked it a lot. If you ever need NOS biopace and rather get a set of a fellow forum person vice harris cyclery, please pm me

I'm familiar with all the words you used, just not the order you put them in. ;)

roffle.
best post ever. :p

Just not the order in which you put them.

I put a 53 tooth biopace on my Pista a few weeks ago and I love it.

I set the chain tension so I have about an .25" play at the tight spots and .75" at the loose spots.

While riding it feels two or three teeth smaller and easier on my knees, though I have not had any knee problems in the past year.

A few days ago I changed chainrings in preparation for winter.
I wanted a smaller chainring so I could brake more effectively and thus stay off the front brake on frosty mornings.
I put on a 47t Sugino/SR chainring.

When I first rode with the 47t chainring the bike felt ridiculously slow, so I took it on 12.5 training ride I know real well.
With the 53t ring I do this ride in 55 minutes.
With the 47t ring I did it in 50 minutes.

Thirteen point six mph vs 15 mph.

What a surprise.

However, my knees felt funny after the biopace.

Ideally, I would like a 49t biopace, which should feel about the same as a conventional 47t chainring but gentler on the knees.
Alas, they don't make, to my knowledge, a 49t biopace.

Next summer I wonder what I'll do.
Will I go back to the 53t biopace?
It sure feels good.
And fast.
How can it go slower? :)

Ken,
People here kept telling you you are riding too tall a gear for your hilly terrain - now you have proved it for yourself ;)
PS. I really enjoy reading your posts, keep it up.
Regards,
v.

I ride a converted late 80's rock hopper with 48x17 gearing, with a 48t biopace chainring. I don' t give it a second thought, I just get on and ride.

My ring is a 52T on the front - what sized gear should I put on the back for a starter?

At least a 19t cog, although it would probably be best to start with a 20t, which would give you about 70 gear inches, a good starting point.