Fixed gear/grass track

Teach

Sorry I've posted this in amateur race but I was getting no response, so I'm posting in here.
I'm interested in buying a cheap but workable fixed gear bike for grass track racing.
Looking on eBay some say they are single speed but not fixed gear. How would I know if others are fixed or single? (there were some advertised as fixed gear with rear mechs on them and 10 speed cassette!)
Do they need to be fixed for grass track. If I was to accidentally buy a single speed that's not fixed are they relatively cheap/ to change. What would need changing?
Is there anything else that I need to look out for.
Do these bikes need greater clearance for knobblier tyres?
Is there anyway this bike would double up as a track bike for an indoor velodrome?
The track racing is at roundhay park Leeds and i found it on the website, will pop down this week or next to ask more questions, but there are a few cheapest bikes on eBay which would finish before I get there.
Cheers.

klep

I recommend you to check out the London Fixed-gear and Single-speed forums

John.T

For Roundhay you will need a fixed wheel bike with no brakes etc. That is one you can not freewheel on. Fixed gear and single speed are the same thing but can be either fixed or free wheel. A high BB such as on a proper track bike is better to stop pedals catching the ground. You do not need very knobbly tyres unless it is wet but I don't think they race then (Not raced there since the 60s). Light CX tyres would be fine. Best to go along and see what everone else is using. You could find a bargain as well.

Monty Dog

File tread CX tyres are the preferred choice for grass-track, so you might struggle with a regular track frame with tight clearances. If you were looking for a suitable modern bike, try an All City Big Block. Most Singlespeed road bikes are sold with a flip-flop hub which has the threaded fitting for a fixed cog and lockring on the opposite side of the hub - simply turn the wheel around in the drop-outs to convert.
You could use such a bike on the Velodrome if fitted with skinny tyres - for indoor tracks like Manchester and Newport, you'll certainly want a higher BB to avoid pedal-strike on the banking.

FSR_XC

How's this?

http://www.ebay.co.uk/itm/Specialized-T ... 2200wt_922

Flip flop hub so fixed or freewheel and CX set up

gmb

Not sure how much you are looking to spend but Planet X/On One have their Pompino fixed gear on sale at the moment.

I have a Pompino which I run as a fixed for my commute/winter trainer/put a smile on my face type bike and can certainly recommend it. It comes with a flip/flop rear which means that if you should wish to change to a single speed you can (Can' think of any sensible reason to do so though )

giropaul

I'd endorse John T's advice - go along and chat to the riders. It amy be that someone has a bike for sale even. Better to get the right thing in the first place.

Beware of the bikes, such as some Specialized etc that are meant for the road fixed commuter/messenger type market if you're wanting to go on a velodrome - most are not appropriate as things like the bracket height are not what is required, and you will not be allowed on the velodrome on them.