BikeGuy2

front wheel hits bike frameHello, I recently bought a second hand Avanti Pista Pro fixed gear velodrome bike, hoping to convert it into a fixed gear freestyle bike (to do tricks on it like barspins, Wheelies etc.). I have a problem though, I wanted to do bar spins with the bike (I put straight bars on the bike) but when the front of the tyre/wheel swings around it hits the frames bottom tube and does not go any further. Can anyone think of a solution for this, so the tyre/wheel clears the frames bottom tube? The only solution I can think of is to get some sort of part that makes the fork longer, so the wheel is further down and clears the frame. I can not afford anything to expensive though.
If anyone could come up with a solution, I would be very grateful!

urbanknight

Track and road bikes aren't designed to let the steering rotate 360 degrees. I suppose there might be a way to shim the steer tube, but I think that would cause problems with the headset race and you'd have to make sure you have enough on the top to still hold the stem. A fork with higher clearance might work (something from a touring bike, maybe?) depending on how much overlap you're dealing with, or you could put a 650b wheel on the front, I guess.

FBinNY 

There are options but none of great, cheap, or easy.

Depending on how much it hits the downtube, you might try a lower profile tire, or a new, smaller front wheel.

If you have the skill you might be able to buy yourself some room by slightly straightening the fork, but this isn't that easy so should be a last resort.

Also if this bike has a threadless headset you might be able to transfer some spaces from above the the frame to below. There's a catch however, and that you'll have to do some work to get the headset to fit properly.

JoeTBM 

Are you sure you didn't turn the fork around when you were swapping the handlebars? a picture of the bike might help us understand your issue better

CliffordK

I see you started a second thread:
https://www.bikeforums.net/general-c...ike-frame.html



While forks look straight, they obviously aren't. And, finding one with straight blades will be a pain since what is called a "straight blade" fork still has rake.

A "Pista" bike or track bike may be the worst for what you're intending as it likely has very tight clearances. The advantages is the fixed gear, but you could do a fixed gear on other bikes as long as you can get the chain adjustment right.

If I was doing it, I would likely build a custom straight steel fork with legs that are about 1/2" or 1" longer than what you have now. And, for your frame, also using a sloping crown to hopefully not hit the frame. Perhaps even custom straight dropouts.

1970's bikes with horizontal dropouts are popular for fixie conversions. And, can have clearance for 27" tires and fenders (great if you wish to convert to 700c). But I fear you would have way too much rake to be comfortable. Thus back to the custom fork.

indyfabz

Cross posting in multiple forums is verboten.

stevel610 

My guess is a track bike won't last all that long doing the types of things you want to do. The solution is to sell the bike and buy one built to do what you want to do with it.

unterhausen

You need a straight fork that fits the frame. Bikes for artistic cycling use straight forks. I don't know if all of those bikes are custom. I was thinking bike polo forks are straight, but the ones I found have some rake.

bboy314

In addition to a straight fork, you’d need a frame designed with geometry to work for barspins. Trying to convert a regular frame (using small wheel or weird fork etc.) will most likely result in a bike that isn’t very suitable for regular riding.

urbanknight

Most likely, that would hit the frame in both directions unless the fork is also noticeable longer. Track bikes just aren't designed with the kind of geometry the OP wants.

CliffordK

Touring bikes, and even most MTBs have tons of wheel clearance. But you still have some type of fork rake which might make spinning the fork odd.

I was wondering about steel rigid MTB forks, and if many of them are mostly straight, and they achieve rake with the dropout being welded ahead of the fork. If that's the case, they might be easy to modify to be straight.

However, the crown probably won't work with the OP's bike.

Iride01 

Normal bicycles never expect to have to turn the steerer tube more than a few degrees much less have their frame spun 360 or more degrees around them. You are probably looking at a new fork with different rake or smaller wheel. Neither a cheap solution.

Welcome to BF!

dabac

I’ve seen a kind of riser collar that extended the headtube downwards in order to create clearence for bar spins. Think the company who sold it was called eightinch or similar.
If you can track down a guy with a lathe, making one is minutes work.

DiabloScott

How about a 24" wheel?

BikeGuy2

I am new to this website and I don't know how this works. I didn't mean to cause confusion. i am blown away by the help i have gotten here. Thank You

veganbikes

The bike is for track usage. Fixed gear freestyle has much different needs. I would look for a frame that is designed for FGFS or at least something with good tire clearance and a steel frame maybe something more like a big person BMX bike. Something with 26" or larger wheels.

dsbrantjr

I agree with stevel610, I think you are trying to make the bike do something it is not suited for and no bolt-on change is going to fix that.

dabac

Here’s the adapter I mentioned earlier: https://www.singlespeedshop.com/Sing...-Extender.html
How well your overall build may turn out, I have no idea.
Perhaps this and a 650B wheel would work?