-
Thanks Jonny69, that was super helpful.
Yeah, the frame is SL tubing but the fork was most likely low end gas pipe. Not even sure if the fork was original or taken off a road bike. I measured again and it was definitely in the 43-45mm rake range.
The bike has track bike geo....75/75 head and seat tube.
Unless you've ridden a bike with a 75 degree head tube and nearly 45mm of rake, I really wouldn't comment. The head tube/fork rake combo gives puts the TRAIL at 45mm which means SUPER twitchy. To give you an example, my last Pista was around 65mm trail. Remember, neutral handling is around 60mm so a 45mm trail is very twitchy.
So I took two wood blocks and sandwiched the lower fork blades between right at the end making sure it was perfectly even on both sides. Not going to tell how I put enough pressure on the blocks but I used a bar on the steerer tube and just pulled down a little. Flattened right out and my final measurement came out to around 32mm which is a lot better. One drop out needed just a tiny tweak but after that they measured perfectly. Axle fit smoothly, etc..
Took the bike out today and it handles SO much better. Just tracks smoothly with none of the previous twitchy handling. I'm getting a proper low rake fork next month (nice Columbus helical tubing this time) so I'm looking forward to this. The bike is 100% easier to ride now.
Yeah, it has a minor kink in the bend but not bad.
Before....
After....
You are reading a single comment by @JRatNW and its replies.
Click here to read the full conversation.
JRatNW
Gas pipe steel yes, 501 yes, 531 probably ok, any heat treated steel or aluminium absolutely no.
10-15mm probably won't do it much harm. It was probably cold set by hand originally. I'd flatten the original bend or it'll look terrible. The problem you'll probably run into is getting both sides the same. You'd be better off clamping the skinny ends between two blocks of wood and pulling the thicker ends of the fork and I'd do the bend in multiple points along the existing curve so as not to over-strain one point.
You can do this with leaf springs to lower a car. Put it on its side on the floor and draw round it with chalk. Then draw a new line with your desired curve/rake. Tweak a little at a time and offer it up to the new line. Repeat until happy. She'll be reet.