Replacement fork versus repair - bianchi 80s
 

Hi folks I recently bought a bianchi and the forks are bent. The steering tube is also bent and a small dent on one of the forks. I'm having trouble sourcing a cheap replacement. The steering tube is quite long at 185mm and a thread of 45mm is required for the head set. I've seen some forks that have the length i.e. Over 230m but the threaded portion is much too long. My question is does this actually matter as the top will screw into the race or does the whole 185mm of the steering tube have to be smooth?

What Model Bianchi?

one word of caution from personal experience: some of the replacement forks with enormous long threaded (and slotted) portions of the steerer result in a weakened steerer where you need the tube to be strong. Like where an expander wedge bears against the inside...I had one split due to a moderate amount of torquing that would not have even dented a better quality (and smooth) steerer tube.

Bent steerer tube would, for me, probably mean a new fork. But good pics result in the best answers.

The problem with bent steerer tubes is that, unless you get them perfectly straight, the top and bottom races will be misaligned, resulting in accelerated headset wear.

I think once the steerer tube is bent, the fork is pretty much toast.......
I don't think any frame builder would suggest bending it back straight, and replacement of the steerer tube might be cost prohibitive as a replacement fork might cost just as much.....or less...
BTW, bending a steerer tube in a crash might mean there's more damage than what's easily seen as it would have taken a lot of impact force to make it happen. Make sure to check the top and down tunes for any bending or buckling......

Hi I am not really sure it's a mid 1980s bike with Omega cranks and Shimano SIS shifters. The tubing Is Bianchi 1-20 so not the nice Columbus of other models.

Hi folks thanks for all the advice. I agree repair I don't think is an option. I'll try to post pictures of the fork and measurements. The Tange fork looks good but very expensive and I've also found a couple of NOS items. Finally a Bianchi fork that looks to be from a later bike.

On the frame it seems ok though the whole thing is very flakey. I'll have it painted and checked anyhow.

As I can't seem to post pictures from my iPad more details on my blog : spindleandspoke.wordpress.com

Thanks for the advice I will try to keep the threaded portion to a minimum.

There are more pics on my blog spindleandspoke@wordpress.com.

I am not certain but 1-20 tubing might be a '70s frame but I don't think they had Ofmega and definitely not Shipmano SIS shifters.

I can't seem to get your link to work. Are you in Europe? That might explain the tubing.

Bianchi 1-20 tubing was their own in house chrome alloy tubing used on several of their bikes. Spindleandspoke@wordpress.com

I'm located in the U.K. And this bike was made in Italy. OFmega was a competitor to Campagnolo but more budget. I have a couple of their hubs on my Holdsworth and they look nice.

Pic Assist.

Thank you for manspainin Ofmega cranks.

Funny when I was at the auto garage this morning I did a little research on the 1-20 tubing and a bike very similar to this was one of the first images. I love that turquoise color. The shifters are friction not the later indexing or SIS shifters, and I believe they belong to the BL- groupings.

I would love to see a good straight side on shot of the head and down tube junction. You see how the pait is flaked and chipped there and has those thin cracks that run around the tubing? That is a good sign that frame itself took a good jarring when the fork get bent. I suspect someone really slammed into a curb or maybe fell into a pothole or sewer grate.

A local framebulder could likely replace the steer tube, and repair or replace the fork blades. But, it would get expensive quickly.

What are your goals for the bike? Commuter/Town bike? Show bike? Somewhere in between?

I'd probably hunt down a good replacement fork. Non-Bianchi. Keep that one in case someone in the future wishes tinker with it. The crown should be good.

Update on Forks
 

Hi folks I've sourced a set of forks from the USA by eBay. Tange forks 3E chromed up they look great. I hope they arrive in one price.

I'll try to send some pictures