Stan Heinricher

My 1978 Serotta road bike cannot be ridden with no hands; the steering is squirrelly. I’ve been thinking that a new fork with more trail might stabilize the steering so that the Serotta would self-steer like my old Bob Jackson touring frame. Do you road riders have any advice on replacing my old fork with a more-forgiving one?

Chr0m0ly 

Tight headset?

Piff 

Only that understanding the myriad of measurements used to convey how a fork will affect how a bike will ride (at differing speeds) is difficult. Prepare to do a lot of reading and trawling ebay/swap meets if you really want to do this. You might save yourself a headache (at the cost of $$) by taking your bike into a reputable custom frame builder to get them to re-rake your fork.

It took me months of checking ebay nearly every day to find a proper (relatively high quality) 1" threaded fork replacement. It still wasn't exactly what I wanted, but it works well enough.

79pmooney

Check that headset. If that isn't an issue (and the quicker your steering the more a poor headset will make riding no-hands difficult), I echo the above suggestion of taking the fork to a framebuilder. But be aware that the process will almost certainly damage the paint. What he has to do isn't subtle.

Re-raking forks is nothing new. Shops. framebuilders and bike owners have been doing it well over a century. Usually to address crash damage but a forumite does it regularly to change ride characteristics (like you are seeking here). (Gugie)

I raced a Fuji Pro built two years before yours. Very, very quick steering. It would be a month in the spring before I had any confidence riding no-hands but by late summer, no-hands wasn't a big deal at all, In fact I liked that initiating turns was far easier than on more conservatively steering bikes.

Stan Heinricher

Headset’s nice and smooth, no problemo!
The steering always was squirrelly, so I stored the bike in the attic for years and rode other frames. Then recently, I put the Serotta back on the road — but it still is twitchy.

Stan Heinricher

Thanks for the quick reply. I do think that I should take it to a good shop connected to a frame builder. I don’t want to do a lot of guessing.

Stan Heinricher

Thanks for the quick reply. I’ll take it to a Bike Doctor.

Bianchigirll 

Obviously you have tried different wheels?

Wileyone 

Why would you want to ride with no hands? It makes using the brakes much more difficult...

Doug Fattic 

i'm a frame builder and my most likely suspect that I would check 1st is that the fork itself is not in alignment. I've aligned hundreds of frames over the years that have come in for repainting and the majority of them were not spot on and many of them were way off. Of course it is possible the problem lies someplace else but assessing the alignment would be were I would start. It can be a surprise to some that even new frames might not be aligned as well as they should be.

3alarmer 

.
...if your wheels are planar true, and your frame is properly aligned, and your fork is properly aligned, and your headset is both properly pre-loaded and not indexed, a Serotta built bicycle frame ought to steer fine. Changing the fork for the problem you describe is not how you want to address it. Any diagnosis I made from here would be guessing. But I'd be looking at the front wheel, (and how it sits in the fork,) the fork alignment itself, and the headset.

I'd also be checking the alignment of the rear wheel in the frame and dropouts. I have a couple of Serotta frames, and they go down the road fine.

Pompiere

Once, while playing around with my fore-aft saddle adjustment, I made my previously stable Miyata impossible to ride no handed. When I moved the saddle to the rear slightly, stability returned.

dddd

If the headset is smooth and free-moving, and if the steering doesn't pull consistently to one side, then I think that 79pmooney summed up how some bikes take some riding time on before their steering response becomes familar enough not to have the rider perhaps twitching in sympathetic response to the steering.
From there even the steepest-angled and twitchy bikes of mine can all be ridden ho-handed, including the dreaded mid-70's Peugeot PX10's with their steep angles, and my 1952 E.Christophe with even steeper angles. Those are bikes that give pause to the thought of grabbing the water bottle, but can still be ridden no-handed on smooth roads.

As far as rider position, more weight on the front wheel is known to enhance steering stability. The stem length shouldn't matter when the hands aren't on the bars though.

AJI125 

Second this - it's an effort for sure. Bought a replacement fork for my 650B - was looking for more clearance, more rake, fender eyelets. Asked lots of questions about suitable vintage forks, sellers probably didn't like me very much on that account. But I had to calculate the height from the dropout to the bottom of the head tube for different rakes and A/C (note many aftermarket forks measure true A/C, i.e. parallel to steerer axis, while most resllers on eBay etc. measure the diagonal, from crown race to dropout). Just trigonometry, but it gets annoying to do over and over for different options. Not smart enough to automate it or solve the equations, but made a little spreadsheet to estimate. From the Sheldon Brown writeup, I tried to stay +/- 10mm of the old height with my new rake to not affect the angle of the bike too much. Verdict is still out, got some parts on their way and some work on my to-do list before it's rideable. Also with 650b, had to double check brake reach (getting brake bolt to crown measurements) just to make sure I didn't bottom out my brakes while moving the wheel forward a bit.

What A/C (either method), steerer length, and rake are you starting with? I have a Tange NOS I didn't end up using (I bought two options and evaluated for my needs). Crown race to dropout is about 378mm, rake about 50mm, steerer about 205mm with 62mm threads, 26.4mm race, about 800g (all per original eBay listing). Can't remember if it's drilled for a recessed brake or not. Chrome, looks nice, little scuffing at crown area. PM me if interested, and I can dig it out and take any measurements or pictures. But I'm guessing you want less rake for more trail, and most of the bikes of the bygone era I had looked at were 43-45mm rake, so 50 may make your situation worse, bringing you into a mid-trail geo. I planned to keep it if my first swap option doesn't work out, but it's really just taking up space currently.

Edit - I also have a red LeMond 2001-ish steel fork (from Tourmalet I think) where the steerer was too short (my lesson learned in getting jumpy with ordering something, especially as specific as a fork). Fender eyelets, steerer somewhere around 150/160mm. Don't remember A/C. Rake is 47mm or 43mm depending on what size it was actually for (53 or 55). Same deal, I can pull out, take pictures and measure if you like.

Manny66 

Ive got about 10 different forks stashed in my garage, I ride a 56 so they are all that size. Steel forks are fairly easy to acquire thru Craigslist or online. Old bikes can be had complete for almost nothing nowadays so keep the fork and trash the frame if you have to.
Find a fork with eyelets, as they usually have a more relaxed Rake , and swap it out. Doing a fork swap is a piece of cake and should only take a few minutes. You said you havent ridden the Serotta in years so take your time and experiment. If it works, send it off to the powder coat shop and your problem is solved.

I have a Crit racing frame that if I stand it side by side with my Road frames , the steering angles are noticibly different. And yes riding no handed on it is touchy.

Doug Fattic 

As a framebuilder I look at solutions to this problem differently than many of the suggestions. I would want a stripped down frame and fork so I could throw them on the alignment table to correct any problems. I would also put it on one of my fixtures to see what the exact dimensions of the frame really are and if after correcting alignment, the fork really needs to be altered to make it work better. It isn't difficult for me to change the rake to match the real frame reading.

Even high quality frames can be made imperfectly. I wouldn't presume yours was made perfectly in the beginning. The picture I'm showing of my 1972 Italian Masi Gran Criterium (I got in Milan before I became a framebuilder) has a 1º sloping top tube. It is supposed to be level and the slope is a mistake (although a minor one). The picture explains how I can get an accurate reading of the frame's geometry. I don't trust published specs or less precise measuring methods. For years I thought I had a seat tube angle of 73 1/2º because I measured the angle between the seat tube and top tube with a precise machinist protractor not realizing the top tube was not level.

Forks have several variables besides amount of fork rake. Fork blade thickness can vary a lot including how thick the wall thickness is down by the front dropout. They have different brake clearances between the front axle and brake hole and space above the brake hole to the lower headset race. Changing any of these dimensions also effects the geometry of the frame too. For these reasons I would try to keep the original fork and modify it if necessary. And if after going through the above steps I find the original fork can't be made to work I would then make a new one. With the information gathered, I would now know exactly what to do.

Stan Heinricher

Yes, in 1978, I was riding Campy high-flange hubs + Fiamme Red rims, and the bike was squirrelly. Today, I have a new set of wheels with the same performance: unstable.