williamskg6

Hello,

I'm working on building up a Specialized Sirrus frame from 1988. It's steel, and I bought it as just a frame off my local Craigslist. No wheels were included. Other than the requisite chipped paint that all old Specialized steel frames seem to have, it was in good shape.

I just picked up a set of wheels, knowing I'll need to cold set the rear triangle for the more modern 130mm spacing. What I didn't know is that the fork is way, way too wide of spacing. I measured at around 112mm spacing for the fork.

What are my options here? Should I attempt to cold set the fork down to 100mm so that it fits my wheels? What are the gotchas/dangers I'm facing if I do so?

-Kent W.

shelbyfv

Just for clarification, did you attempt to fit your wheel?

mstateglfr 

Check to make sure the fork blades are straight. 112mm is wide and a fork's dropout spacing isnt exactly easy to knock out of alignment so maybe something caused it that has made a blade uneven compared to the other.
Assuming everything is structurally good- just cold set it back using some threaded rod as a guide to keep the blades aligned. Curved forks are made with some pretty rudimentary brute force and the same process is used to align dropouts(twist and check process). Blades will wantt to spring back to the current width, so it may take time to adjust.

williamskg6

I did some checking. It's nearly impossible to mount the wheel as it is - you need three hands. I checked the forward/back alignment of the blades by setting the fork on a flat surface and measuring the distance from the surface to the dropouts and at least those appear to match. What it looks like is that one fork leg is splayed outward at a pretty noticeable different angle than the other. I can't tell if it's the crown itself or the leg or a combination of both. I guess this is a perfect illustration of the dangers of buying an old frame off Craigslist.

I put a skewer (no hub) in and tightened it down as far as it would go and closed it. The fork sprung back open to only about 107mm, but the legs are still different. It looks like the dropouts are probably also not aligned very well either.

At this point I am going to be looking for another fork, but it's that lugged Specialized fork with the "S" in the crown and I need one with a steerer tube of about 205mm. I may be looking for one for a long time - they're rare.

As for this fork, I may try bolting it down to a piece of MDF by pinning the steerer tube and the good (I assume) leg in place, leaving the other leg free to move, and then try to cold set it down to the right spacing. That should prevent the good leg from deforming inward, hopefully.

I think I can get it close to the right spacing, but I'm a little concerned how safe it'll be. What to I look for (other than the obvious - cracks)?

Iride01 

How stiff are those fork blades? I have a couple old forks in the garage, while they measure 100 mm. I can squeeze them together without even using much muscle and they'll narrow up over 10 mm. So with a skewer or nut to hold the wheel on, what's the issue?

Of course not knowing the history on the bike, you do need to do some measurements to make sure the fork wasn't the previous owners wreck they wished to rid themselves of. Frame builders have a lot of tricks for checking this sort of thing, so maybe check in that forum or google for ways to check alignment of a bicycle frame.

Cyclist0108

Replace the fork. It is either damaged or not the original. If it is sprung like that, it can eject the wheel.

Iride01 

Oh.... since the Sirrus is sort of a hybrid who knows what, are you certain that the fork isn't supposed to be 110 mm as are some mountain bike forks?

williamskg6

The late 80's Specialized Sirrus and the late 80's Specialized Allez were the same frame. It's no hybrid in any sense. It is a steel framed road racing bike. The components were different and the paint was different, but the frame was the same. The current Sirrus is totally different - it's a flat bar road bike, which could be considered a hybrid. Mine is a late 80's model with the steel racing frame.

mstateglfr 

In '88, the Sirrus was a quality road bike with 100mm fork spacing.

mstateglfr 

I would look for a frame builder near you. Or google around, call one, and ask to ship the fork. The guy that I took a framebuilding class from repairs damaged frames and forks- its really just bending then checking alignment and cracks. To build a fork initially, there is a lot of manual bending of the blades(multiple times, if you arent good at it), and bending the dropouts to align.
For your fork, since it splays out it may be toast, but I certainly wouldnt just call it a loss and mess around with bending it on my own while searching for who knows how long for a new fork. If that letter S is really what matters to you, then look into getting it properly fixed. If the fork blade cant be moved back, then look into having the blades replaced. You could keep the crown with that special letter S and get blades with an offset that matches what you want for trail.

williamskg6

I hate it when people don't post updates, so here's an update.

I took the fork to Black Sheep Cycles here in Fort Collins. They measured it and were able to just cold-set it back into shape. The left leg was out by about 9.5mm and the right leg was in by about 9 mm. They wrestled them back into position, which didn't take nearly as much effort as I expected. Then, they fixed the dropouts' alignment. At current it's probably at least as well aligned as it was new. Their best guess is that it was tweaked in a car roof rack.

As an additional bonus, they were able to mill the crown race down from 27mm to 26.4mm so I can use the new headset I bought. All this and they charged me $30 less than they said they would. Awesome!

With respect to safety, they didn't see or feel any reason for concern. They said it's pretty noticeable when the steel has exceeded its ability to maintain its strength.