1" threaded MTB forks.

[meic]

The forks on my 1980's Raleigh 531 have snapped their steerer tube and I am not having much luck finding suitable replacements.

The bike is a 531 All Terrain butted frame from the Special Products Division, so I am willing to spend a decent amount on reasonable quality forks. Though it did originally come with Unicrown forks that didnt seem quite as elegant as the rest of the frame.

26" forks with cantilever posts, approx 390mm axle to crown and 40-45mm offset.
220mm steerer with 45mm threaded 1" steerer.

I have only found these two that will fit

http://www.ebay.co.uk/itm/SPRINT-26-SIL ... 20fec63725

http://www.ebay.co.uk/itm/26-MTB-FORK-W ... 1832107515

Can any of those of you with a better nose for finding stuff suggest anything better than these?

I dont think I am up to having new ones made as I have let the frame get somewhat rusty and battered and the bike is mostly just a workhorse with other bikes available for "best" riding.

[Brucey]

I'm pretty sure I have a set of 1" threaded MTB forks in the shed somewhere, I'll see what I have, if the steerer is long enough etc. If I do, be warned, they won't be the same quality as you had before, they'll most likely be welded unicrown jobbies.

cheers

[meic]

Welded Unicrown is all I have ever had on the bike.

I just had the scales out and the frame is 2450g with an additional 1Kg for the forks

Compared to my lightweight 531 Holdsworth "racer" which is 2416g with an additional 748g for the forks.

I would have said that the Forks on the Raleigh were much more rugged but they have proven that to be not the case by snapping! The rest of the frame is one of those gems that you find in life and even though it is financially worthless not many people have a shopping bike to compare with it.

[james01]

If you're not in a hurry I'd keep an eye out on Gumtree and local shop window ads for a cheap large size mountain bike - something should turn up and a non-runner usually goes for well under £30. Many on sale are from the 1980s, and 1" quill stems were very common then. You may even get lucky and get a decent Chromoly fork. Just make sure the stem hasn't seized into the steerer before you buy!
Incidentally I too have a battered 1980s Raleigh 531 MTB (although not the Unicrown fork variety, mine has quite elegant 531 forks ) . Lovely old bike which I've always treated as bombproof in the most appalling conditions, but after your experience I'm starting to wonder about that 35 year old fork...

[jimlews]

The forks on my 1980's Raleigh 531 have snapped their steerer tube and I am not having much luck finding suitable replacements.

Can any of those of you with a better nose for finding stuff suggest anything better than these?

I dont think I am up to having new ones made as I have let the frame get somewhat rusty and battered and the bike is mostly just a workhorse with other bikes available for "best" riding.

You might keep an eye out for the scrap metal guys. I often see quite reasonable bicycles balanced precariously atop the scrap in the back of their trucks but old MTBs seem to predominate. Flag them down and offer a swap for an old rusty dustbin or something - its all just scrap to them.

New steerer £ 60.00 from Jacksons in Leeds though they won't touch anything tig welded.

Incidentally, you have a very good frame builder in Caerfyrddin.

EDIT: I'm behind the curve again. Paulos Quiros bikes have moved to Swansea - Pilot House Warf, Swansea Marina SA1 1UN ( if the frame is 'one of those gems' it may be worth the expense ).

P.S. The clue as to the cause of your predicament is probably in your phrase 'I have let the frame get somewhat rusty'. Evidently the forks as well. Just a thought.

[Brucey]

I had a forage in the shed and I found the forks I was thinking of; just the job, except that the steerer is too short....

so, no cigar, sorry!

There's an outside chance that I have some others that are the right size but if I do they will be very low quality I think.

cheers

[meic]

Thanks for looking Brucey. No need to hunt out the poor quality ones, I can buy those I listed above.

The forks do need a longer than average steerer tube and the chances of finding any long enough are pretty slight, especially in very sparsely populated West Wales.
I have already had an eye out for any such lucky chances and they just dont come along around here for large frames.

The forks are unicrown so cant just have a new steerer fitted to them.

The rest of the bike may be very rusty but the fork steerer doesnt have a spot of rust on it and the snap is absolutely corrosion free, it must have been a different type of neglect that I am guilty of in that case.

There may be a decent frame builder in Carmarthen but if it is the same one as last time, then I have already learned to avoid him.
viewtopic.php?f=5&t=17078&p=135907&hilit=Holdsworth+headset#p135907

I do still at least have those two cheap forks available to buy from the internet, when the tube snapped I thought that the bike was to be written off and canabalised for spares.

[deliquium]

Keep an eye on http://www.retrobike.co.uk/forum/

In response to a WANTED advert/post I acquired a very good condition 1990 Raleigh 531 'Blueridge' frame and forks for free, just had to pay £7 postage. Plus a 1987 Raleigh 531 'Avanti' frame and forks for £30 + postage.

Both large-ish frames with 1" steerer forks, both now with new paint* and greatly enjoyed

BLUERIDGE and AVANTI

*the original colour schemes and graphics were easily the most unappealing I have ever seen on a bicycle

[Brucey]

I'd be interested to see which steerer they actually used in this tubeset. IIRC (and maybe I don't, this is from memory) there was talk of the ATB tubeset using tandem gauge forks and steerer originally.

However at about this time they downgraded the quality of the steerer that was supplied with many other '531' tubesets, so both 531C and 531ST started to be supplied with a steerer that was thick enough, but was clearly not made to the same quality as the older steerers that would be supplied with the older '531DB' tubesets. Maybe they did the same thing with the ATB tubesets too...?

The older 531DB steerer was (faintly) marked externally with 'REYNOLDS BUTTED TUBE" or somesuch and there was no seam evident within. The later tubes were not so marked and often there is an obvious mark which looks like (and may even be) a seam in the thicker section of the tube. I think they used this tube as a cost-cutting measure, (it is in a place where it won't show... ) and perhaps reworded the description of the tubeset to suit.

A chum had an ST frame built in the mid '80s and he managed to bend the ST steerer just by putting the front brake on hard, when the bike was loaded. BTW if I had been simply told this I might have dismissed the idea as fanciful nonsense of some kind and that actually the bike had run into something solid. But in fact I was riding alongside him at the time, and I saw him do it. He had better brakes than me and I didn't stop as quickly. But just then the benefits of more powerful brakes seemed somewhat dubious. Admittedly he also had a plastic headset (which may have made things a bit harder on the steerer tube) but even so it was not terribly confidence inspiring....

[That evening (in a French campsite, mid-tour) we removed the forks and jumped up and down on them a bit and this made them straight again. The steerer tube seemed to be a much less strong steel than the fork blades, even if it was a lot thicker. We checked the forks for cracks and he (also a trained materials scientist ) promised to replace them when he got the chance and in the meantime to keep an eye on them. I don't know if he did the latter but I do know that he still had that bike with the same forks in it about ten years later... ]

So if a steel steerer breaks like that I think it means one of three things

1) that the service stresses were routinely well over about 1/3 yield and that this meant the fatigue life was shorter than you would like, or

2) that the steel was embrittled in some way (eg because of the joining process used) or

3) that there was a notch or other feature that acted as a stress concentration thus starting a fatigue crack.

Now 1) seems quite likely in some cases in that every vigorous application of the brakes clearly stresses the whole thing more than 1/3 of yield. I guess if you carry a heavy load and ride a lot on the bumps, the same thing could be true without using the brakes. But also if the steel used is downgraded in terms of strength the same thing can happen.

So if you get the chance to take any pics or examine the steerer in detail, I'd be interested to see what you find.

BTW I am in favour of using (where appropriate) some kind of a 'long bolt' through the steerer, so that if the steerer fails, the parts are at least held together long enough to bring the bike to a halt using the rear brake.

When the steerer broke, were you riding the bike at the time? Was the failure abrupt? What happened exactly?

cheers

[meic]

The steerer is one of those with a slot in the tubes for the tabs in the headset washers. It went fairly cleanly and horizontally along the threads one turn above the end of that slot.

Removal of the annoying brake pulley tens of thousands of miles ago meant that I had inserted a brake hanger in place of the tabbed washer and it interfered with adjusting the headset and its rather impressive collection of rubber boots.

The headset had a bit of a knack for coming loose every couple of years. I tightened it up the night before and it was surprisingly easy to tighten, with hindsight that was probably because I was taking up the slack created by the crack on this occasion and considerably enlarging it.

When I got on the bike at a cycling festival, I realised at once that something wasnt right with the handlebars they were no longer rigidly attached. At the first bit of an incline there was a small snapping noise and clearly too much play at the bars.

I rather gingerly rode the six miles to fetch some food, then investigated and found that I could lift out the bars complete with headset top cups and a bit of steerer tube. I didnt investigate before tea because I didnt remember if the balls were caged or not.

In order not to waste my and my daughter's trip, I fully lowered the bars so that the very long quill stem was doubling up the length of the steerer tube and used it to clamp the steerer tube break together a bit.
I was then able to ride the thirty miles of the event as it was all very gentle riding and I was very precious about keeping the frame pressing on the forks and using the bottom bearing of the headset.

[Brucey]

so are you saying that the steerer broke in the threaded section, and that until you lowered the bars the quill did not extend below that point?

cheers

[meic]

It broke near the bottom of the threaded section and the quill was certainly below that as it held together after the break.

Pushing the quill deeper, after the break, reduced the leverage that it could exert and the head of the quill was pushing down on the top headset upper half to hold the broken stem together a little bit.

[Brucey]

crikey.... was it a slash-cut wedge?

You know, all the bikes I had as a nipper all had conical wedges. The first time I saw a slash-cut wedge I viewed it with some suspicion; it seemed to me that in order to be really secure, and not load up the threaded part of the steerer in shear (just from the clamping loads), it would have to go into the steerer a fair bit further than a conical one. I wonder if the same thing applies to shielding the steerer from bending loads too?

It does sound like you dodged a bullet there though.

BTW I would happily weld repair that break, provided a full length quill (i.e. one that reaches at least 1.5" below the repair) was used in it subsequently.

cheers

[meic]

Yes, it was a slash cut wedge.
Also when reassembling the broken off part of the steerer onto the stem using the dirtmarks to get it as it was, the crack happened exactly at the tip of the wedge.

I dont think the failure really endangered me much, the frame weight holds the forks in place and the stem was fairly firmly connected to the remains of the steerer. The stem also partly took on the role of the steerer tube as the broken off part seemed to stay in its place.

[meic]

New Forks arrived, these ones.

http://www.ebay.co.uk/itm/BLACK-THREADE ... 41783cac73

I didnt mind the few chips in the paintwork but when I looked along the legs from the dropouts I noticed that the cantilever studs are not parallel to each other, the left one is flared out by about 15 degrees.