Front Suspension: R&R for older bikes possible?

Greetings.

My current ebike is 19 years old. It was upgraded at the time of purchase to a newfangled piece of equipment called Rockshox that promised to improve the riding experience. Indeed, it proved to be an outstanding addition time and again for all types of terrain in all conditions. :wink:

Time has not been kind to my fork: In the last couple of years the right side developed a slow leaking valve, and later a ruptured seal. The left side fared much better until this week when the value completely blew out taking the protective cap with it.

The type of frame is not modern by any means; a tapered head piece having nothing in common with frames of the last… gosh decade?

It appears that RockShox/SRAM do not carry parts back that far.

The question begs: Is there a Repair and/or Replacement path possible for these older style frames? I’d hate to junk it over this one item when I appear to finally have things dialed in.

FWIW, my second ebike frame uses a DH fork and is not compatible with the 9C motor.

Thanks in advance, KF

Addendum:
Digging about the Specialized website I found a link to the place where the information on geriatric bikes go once they are beyond 10 years of service life: http://www.bikepedia.com

Though I didn’t find my 1991 model, bikepedia does go back to 1993 – and it seems to me that the frames would have been close enough back then for a match. As I recall, my Rockhopper didn’t have a sub-model other than Sport; I honestly don’t recall. Anyways, I found all sorts of details about the 1993 unit. Unfortunately the headset and fork sections are E M P T Y and D E V O I D of pertinent information for ascertaining a proper replacement.

Woe is me. KF

I think you should be able to bolt on any fork meant for a 1" threaded headset.. I have bikes a lot older than that. Blasphemous mebbe, but I have a rock shox on a 60's frame!

Ah if you're wanting to repair the old fork and not replace it.. I'm clueless on that!

Thanks for the encouragement Vanilla!
I’m all for replacement; the dang shock is 19 years old. :lol:

Stupid question time: So shocks for 1” threaded post still exist?!? :?

BTW – I found this site as a fun reference: Museum of Mountain Bike Art & Technology
Hopeful. KF

You can find many new suspension forks that will fit your old headset. The best forks are not made anymore for it, though.

Here's one with 160mm 1 inch threaded steer:
http://www.amazon.com/RST-T6-Suspension-threaded-steerer/dp/B000FIDKSQ

Good find! a nice shock with 26" wheel and 1" head tube isn't that common. That's what he needs though, unless he wants to go to a really cheap pogo stick steel shock from a wallbike.

I don't know what that tapered stuff is, I bet it's just a 1" threaded headset. If you can't find threaded steer tube shocks, you can get the bike converted to 1" threadless headset pretty easy.

MadRhino: Awesome! I found that on Amazon yesterday as well.

Here’s another query link to more variety:
All "FORKS - SUSPENSION" Manufacturers – sorted by 1”

I dug and I dug but the older bike threads links to even older components, such as the Marzocchi MX Comp are as rare as a pink whale.

I have nearly settled on the “RST Gila T6 80mm Suspension Fork with 1" threaded steerer 160mm” from Amazon though.

But then friend DogMan gives new hope; I have this already configured if it can be adapted:


Marzocchi 44 RLO

This assembly was created for my P1 ebike late last winter, however after the initial 101 Club adventure I decided I wanted a DH fork instead. This unit though is fully constructed and ready to install – if we could figure out how to adapt it from 1-1/8 to a 1 inch. Much of the reading I have done suggests this may not be possible, with exceptions to where the manufacturer provides for various sizes (as with the RST).

DogMan, what news have you about such potential?

Shocked, in a good way, KF :wink:

You would have to find a 1" steerer tube that fits your fork, press the old steerer tube out then press the new one in.. Even if you can find a suitable steerer (im betting none exists) the labor alone probably makes it not worth while. Best bet is to go with the nicest 1" you can find. I realize there are probably not many mid or high end ones made anymore.

I bet you can find one that isn't too lousy for less than $100.

I've pondered on how to use 1-1/8" stuff on 1" headtubes, and the only way I can see to do it would require a custom-made bearing race/cup for each end of the headtube. It'd have to have the headtube end of the cup small enough for 1" type, but the bearing end big enough for 1-1/8" stuff. In addition, the headtube end needs to be large enough inside-diameter to clear the 1-1/8" steerer tube, so it might have to be thinner than normal.

I've considered cutting apart one each of the 1-1/8" and 1" bearing cup/race sections, and then welding the necessary pieces back together to make such a beast. Haven't tried it yet.


I also considered cutting the 1-1/8" steerer off on a fork at the crown, filing out the leftover steerer still in the crown until it was just smaller than the 1" steerer tube I'd need to have for the frame. Then heat the fork's crown end and stick the steerer in the freezer, and then press in the 1" steerer into that crown. Just to be sure I might also weld a bead around the bottom end of the steerer, to ensure it is firmly fixed to the existing steerer ring left from the larger tube.


All of these options are a lot of work, and I am not totally certain that they'd even work at all, but that's my musings on the subject, given that I don't usually have the option of just going to get another fork with teh right steerer tube for any particular bike I'm fixing or building up.

All my LBS's cannot replace a steer tube. A machine shop might be able to, and might only break a few forks learning how.

I think you have to hunt down a 1" steer tube fork. Most avaliable are crappy steel pogo sticks. At least the hunt is half the fun.

Rick changed a steer tube:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=15574&p=231176&#p231176

TylerDurden said:

Rick changed a steer tube:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=15574&p=231176&#p231176

Click to expand...

That is certainly an option; I like the DH fork adaptation because any point of failure would have to happen in two places, and being more difficult.

The options are still open, and I haven’t yet committed. At the moment the riding experience is approaching rigid but not hard; the right-side of the shock has small dampening abilities. :?

On a related note:
I have been experiencing some slippage when pedaling; it has become pronounced this week about the same time as the shock. I took it into REI last Thursday eve for a look-over/safety-check. The guy in the bike shop suggested that my chain and rear freewheel are experience extra wear from this high-speed commute. The chain is easy enough to replace, though the freewheel (having the inner-most 11-tooth cog) is less so. (Sorry - not interested in Chinese mfg).

(AW, I’d think you’d approve of this one…)
Hence the guy suggested I go to http://www.recycledcycles.com/ and scavenge another freewheel. Might be a good opportunity to lurk for a replacement shock and/or sacrificial 1” steerer tube.

If the weather is good maybe I'll do just that. I need to make a run to Seattle Fabrics anyway; just call it another glorious winter day on the bike...

Appreciative of the help! KF

Well, the weather remained cruddy; going over the I-90 Floating Bridge in a 35+ mph windstorm is something else – but what is even stranger is that I wasn’t the only one. :lol: The trick that worked for me was to ride beside the 3-foot high concrete barrier so the majority of the wind blows over, like catching a wave and surfing through the tube. :wink:

Following a circuitous route around Lake WA, found Recycled Cycles nestled in by the Ship Canal & University Bridge; I bet they get a lot of business from the kids. As soon as I arrived the first person exiting the establishment was impressed by my ride; I gave him the ES ditty and moved on inside. Older space, timbers, warm & rustic, filled to the gills with parts galore, and friendly.

Soonly found the copious fork section and was beholden like a leprechaun to a crop of old suspensions of various vintages. Upon close examination though, I was not entirely sure that the majority were worth salvaging - being completely battered and nearly inelastic lunks of iron. Molasses would have moved quicker. However there were a tiny handful of gems to be mined – they just didn’t match a 1” steerer.

Around the bend was a bin of freewheel cogs and cassettes; bring a rag to wipe yer hands clean. Most, no – all were of common sizes; nothing unique or close to my edge-case needs. Although the hallmark of the time invested was the tireless patience of staff waiting to assist, and even going online to find it. For an inventive sort, this is a great resource.

The next part of my journey took me to Seattle Fabrics and back over the top of the Lake. I’ll cover that in the Epic Battery Bag Story thread shortly.

Dauntless, I dig around a bit more last night on the cycling archives and at http://www.mtbr.com/ to find more options, and wanted to pass this along:

• White Brothers fabricates nearly all but the high-performance forks with both 1-inch and 1-1/8 inch options. Be prepared to blow the moths out of yer wallet, though I am sure it is worth it.

Thinking hard; I have one side completely blown, and another that can’t hold pressure for long. Here’s a close-up of the blown side: Notice the threading.



One of the guys at Recycled Cycles though it was a Schrader-value size; I checked that last night and the value nearly fell through the hole – and so that is a negatory big buddy. However it gets me to thinking about tapping the hole out large enough to stuff a complete valve assembly – like some of the more advanced shocks have and use that to do an Arnie and pump it up! The fork only needs to last another 6 months or so; enough to finish the wheels for P1. :wink:

Fun distractions. The great thing about this hobby is that a small repair or mod is instantly appreciated.
~KF

Update:
I noticed that after affecting a mod to the Epic Battery Bag that the bike was sitting a bit low. Inspecting the other side, I removed the cap and – the valve is missing. That’s two valves gone.

Reviews of the RST shocks w/ 1-inch steerers (made available at Amazon) are not positive on the biking forums, and less so for the ebike applications. White Brothers is looking more interesting, though I am humbled by the >$700 price tag. More searching is required.

I keep looking at P1: Unfortunately that frame can't be utilized because the 9C hub is incompatible with a 20mm thru-axle DH fork… unless someone knows different.

Momentarily deflated, KF

I picked up an old but refurbed set of Marz Bomber M3 forks and fitted them to my 20yr old Claud Butler. Luckily for me the forks came with a choice of steer tubes and there was a 1" tube that perfectly suited my frame. I don't know about later Bombers, but the M3 steer tube is simply clamped in place at the crown.
I then found an Ahead head set with the right dimensions (the original set worked after a fashion and got it mobile, but there was a bit of slop on the bottom bearing cup/steer tube). The topwear involved a 1" to 1-1/8th" packer and a 1-1/8th riser, allowing me to use modern bars and a v-brake, etc, as the old brake used a pulley in the (old) stem.
In short, just a mix and match of old/new bits, but perfectly do-able by scouring the ads on ebugger, but a decent LBS should have a bin of old parts to suit, I would hope.

Thanks Eclu; searching is wot I have been doing these past few days.

Update on the Front Shock saga:

Since the shock blew out I have limited my riding as the experience is like having a hard-tail on the front. I did go to eBay and I won a bid for a Rock Shox Indy XC, probably a 1997 by my guess. It arrived today.



The condition is not the best, but at least it is good enough to mount right now. The problem is that I think my original RS-1 was a better shock being that it was air-dampened over this Indy XC which is elastomer-dampened. Certainly I have learned more than I wanted about this. However I am also spoiled rotten having two brand new Marzocchi shocks to play with. The 44 RLO obviously cannot be adapted, but I am very tempted to steal the 888 RC3 and fab a pair of custom crowns and stuff a 1” steerer into it. Problem is that it takes a 20mm axle and not Quick Release which screws me for both brakes and hub. Arrrg! :?

Does anyone own an elastomer shock, and if so do you like it? Would it be worth it to spend coin to have the elastomers replaced and the unit R&R’d?

Curiously KF

Kingfish said:

Does anyone own an elastomer shock, and if so do you like it? Would it be worth it to spend coin to have the elastomers replaced and the unit R&R’d?

Click to expand...

Every shock I have except for the Manitou is spring-and-elastomer, if that's what you mean. They certainly work, but I can't say they give the greatest ride. I have not tried the Manitou on a bike as a fork yet, as I still need to redo it's seals to make the hydraulic damping work (as yet only the pneumatic "spring" part works).

The ones on my DayGlo Avenger are the best of the ones I have installed on anything, and they're RST something Omni 700-something I think. I forget exactly; they've been painted dayglo for too long for me to recall for sure. :lol:

Next best are the things off the Specialized alloy bike with the cracked rear frame; I forget what brand they are but they're alloy fork legs, with a steel crown/steerer and the inside tubes of the shocks. They're probably worn out from the previous owner's usage of them in trail riding, though, and hopping curbs and whatnot, since he was a 250lb+ rider and not particularly skilled.

After that are the 24" ones I had on CrazyBike2 before; they're a little better than the ones I have on there now for the 26" wheel, but neither is very good. Both are also pretty worn, though, I think.

Problem I really have with all the spring/elastomer ones I have is that basically the spring has a fairly linear compression feeling to it right up until it SLAMS into the elastomer block at the end, where it has just a tiny amount of give but mostly is just BUMP without CRUNCH.

Worth it to fix if worn? I don't know--maybe, depends on cost vs a new one. Although one option you'd have when repairing one is that you could use a different elastomer and perhaps a different size block, that would give it a different feel.

Thanks AW. There are two choices that I can envision: Elastomer kit for $45 or send it off to HippieSuspension (if they’d take it) for R&R. In truth, I don’t think I want to mess with me repairing it; I’ve read that it could be a messy job – and the last thing I need is to spill oil on the floor of my hidden urban cave. I suppose a third alternative is the local bike shops; that’s worth a look.

Regardless, I appreciate your words of encouragement; thanks friend.
~KF

1" steer tube, I have thought about this and I've been keeping my eyes open. Still looking. I'm glad someone else is looking too!

Took some poking around, but found out the "Gila RST T6 fork" has both the V-brake mounts and also disc brake mounts (most pics didn't show the disc side). It would be great if the drop-outs are steel, but that is unlikely. (anyone know for certain?)

That model did hold my attention for some time, however the bike boards gave it poor reviews and not worth the money. <sigh> :|

~KF

TylerDurden said:

Rick changed a steer tube:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=15574&p=231176&#p231176

Click to expand...

I was planning a slightly different route to swap a 1" steerer tube onto a newer fork.

The Manitou 5 on my old 1" steerer Stumpjumper frame is worn and sloppy to the point of rebuild being too tedious.
I purchased a newer, but similar looking Manitou fork. It *looks* to me that I can simply unclamp the stanchions from the new fork and clamp them onto the crown of the 1" old fork. So I haven't done it yet. (Only proceeded as far as bringing bike from -20 degree garage to +4C basement...) Anyone can see why it would or would not work?

Those older/low end forks will do the jub on the street, and so the mod to fit a better one on your 1in headset. If you will be riding any serious offroad, I would not recommend any of this.

Your frame is 3 generations behind in the MTB world, it had suffered metal fatigue, it is not safe for mountain use anymore. Keep it for the road, and do with available forks. If you will be riding in the mountain, find a recent frame, and forget about any steel, chromoly, colombus... They all proved unfit, and the best steel frames are to be discarded after 1 season speeding repeated bumps and drops in mountain trails (when they last that long).

Madrhino,
Your statements are completely opposite of everything I have trad about steel framed bikes, and while all metal does fatigue, it is my understanding that aluminum is the frame material that has a limited service life because it fatigues much faster than does steel. Although, I agree that these guys are trying to resurrect these MTB's that are, as you say, at least 3 generations old which doesn't make sense to me unless doing it from a collector standpoint.

If you want to get an old frame cheap that has a 1 1/8" steer tube, look no further than an old CroMo GT or similar and put a decent fork on it that has the disc brake mounts, and there is also a kit that can add rear floating disc brakes to early frames. I guess I don't understand why you guys are trying to turn these road bike frames into mtb's. Even most newer road bikes have 11/8" steer tubes, to each his own I guess. Craigslist and pinkbike and mtbr and ridemonkey and even eBay are your friends, embrace the new. :wink:

etard said:

Madrhino,
Your statements are completely opposite of everything I have trad about steel framed bikes, and while all metal does fatigue, it is my understanding that aluminum is the frame material that has a limited service life because it fatigues much faster than does steel...

Click to expand...

It is true that steel can stand more repeated stress than alu, before structural failure, when a small crack develops inside the metal. For this mechanical property, steel alloys was used in the construction of all the first generation MTB.

Then, after so many crashes due to frame failure, the development splitted into 2 different avenues: Better steel, and bigger alu. The 2nd generation proved better and longer but still, frequent frame failures caused dramatic crashes. Bigger steel, and even bigger variously shaped alu was tested, along with better suspension design and components. This was the main research period, for we could compare frame failures and experiment various tube and design geometry. During this period, we undrestood that a steel frame that would be suitable for speeding in the mountains, would have to be as big and heavy as a motorcycle frame. We also understood that failures in properly designed alu frame, were minimal and less likely to develop into a complete failure as to cause a crash. One generation before, the motorcycle industry had turned to alu for any off road application.

The 3rd generation was all alu, and frame builders became hi-tech specialists, equipped with the latest building and testing equipment. We saw the arrival of some of the best frames ever produced for mountain use, but almost none of them could be delivered with quality consistency. The same frame, was sometimes very resistant and durable, or sometimes quickly developped micro failures, or small cracks in the solderings. Only after being put at hard use, and carefully inspected, a frame could be declared free of manufacturing defect. This generation concludes with the development of post production hardening, improved soldering quality control, and fluid design meant to spread the forces.

The 4th generation, in which we are now, is experimenting with composite materials, mixed material construction, and improved fluidity in the design. We've seen the birth of laminated frames, made with alu, titanium, carbon fiber and resin. I believe that the next generation will be the one to achieve a near perfect MTB frame, for all the previous experiment and long term tests in extreme conditions, will supply enough information to make the best choices of materials and design.

Madrhino,
It sounds like you know what you are talking about, but I must respectfully disagree.

I suspect the progression into exotic materials like carbon fiber and titanium has more to do with the bicycle manufacturers running out of new frame styles to appeal to the necessity of rich consumers ever-quest for the newest big blingy thing. While there has been much much progression in the components like shocks, forks, spokes, hubs, brakes and shifters; frame geometry and suspension design have plateaued at the current level for the last 5 years. The only "advancements" being made are in the balance of compromises accepted by the MTB community. The new materials being used for MTB's is to attain lightness not necessarily sturdiness. While a 10 lb frame might feel like a brick to the avid cyclist, it will be negligible to the average e biker that adds 40 lbs of weight on top of that. Also, steel is coming back into mainstream use, not fading away as you allude to. Most of the cargo bikes are steel, alot of the hardtail 29ers are steel, most single speeders seek out steel; all these guys are VERY hard on bikes, rarely will you hear of one breaking ( I have never, I'm sure there are reports though).

Back on topic, have you guys considered buying a decent dirtjumping fork? These are a lot stronger than the expensive XC forks currently on the market and if you really are stuck on your 1" headset you might be able to take it to a local machine shop and get your old steer tube pressed into the new fork. It's not gonna be cheap though...