stephr1

I recently went thru a process of trying to determine a noise that took time to determine the source/cause (https://www.bikeforums.net/bicycle-m...showed-up.html). 1st off, thanks to all the folks who offered their insight. It was very helpful in so many ways (especially since at my age I seem to be forgetting more than I should remember

Final resolution of this issue appears to be the free hub (is that 1 word or 2 words?) failure. While the pawl/latch process works fine (quite, smooth, solid), it appears either the bearings or the race(s) has worn out. I wasn't sure that could be cuz I thought the free hub was replaced fairly recently. After searching thru my records it turns out I replaced the free hub nearly 10 years ago. Loosely based on my average weekly mileage, my guess is the free hub has between 11,000 to 14,000 miles on it This particular Shimano free hub is not serviceable. So it most likely needs to be replaced. Before I get to that somewhat gnarly issue, tho...

For those of you out there with a better grasp of physics/forces, I'd be interested in your theory of why the ticking/clicking noise happens at the bottom of a down stroke on the drive/chainring side (seems the noise is generated when the tension is released from the chain, not when the chain is tight and becomes taut...my misinterpretation but does not happen at all when I reach the bottom of the down stroke on the non-drive side.

OK. Now to the reason I'm back. Obviously, the free hub needs to be replaced. 7-Speed Shimano free hubs are few and far between (this is an MTB). Either not available/OOS or could be gotten from overseas for double the price (shipping costs).

I realize I have some options and would appreciate any feedback or insight on them...

1. Assuming it is actually available, buy one from overseas and eat the cost to get it here (or I could try and wait for one to be available domestically, if that ever happens).

2. I have an unused 8-speed free hub (might even support 9-speed cassettes) that I bought when I thought of going to 8-speed because all the noise was saying 7-speed was pretty much going away (was not true at the time, but appears that's where things are now). I could install that but it might also require a new, longer axle (unsure what my current O.L. dimension is...possibly 135 mm because of the spacers used) and re-dishing of the rear wheel. Axle, no problem. Re-dishing...well....

3. Buy a new wheel with free hub attached (Shimano cassette compatible, maybe? Maybe not?). More expensive but at least the wheel and free hub are already set up.

4. Bite the bullet and just get a new MTB

5. Other suggestions?

As usual, thanks in advance for the help...cheers.....

BTW - I'm here in the SF Bay Area and, for the most part, our skies have been relatively clear/clean even with all the fires burning in the Sierra (~240 miles from here). This morning, however, I got out and started my ride, noticing the sun was a bright orange (with some red tint to it) indicating the smoke has reached the Bay Area. I'm on the peninsula and, for the moment, our AQI (Air Quality Index) is reasonable (below 30). However, East Bay (Oakland, etc.) is already up to the 50s, and it's not even 9AM.

Wherever you are, especially if it's OR, WA, ID ,etc., be safe out there.....

Phil_gretz

Shimano FH-RM30, new condition, $12.95 + 5.95 shipping on eBay at this moment.

rccardr 

If the RM 30 freehub spline pattern matches yours, then buying the entire hub is a good idea You’llget ew cones, axles, seals, etc.
If not the same pattern, post a pic of thr spline pattern of what you have. I know there’s a 7 speed UG only freehub somewhere in the Lab…free to you.

stephr1

@Phil_gretz, @rccardr -

Thanks much for the link and the offer. It may not have been obvious from my post but my bike is a 1999 Specialized Hardrock FS. The specs for the bike call out an FM-RH40 hub and the freehub (both 7 and 8+ speed) looks more like this:




@rccardr - Now, if you have one these hanging around, you'd definitely be my hero

Otherwise, a whole new hub sounds like it may be the best solution. My current wheels/rims are in fairly good condition (Weinmann 519, 36-hole). Dirty, but no cracks and are trued up really well. Guess if I'm forced to go to an 8-speed freehub, getting a brand new hub makes sense: Already have the freehub, new hub comes with the axle (and new cone and bearings, etc.) and I (or some expert) would have to redish the wheel anyway. Might as well start from scratch, so to speak.

I'll do some research on what the possibilities are (as in available for the hub I have) and what's involved. Any idea what the typical cost is to do a hub replacement at the local LBS? Also, I did check for hubs/freehub combos on ebay and, while the hubs themselves are printed with "Shimano", the price seems awfully low for them. Knockoffs/forgeries, maybe?

Also, is there a standard diameter for the part of the hub where the spokes are inserted? Or is that a "depends on who mfg'd" it??

Cheers....

stephr1

I may have found a pretty good hybrid solution (actually, a more immediate solution and a backup for sometime down the road). Found a freehub on ebay that's ~$18.00 delivered. Not a bad deal. Only thing is, while it has the right Shimano part reference no. in the posting, it's different than both my current hub and the one it replaced that came with the bike. The one I ordered is designed to support both a freewheel (threads at the top of the freehub) and a cassette. Never knew Shimano made 1 of those. And, maybe they didn't and I'm getting ripped off for a non-Shimano product

The other is, even tho these particular freehubs aren't designed to be serviceable, I may be able to do so to the original one. I can't remember why I replaced it (those brain cells escaped my head a long time ago but it may have been because it was all gunked up inside. Another smoke-not-free project on my list....

Andrew R Stewart 

Shimano changed from the twist tooth design cassettes to the HG ones long before 1999, maybe 10 years before. Over the years Shimano has used increasingly longer splines (to fit more cogs) on their freehubs (one word). The interface with the hub shell remained the lobed fit but the seals (or not) between the FH back side and the shell's face differed with grade. The RH cone and axle spacers also have seen some changes in dimensions and sealing designs. So when replacing a FH body with a different version often means some playing with cone and spacers to end up with both correct overall lock nut length and small cog/frame clearances.

My first thought on reading this thread was that the shell's cups are pretty old, as these are not replaceable. Then there's the spokes age. At some point a replacement wheel might be the best long term choice. When that time comes is your guess

I always thought poorly of the freehub design for a few reasons. The Shimano designs used fewer balls and smaller cup/cones (for the FH body bearings) yet the FH body is not replaced when the cogs wear out. So we see far more cog set bearing wearing out then was the case for freewheels. The smaller diameter of the pawls and ratchet teeth mean higher forces going through them. All this to handle smaller cogs (higher gearing). For those like me who spin high cadences the offer of 11,12 tooth high gear cogs is un needed. BUT having said that I run cassetted hubs because the market has decided that freewheels are not the way a few decades ago. Shimano's FH bodies are fairly well made and tend to outlast the low cost copies so common on "affordable" bikes. Andy

KCT1986

This is not the main reason. The design of the freehub body hub vs. freewheel hub became necessary when the rear dropout width began to increase. Going to 130/135 OLD would leave too great an unsupported area between the axle bearing and the frame with freewheel hubs. This lead to bent axles.

The freehub contains the axle balls and put the ball closer to the frame. In a freewheel hub the ball are about in-line with the 2nd largest cog. A freehub hub has the bearings more in-line with 2nd smallest cog, thus closer to the frame. Even with 6 or 7 speed, this was a difference of 15+mm in the placement of the bearings. As we went to more speed this would have been an even higher difference in unsupported length. With 11 speed, we would have 30+mm of unsupported length from the bearing to the frame with the old setup.

Andrew R Stewart 

I agree with the goal of reducing broken axles as part of the reason why Shimano pursued the FH system. This could have been accomplished but with a greater body diameter too. That would have prevented the small cog options (unless they went with a stepped and paired last couple of cogs like so many freewheels use) but would have also allowed for greater material in the bearings and ratchet aspects.

So much of my views are driven by my working the LBS wrenches and how I ride. Both seem to be in a manor that most don't do. So it's no surprise that I feel somewhat different in how parts are designed and the features they offer, then most riders do. Andy

stephr1

Andy,

Very much appreciate the background and insight on this. Background info I did not know.

I went back to Shimano tech docs and uncovered the freehub (1 word I ordered as part of FH-M550, FH-M452 (and about 2 or 3 other) hub sets, maybe lower end/early Deore versions (Mine is/was Alivio). Based on the dimensions of the axle and QR in the specs for a 7-speed, it does not appear any spacer adjustments are needed. The freehub I ordered is a Uniglide/Hyperglide cross over...it can use either cassettes or freewheel. While it is not an exact duplicate of my "failed" freehub, it seems like it may well be a viable replacement. The only differences I can determine are, in my freehub the ridges (raised areas between the splines) do not go all the way to the top of the freehub (which I believe makes it a Hyperglide-C) so I am unsure what kind of impact that has on mounting my cassette (tho, I do have a grinder, if needed), and is not threaded on the outside at the top (for Uniglide cassettes/freewheels). Having the threads could compromise mechanical grip for the 1 or 2 top/outside cogs (where I spend most of my ride).

Overall I'm optimistic. I'll only know for sure when it arrives in the next week or so. I may be able to use the new freehub as a temporary fix to be able to ride while providing time to resolve issues of the old freehub and consider new wheel options (which, while a new wheel may not be the most cost-effective, it certainly seems to be the best solution decision given the age of, and miles on, the bike).

Thanks again....

stephr1

Back to my saying "The shortest distance between two points is rarely a straight line." I thought this posting would be one of celebration...not today, my brethen....

Got the Uniglide/Hyperglide Freehub (must have been introduced when Shimano was planning to obsolete the Uniglide products). Since my Freehub and cassette are Hyperglide-C I had to shave off the top ends of the hills between the splines (if that's the correct way to refer to them). Put it all back together. New freehub and cassette are nice and tight (convinced me the old freehub was worn out...but, not so fast, Skippy)....The tick is still there.

Arrrrrrrrggggggggggggghhhhh!!!

My best guess now is that either the chainrings have been damaged and I just haven't been able to figure that out (tho, I still doubt this because it happens on all chainrings, so I doubt all three of them developed problems at the same time). Or, I kicked up a rock or something and now my rear der is somehow out of alignment. Not riding tomorrow so I have time to do some more re-investigation.....damn....I mean...gosh darn it Well, at least I have a known good "backup" freehub.

Cheers....

Pantah

If you'd like to swap out the entire wheel to see if that solves the problem, I've got a perfectly functional mid-90's M560 rear hub laced up you can just have. Found it leaning against a tree and to my surprise, all of the bearings are silky smooth, it's just old. I've already robbed a couple of the cogs off the 7 speed cassette it came with for my older Klein project, but I've got a stack of 7 speed cassettes in a bag, I could very easily whip one up for you and install it.
I think I also have another couple of older 7 speed Deore LX hubs kicking around my brother's shop, I'll have to check.

In the meantime, your derailleur could just be slightly out of adjustment. Check the b-limit screw too, if the idler gear is contacting the cogs, it'll make some irritating noise.

stephr1

I will definitely take you up on your offer. Thank you. Anything in the very late '90s (bike is 1999 mtb vintage) or early 2000s should work. If it's a whole wheel (would be nice if it was Shimano cassette compatible from that time), as long as I can make it fit into my drop out, I expect that would work. Also, if it's an 8-speed configuration, I can work with that as well.

I really appreciate it. Nice that, not only are we both in the same state, but by the same bay (tho, sort of at opposite ends...I'm down in Mt. View/Sunnyvale area). We'll have to figure out the best way for me to get the wheel/parts from you, and what, if anything, I might be able to do for you.

Today is about doing a closer check on the rear der (including the b-screw). It's possible I could have kicked up a rock or a small limb and that messed it up. I know that, at this level, the drive chain is tolerable of a lot more misadjustment than anything that ranged
at 9-speeds or above. Seems like something happened that pushed it beyond even what it's capable of handling. Back to troubleshooting...

Cheers....

Pantah

The M560 is a 90's MTB groupset, Shimano Deore LX as it is known. So, 135mm rear spacing means it'll drop right into your bike no problem and it's designed for a 7 speed hyperglide cassette, so again, yours will drop right on no problem, no extra spacer needed. I'll grab it from my brother's shop in the next few days and clean it up a bit, make sure he hasn't robbed any parts off it to keep another bike on the road.

I am, indeed, on the opposite end of the bay, but often venture down into SF most Monday evenings for a running group I'm a part of. Additionally, I'll be in SF Labor Day weekend (though not Labor Day itself) and will be in San Jose that Saturday for several hours, I'm sure we can figure out a way to meet up somewhere in there.

Very true, 7 speed and older systems can tolerate a good deal of nonsense and still work reasonably well. Still, it's nice when things work their best and I don't blame you for chasing it down. Slight noises I know aren't supposed to be there drive me nuts and I know it means something isn't right and that just will not do. Keep us posted on the results.

stephr1

Sent you a private msg.

Cheers....

Pantah

Can't view it just yet until I have 10 posts, but that will happen in short order.
However, it may be moot as it appears I spoke too soon. Did not realize that those hubs also came in 130mm. It's rare, but I seem to be a magnet for weird stuff from the 90's and that's what I got. Your bike will definitely have a 135mm width rear dropout so this definitely won't work. A shame too, bearings are perfect, freehub feels great and even the rim is perfectly true.

stephr1

It is a 135mm.

Oh well. It was a nice dream while it lasted. I appreciate the consideration. Let me know if you come across something down the road. Thx.

Cheers....

stephr1

An update to my issue (still not resolved

1. Removed the chain and checked out the chain rings (tested the bolts and all were tight) and pedals, crank/bottom bracket. No noise. Bottom bracket, chain rings (no obvious issues) and cranks are all solid and tight.
2. Put on a different chain that is in similar or newer condition.
3. Went thru a complete readjustment of rear der: high limit, low limit b-screw. shifting. Checked alignment.
4. Freehub - using new freehub (problem was on old freehub, as well), everything tight (was some obvious play in the old freehub, but apparently, that's not the problem.
5. The cassette, while not new, is still in reasonably good condition.

What I did discover...with the back wheel rotating forward I slowly rotated the cranks (forward) and could hear a tick/ting sound coming from the back wheel. As I slowed my cranking I could see that as the chain went from the rear der jockey wheel to the cog, it would squarely land on the cog but would take a moment to settle completely onto the cog, as if something was resisting it (checked the cassette, it was fairly clean). It wasn't a lot of movement, maybe 1/16", but enough to make the noise I believe I'm hearing. Believing it was some kind of misalignment (even after the rear der (re)setup) I played with the cable barrel on the rear der. Didn't seem to make a difference (other than to screw with the shifting).

Overall, shifting is fine. Just this darn noise and the possible wear and tear on the cassette and cable, especially on longer rides, that concerns me. Driving me a bit nuts.

Bike was doing so well for so long up to this issue

Any ideas or suggestions out there? The only thing that *seems* to be left is the rear der. I have an older rear der (that this new one replaced) but the shifting is really loose. I suppose I could reinstall it and see if it's the rear der causing causing the noise. Really don't want to spend the money but....

Thanks in advance....

stephr1

Just wanted to circle back around and stated that I solved this problem. Check out this posting: https://www.bikeforums.net/22214247-post11.html

Thanks again for all the suggestions and help. I am grateful I have this forum to check in with.