seanrooney

Hi

I have a 1986 Univega Gran Rally with Shimano 600EX components. Freewheel is the MF-6207 6 speed. I have a freewheel that won't spin freely


I recently broke the rear axle and swapped it out at a local bike co-op. The freewheel needs a hard-to-find removal tool (TL-FW10) that that co-op didn't have, so we just re-packed the bearings with the freewheel still on (tedious, but managed fine). Bike was working fine. I decide to add some new lubricant to the freewheel last night (Tri-flow, aerosol), and followed the instructions many posts online said if the freewheel is still on the bike - take the wheel off, turn on it's side, and spray lubricant into the gap in the freewheel where the cogs spin but the body remains static (started from the smallest cog side). I was spinning the freewheel to draw the new lube down, and sure enough saw some dripping out from behind the largest cog, but the wheel started to stick and then fully locked up. I put it on the bike stand and occasionally it spins free, but not safe to ride.


This seems odd it's sticking after I've been re-lubing it, and I had a few questions

1. Did I likely loosen up some old sticky grease and force it all into one area? Or sound more like a broken pawl?
   
2. A LBS has the tool and will pull the FW for me for a small charge (probably $10 or so). Once they do this, is it worth completely soaking/flushing, re-lubing, and putting back on if it's spinning freely? Or - with a replacement like the Shimano MF-TZ500-6 being <$20 and accepting a normal freewheel removal tool, should I just put a new on one there? It would save me needing a LBS to remove in the future. Also a bit anxious it locks up again while i'm coming down a hill...
   
3. The 600EX FW is 13-28 (13-15-18-21-24-28), the MF-TZ500/510 and others I've found are all 14-28, this should swap on with issue correct?
   

I realize the best choice longer term is expanding the frame and putting a newer 130mm 7-speed cassette on there, but (as from my previous post re:the broken axle) would like to get it running and not be rushed for the rear dropout expansion


appreciate the help

HillRider

For the $20, I would just replace the old freewheel. If it's broken internally or just badly gummed up it's not worth the time and effort to revive it and when/if it fails in the future you have the same removal problem. The newer 6-speed freewheels you've found should work fine.

As to a new cassette hub, your frame is spaced 126 mm already and will take a 7-speed cassette wheel perfectly with no cold setting. It could be cold set to 130 mm or, just use a 130mm hub which will be a snug fit but doable with no other changes. That will open up you choices to 8-speed and above.

70sSanO

If your hubs are smooth, you should clean, maybe replace the ball bearings (grade 25) re-grease, and put it back together unless this has been done recently.

Shimano 6207 is non-SIS so you can run a 7 speed freewheel. You can go with 13-28, or similar. Maybe Sunrace. With new freewheels, especially cheaper ones, I let oil, such as Phil’s soak into them from the back to make sure there is sufficient lube.

There is really no need to go to a new hub/wheel to run a cassette if you are happy with your setup and the rim/hub doesn’t need to be replaced at this time.

John

etherhuffer 

Internal goo and crud is just goo and crud. Sometimes you can get it out, sometimes not. Getting it off the hub and soaking in mineral spirits would be a reasonable choice. You are correct on that tool, its old and hard to find. Here is a link to a guy who has a way to get it off using a modded Park Tool and socket. Its irritatingly verbose but he finally gets to the point at the end. Looks like the key is having a socket placed inside to prevent slipping of the tool. You local bike shop should have that Park tool, its quite common

JohnDThompson 

If your freewheel requires the TL-FW10 tool, it's from the late 70s or early 80s at the latest. While the TL-FW10 may be hard to find, the freewheel uses the same two-slot pattern as Regina, Atom, and other freewheels of that period, so other tools will also work, e.g. Bicycle Research CT-1, Cyclo (English), and VAR 188 (not the Park FR-2, unless you grind the prongs down to fit). Of these, the Shimano TL-FW10 and Bicycle Research CT-1 are the best, as they have a stabilizing ring that helps prevent the tool from slipping out of the slots and damaging the slots. The other tools will work, but you need to take more care to prevent the tool from slipping when applying torque.

Check to be certain that your freewheel requires the two-prong remover; by 1986 Shimano freewheels had standardized on a splined remover that is much more secure than the two prong remover. The splined tool is still widely available from Park Tools (FR-1.3) and others.

etherhuffer 

Also, if you find a tool, put it in a vise and set the wheel on top of it. You can press down and prevent tool slippage. And, you get better leverage by turning the wheel instead of the tool.

ThermionicScott 

If the freewheel teeth are in good shape, consider sending it to Pastor Bob @pastorbobnlnh to be cleaned and rebuilt.

SurferRosa

I think that model's very easy to overhaul with it still secured on the hub. It can actually be easier to remove the lock ring that way, because it's left hand thread. So using a hammer and punch, the freewheel doesn't move as long the rim is secured. You can do this simply on a table or floor; you don't even need a bench vise. If you don't have an easy to find punch, you can maybe use a nail.

I don't know why folks don't do this more often. You don't even have to adjust it, like a hub or bb. Those micro thin spacers do that for you.

If one of your pawls is mangled, then, in the immortal words of Emily Litella, "never mind."

pastorbobnlnh 

Thanks for the mention, Scott.

seanrooney does your freewheel look similar to this 5 speed variation?


IMO, and in my experience, dribbling oil into a freewheel is only a stopgap remedy. It will never flush the internals clean, any corrosion and/or damage cannot be seen nor corrected, the leaking oil will retain more road grime on your drivetrain components, and Shimano, Suntour, Sunrace, Sachs, Regina, etc., never manufactured them in this way in the first place. Also, certain models of Sachs, Shimano, and Suntour freewheels have seals which complicate flushing and dribbling.

The fact that the OP's 600 began to spin (after being locked) with the oil dribble method, and subsequently locked again, tells me something is seriously amiss with the pawls, springs, and/or bearings.

However, this does not make the freewheel trash, and at the least, it should be saved for spare parts (i.e. sprockets, spacers, outer retaining ring/bearing race, shims, pawls and springs). If the OP doesn't want to be bothered, I'll be glad to cover the postage in order to at least salvage possible spare parts.

BUT---- if Sean can successfully remove the freewheel, and is willing to cover postage both ways, I'd be willing to give his 600 the royal Freewheel Spa treatment and document what I discover and correct here with pictures and a tutorial in how to properly service a freewheel which will give you years of trouble-free service (instead of constantly dribbling oil and making a mess every few months).

JohnDThompson 

Even better is to use the quick release skewer to hold the tool in place. Leave it slightly loose (about a millimeter or so), but engaged enough to prevent the prongs from coming out of the slots. Clamp in vise, apply torque, and as soon as the freewheel breaks free, remove the skewer and unthread by hand.

etherhuffer 

Just wondering, what grade of bearings do you use? I was shopping for some last year and was surprised at the various ranges and ratings on line. Hard to imagine spinning a bike part at the level some bearings are rated for.

Gonzo Bob

I recommend replacing. Sounds like the MF-6207 needs more than just flushing to return it to reliable working order, plus you don't have the correct removal tool.

I'd go with a 7-speed, unless your shift levers are indexed (many Shimano 600 equipped bikes from 1986 were indexed but I'm pretty sure they came with MF-6208).

pastorbobnlnh 

When buying 1/8 inch bearings in bulk, I purchase the highest-grade ones I can find at a good price. For instance, these.

seanrooney

HillRider thank you for the advice.

What I ended up doing- LBS took the freewheel off with their TL-FW10 for $15. The MF-TZ500 and FR1.3 were <$30 so I swapped the new freewheel on there, and now I don't have to deal with the removal of the 600EX again. It definitely feels smoother. I didn't know about the 7-speed Megarange Shimano though (14-34t) which is very tempting for hill climbing....only $25, maybe i'll buy it later

Follow-up question - It sounds like the freewheel cogs are almost trying to "flick" my chain sideways, every 6 or so links, Is this something to do with the UG/HG freewheels? I don't know much about chains and cogs, but I read the freewheel cogs on the Shimano HG systems have "ramps" or something to work correctly.

1. Is it a good time to replace the chain?
2. If I replace the chain, i was planning to go with teh HG71. I've read on other posts that 9-speed chains can be good for 6-7 speed freewheels, would the HG93 be a good choice?

pastorbobnlnh that is an enticing offer, I will DM you directly. The freewheel is indeed off and sitting in a box right now

thanks
-Sean

SurferRosa

I used to sorta think so too. But later, I learned repeatedly, it can be even more finicky.

​​​​​​​My advice: don't do it. Just use an 8-speed chain.

seanrooney

Thank you, already had the HG71 ordered so i'll be swapping it on soon