Overhauled drivetrain, now it is "crunchy". Ideas for debugging this?
#1
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Thread Starter
Overhauled drivetrain, now it is "crunchy". Ideas for debugging this?
I'm working on overhauling a 1984 Trek 620. After cleaning/repacking adjustable BB, installing a new 7-speed freewheel, new derallieur, shifters, etc. Everything is back together but when pedaling under any kind of load, I hear "crunching" from somewhere. Can't hear it under light load (like using the granny hi gears) or on the bike stand.
My suspects:
1) BB-- I initially replaced the two caged bearings with loose ball bearings (9 each side). I put it all together and heard the crunching. But then I read that I should have used 11 bearings on each side, so I took it all apart again and re-did it with 11 loose bearings. The adjustment cup is pretty tight so that there is no knocking/play yet is smooth when turning it on the stand. On the other hand, this is my first attempt at rebuilding/repacking an adjustable BB.
2) 7-speed freewheel. Bike originally had a 5-speed freewheel on this 126mm rear. The freewheel went on no problem with plenty of axle space, but to get enough chain clearance for the bottom cog, I ended up removing a spacer. It seems ok, but I haven't yet tried reverting to the 5-speed freewheel. Nonetheless, I hear crunching on any of bottom 3-4 cogs.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
4) KMC Z50 6-7-speed chain on a new Tiagra 9-speed derailleur. I tried the old Shimano 600 derailleur. Still crunchy. With 7-speed freewheel and 7-speed chain, seems like there shouldn't be a problem here even though it looks like there is very little space between the chain and the rear adjacent cogs.
Tomorrow I guess I'll try the original freewheel and if I still hear the crunches, I guess I'll either go back to the caged BB bearings or go for a new cartridge BB.
Anything else I'm missing?
My suspects:
1) BB-- I initially replaced the two caged bearings with loose ball bearings (9 each side). I put it all together and heard the crunching. But then I read that I should have used 11 bearings on each side, so I took it all apart again and re-did it with 11 loose bearings. The adjustment cup is pretty tight so that there is no knocking/play yet is smooth when turning it on the stand. On the other hand, this is my first attempt at rebuilding/repacking an adjustable BB.
2) 7-speed freewheel. Bike originally had a 5-speed freewheel on this 126mm rear. The freewheel went on no problem with plenty of axle space, but to get enough chain clearance for the bottom cog, I ended up removing a spacer. It seems ok, but I haven't yet tried reverting to the 5-speed freewheel. Nonetheless, I hear crunching on any of bottom 3-4 cogs.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
4) KMC Z50 6-7-speed chain on a new Tiagra 9-speed derailleur. I tried the old Shimano 600 derailleur. Still crunchy. With 7-speed freewheel and 7-speed chain, seems like there shouldn't be a problem here even though it looks like there is very little space between the chain and the rear adjacent cogs.
Tomorrow I guess I'll try the original freewheel and if I still hear the crunches, I guess I'll either go back to the caged BB bearings or go for a new cartridge BB.
Anything else I'm missing?
#2
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Thread Starter
I'm working on overhauling a 1984 Trek 620. After cleaning/repacking adjustable BB, installing a new 7-speed freewheel, new derallieur, shifters, etc. Everything is back together but when pedaling under any kind of load, I hear "crunching" from somewhere. Can't hear it under light load (like using the granny hi gears) or on the bike stand.
My suspects:
1) BB-- I initially replaced the two caged bearings with loose ball bearings (9 each side). I put it all together and heard the crunching. But then I read that I should have used 11 bearings on each side, so I took it all apart again and re-did it with 11 loose bearings. The adjustment cup is pretty tight so that there is no knocking/play yet is smooth when turning it on the stand. On the other hand, this is my first attempt at rebuilding/repacking an adjustable BB.
2) 7-speed freewheel. Bike originally had a 5-speed freewheel on this 126mm rear. The freewheel went on no problem with plenty of axle space, but to get enough chain clearance for the bottom cog, I ended up removing a spacer. It seems ok, but I haven't yet tried reverting to the 5-speed freewheel. Nonetheless, I hear crunching on any of bottom 3-4 cogs.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
4) KMC Z50 6-7-speed chain on a new Tiagra 9-speed derailleur. I tried the old Shimano 600 derailleur. Still crunchy. With 7-speed freewheel and 7-speed chain, seems like there shouldn't be a problem here even though it looks like there is very little space between the chain and the rear adjacent cogs.
Tomorrow I guess I'll try the original freewheel and if I still hear the crunches, I guess I'll either go back to the caged BB bearings or go for a new cartridge BB.
Anything else I'm missing?
My suspects:
1) BB-- I initially replaced the two caged bearings with loose ball bearings (9 each side). I put it all together and heard the crunching. But then I read that I should have used 11 bearings on each side, so I took it all apart again and re-did it with 11 loose bearings. The adjustment cup is pretty tight so that there is no knocking/play yet is smooth when turning it on the stand. On the other hand, this is my first attempt at rebuilding/repacking an adjustable BB.
2) 7-speed freewheel. Bike originally had a 5-speed freewheel on this 126mm rear. The freewheel went on no problem with plenty of axle space, but to get enough chain clearance for the bottom cog, I ended up removing a spacer. It seems ok, but I haven't yet tried reverting to the 5-speed freewheel. Nonetheless, I hear crunching on any of bottom 3-4 cogs.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
4) KMC Z50 6-7-speed chain on a new Tiagra 9-speed derailleur. I tried the old Shimano 600 derailleur. Still crunchy. With 7-speed freewheel and 7-speed chain, seems like there shouldn't be a problem here even though it looks like there is very little space between the chain and the rear adjacent cogs.
Tomorrow I guess I'll try the original freewheel and if I still hear the crunches, I guess I'll either go back to the caged BB bearings or go for a new cartridge BB.
Anything else I'm missing?
#4
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what about the chainrings? It may quite down after a little break in time.
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Better try the first freewheel. You said it only crunches on the bottom 3 or 4 cogs with the new freewheel.
When you moved spacers on the hub you may have messed up the wheel bearings. Does the rear wheel spin true and quietly?
When you moved spacers on the hub you may have messed up the wheel bearings. Does the rear wheel spin true and quietly?
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I'm working on overhauling a 1984 Trek 620. After cleaning/repacking adjustable BB, installing a new 7-speed freewheel, new derallieur, shifters, etc. Everything is back together but when pedaling under any kind of load, I hear "crunching" from somewhere. Can't hear it under light load (like using the granny hi gears) or on the bike stand.
My suspects:
1) BB-- I initially replaced the two caged bearings with loose ball bearings (9 each side). I put it all together and heard the crunching. But then I read that I should have used 11 bearings on each side, so I took it all apart again and re-did it with 11 loose bearings. The adjustment cup is pretty tight so that there is no knocking/play yet is smooth when turning it on the stand. On the other hand, this is my first attempt at rebuilding/repacking an adjustable BB.
2) 7-speed freewheel. Bike originally had a 5-speed freewheel on this 126mm rear. The freewheel went on no problem with plenty of axle space, but to get enough chain clearance for the bottom cog, I ended up removing a spacer. It seems ok, but I haven't yet tried reverting to the 5-speed freewheel. Nonetheless, I hear crunching on any of bottom 3-4 cogs.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
4) KMC Z50 6-7-speed chain on a new Tiagra 9-speed derailleur. I tried the old Shimano 600 derailleur. Still crunchy. With 7-speed freewheel and 7-speed chain, seems like there shouldn't be a problem here even though it looks like there is very little space between the chain and the rear adjacent cogs.
Tomorrow I guess I'll try the original freewheel and if I still hear the crunches, I guess I'll either go back to the caged BB bearings or go for a new cartridge BB.
Anything else I'm missing?
My suspects:
1) BB-- I initially replaced the two caged bearings with loose ball bearings (9 each side). I put it all together and heard the crunching. But then I read that I should have used 11 bearings on each side, so I took it all apart again and re-did it with 11 loose bearings. The adjustment cup is pretty tight so that there is no knocking/play yet is smooth when turning it on the stand. On the other hand, this is my first attempt at rebuilding/repacking an adjustable BB.
2) 7-speed freewheel. Bike originally had a 5-speed freewheel on this 126mm rear. The freewheel went on no problem with plenty of axle space, but to get enough chain clearance for the bottom cog, I ended up removing a spacer. It seems ok, but I haven't yet tried reverting to the 5-speed freewheel. Nonetheless, I hear crunching on any of bottom 3-4 cogs.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
4) KMC Z50 6-7-speed chain on a new Tiagra 9-speed derailleur. I tried the old Shimano 600 derailleur. Still crunchy. With 7-speed freewheel and 7-speed chain, seems like there shouldn't be a problem here even though it looks like there is very little space between the chain and the rear adjacent cogs.
Tomorrow I guess I'll try the original freewheel and if I still hear the crunches, I guess I'll either go back to the caged BB bearings or go for a new cartridge BB.
Anything else I'm missing?
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
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New chain with old freewheel will do this. The old freewheel's teeth may have been slightly reshaped by a stretched old chain. This happens most on the gears used most - which could explain why it's only a few of the gears playing up.
If this is the case then a new freewheel will fix it.
Indicative diagnosis would be to run the old chain if you still have it. If it's quiet with the old chain then it's unlikely to be the BB.
You can only run a new chain on an old freewheel if you change the chain before the old one stretches beyond a certain point.
If this is the case then a new freewheel will fix it.
Indicative diagnosis would be to run the old chain if you still have it. If it's quiet with the old chain then it's unlikely to be the BB.
You can only run a new chain on an old freewheel if you change the chain before the old one stretches beyond a certain point.
#9
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Thread Starter
Here are pics. While this is supposedly a 7-speed chain (KMC Z50) with a 7-speed freewheel, it looks pretty tight such that the adjacent cog could be rubbing. Perhaps this is my problem?
#10
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Shimano HG-37 7-speed....
That's a good choice of freewheel with a 31.9 width - which is right at the limit for a 126mm rear hub with freewheel stop to locknut dimension of 36mm. It looks like the chain also clears the the seat stay. I don't see any outright obvious indication of a misaligned derailleur hanger. I don't see a reason at this point to make any changes to the hub. However, if you did make spacer/locknut changes - then you do need to check the dish of the wheel.
Other than checking the wheel to ensure that it is properly dished (rim centered between the lock nuts of the hub) and then re-centering the wheel between the chain stays,
my guess here is that others are going run with this as a chain, freewheel, derailleur adjustment or perhaps a chainline issue.
Nice photos...exactly what I needed!!!
=8-)
That's a good choice of freewheel with a 31.9 width - which is right at the limit for a 126mm rear hub with freewheel stop to locknut dimension of 36mm. It looks like the chain also clears the the seat stay. I don't see any outright obvious indication of a misaligned derailleur hanger. I don't see a reason at this point to make any changes to the hub. However, if you did make spacer/locknut changes - then you do need to check the dish of the wheel.
Other than checking the wheel to ensure that it is properly dished (rim centered between the lock nuts of the hub) and then re-centering the wheel between the chain stays,
my guess here is that others are going run with this as a chain, freewheel, derailleur adjustment or perhaps a chainline issue.
Nice photos...exactly what I needed!!!
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
#11
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Bro, douse that everloving thing in oil--and ride for a week at least....
I'm not being glib: it's way dry.
I'm not being glib: it's way dry.
#14
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OP:
In your original post, you did mention removing a spacer on the hub. That alone suggests that a re-dishing of the wheel is required. Re-dish the wheel such that the rim is centered between the locknuts - done using a dishing tool or the flip flop method.
Then re-install the wheel centered between the chainstays.
That will ensure that both the crankset and the freewheel and hopefully the derailleur are ALL operating in parallel to the bicycle frame centerline.
Then proceed with all else...
=8-)
Hopefully when you do this, you'll have smoother operation at the small chainring and one of the middle rear cogs.
In your original post, you did mention removing a spacer on the hub. That alone suggests that a re-dishing of the wheel is required. Re-dish the wheel such that the rim is centered between the locknuts - done using a dishing tool or the flip flop method.
Then re-install the wheel centered between the chainstays.
That will ensure that both the crankset and the freewheel and hopefully the derailleur are ALL operating in parallel to the bicycle frame centerline.
Then proceed with all else...
=8-)
Hopefully when you do this, you'll have smoother operation at the small chainring and one of the middle rear cogs.
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
#15
Senior Member
Thread Starter
OP:
In your original post, you did mention removing a spacer on the hub. That alone suggests that a re-dishing of the wheel is required. Re-dish the wheel such that the rim is centered between the locknuts - done using a dishing tool or the flip flop method.
Then re-install the wheel centered between the chainstays.
That will ensure that both the crankset and the freewheel and hopefully the derailleur are ALL operating in parallel to the bicycle frame centerline.
Then proceed with all else...
=8-)
Hopefully when you do this, you'll have smoother operation at the small chainring and one of the middle rear cogs.
In your original post, you did mention removing a spacer on the hub. That alone suggests that a re-dishing of the wheel is required. Re-dish the wheel such that the rim is centered between the locknuts - done using a dishing tool or the flip flop method.
Then re-install the wheel centered between the chainstays.
That will ensure that both the crankset and the freewheel and hopefully the derailleur are ALL operating in parallel to the bicycle frame centerline.
Then proceed with all else...
=8-)
Hopefully when you do this, you'll have smoother operation at the small chainring and one of the middle rear cogs.
I do think this is coming from the rear freewheel area as when I turn things slowly and put my ear close to the freewheel, I'm definitely hearing the noise.
I suspect it is possibly chain-line related or that maybe just a narrower chain would help.
#16
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No idea what's causing your crunching, if the chain isn't too wide... nasty sounds are the hardest things to diagnose over the net. If you shot some video, that might help.
You don't need a tool to dish your wheel quite accurately; put a zip tie around one of your stays and cut it so it rests against the rim, then pull the wheel and flip it.
More accurate than a dish gauge that uses the axle ends rather than the locknut faces.
More accurate than a dish gauge that uses the axle ends rather than the locknut faces.
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#17
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No idea what's causing your crunching, if the chain isn't too wide... nasty sounds are the hardest things to diagnose over the net. If you shot some video, that might help.
You don't need a tool to dish your wheel quite accurately; put a zip tie around one of your stays and cut it so it rests against the rim, then pull the wheel and flip it.
More accurate than a dish gauge that uses the axle ends rather than the locknut faces.
You don't need a tool to dish your wheel quite accurately; put a zip tie around one of your stays and cut it so it rests against the rim, then pull the wheel and flip it.
More accurate than a dish gauge that uses the axle ends rather than the locknut faces.
The dishing guage however avoids this as the arms rest on the rim - and you see the entire relation of the point to the axle entirely. Flip over and compare...done.
I do about a dozen electric bike wheels per years, my dishing tool is almost useless with some of the hubs used.
So I go the flip flop route. Set one way, rotate axle 360 - check the farthest and closest extent at which the rim is from the reference point...
Flip...rotate axle again...check the farthest and closest extent at which the rim is from the point.
If the extents are the same, dished - done. If not, got more work to do. I would say that I end up within a millimeter of being "dished".
The dishing tool is much faster...but there's an even more important reminder. Buy quality hubs to begin with - you don't have to put up with such annoying caveats.
=8-)
I use the Park TS-2 so I have no way to guarantee that I've "snugged" a hub perfectly parallel in the arms. I bet someone here has a stand that does...
=8-)
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5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
Last edited by mrrabbit; 09-12-12 at 01:04 AM.
#18
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Thread Starter
Definitely caused by going to the 7-speed Hyperglide freewheel. I put the original 5-speed freewheel back and everything runs smooth. I'll have to check dish and/or try a narrower chain.
#19
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I'm thinking you should be able to stick with the 7-speed freewheel and get a chain that will work with it. According to the Shimano doc I'm viewing the chains are:
CN-HG50, CN-HG40 and CN-UG51
Yaban makes compatible chains for those and so should KMC / Taya
=8-)
In the archive is a post where someone asks if KMC Z50 = CN-HG50, but it didn't seem as though anyone directly answered the question.
https://www.bikeforums.net/archive/in.../t-162570.html
=8-)
CN-HG50, CN-HG40 and CN-UG51
Yaban makes compatible chains for those and so should KMC / Taya
=8-)
In the archive is a post where someone asks if KMC Z50 = CN-HG50, but it didn't seem as though anyone directly answered the question.
https://www.bikeforums.net/archive/in.../t-162570.html
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
Last edited by mrrabbit; 09-12-12 at 10:41 PM.
#20
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Just talked to a mechanic I deliver wheels to - and he prefers to not use the Z50 on Shimano 7-speed hyperglide freewheel - but rather the actual Shimano recommended chain - or a third party 7/8 speed or 8 speed chain.
Yaban would be S52 and S8. Don't know the KMC or Taya models.
=8-)
Yaban would be S52 and S8. Don't know the KMC or Taya models.
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
#21
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Join Date: Oct 2011
Location: Fairplay Co
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Bikes: Current 79 Nishiki Custum Sport, Jeunet 620, notable previous bikes P.K. Ripper loop tail, Kawahara Laser Lite, Paramount Track full chrome, Raliegh Internatioanl, Motobecan Super Mirage. 59 Crown royak 3 speed
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) 7-speed freewheel. Bike originally had a 5-speed freewheel on this 126mm rear. The freewheel went on no problem with plenty of axle space, but to get enough chain clearance for the bottom cog, I ended up removing a spacer. It seems ok, but I haven't yet tried reverting to the 5-speed freewheel. Nonetheless, I hear crunching on any of bottom 3-4 cogs.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
3) 8-speed Ultegra bar-ends with 7-speed freewheel (with alternate derailleur routing). I eliminated this suspect by just using friction-mode shifting for now. Still crunchy. I'm hoping that once I solve the crunchy noise, that this combo might just shift ok even though the spacing isn't exact.
#22
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Join Date: Dec 2007
Location: San Jose, California
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I would suspect the combination of 8 speed shfiters and likely a cheaper lesser 7 speed freewheel are causing your problems. Your chain and front chain rings are fine. Switching to a good new or used 6 speed freewheel or wheel with a actual 8 speed cassette are likley needed to make things work.
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
#23
Senior Member
Join Date: Oct 2011
Location: Fairplay Co
Posts: 9,582
Bikes: Current 79 Nishiki Custum Sport, Jeunet 620, notable previous bikes P.K. Ripper loop tail, Kawahara Laser Lite, Paramount Track full chrome, Raliegh Internatioanl, Motobecan Super Mirage. 59 Crown royak 3 speed
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Well the Op has said changing the freewheel back to old 5 makes things work. From experiance I have found 7 speed freewheels problematic even in fricrtion mode they just don't seem to play well with other stuff. I avoid 7 speed stuff on pretty much every bike I build up including free coop builds as a voluteer unless it works good and is complete and already on the bike.
#24
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Well the Op has said changing the freewheel back to old 5 makes things work. From experiance I have found 7 speed freewheels problematic even in fricrtion mode they just don't seem to play well with other stuff. I avoid 7 speed stuff on pretty much every bike I build up including free coop builds as a voluteer unless it works good and is complete and already on the bike.
And you will discover that many people have for 3 decades used 6 AND 7 speed freewheels in friction mode with the correct chain without issues. For me: $count = $count + 1;
And you seem to be unaware that 7-speed has been the staple for entry level factory MTB, Comfort and Commuter bikes for over two decades. And it hasn't entirely lost that crown to 8 speed yet.
=8-)
__________________
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
5000+ wheels built since 1984...
Disclaimer:
1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:
Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
#25
Senior Member
Thread Starter
I would suspect the combination of 8 speed shfiters and likely a cheaper lesser 7 speed freewheel are causing your problems. Your chain and front chain rings are fine. Switching to a good new or used 6 speed freewheel or wheel with a actual 8 speed cassette are likley needed to make things work.
If it doesn't shift well enough, my options are to stick with friction-mode or just rebuild with an 8-speed cassette (and new hub).