Trek 620: change freewheel to freehub?
#1
Senior Member
Thread Starter
Trek 620: change freewheel to freehub?
I've got a 1983 Trek 620 that was updated (by someone else) in the 1990s -- at least, I think that's when it picked up the Biopace gears on the front. The freewheel was updated, too; it came stock with a 6 speed 13/14/17/20/24/28 gearing, but I counted 30 teeth on the largest wheel.
In updating the bike, I'd like to move to 7 gears with a wider range. I've found freewheels with 13-32 and 14-34 ranges that look like they'll do the job. But before I do that, I want to doublecheck something with the assembled wisdom: is it possible to relpace a freewheel with a freehub cassette?
Thanks!
In updating the bike, I'd like to move to 7 gears with a wider range. I've found freewheels with 13-32 and 14-34 ranges that look like they'll do the job. But before I do that, I want to doublecheck something with the assembled wisdom: is it possible to relpace a freewheel with a freehub cassette?
Thanks!
__________________
- Jeneralist
- Jeneralist
#2
Senior Member
Join Date: Aug 2005
Location: Hudson Valley, NY
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
Only if you replace the freewheel hub with a cassette hub and rebuild the wheel. I don't know of any way to put a freehub cassette on a freewheel hub.
__________________
Steve
Steve
Last edited by strock; 01-11-12 at 06:36 AM.
#3
Lover of Old Chrome Moly
Join Date: May 2011
Location: NW Minnesota
Posts: 2,949
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Likes: 0
Liked 23 Times
in
17 Posts
If it's an old factory wheel, you are probably better off just replacing it with a decent handbuilt one with the hub of your choice. Since you are going to have to replace the shifter anyway, I suggest skipping 7-speed, which is obsolete and getting harder to find, and going to a 9-speed cassette. I did this on my Trek 700 going with an 11-28 cassette and at the same time swapped my old Biopace ringed crankset for an Alevio 48-36-26. I've got all the range I could ever want.
#4
cowboy, steel horse, etc
Join Date: Sep 2008
Location: The hot spot.
Posts: 44,712
Bikes: everywhere
Mentioned: 71 Post(s)
Tagged: 1 Thread(s)
Quoted: 12576 Post(s)
Liked 7,471 Times
in
3,956 Posts
I'm guessing the bike has shifters that are either friction or have a friction option, so shifter change is not likely necessary.
Rear triangle spreading may be required to accommodate some hub changes (which would need to be done to get a freehub cassette).
Cheapo 7-speed freewheels are still available. I've shifted 7-speed Sunrace freewheels with friction downtube shifters just fine.
Just weighed my Sunrace 13-28T (I've been on a weigh everything spree lately) and the weight seems immense! 460.6 grams.
Interloc has 7-sp freewheels which cost twice as much, wonder if they're any lighter.
Rear triangle spreading may be required to accommodate some hub changes (which would need to be done to get a freehub cassette).
Cheapo 7-speed freewheels are still available. I've shifted 7-speed Sunrace freewheels with friction downtube shifters just fine.
Just weighed my Sunrace 13-28T (I've been on a weigh everything spree lately) and the weight seems immense! 460.6 grams.
Interloc has 7-sp freewheels which cost twice as much, wonder if they're any lighter.
Last edited by LesterOfPuppets; 01-11-12 at 08:27 AM.
#5
Senior Member
Join Date: Aug 2005
Location: Hudson Valley, NY
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
If it's an old factory wheel, you are probably better off just replacing it with a decent handbuilt one with the hub of your choice. Since you are going to have to replace the shifter anyway, I suggest skipping 7-speed, which is obsolete and getting harder to find, and going to a 9-speed cassette. I did this on my Trek 700 going with an 11-28 cassette and at the same time swapped my old Biopace ringed crankset for an Alevio 48-36-26. I've got all the range I could ever want.
If your current wheels are original and in good shape, there would be two reasons for me to consider going to a 9-speed cassette. First, you can get a wider gear range (11-34 or 12-36), have smaller gaps between the gears, or both. That matters to some people. Second, it will allow you to replace the stock 27" wheels with 700c wheels, so as to take advantage of the fact that many more tires are available in 700c. (This is not to say that good tires are not available in 27"; they are. It's just that there's not as much variety.) If you've got brakes with enough reach, it's easy to make the switch. I put a set of 700c wheels on my Gran Turismo, but then went back to the original 27s, since I thought they looked a little better.
Anyway, I think the 7-speed freewheel is the simplest and cheapest upgrade, but there is a case to be made for getting a new wheel with a freehub and 9-speed cassette.
BTW, if you go from a freewheel with a large cog of 30t to a freewheel or cassette with a large cog of 32t, 34t, or 36t, you might need a new rear derailleur, depending upon what's currently on the bike.
__________________
Steve
Steve
#6
Senior Member
Join Date: Nov 2009
Posts: 589
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I've got a 1983 Trek 620 that was updated (by someone else) in the 1990s -- at least, I think that's when it picked up the Biopace gears on the front. The freewheel was updated, too; it came stock with a 6 speed 13/14/17/20/24/28 gearing, but I counted 30 teeth on the largest wheel.
In updating the bike, I'd like to move to 7 gears with a wider range. I've found freewheels with 13-32 and 14-34 ranges that look like they'll do the job. But before I do that, I want to doublecheck something with the assembled wisdom: is it possible to relpace a freewheel with a freehub cassette?
Thanks!
In updating the bike, I'd like to move to 7 gears with a wider range. I've found freewheels with 13-32 and 14-34 ranges that look like they'll do the job. But before I do that, I want to doublecheck something with the assembled wisdom: is it possible to relpace a freewheel with a freehub cassette?
Thanks!
#7
cowboy, steel horse, etc
Join Date: Sep 2008
Location: The hot spot.
Posts: 44,712
Bikes: everywhere
Mentioned: 71 Post(s)
Tagged: 1 Thread(s)
Quoted: 12576 Post(s)
Liked 7,471 Times
in
3,956 Posts
Hruh? Spending $20-$150 on a bike you love to make you love it more is a waste of funds? Does not compute.
Last edited by LesterOfPuppets; 01-11-12 at 08:28 AM.
#8
Cat 6
Join Date: Dec 2007
Location: Mountain Brook, AL
Posts: 7,519
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked 183 Times
in
118 Posts
And you'll also find that if you put a larger tooth freewheel or cassette on the rear, you may need a longer chain, too.
And that's a nice riding frame. I have an '83 600, and in '83 all the 6xx series shared the same frame. On mine, I've kept the 6 speed rear, but changed the front out to a triple 52x42x28.
Edit: Strock talks a couple posts above about swapping to 700c. I did that on my 600, am running 700x29 tires, and they have plenty of clearance on that frame, even with the fenders I added, too.
And that's a nice riding frame. I have an '83 600, and in '83 all the 6xx series shared the same frame. On mine, I've kept the 6 speed rear, but changed the front out to a triple 52x42x28.
Edit: Strock talks a couple posts above about swapping to 700c. I did that on my 600, am running 700x29 tires, and they have plenty of clearance on that frame, even with the fenders I added, too.
__________________
72 Frejus (for sale), Holdsworth Record (for sale), special CNC & Gitane Interclub / 74 Italvega NR (for sale) / c80 French / 82 Raleigh Intl MkII f&f (for sale)/ 83 Trek 620 (for sale)/ 84 Bruce Gordon Chinook (for sale)/ 85 Ron Cooper / 87 Centurion IM MV (for sale) / 03 Casati Dardo / 08 BF IRO / 09 Dogma FPX / 09 Giant TCX0 / 10 Vassago Fisticuff
72 Frejus (for sale), Holdsworth Record (for sale), special CNC & Gitane Interclub / 74 Italvega NR (for sale) / c80 French / 82 Raleigh Intl MkII f&f (for sale)/ 83 Trek 620 (for sale)/ 84 Bruce Gordon Chinook (for sale)/ 85 Ron Cooper / 87 Centurion IM MV (for sale) / 03 Casati Dardo / 08 BF IRO / 09 Dogma FPX / 09 Giant TCX0 / 10 Vassago Fisticuff
Last edited by Ex Pres; 01-11-12 at 08:33 AM.
#9
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2025 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
As noted, you cannot install a freehub cassette on a freewheel hub and you cannot install a freehub body on a freewheel hub. Your only alternative is a new hub and, for cost purposes, a complete new wheel will be more economical.
There are 7-speed freehub wheels still available but increasingly hard to find since, as Myosmith said, 7-speed is obsolete. You could go to a 9 or even 10-speed cassette (and shifters unless you stay with friction shifting) since current Shimano hubs are 8/9/10-speed compatible. You will also need a matching width chain but a new chain is called for even if all you do is install a new freewheel.
Be aware that your frame's dropouts are spaced 126 mm for your 6-speed wheel. This is the same spacing as 7-speed freehubs but 8/9/10-speed hubs are 130 mm wide and will be a snug, but usable fit in your frame. You can either use the frame as is and struggle slightly with every wheel removal/reinstallation or have the spacing "cold set" to 130 mm for the newer hubs.
You may also want to get a more modern crank and bottom bracket to accompany this change but this is going to be a costly upgrade.
There are 7-speed freehub wheels still available but increasingly hard to find since, as Myosmith said, 7-speed is obsolete. You could go to a 9 or even 10-speed cassette (and shifters unless you stay with friction shifting) since current Shimano hubs are 8/9/10-speed compatible. You will also need a matching width chain but a new chain is called for even if all you do is install a new freewheel.
Be aware that your frame's dropouts are spaced 126 mm for your 6-speed wheel. This is the same spacing as 7-speed freehubs but 8/9/10-speed hubs are 130 mm wide and will be a snug, but usable fit in your frame. You can either use the frame as is and struggle slightly with every wheel removal/reinstallation or have the spacing "cold set" to 130 mm for the newer hubs.
You may also want to get a more modern crank and bottom bracket to accompany this change but this is going to be a costly upgrade.
#10
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2025 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
I did the same 27" to 700c change on an '83 Trek 400 and it worked out very well. The brakes adjusted enough to match and it greatly increased the frame and fork clearance for fenders and even larger tires. The only problem for the OP is the cost since he will have to replace both wheels.
#11
Senior Member
Join Date: Apr 2011
Location: Alpharetta, GA
Posts: 15,280
Bikes: Nashbar Road
Mentioned: 71 Post(s)
Tagged: 0 Thread(s)
Quoted: 2934 Post(s)
Liked 341 Times
in
228 Posts
There are 7-speed freehub wheels still available but increasingly hard to find since, as Myosmith said, 7-speed is obsolete. You could go to a 9 or even 10-speed cassette (and shifters unless you stay with friction shifting) since current Shimano hubs are 8/9/10-speed compatible.
#12
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2025 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
#14
Senior Member
Join Date: Nov 2009
Posts: 589
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
[QUOTE Hruh? Spending $20-$150 on a bike you love to make you love it more is a waste of funds? Does not compute.[/QUOTE]
OK.. I missed the hole between the 14 and 17. But going 7 is just a complete waste. Find a 14, 15, 17, 20, 24, 28.. assuming a TC on the front.. no need to mess with moving to seven rear gears. Those older usually Suntour FW's are so much better quality than those made today.
Whatever you do.. do NOT bother buying the Shimano 14-28 FW... the z body.. cogs are thin, made of less than junk steel.. and wear very poorly.
IF.. you going to bother with a gear chg.. why stop at 7 ????
OK.. I missed the hole between the 14 and 17. But going 7 is just a complete waste. Find a 14, 15, 17, 20, 24, 28.. assuming a TC on the front.. no need to mess with moving to seven rear gears. Those older usually Suntour FW's are so much better quality than those made today.
Whatever you do.. do NOT bother buying the Shimano 14-28 FW... the z body.. cogs are thin, made of less than junk steel.. and wear very poorly.
IF.. you going to bother with a gear chg.. why stop at 7 ????
#15
Senior Member
Thread Starter
Because then I could get a slightly wider range (from 30T at the large end to 32 or 34) without needing to replace the whole wheel.
Someone already did the 27 inch to 700c conversion, somewhere in the bike's history, so I don't have much impetus to swap out the whole wheel. At least, not yet.
Someone already did the 27 inch to 700c conversion, somewhere in the bike's history, so I don't have much impetus to swap out the whole wheel. At least, not yet.
__________________
- Jeneralist
- Jeneralist
#17
Banned
one advantage of replacing a common freewheel hub, avoiding bent axles ,
is taken care of by hubs with a solid axle.. Phil wood is one.. The axles just don't bend.
though a nut fitted solid axle instead of a hollow QR one is a modest change.
look at changing the ratios of the gears , before adding 'speeds' past 7,
as the frame has to be spread to fit +8 on a 7 speed stack.
invariably the added cogs are the little ones a 12 instead of a 13.. no BFD.
+1,older wheel to put a cassette hub in/on , just buy another whole wheel..
is taken care of by hubs with a solid axle.. Phil wood is one.. The axles just don't bend.
though a nut fitted solid axle instead of a hollow QR one is a modest change.
look at changing the ratios of the gears , before adding 'speeds' past 7,
as the frame has to be spread to fit +8 on a 7 speed stack.
invariably the added cogs are the little ones a 12 instead of a 13.. no BFD.
+1,older wheel to put a cassette hub in/on , just buy another whole wheel..