Clamp On DT Indexed Shifters for Shimano
#1
Junior Member
Thread Starter
Join Date: Sep 2012
Location: Ohio
Posts: 123
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Clamp On DT Indexed Shifters for Shimano
I'm continuing my 1990 Trek 330 refurbish which came with 6 speed indexed Light Action parts and wonky shifters that clamp on the handlebars (they are shimano). The shifters are goofy looking but the main problem is the thumb levers don't shift easily. I dropped some oil in them but it doesn't seem to help so I'm considering some clamp on DT index shifters for 6 speed and would like to know of my brand options - Shimano only? I saw some cheap Sunrace 6/7 speed that claim to be Shimano compliant. Any other options?
Thanks, also there are brazed on cable stops on the DT.
Thanks, also there are brazed on cable stops on the DT.
#2
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,629
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3871 Post(s)
Liked 2,568 Times
in
1,579 Posts
Does the bike have cable stops, or braze-ons for shifters? If the latter, you can find lots of NOS and used 6/7 speed DT shifters out there.
Alternately, I've had good luck with Shimano A070 shifters -- they also mount onto the tops of the handlebars.
Alternately, I've had good luck with Shimano A070 shifters -- they also mount onto the tops of the handlebars.
#3
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: 2026 Post(s)
Likes: 0
Liked 1,096 Times
in
742 Posts
About all of the band-on downtube shifters I've seen are friction. If Sun Race offers indexing band-on shifters they are probably the only ones.
#4
Senior Member
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,547
Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1529 Post(s)
Liked 718 Times
in
510 Posts
I've seen a clamp band with generic mounts for DT shifters. You can hang Dura-Ace off gas pipe if you like.
But IMO the cable stops make some sort of bar-mounted shifter a no-brainer IMO.
If the frame's OLD is 130mm I'd stick a cassette hub in the wheel and go 8 or 9s and STIs or bar-ends (10s Shimano indexing is sketchy), otherwise I'd just bung on a 7s HG freewheel and re-space and dish if necessary, and get some 7s STIs or bar-ends.
It's possible to make do without the adjusters since there's one on the RD and a technique exists to adjust the FD tension without a barrel adjuster.
But IMO the cable stops make some sort of bar-mounted shifter a no-brainer IMO.
If the frame's OLD is 130mm I'd stick a cassette hub in the wheel and go 8 or 9s and STIs or bar-ends (10s Shimano indexing is sketchy), otherwise I'd just bung on a 7s HG freewheel and re-space and dish if necessary, and get some 7s STIs or bar-ends.
It's possible to make do without the adjusters since there's one on the RD and a technique exists to adjust the FD tension without a barrel adjuster.
#5
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: 2026 Post(s)
Likes: 0
Liked 1,096 Times
in
742 Posts
If the OP's came with a 6-speed freewheel it was obviously changed by the previous owner and perhaps that's why the OEM shifters (7-speed SIS) don't work well.
#6
Senior Member
Join Date: Oct 2005
Location: Fresno, CA
Posts: 4,454
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 128 Post(s)
Likes: 0
Liked 12 Times
in
10 Posts
Your easiest option may be to buy the SunRace 7-speed clamp-on DT shifters (which work fine in my experience) and buy a cheap 7-speed freewheel (for about the same cost again as the shifters). As HillRider points out, your shifters (if they are original) might actually be 7-speed.
A 7-speed freewheel will be wider than the 6-speed, though not by the full width of a cog (as the gears are spaced slightly closer together). But many rear wheels from that era have spacing to fit wider freewheels (or respace decrease the amount of dish on the wheelbuild). You need room for the chain to fit on the smallest rear cog without rubbing against the dropout. Here is an example of a 5-speed freewheel spaced close to the dropouts to minimize dish of the rear wheel, but not close enough that the chain rubs against the dropout when the chain is on the smallest cog.
A 7-speed freewheel will be wider than the 6-speed, though not by the full width of a cog (as the gears are spaced slightly closer together). But many rear wheels from that era have spacing to fit wider freewheels (or respace decrease the amount of dish on the wheelbuild). You need room for the chain to fit on the smallest rear cog without rubbing against the dropout. Here is an example of a 5-speed freewheel spaced close to the dropouts to minimize dish of the rear wheel, but not close enough that the chain rubs against the dropout when the chain is on the smallest cog.
__________________
"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
#7
Senior Member
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,547
Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1529 Post(s)
Liked 718 Times
in
510 Posts
Yeah, the other day I threw a 7s freewheel on a guy's wheel in place of a 6s one and there was plenty of room.
#8
Senior Member
Join Date: May 2012
Location: western Massachusetts (greater Springfield area)
Posts: 699
Bikes: Velosolex St. Tropez, LeMond Zurich (spine bike), Rotator swb recumbent
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Likes: 0
Liked 67 Times
in
32 Posts
I bought that same bike for my wife as a wedding present! Hers has a 6 speed freewheel, 126 mm frame spacing, and cable stops on the down tube.
Having said that, a few years ago I picked up and refurbished an old Schwinn (I think LeTour?) at the swap shop at the local dump. It had indexed 7 speed down tube shifters. Looking through Bikepedia, they were probably shimano 300 EX or RSX levers. I have no idea how hard they are to come by, and they were on braze-on bosses as I recall.
Having said that, a few years ago I picked up and refurbished an old Schwinn (I think LeTour?) at the swap shop at the local dump. It had indexed 7 speed down tube shifters. Looking through Bikepedia, they were probably shimano 300 EX or RSX levers. I have no idea how hard they are to come by, and they were on braze-on bosses as I recall.
#9
Junior Member
Thread Starter
Join Date: Sep 2012
Location: Ohio
Posts: 123
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Duh, I forgot the specs said 7 speed but this came with a 6 speed freewheel! Yes it has the bar mounted shifters and they are 7 speed (6 clicks), brazed-on cable stops, not shifter bosses. Its indexed shifting, shouldn't the shifters work for 6? Maybe, but the main thing is to see if I can get those shifters working well and maybe put a new/old 7 speed freewheel on the back. Then I can get the Sunrace 6/7 clamp-ons if I have to. No wonder I got this bike cheap. I'm learning.
#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: 2026 Post(s)
Likes: 0
Liked 1,096 Times
in
742 Posts
I had the same problem on an old Trek I bought used. The original owner had put a 7-speed indexed barend shifters on bike that came with 6-speed freewheel and the shifting was so bad he was running the shifters in friction mode. A 7-speed freewheel made everything work perfectly.
#11
Old fart
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,786
Bikes: Several, mostly not name brands.
Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3588 Post(s)
Liked 3,400 Times
in
1,934 Posts
Duh, I forgot the specs said 7 speed but this came with a 6 speed freewheel! Yes it has the bar mounted shifters and they are 7 speed (6 clicks), brazed-on cable stops, not shifter bosses. Its indexed shifting, shouldn't the shifters work for 6? Maybe, but the main thing is to see if I can get those shifters working well and maybe put a new/old 7 speed freewheel on the back. Then I can get the Sunrace 6/7 clamp-ons if I have to. No wonder I got this bike cheap. I'm learning.
https://loosescrews.com/index.cgi?nr=...d=422266712276
Thread
Thread Starter
Forum
Replies
Last Post
illwafer
Classic & Vintage
15
12-10-13 07:09 PM