Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

1x7 and chain drop

Notices
Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

1x7 and chain drop

Old 12-16-17, 02:24 PM
  #1  
Shinkers
Senior Member
Thread Starter
 
Join Date: Jan 2014
Location: Utah
Posts: 754

Bikes: '88 Trek 1200, '91 Trek 1400

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked 7 Times in 5 Posts
1x7 and chain drop

Hey,


Has anybody had any success running 1x7 with a large chainring and shortening the spindle a bit?


I've tried 1x10 before and it was a complete failure since I'd drop my chain as soon as I pedaled backwards on either end of the cassette. I've got a bottom bracket that splits the chainline on a regular double and I'm thinking the chainline on a 7 speed would be less extreme so it may work better. Gearing would be a 53t chainring with a 13-23 cassette.


I've got everything to go 2x but got to thinking that I may dig 1x for a bike that won't see any hills. On my Trek, I only use my 39t for climbing.


Thanks for any info.
Shinkers is offline  
Old 12-16-17, 02:35 PM
  #2  
fietsbob
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,599

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,343 Times in 850 Posts
On the cheap, put a FD Back on and run the L limit screw in , to center it over the chain, no cable attached..

& how about.. don't use a chainring from a STI crank, use full height tooth chainrings for single speeds
(I have that on my IGH bike with a chain tensioner..)

there are chain keepers that do that too... K edge one US maker https://k-edge.com/product-category/chain-catchers/



1 by you center the chain ring on the chain line aligned with #3 of 7...









.....

Last edited by fietsbob; 12-16-17 at 02:50 PM.
fietsbob is offline  
Old 12-16-17, 02:38 PM
  #3  
HTupolev
Senior Member
 
Join Date: Apr 2015
Location: Seattle
Posts: 4,148
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 1912 Post(s)
Liked 1,191 Times in 576 Posts
Most chainrings are designed to allow the chain to derail easily. If you want to use 1x, use a retention mechanism of some sort, and/or get a narrow-wide chainring whose tooth profiling grabs the chain better.
HTupolev is offline  
Old 12-16-17, 02:46 PM
  #4  
fietsbob
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,599

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,343 Times in 850 Posts
Or, this being C&V, get old chainrings from before the index shifting thing became dominant..

I have steel chainrings from BITD on a couple bikes, they last a very long time..
fietsbob is offline  
Old 12-16-17, 02:55 PM
  #5  
Shinkers
Senior Member
Thread Starter
 
Join Date: Jan 2014
Location: Utah
Posts: 754

Bikes: '88 Trek 1200, '91 Trek 1400

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked 7 Times in 5 Posts
My rings are standard vintage rings without pins or ramps but some short teeth (shift cages?). Anyway, if a chain retention device is still going to be required, I'm going to stick with 2x. If I need to have a front derailleur mounted, I might as well use it. I was hoping with a better chainline, bigger ring, and smaller range cassette I may have enough chain tension to keep everything on.


Thanks for the input.
Shinkers is offline  
Old 12-16-17, 02:56 PM
  #6  
ThermionicScott 
working on my sandal tan
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 22,158

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: 95 Post(s)
Tagged: 0 Thread(s)
Quoted: 3680 Post(s)
Liked 2,155 Times in 1,362 Posts
I have a Surly steel 49T/130BCD ring (full height teeth, no ramps or pins) if you're interested.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 12-16-17, 03:15 PM
  #7  
Shinkers
Senior Member
Thread Starter
 
Join Date: Jan 2014
Location: Utah
Posts: 754

Bikes: '88 Trek 1200, '91 Trek 1400

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked 7 Times in 5 Posts
Originally Posted by ThermionicScott View Post
I have a Surly steel 49T/130BCD ring (full height teeth, no ramps or pins) if you're interested.


Thanks for the offer but I'm going to pass. I'm looking at chain guides at the moment, but will still likely just run my double.
Shinkers is offline  
Old 12-16-17, 03:17 PM
  #8  
ThermionicScott 
working on my sandal tan
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 22,158

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: 95 Post(s)
Tagged: 0 Thread(s)
Quoted: 3680 Post(s)
Liked 2,155 Times in 1,362 Posts
Originally Posted by Shinkers View Post
Thanks for the offer but I'm going to pass. I'm looking at chain guides at the moment, but will still likely just run my double.
Rats, I'm never gonna get rid of this thing.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 12-16-17, 09:01 PM
  #9  
Jadesfire 
Senior Member
 
Jadesfire's Avatar
 
Join Date: Jul 2015
Posts: 1,500

Bikes: '88 Bianchi, '94ish Trek

Mentioned: 43 Post(s)
Tagged: 2 Thread(s)
Quoted: 1085 Post(s)
Liked 128 Times in 58 Posts
Originally Posted by Shinkers View Post
Hey,


Has anybody had any success running 1x7 with a large chainring and shortening the spindle a bit?


I've tried 1x10 before and it was a complete failure since I'd drop my chain as soon as I pedaled backwards on either end of the cassette. I've got a bottom bracket that splits the chainline on a regular double and I'm thinking the chainline on a 7 speed would be less extreme so it may work better. Gearing would be a 53t chainring with a 13-23 cassette.


I've got everything to go 2x but got to thinking that I may dig 1x for a bike that won't see any hills. On my Trek, I only use my 39t for climbing.


Thanks for any info.
Not a 1x7, but a 1x8 with a 42t chain ring. No retention system, I did just need to spend a little time getting the RD adjusted exactly right. IIRC, the BB axle is 118mm...maybe 120.
__________________
Originally Posted by LAJ View Post
Everyone thinks they have had a long strange trip, until they look at other folks' journeys. Then they realize everyone has had a long strange trip, just using different modes of transportation.
"The mystery of life isn't a problem to solve, but a reality to experience."
Jadesfire is offline  
Old 12-17-17, 01:37 AM
  #10  
Lascauxcaveman 
Senior Member
 
Lascauxcaveman's Avatar
 
Join Date: Nov 2011
Location: Port Angeles, WA
Posts: 7,924

Bikes: A green one, "Ragleigh," or something.

Mentioned: 191 Post(s)
Tagged: 0 Thread(s)
Quoted: 1591 Post(s)
Liked 535 Times in 307 Posts
Originally Posted by Jadesfire View Post
Not a 1x7, but a 1x8 with a 42t chain ring. No retention system, I did just need to spend a little time getting the RD adjusted exactly right. IIRC, the BB axle is 118mm...maybe 120.
Similar to what I had to do. Chain length, spindle length, RD adjustment all had to be messed with as
I changed the bike around from 1x7 to 1x8 to 1x9.
__________________
● 1971 Grandis SL ● 1972 Lambert Grand Prix frankenbike ● 1972 Raleigh Super Course fixie ● 1973 Nishiki Semi-Pro ● 1979 Motobecane Grand Jubile ●1980 Apollo "Legnano" ● 1984 Peugeot Vagabond ● 1985 Shogun Prairie Breaker ● 1986 Merckx Super Corsa ● 1987 Schwinn Tempo ● 1988 Schwinn Voyageur ● 1989 Bottechia Team ADR replica ● 1990 Cannondale ST600 ● 1993 Technium RT600 ● 1996 Kona Lava Dome ●


Last edited by Lascauxcaveman; 12-17-17 at 01:45 AM.
Lascauxcaveman is offline  
Old 12-17-17, 06:06 AM
  #11  
jimmuller 
What??? Only 2 wheels?
 
jimmuller's Avatar
 
Join Date: Apr 2010
Location: Boston-ish, MA
Posts: 13,431

Bikes: 72 Peugeot UO-8, 82 Peugeot TH8, 87 Bianchi Brava, 76? Masi Grand Criterium, 74 Motobecane Champion Team, 86 & 77 Gazelle champion mondial, 81? Grandis, 82? Tommasini, 83 Peugeot PF10

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 1218 Post(s)
Liked 578 Times in 217 Posts
Not 1x7 but 2x8: My Tommasini has a Shimano 8-speed cassette. Chainline is problematic. In gears I tend to use a lot, rotating the crank backwards to pick up a toe clip after stopping can sometimes cause the chain to jump chain rings. The FD at least provides some control over the chain. Without the FD and the second ring I'd have to reach down and re-attach the chain manually.
__________________
Real cyclists use toe clips.
With great bikes comes great responsibility.
jimmuller
jimmuller is offline  
Old 12-17-17, 10:07 AM
  #12  
63rickert
Senior Member
 
Join Date: Dec 2013
Posts: 2,068
Mentioned: 44 Post(s)
Tagged: 0 Thread(s)
Quoted: 1087 Post(s)
Liked 326 Times in 244 Posts
The short teeth are almost certainly the problem. A very badly worn chain or sprockets, bad chainline, bad frame alignment could cause similar problems. Perfect chain and perfect alignment are not necessary, but horrible won't work.

I rode CX with 1x7, no problem. MTB with 1x8 and 1x9, no problem. For those who remember early days of offroading doubles and triples caused nasty chainsuck, chain snarls, and the chain broke frequently. Using a single stopped all that and caused no new problems.

Vintage parts work. Their default program is to just work. Modern parts work perfectly. Until you attempt to use them one micron beyond their assigned role. They do exactly what they were created to do and will not do anything else.
63rickert is offline  
Old 12-17-17, 11:03 AM
  #13  
Shinkers
Senior Member
Thread Starter
 
Join Date: Jan 2014
Location: Utah
Posts: 754

Bikes: '88 Trek 1200, '91 Trek 1400

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked 7 Times in 5 Posts
Success! I swapped my ring for a nearly new vintage ring and decided to leave the FD on. I was able to set the FD in a position so it doesn't rub anywhere yet it should still keep me from derailing. A plus is that it's a lot more stylish than a standard chain guide.


I'm stoked.
Shinkers is offline  
Old 12-17-17, 11:49 AM
  #14  
tashi
Senior Member
 
Join Date: Apr 2005
Location: Victoria
Posts: 1,321
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 75 Post(s)
Liked 36 Times in 23 Posts
Glad it's working for you, i've never had much luck on anything rougher than smooth pavement with regular rings. If you want to drop the derailleur and eliminate the possibility of dropping the chain a narrow-wide ring will work very well.
tashi is offline  
Old 12-18-17, 06:59 PM
  #15  
MarcoBianchi
Senior Member
 
MarcoBianchi's Avatar
 
Join Date: Jul 2014
Location: Saragossa. Spain
Posts: 260

Bikes: Peugeot Mont Blanc . Bianchi 28c 1980. Coppi Giro di Lombardia. Vitoria Vintage 1990. Orbea Luarca 1977. Trek 950.

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 51 Post(s)
Likes: 0
Liked 12 Times in 10 Posts
Running 1x8, 38-11/28 on my commutter with really cheap parts, Alivio RD , the key is a 15$ single speed chainring, no retention mechanism is needed.
MarcoBianchi is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ILClyde
Bicycle Mechanics
14
10-12-12 02:00 PM
aprhockey
Bicycle Mechanics
4
03-30-11 05:51 AM
Joseph Vigue
Bicycle Mechanics
5
08-14-10 09:42 PM
gzhelnin
Bicycle Mechanics
1
07-21-10 07:25 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.