Double fixed hubs.
#1
Senior Member
Thread Starter
Join Date: Apr 2007
Posts: 186
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Double fixed hubs.
It seems like a comical idea because even if you flip your wheel over to a different size cog, you will have too much or too little chain to run the other side, so whats the point. Or perhaps I am missing something here?
#3
:)
Join Date: Nov 2006
Location: duluth
Posts: 3,391
Bikes: '07 Pista, '09 Fantom Cross Uno, '8? Miyata, '67 Stingray, '0? Zoo mod trials, Tallbike, Chopper, '73 Schwinn Collegiate, '67 Triumph Chopper, '69 CB350, '58 BSA Spitfire, '73 CB450
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
The whole point is that you can run more than one ratio by flipping.
Or, bugger up the threads on one side and not have to buy a new hub.
Or, bugger up the threads on one side and not have to buy a new hub.
#4
FNG
Join Date: Nov 2007
Location: Toronto, ON
Posts: 2,313
Bikes: 2008 IRO Angus, 2008 Jamis Exile 29er
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
If you keep it within 1-2 teeth, you shouldn't have any problems. I have 16t and 17t on mine.
#6
Senior Member
Join Date: Jun 2007
Location: four 1 OHHH , Maryland
Posts: 2,849
Bikes: nagasawa, fuji track pro
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
ride to the velodrome on 48/17 then flip the wheel around and ride 48/14
#7
Senior Member
Join Date: Aug 2008
Location: SoCal
Posts: 2,694
Bikes: A few BSO's.
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 164 Post(s)
Likes: 0
Liked 55 Times
in
27 Posts
Exactly. 14t and 15t for me. Ride hard one day on the flats and the next ya wanna make it easier or it might be really windy, just flip it and make it easier. No chain problems for me. Of course if you are at the end of the track end with the bigger cog and flip it then it might be a problem.
#8
Senior Member
Join Date: Aug 2006
Location: Toronto
Posts: 1,779
Bikes: Leader 735TR 09 58cm 46/17
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Track ends allow you to move the wheel back or forth for good chain tension. So if the cogs are within 2 or so teeth, you will be able to get correct tension with no problem.
#10
Senior Member
Join Date: Jul 2006
Location: Columbus, OH
Posts: 11,375
Bikes: '08 Surly Cross-Check, 2011 Redline Conquest Pro, 2012 Spesh FSR Comp EVO, 2015 Trek Domane 6.2 disc
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 7 Times
in
6 Posts
Also gives you the most versatility for a flip-flop since you can run a freewheel or a fixed cog on either side. (Sure, you can run a fixed cog on both sides of a fixed/free hub, but you're sans lockring on one side.)
#11
Senior Member
#13
Senior Member
Join Date: Jun 2007
Location: four 1 OHHH , Maryland
Posts: 2,849
Bikes: nagasawa, fuji track pro
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
#15
bike bike bike
Join Date: May 2007
Location: philly
Posts: 241
Bikes: eai bareknuckle, cayne uno beater, raleigh sprite 27 conversion
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
yeah i run a 17t on the street and a 15t on the track with no need for additional/fewer chain links
#16
antisocialite
Join Date: Apr 2006
Posts: 3,385
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
if you show up as a new track racer and you don't have a lockring on your hub, i'd advise keeping your mouth shut about it.
as to what does and does not fit, let's be quantitative about it.
1 tooth on a cog engages 1/2 link of a chain or 1/2 inch of chain. but the chain only wraps around half the cog, so 1 less tooth on the cog means 1/4 inch of extra chain.
that extra 1/4 inch, though, is shared between the sections of chain above and below the chainstay, so the axle only moves 1/8 inch back in the dropout.
the axle is about .4 in thick, so if your dropouts are 1.4 inches long you can theoretically deal with an 8 tooth difference. in practice you have to account for space for the track nuts to grip and things don't always line up as you'd like them to, but a 4 tooth spread is usually no problem.
just remember that if you have a rear brake it'll probably not line up and may rub the tire or spokes because the rim's position will have changed along with the axle.
as to what does and does not fit, let's be quantitative about it.
1 tooth on a cog engages 1/2 link of a chain or 1/2 inch of chain. but the chain only wraps around half the cog, so 1 less tooth on the cog means 1/4 inch of extra chain.
that extra 1/4 inch, though, is shared between the sections of chain above and below the chainstay, so the axle only moves 1/8 inch back in the dropout.
the axle is about .4 in thick, so if your dropouts are 1.4 inches long you can theoretically deal with an 8 tooth difference. in practice you have to account for space for the track nuts to grip and things don't always line up as you'd like them to, but a 4 tooth spread is usually no problem.
just remember that if you have a rear brake it'll probably not line up and may rub the tire or spokes because the rim's position will have changed along with the axle.
#17
mechanically sound
Fixed/free flip flop hubs are a foolish buy IMO seeing as how you can run a freewheel on the fixed threads.
#18
Senior Member
Join Date: Apr 2007
Posts: 562
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 5 Times
in
4 Posts
I beg to differ. A fixed/fixed hub will yield the greatest versatility as one could use 2 fixed cogs, 2 freewheels, or a fixed cog and freewheel. From what I understand, the few threads not utilized by a freewheel on the 'fixed' side aren't a problem.
#20
Senior Member
Join Date: Jul 2008
Location: Seattle, WA
Posts: 71
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
A fixed/fixed will also allow all those combination, and you will be able to have a lockring for your fixed cogs. Fixed/free, if you run double fixed cogs, one side won't have a lockring.
Last edited by Plecks; 01-27-09 at 11:06 PM.
#21
shaken, not stirred.
Join Date: Aug 2006
Location: The Shaky Isles.
Posts: 5,250
Bikes: I've lost count.
Mentioned: 40 Post(s)
Tagged: 1 Thread(s)
Quoted: 1412 Post(s)
Liked 971 Times
in
390 Posts
I like the double fixed hub. 15t for flats and low wind conditions or 14t for towing a trailer or strong headwinds.
Provided you're not running a "magic ratio" on a bike with vertical dropouts there should be enough room to swap one side or the other without chain problems.
Provided you're not running a "magic ratio" on a bike with vertical dropouts there should be enough room to swap one side or the other without chain problems.
__________________
Get a bicycle. You will not regret it if you live. ~Mark Twain, "Taming the Bicycle"
vBulletin: snafu
#22
∞mpg
Join Date: Jul 2008
Location: Austin via Houston
Posts: 172
Bikes: Nishiki Riviera GT and a Sparton
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Croscoe is talking about fixed/fixed.
And Plecks, it is ill advised to run fixed on the freewheel side. No threads at all for a lockring so too much back pressure and you've got yourself a mess of trouble.
And Plecks, it is ill advised to run fixed on the freewheel side. No threads at all for a lockring so too much back pressure and you've got yourself a mess of trouble.
#23
Senior Member
Join Date: Jul 2008
Location: Seattle, WA
Posts: 71
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
#24
Senior Member
Join Date: Oct 2008
Location: Fremont, CA
Posts: 211
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I love my Shimano DA fixed/fixed, merely because of the security if I accidentally strip the threads on one side. But I rarely keep a cog on the non-drive side because of the added rotational weight.