Single speed dropout conversion kits?

[mpemburn]

I have an older Trek carbon frame that I trashed by severely bending the derailleur hanger. It’s sitting in my barn, staring at me reproachfully every time I go in to get my shiny new ride. This morning, I was wondering if there was some way to convert the dropouts to accept a fixie/single speed wheel, and ran across this:

https://www.trekbikes.com/us/en_US/...s/trek-convert-hardtail-dropout-kits/p/24321/

Has anyone here done this? I have no idea at this point how this actually works, and would appreciate your input.

 

[MichaelW2]

You can get some bottom bracket assemblies with built in eccentric tensioning such as Trickstuff Exzentriker.

 

[Sharky]

If you are referring to the
Trek 2012 Ticket Single Speed Rear Dropout Kit,
then, if those bolt holes are in the right place for your frame, it must be OK.

But I can't visualise how they fit and I don't know why the left/right dropouts have different bolt holes?
Other issues might be the OLD - a track wheel will be 120mm and the trek road frame probably 130mm?
But at 63$, it seems an expensive modification.

You could use a half link chain with the existing vertical dropouts, if the bent hanger is not too bent, but this would make it tedious every time you changed the sprocket combinations.

Or if just for a SS freewheel, you coud use a chain tensioner.

Good luck

 

[ColinJ]

I also suggest using a tensioner.

I would like not to use a chain tensioner on my DIY singlespeed bike but never got round to experimenting with half-links to get the chain length right.

TBH, the tensioner works flawlessly so I'll stick with it unless I spot a bargain frame with horizontal dropouts. (It was sprung and pulled the chain down but it bumped about and rattled on rough roads, dropping the chain a couple of times. I took the spring off and modded it to lift the chain up. No problems since!)

The attentive reader may spot a second, smaller sprocket. I added that so the lock ring had something grippy to tighten against. I originally just had a pile of spacers, but the lock ring kept coming loose.

And I did clean the transmission after that picture was taken!

 

[sleuthey]

I also suggest using a tensioner.

I would like not to use a chain tensioner on my DIY singlespeed bike but never got round to experimenting with half-links to get the chain length right.

TBH, the tensioner works flawlessly so I'll stick with it unless I spot a bargain frame with horizontal dropouts. (It was sprung and pulled the chain down but it bumped about and rattled on rough roads, dropping the chain a couple of times. I took the spring off and modded it to lift the chain up. No problems since!)

View attachment 623240

The attentive reader may spot a second, smaller sprocket. I added that so the lock ring had something grippy to tighten against. I originally just had a pile of spacers, but the lock ring kept coming loose.

And I did clean the transmission after that picture was taken!

This ^^

 

[mpemburn]

I also suggest using a tensioner.

I would like not to use a chain tensioner on my DIY singlespeed bike but never got round to experimenting with half-links to get the chain length right.

TBH, the tensioner works flawlessly so I'll stick with it unless I spot a bargain frame with horizontal dropouts. (It was sprung and pulled the chain down but it bumped about and rattled on rough roads, dropping the chain a couple of times. I took the spring off and modded it to lift the chain up. No problems since!)

View attachment 623240

The attentive reader may spot a second, smaller sprocket. I added that so the lock ring had something grippy to tighten against. I originally just had a pile of spacers, but the lock ring kept coming loose.

And I did clean the transmission after that picture was taken!

Thanks, but I don’t think the damaged hanger would support the tensioner in the style to which it’s accustomed:

 

[ColinJ]

Thanks, but I don’t think the damaged hanger would support the tensioner in the style to which it’s accustomed:
View attachment 623255

I can see that there is a chunk of metal gouged out but I can't see if there aren't any cracks coming off that?

If crack-free, I'd be inclined to fit a tensioner, give it a go, and keep an eye on it for cracks developing.

There isn't a huge amount of force acting on the tensioner - it is only there to guide the chain back round the bottom of the sprocket.

 

[Sharky]

You can get chainstay chain tensioners. I've googled and found references to them. But not found any links to good examples. But if you percevere with searching, you might find one.

 

[mpemburn]

I can see that there is a chunk of metal gouged out but I can't see if there aren't any cracks coming off that?

If crack-free, I'd be inclined to fit a tensioner, give it a go, and keep an eye on it for cracks developing.

There isn't a huge amount of force acting on the tensioner - it is only there to guide the chain back round the bottom of the sprocket.

No, it’s a serious, deep crack. The hanger was bent more than 90°. I had to straighten it to get the derailleur off, but was trashed, too.

 

[ColinJ]

No, it’s a serious, deep crack. The hanger was bent more than 90°. I had to straighten it to get the derailleur off, but was trashed, too.

Oh well, an alternative plan IS required then!

Either: Find a chainstay-mounting tensioner (or make one)?

Or: Find a combination of ring size, sprocket size, and chain length that works, possibly with the help of a half-link?

I reckon that I could have just about got away with taking one pair of links out of the chain in my photo above then adding a half-link. Maybe once the chain started to lengthen with wear, remove the half-link?

 

[DCLane]

Oh well, an alternative plan IS required then!

Either: Find a chainstay-mounting tensioner (or make one)?

Or: Find a combination of ring size, sprocket size, and chain length that works, possibly with the help of a half-link?

I reckon that I could have just about got away with taking one pair of links out of the chain in my photo above then adding a half-link. Maybe once the chain started to lengthen with wear, remove the half-link?

We run a half-link chain on my son's Carlton fixie conversion. That helps in terms of getting the chainline correct without a tensioner.

 

[FrankCrank]

If it was me, I'd go for a home made chainstay tensioner. You may get lucky with a half-link, or different sprocket/chainring combo, but chains do stretch over time as we all know, so the tensioner is the best long term solution methinks