Single up front, gears at rear

@sparky, that's fairly common. Mech hangers are separate from frames for a reason! :) What kind of frame is it? Most bike shops keep a fairly good stock of mech hangers, should be dead easy to get a replacement. Word of warning - you do need to get the right one though, otherwise it'll snap again really easily.

I'd love one to build up one of those, might build one for when i'm back in Ireland, i'm guessing off-road frames with track ends or horizontal dropouts are pretty rare? Chain tensioners spoil the look of SS MTBs for me.

Here

https://www.londonfgss.com/thread11107.html

@sparky, that's fairly common. Mech hangers are separate from frames for a reason! :) What kind of frame is it? Most bike shops keep a fairly good stock of mech hangers, should be dead easy to get a replacement. Word of warning - you do need to get the right one though, otherwise it'll snap again really easily.

Was a Kona, but 'twas rented. Really need to bulid a mountain bike, but I have cash for just one bike and want a new road bike. I'll um and ah for a few weeks and then choose.

Thetford Forest, Monday....

bent/snapped, its all semantics! :P

how'd you do it?

I stacked it a couple of times during the day, which may have weakened it, but it was shifting fine. Then I was coming up a climb and something went bang, looked down and my derailleur was scraping up the mud...

The best thing to get if you want to do this is the MRP device designed for this very thing...

I can't remember what it's called, but I've been running it on my Cotic Soul for about 1,000 miles and the chain has never dropped (including some trips to Afan and an Alps trip).

Recommended.

i.e. http://www.chainreactioncycles.com/Models.aspx?ModelID=1477

this is the one reference in the article.

http://www.chainreactioncycles.com/Models.aspx?ModelID=40904

yep, the bottom one of those... although I now think they also have one that is seat tube mounted. By the way, Velo libre, are you from KCL?

any opinions on the almost identical Sturmey:
http://www.sjscycles.co.uk/src/froogle/product-Sturmey-Archer-Sturmey-Archer-8-Speed-Aluminium-Hub-with-Attachment-to-Accept-Disc-Brake-X-RK8--36-Hole-19025.htm

i like the fact its ISO rather than centre lock too....
and SA is king of internals.

Its a while since I was reading up on these, but I seem to the SA to be a pretty solid hub gear. Its like 300g heavier then the Alfine though :(

Nahh.. you want a rohloff! :P £1100 for the hub unit, alone. Supposedly indestructible though!

Well yes.
But I dont really need the extra range, weight, and cost. As it'd be off-road, unloaded only really.

I used to run a single chainring up front and gears at the rear, still do on my klein MTB.

If you keep the rear range quite small (I use 5 cogs - just split up a standard 9 speed) then there are no problems with dropping the chain because of a bad chain-line.

Also use a chainring with long teeth (TA etc) - not a chainring with shallow profiled teeth/drop pins (Shimano etc) - which really really really helps stop dropping the chain.

• Keep the tension on your rear mech pretty high.
  
  
  

I used to run a home made chain-guide a few years back, but going down to 1x5 and with a chainring with long teeth I was able to dump it . . . . might have it lying around somewhere . . .

If you keep the rear range quite small (I use 5 cogs - just split up a standard 9 speed) then there are no problems with dropping the chain because of a bad chain-line.

Also use a chainring with long teeth (TA etc) - not a chainring with shallow profiled teeth/drop pins (Shimano etc) - which really really really helps stop dropping the chain.

• Keep the tension on your rear mech pretty high.
  
  
  
  
  
  
  

+1

any opinions on the almost identical Sturmey:
http://www.sjscycles.co.uk/src/froogle/product-Sturmey-Archer-Sturmey-Archer-8-Speed-Aluminium-Hub-with-Attachment-to-Accept-Disc-Brake-X-RK8--36-Hole-19025.htm

i like the fact its ISO rather than centre lock too....
and SA is king of internals.

Note that direct drive is gear 5 on the Alfine, but gear 1 on the Sturmey Archer hub - all the other gears gear up. This is great for bikes with small wheels (you no longer need insanely large chain-rings), but less appealing for bikes with sensible size wheels (pick sprockets and chainrings to give similar gear ranges and the SA hub will see a higher input torque than the Alfine, probably making life harder for the hub).

(Irrelevantly, he Alfine is a 2x4 speed hub, the SA is a 2x2x2 speed hub.)