TCX SLR1 single ring conversion

milese

Sorry if this has been done before.....

I want to change to single ring, planning for 11/32 cassette with a 38t chainring.

Will convert a compact chainset with new bolts.

Superstar chainring.

Which rear mech should I go for? Dont want to spend too much, but don't want to drop the chain or carry loads of weight around.

I've heard something about the 10 speed shadow rear mech with a clutch being the best, if so any particular ones?

imposter2.0

No specific mech needed, IMO. Running a superstar narrow/wide 34 front with a standard 105 short cage mech and 12-28 here. Never dropped the chain once last season...

Pooter

I use the same set up as Imposter (105 short cage, 38 Superstar ring) and the chain doesn't come off. I use a dog chain catcher too.

trek_dan

Milese wrote:

I've heard something about the 10 speed shadow rear mech with a clutch being the best, if so any particular ones?

I don't think any 10 speed Shimano MTB mech are compatible with road shifters, only 9 speed and they are getting very hard to find now. The 9 speed Shadow mech that used to be the 'Holy Grail' for Shimano cross riders may work with 10 speed shifters though. In reality you don't 'need' a clutch mech anyway. if you run a narrow wide and have it setup properly you'll not drop the chain but depends how much chain slap your willing to tolerate over rough stuff.

roastie_cyclocross

What about the new clutched Shimano R7000 rear derailure?? Not sure if that is for sale yet, but I did hear that it was going to be compatible with 105 5800.

tgotb

trek_dan wrote:

depends how much chain slap your willing to tolerate over rough stuff.

There's another factor, which I only discovered at the end of last season, after 3-4 seasons on a single-ring setup: As your mech gets more heavily clogged, you approach a point where you back-pedal a small amount, and the spring force isn't enough to overcome friction between chain and mech cage. At this point, the mech arm is pulled forward by the tension in the lower span of chain (between mech and chainring). The upper span (between cassette and chainring) goes slack, and you're pretty much guaranteed a chain drop when you start pedalling again.
With my setup (SRAM MTB clutch mech) this requires a very badly clogged mech, which you're only likely to get in very muddy conditions if you're doing the whole race on one bike. Worth bearing in mind if your mech has a weaker spring, and you suddenly start getting unexplained chain drops; I dropped mine 5-6 times in 2 laps, despite zero drops in the previous 80-odd races...

trek_dan

TGOTB wrote:

trek_dan wrote:

depends how much chain slap your willing to tolerate over rough stuff.

There's another factor, which I only discovered at the end of last season, after 3-4 seasons on a single-ring setup: As your mech gets more heavily clogged, you approach a point where you back-pedal a small amount, and the spring force isn't enough to overcome friction between chain and mech cage. At this point, the mech arm is pulled forward by the tension in the lower span of chain (between mech and chainring). The upper span (between cassette and chainring) goes slack, and you're pretty much guaranteed a chain drop when you start pedalling again.
With my setup (SRAM MTB clutch mech) this requires a very badly clogged mech, which you're only likely to get in very muddy conditions if you're doing the whole race on one bike. Worth bearing in mind if your mech has a weaker spring, and you suddenly start getting unexplained chain drops; I dropped mine 5-6 times in 2 laps, despite zero drops in the previous 80-odd races...

Yep once you add a bit of mud cloggage into the equation its very easy for chain slap to become chain jam and chain drop.