Current Projects chat and miscellany

Anyone know how I can tell if I have a short or medium cage 5800 RD?

Measure the distance between the centres of the two pulleys. Short cage is something like 55-60mm, medium is more like 80-85mm

if it will take 11-32?

According to Shimano, no RD-5800 will work with 11-32. The RD-5800-SS (short) will do up to 28T but only with a 12T top sprocket, likewise the RD-5800-GS (medium) will do up to 32T but again only with a 12T top. Confusingly, the total capacity of the GS is listed as 37T alongside a maximum front difference of 16T, so they somehow expect you to make 32-12=21 :-) Realistically, the GS will be fine with 52-36/11-32, but the shift into top gear might not be up to Shimano's snappy standards as the B-tension will pull the upper pulley about 0.1mm further away from the sprocket than is ideal.

Shimano have subtly different methods for setting chain length according to how big your bottom sprocket is, and the user manuals are completely fucking hopeless these days, they no longer trust end users with anything more complicated than phoning their LBS, so you have to download the dealer manual.

Compact 5800 crankset is £69.99 btw.

Thanks, massive help. Do I still need the right size bearings though? Or can I just cram more small ones in?

@mdcc_tester thanks for the info, that sounds incredibly complex! I see now that they used to stamp the derailleur with the capacity, that makes way more sense.

@amey cheers for that too - hadn't thought of going that route instead

Do I still need the right size bearings though?

Yes, that's absolutely critical. The curvature of the cup and cone races is cut to match only one size of bearing ball. If you use the wrong (too small) size, the contact pressure will destroy the races in no time at all.

Compact 5800 crankset is £69.99

He already has 36T, the compact only drops his bottom gear by 5.5%, whereas swapping from a 28T bottom sprocket to a 32T gives a 12.5% drop in bottom gear.

Anybody know what spindle length of shimano un55 bb I need to buy to get proper chainline on italian threaded bb shell? Miche primato crankset. Thanks

What crankset?

That depends on the crankset you are planning to use.

When Le Manfriend destroys the alu cup on the bottom bracket by sheer ignorant force

I guess that's sorta #boastpost but that means I'm off to CRC...again! ;)

CP related - does anyone in London have a 27.0 inline seat post I can grab off them?

I'm pretty sure I have one at home and I will be in London tomorrow night if thats any good to you?

Its just a cheap brand x thing off chain reaction

Oh yeah miche primato it is. ;p

do you have a track or road frame?

It's a trap.

You should use an ISO taper bb, not a JIS Shimano bb.

Campag make one in 110mm, Token and Tifosi brand one in 111, both are fine for a normal track hub.

newer miche primato cranks have jis taper

track, I guess 42mm chainline is what I'm looking for

i would suggest 70x113mm bottom bracket.

Just changed the crankset for a nearly brand nex suntour superbe pro NJS. Waiting for a chain tool to put the black and gold izumi's on it.

Any suggestions welcomed !

In that case I'd go with the recommended 107 or 110mm.

That would be amazing - I'll pm you.

This is hot.

Anyone got a low stack Italian threaded headset?

According to Sheldon Italian and English headsets are interchangeable. Is this true?
Paging @mdcc_tester

Thank you, is there some things you'd change ?
I plan to change these tyres for tubular vittoria evo sc