Cycling UK Forum

Gattonero wrote:

cycleruk wrote:I like the idea of swapping the screws for socket heads. So what size would I need and are there any drawbacks.?

You can swap the screws, IIRC the Shimano RD does use M4x12 but you better use 15mm to leave more room for the head.
The drawback is that you will have a 3 or 2.5mm allen key head, both are not the best when dealing with a rusty or stuck screw. Though you can chase the thread and use some very light threadlock, I'd use a Torx head which is far more robust and won't round off, but you have to carry another tool which is likely to be a T20 and that is not used in common multitools

landsurfer wrote:

Spinners wrote:

landsurfer wrote:Seriously .... what screwdriver ? ..... your doomed ......

Not really. I've fettled my own bikes for 26 years now but I changed my chainset last night and when adjusting the front mech I realised that what I was using wasn't quite an exact fit.

Thanks again to those who have made a positive contribution and not a derogatory one albeit with a smiley face.

After 40 years as an engineer i can tell the difference between real need and OCD behaviour ...
It's a screw ... Turn it ......
Exact fit cross point, kitchen knife, what does it matter as long as it works !!!!!!!



"Oh no ... my LEJOG is over ... I haven't got the right screwdriver to adjust the derailleur " ....

Perspective .....
ETP

keyboardmonkey wrote:As SamuelD writes, such Japanese Industrial Standards are reported as no longer being 'standard', but my relatively modern 9sp M772 and 10spd 6700 rear derailleurs have the tell tale single dimple on the head of each limit screw. More on this, which I have to confess is fairly recent news to me, too...

http://www.bikeradar.com/gear/article/t ... ove-45914/

Samuel D wrote:I think it’s technically a JIS #2, and I furthermore think the whole JIS screwdriver sizing system is basically obsolete, with screwdrivers unavailable.

There are a few independent retailers in the UK who sell them, mainly for motor bike fans, but Amazon.co.uk will sell you them, too. Search for 'Vessel screwdriver', especially if you've rounded off a limit screw or don't want to. Not cheap, though.

The utility cyclist wrote:

Brucey wrote:SRAM rollers are routinely a slacker fit and they also wear faster than some other makes too. I find that SRAM chains often run a bit more noisily than some other makes well before they are worn out. There are also significant differences in 10s and 11s chains between manufacturers which don't apply in the same way with (say) 9s chains. I can't say that I've completely got to the bottom of it yet but lets put it this way, it may not just be your imagination that the SRAM chain wasn't as good as the shimano one.

The main functional differences between 10s cassettes are price, finish, and weight. Since the cassette wears (as in 'wears badly') when the chain elongates, I'd sooner have a cheap cassette with a posh chain than a posh cassette with a cheap chain, if that is the choice.

cheers

Given your previous comment on weight difference of 80g for brake calipers I'm suprised you are suggesting the heavier component is advisable, isn't that more than a bit hypocritical?

I've run a PC1030 chain on my commuter with a Tiagra cassette (because I don't worry about a few grams on a non compeition bike unlike some posters) used and abused with a couple of removals for cleaning I got about 5000 miles before replacing it though could have gone on. It was also very quiet with my set up and superb shifting with a Tiagra 9 speed long cage. Clearly some people have differing experiences with similar bits of kit.

currently using a 6700 shimano chain because it cost me £7 as it'd been delinked too short for the original user and I got it new for cheaps because of that, IME it's no better than the SRAM but no worse either, longevity wise I haven't noticed much if any differential over the years.
I've bought three more SRAM 10 speed chains in any case.
for commuter/touring duties Tiagra, even lower is fine.

fausto99 wrote:

Gattonero wrote:So how does it fit? Do you really have radial play with new cups? Sorry I may have missed something

All I can say about the fit is pretty much as per my page two posts. I don't have the frame atm, so I can only test by slipping the bearing on and off the shaft and sliding them around and trying to rock them. I can't feel any radial play apart, from over the central, undersized part of the shaft. I can rock both the new and old bearings in their approximate "correct" shaft location, the old bearing slightly more, but I'm not sure this is a meaningful test, out of the frame.

Brucey wrote:the bearings do need a little preload via the end cap. A few tens of kg (as produced by a torque of ~1Nm or so) would be plenty, I would have said. The most common fault is that the preload is too high rather than too low.

It occurs to me that if the designers were very cunning indeed, the plastic top hats could be made in such a way that when the preload is applied, the top hat nips up more onto the BB spindle. I have no idea if this is the case or not but I wouldn't dismiss this as a possibility.

BTW I have seen quite a few worn spindles and they often look as if the spindle has been rotating wholesale within the top hat. Maybe some have been. However I think that it usually just looks that way; if the spindle moves via precession instead, (which I think is more likely to happen) maybe the marks can look very similar.

cheers

fausto99 wrote:Pictures of the old cleaned up bearings below don't seem to show any significant difference between the drive non-drive side.


non-drive side

drive side


However, there clearly has been rotation of the shaft with respect to the inner of the non-drive side bearing; the shaft is polished where there are no black marks. So, why do Shimano use (soft) plastic on the i.d. of the bearings? Why not something grippier? Why has the same thing not happened on the chainwheel side? How does this occur? I could understand if the bearing was dirty or seized, but if it is still rotating freely why would the shaft rotate in the plastic, in preference to the bearing itself?

As I do not possess inside and outside micrometers and it would be difficult to get to the chainwheel side, I have measured as best I can with digital calipers. I have also tried test fitting of new and old bearings to the shaft. The shaft is at most 1 thou smaller id on the non-drive side compared to the drive side. The shaft is more like 5 thou smaller od for the whole of the middle portion. I can't feel any play on the drive side. I can feel play on the non-drive side which is slightly worse with the old bearing.

I think it would be wastful to scrap the crankset which has such little measurable wear. My current plan would be to use new bearings and dribble in some Loctite 222 into the non-drive side just before the final preload and assembly.