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Was riding at the weekend and found that my left hand gear shifter was hanging by the cable. The I-spec B bolt had dropped out and left it dangling close to the spokes of my front wheel.
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The bolt that fell out is like the one one right with the loctite on it. I've replaced it with one like the bolt in the middle. On the one that fell out there is a bit near the end of the bolt with no thread on it.
My question is what does the bit with no thread on it do? Everything seems fine with one I've replaced it with - the shifter is fastened firmly to the clamp. Should I shell out for a proper replacement or will the one I've used be OK?
Presumably you would do only the 2 threads in an have a bit of wiggle room during assembly? Can't be for "weight optimization", otherwise they would have made it shorter to begin with.
Same issue a few weeks ago! Despite being assembled with loctite I lost the same bolt. I've also replaced it with an appropriate length button head with no apparent loss of function.
I assumed the flat length of shank was for a grub screw or locking screw to mate with but my i-spec B didn't have that. Maybe it's a feature from i-spec A?
Can anyone confirm?
I think (cant remember exactly) the initial thread is there to catch the shifter so if the bolt comes undone it doesnt just drop out, clearly not working or you were all riding around with a rattly shifter and didnt realise!?
1st rattly descent of the day (parkamoor off grizedale) and it dropped out! My LH shifter is connected to my KS Lev. It may have been loose and it wouldn't have affected the function.
I'd been making shifts with mine up to the point it fell off and didn't notice anything amiss!
I did suspect that it was there to catch the shifter but wondered if it was serving any other purpose that I wasn't aware of.
Shimano seem to design most stuff so it cant just fall off, brake levers have catches, calipers have bolts with retention clips or wire etc.
Shimano seem to design most stuff so it cant just fall off, brake levers have catches, calipers have bolts with retention clips or wire etc.
Yeah, the only sensible reason for having a flat surface on the shank would be for a locking screw. Otherwise you've made a simple bolt much more expensive for no good reason.