blknwhtfoto

Hey guys,
Is there any reason that I shouldn't replace the limit screws on my SRAM X-7 rear der and Sora front der with allen bolts? I just want to have as much of the bike hex head as I can, because I am sick of hunting screw drivers of various sizes and shapes.
Any reason not to make the switch?
Thanks,
Mike

sykerocker 

No reason whatsoever, although I think it would be a touch of overkill. Think about it for a moment: once you have the limit screws set properly, how often do you touch them again? At which oint, does it really matter what heads are used?

As you can probably guess, the manufacturers use philips and straight head screws for cost. Probably saves them $00.005 per derailleur - which adds up over a year's production.

Grand Bois

For just a little bit more you can use stainless allen screws that won't rust. For a whole lot more you can use titanium and save a couple of grams. That would be ridiculous, but I've done it.

blknwhtfoto

I have to adjust my front derailleur a lot for some reason. Every two months, usually. The heads are getting a bit too close to stripped for my tastes as well.
I'm not too worried about weight weenie issues, I ride a SWB recumbent and while a light 'bent compared to other bents, a gram or two isn't going to kill me.
Thanks
Mike

percy484

Id be afraid the smaller allens would strip more easily... they seem to do that.

The Great Stonk

small allen key bolts are alot easier to use then screws, and wont round off as long as your using a high quality allen key.

but on the other hand a high quality screwdriver of the correct type and size wont round off a screw head either....

bkaapcke

Boy, I thought some of my upgrade ideas were overkill. Apparently I'm just an apprentice. bk

Retro Grouch 

If you find yourself adjusting your derailleur limit screws that often, you're doing something wrong. That should be a set it and forget it adjustment.

pahearn

I don't think it's a matter of overkill at all, in fact I think it's a great idea in certain circumstances. Consider this: Due to the linkage/swingarm design on my FS bike, it's damn near impossible to fit a screwdriver in to adjust one of the limit screws. If it were an Allen, the small right-angled wrench would fit in there perfectly. This is a great idea and I think I'll do just that -- thanks for the idea.

-pete

operator

Ironically it's the complete opposite. The phillips head is deisnged push the bit back before it can strip. Allen bolts on the other hand do not have this "feature".

The Great Stonk

and at the tiny ammounts of torque needed to turn the screws in question, that feature is not exactly important.

HardyWeinberg

That's interesting to hear. I've been amazed at how much tweaking my one bike takes for its derailers, and so very relieved at how little the other one requires. I guess it's kind of like how your head feels so much better when you stop whacking it with a stick.

DMF 

Yes, but the Phillips is expressly designed for machine drivers. A human driver should not strip a slot head unless the bit is fubar (and it's surprising how many are). A fubar Phillips bit will strip the head over time, too.

A clean Allen head should never strip if the key is fully seated. The problem is that an upright Allen head collects dirt and prevents the key from seating. It's a pain to clean. Same with Torx. A better replacement would be hex-head.

blknwhtfoto, a dérailleur will gradually go out of adjustment with cable stretch. That should be adjusted with the barrel adjuster or trim instead of the limit screws. The limit screws should be set-and-forget. Are you sure you're adjusting the right thing? Are both ends of the bike index-shifted?

blknwhtfoto

There is a good chance that I am adjusting the wrong thing. But, whenever I sit down to work on my bike I try to set the barrel adjuster and the problem is still there. The front derailleur I have shifts a little bit 4mm or so to either the left or the right. It is enough that when I grab a big pile of shifter, it'll derail if I don't keep it in adjustment. I am thinking that a new front der might be good. I don't think this is overkill because I would much rather have to only collect one set of good tools, rather than multiple sets for all the different heads. Also, it isn't very hard to replace a screw...I'm not doing this for weight, only that want a bike that can be worked on with a minimal tool kit, when I am out on the road, the fewer extra things the better.

top506

Great idea!
I have often replaced DR and 'B' adjustment screrws with longer ones to increase the range of adjustment, but never thought to use allen screws.
I guess I don't have to turn down any more screwheads
Top

DMF 

Do you sit on the bike while adjusting? There may be enough frame flex (especially on a 'bent) to make the difference.

operator

You should try working at a bikeshop.

MnHPVA Guy

Another good spot to replace the soft phillips heads screws with stainless socket heads is the spring tension adjusting screws on linear pull brakes. Also 4mm.