the 'there's no such thing as a stupid question' bike maintenance thread

I know it is unrelated to bike maintenance, but since the chat is about using heat guns. Would anyone know any that would be good enough to work on a driveway gate hinge? I’ve been applying wd40 and got it freed a very slight bit....moves slightly with every sledge hammer hit now!

cletus wrote: »

I can't see a heat gun working, you'd want a torch. Normally though, heat is applied to try an loosen fasteners etc. Parts heating up mean differential expansion.

Once they cool down, though, you're back to square one. Heat is often used to create a friction fit. I'm not sure it will work on a hinge

Thank you. Always someone with good knowledge in the cycling forum

Joey Joe-Joe Jr wrote: »

I’m having trouble with a stainless steel stem stuck in a steel steerer tube. Everything I’ve seen online so far seems to be about aluminium stems getting stuck in steel steerer and there are some chemical solutions to that but not sure what to do to try and unstick steel on steel. I’ve tried wd-40 but no joy.
I’m actually not 100% sure if the wedge is loose. I’ve unscrew the bolt and given it a few solid whacks.
Any miracle fixes out there?

First make sure the wedge is loose. Then you might need a mechanical advantage. Do you have a bench vice?

I was afraid to remove the bolt completely. I thought if the wedge dropped, but I still can’t get the stem loose, I’d have trouble getting it back on. I’ll probably give it a go.

Might be able get access to a mates bench vice but
I have a secondary issue with leverage. The stem is a two part, stainless shaft but with an aluminium top piece(where the bars go through. Under extreme force the top piece rotates on the shaft.
I’ll have another go tomorrow and take some photos if I’ve no joy.

two wheels good wrote: »

I not sure WD40 is any good as a releasing fluid. It's just readily available.
Better to find a dedicated releasing fluid - any well known brand. PlusGas is great but pricey. 3-in-1 or brands from a motorbike shop.

I opt for GT85 as a budget alternative to WD for general use.

Thanks for that, there’s a motorbike shop down the road from me, they might have a good penetrating fluid. ðŸ‘

GT85 is definitely way longer lasting judging by the smell anyway.

Joey Joe-Joe Jr wrote: »

OK - so the wedge hadn't released but it is definitely free now. Unfortunately the stem refuses to budge. As I mentioned, the secondary problem is that the stem is a two piece, and the top (aluminium) piece is rotating on the shaft (stainless).
I have no idea how these are actually connected, but it is leading me to think that I'm going to need to saw off the stem and try cut it free using a jab saw. Anyone got any experience with that, is the stem likely to come away cleanly from the steerer or will it be a mess?
Does anyone know how these two part stems are connected are connected together? Is it a compression fit of are they glued or something?

Don't cut anything off yet.

Do you have access to a bench vice? If you do, take off the front wheel, and turn the frame upsidedown, clamping the stem in the vice (soft jaws here, if you have them).

Then get a piece of 4x2, put it between the forks, and use it as a lever for mechanical advantage. Go slowly, you don't want to twist the forks out of shape, but they can take a bit of force. If you can apply heat to where the stem sits into the fork, that would help as well

Joey Joe-Joe Jr wrote: »

Awww!! But I'm all fired up to use my new hacksaw!!!!

Seriously though, thanks for the advice. A mate has a bench vice I can use, so i'll try that later.
Still a bit concerned that the top part of the stem moves on the shaft though.
Now it does take a fair amount of force so wouldn't be likely to happen mid cycle, but I am curious as to how they are fixed together.

There's a good chance the stem bolt passes through both sections of the stem, and into the wedge. Once it's tight, the top piece is unlikely to move

Joey Joe-Joe Jr wrote: »

You’re absolutely right. :-)

Does that mean you got it out?

keane2097 wrote: »

Thanks everyone, some more stuff to try there. I'll let ye know how I get on.

Cranks now off - all it took was someone stronger to have a go

cletus wrote: »

Good stuff. What did they end up doing?

Eating an extra Weetabix.

My rear disc brake is constantly losing pressure every few hundred km. It's a Shimano RS505. I've had it bled and it works perfectly for a while, but then goes back to the brake lever hitting the handlebar if you pull on the brake hard. Odd thing is the front brake has never been touched in thousands of km, the rear brake has always given trouble.

I've taken it to a good mechanic to see if there was anything loose or something wrong with my bleeding method but he did a new bleed and didn't find anything wrong, worked perfectly but less than 500km in and it's gone again. I can't find any loose connections - would a new hose potentially solve it?

Thanks for all the suggestions folks. Turned it upside down and filled the steerer with WD-40 “specialist fast release penetrant”, left it sit for most of the day.
Then across to my mates bench vice... much twisting, hammering, heating, swearing and finally it came free.
The only downside was that we didn’t have soft jaws, and the various cloths and duck tape attempts wouldn’t bite the stem hard enough, so ended up scratching it quite a bit. Still, delighted to have gotten it out.

SA Axles are 13/32" diameter with 26TPI (threads per inch) so basically, the threads are unique to SA.

If you fall across two sizes in a manufacturer's recommendation, it can come down to your bodily proportions, as well as your overall height.

If you have a long back and relatively short limbs, you might consider the bigger size, as you might feel you're too far forward over the bars (smaller frame may feel too short, saddle-to-bars, and bars may feel too low), but if you are relatively proportional, or have longer limbs than torso, then the smaller size is probably better. 183 and 85 sounds fairly proportional, so the Medium may well be fine, but a red flag might be if you feel that the front end is a bit low/short, which might not be confidence-inspiring on gravelly descents (but which might be fine on a road bike).

Given that you'll be at the edge of either size, be prepared to move things (saddle, bars, stem) about a bit and maybe flip/change the stem, etc.