Mtb issues

[nickg]

Right, I bought a 2nd hand cube mtb last week. Not had a real chance to ride it until today. A couple of issues I've noticed

1 - what tyre pressures to do run a 27.5 wheel at?

2 - Hydraulic disc brakes- was on a downhill section and got a bit carried away, applied the rear brake and it was not very sharpe at all and a loud vibrational squeal come from the brake disc. The pads have a fair bit of friction material left on them. Now I dont know when it was last used so is it possible the pads have glazed over causing this and they just need a good clean up including a bit of roughing up? Do the brakes need bleeding?

Any help would be great.

 

[iluvmybike]

1 - The tyre pressure min & max will be on sidewall. Assuming you are running with inner tubes you may need to adjust pressure up/down within that range depending on your wieght and/or terrain - so if it is muddy and you want more grip - lower pressure. If running tubeless then pressures can be lower. Pressure required may well change if you change tyres.
2 - Probably contaminated pads. Fit new ones and problem will likely go away. You do not need to bleed a brake as a matter of routine - only if there is air gotten into the system.

 

[figbat]

As above really. Tyre pressure is a matter of many factors - the tyre design, the usage, tubes/tubeless, personal preference and so on. I tend to run mine harder than typical as I prefer the feel I get and can deal with the inevitable trade-off in comfort. Don't run harder than the maximum on the sidewall and don't run so soft the wheel rim hits the ground. Maybe next time out you can have a play with the pressures and see what you prefer - start hard, ride a bit, let some air out, ride a bit more and so on. Have a pump with you in case you let too much out or decide you prefer it harder (double entendre not intended but also not avoided).

Brakes - yeah, probably the pads are contaminated. You may be able to burn it off with some long, hard braking but this has limited success. It's possible the pads are contaminated with something external - polish, chain lube etc in which case replace and enjoy. Or it may be that they have brake fluid on them, meaning the caliper may be leaking. This is far less likely though.

 

[nickg]

Thank you for your responses. I will get some pads on order now. Any pads that are a must have or stay away from?

Also thinking about going tubless but I need to look into that. I will have a play with the pressures and see how I get on.

Also, where do you carry your kit? Like patches, spare inner tubes while out on a ride? I've got a saddle bag but it dont fit as the rails are to far apart for the bracket to clamp to so looking for other options.

 

[nickg]

How do I know what pads I need? Just looked at my levers and calipers and all it says is Shimano.

 

[iluvmybike]

Pads are much of muchness in terms of quality really. Make sure you get thr right ones for your brake though - best to remove one and check it out against a piccy - there are lots of different ones. If in doubt take to yuor LBS. EBC, Superstars, Disco, Clarks are some of regular brands to use.
if you are considering tubeless then you'll be looking at new tubeless ready tyres and possibly new tubeless ready rims plus tapes/sealant. Don't try a 'ghetto' job - liable to go wrong. Do it properly if you are going to.
Carrying spares - get a different saddlebag or many have a small mtb backpack instead like the camelbak - which also have a hydration pouch

 

[iluvmybike]

Pad identifier here for superstars pads https://www.superstarcomponents.com/library/pdf/BrakePadIdentifiier.pdf

 

[nickg]

I've just found Br-355 on the back of the caliper. But just search this and nothing comes up.

 

[iluvmybike]

You didn't do a proper search! This show your brake:
https://bike.shimano.com/en-EU/product/component/shimano/BR-M355.html
and this here shows you the pad:
https://ebcbrakesdirect.com/mountain-bike/shimano/br-m355/10000181

 

[Yellow Saddle]

How do I know what pads I need? Just looked at my levers and calipers and all it says is Shimano.

There are two categories of pads. Sintered metal and resin.

The discs themselves determine what pads can be used. Some discs will say "Resin Pads Only." That's pretty self-explanatory.
The rest don't say anything, meaning that both resin and metal pads can be used on them. However, once a resin pad has been used on a disc, you can't switch to metal and vice versa, without a huge amount of noise and vibration coming from them. That's because pads transfer a layer of pad material to the disc and it thus knows what's what.

Plenty has been written about that here, do a search. It will explain why, how and when.

 

[nickg]

You didn't do a proper search! This show your brake:
https://bike.shimano.com/en-EU/product/component/shimano/BR-M355.html
and this here shows you the pad:
https://ebcbrakesdirect.com/mountain-bike/shimano/br-m355/10000181

I search it on google nothing else.

 

[Gunk]

Also, where do you carry your kit? Like patches, spare inner tubes while out on a ride? I've got a saddle bag but it dont fit as the rails are to far apart for the bracket to clamp to so looking for other options.

We just use the small saddle bags which secure under the seat using Velcro straps, there’s room for patches etc, levers and some Allen keys, I also usually slide a small pump down the side of the bag.