The MTB thread

[Jayneflakes]

Originally Posted by yorkie_chris

There's brand new shimano deore stuff, hollowtech 2 for £55 including bottom bracket and everything I need. Some sort of splined drive this, any good?

Pretty good, but ugly to look at.

Originally Posted by yorkie_chris

a mate of mine has some SR suntour stuff in square drive for £20. Worth scrap value or what? (I'd also need a bottom bracket at £15)

Suntour SR is cheap and as new from the shop will cost between £15 and £30 depending on the model.
Old Suntour such as the XC Pro MD I have on my MTB is fantastic. Fifteen years old and I have only had to replace the middle ring.

Originally Posted by yorkie_chris

has anyone used ISIS drive? Anyone know where and how much a half decent bottom bracket is for that?

Isis is good stuff and not compatible with Shimano bottom brackets, however a good Truvative unit will only be about £25.

Working in a bike shop I see a lot of these bits. Every day a Suntour SR unit fails, yet in the ten months I have been working here I have seen only one ISIS and one Shimano fail.

Originally Posted by Jayneflakes

Isis is good stuff and not compatible with Shimano bottom brackets, however a good Truvative unit will only be about £25.

Working in a bike shop I see a lot of these bits. Every day a Suntour SR unit fails, yet in the ten months I have been working here I have seen only one ISIS and one Shimano fail.

Are you for real????

ISIS is the worst of all the bottom brackets going!

All the big drivetrain companies tried to copy Shimanos 8 Spline Octalink by producing the ISIS 10 spline, it was a design flaw from say one as the bearings was too small and wear out too quickly. Average life of a ISIS BB thats used on a regular basis is only 6months, i've seen the £70 FSA Ceramic jobbies wear out in 3 months.

Square Taper is ok for bearing life but if you abuse your bikes/ride hard then the actual square taper axle is prone to snapping/wearing.

HollowTech II / X-Type/ External bottom brackets have 30% larger bearings than conventional internal BB's and the design allows the axle to be bonded onto one of the crank arms allowing an overal stiffer set-up. Bottom brackets still wear out but not as bad as ISIS.

Octalink is shimano's brainchild and i think is by far the best even by todays standards. I've got an old XT Octalink BB in the garage that had sh!te loads of miles and hammer and is still buttery smooth. Just a shame they have superceeded it with the HollowTech II.

[Jayneflakes]

Originally Posted by Girth

Are you for real????

ISIS is the worst of all the bottom brackets going!

Chill man, seriously, the only ISIS unit I have seen fail was on a Kona jump bike that came in just over three weeks ago. For general riding it works as well as similarly priced Shimano and Suntour SR. However if your experience is different, then this debate has been worth while for sharing that experience.

I do agree with your comment on square taper cranks not taking serious abuse, but have only seen a Titanium Axel snap (fitted to a GT Zaskar in the late 90's), never a steel one.

I stand by my comment on Shimano stuff being ugly though. Some of it may be strong, but the inherent designed obsolescence that comes into play after a few years puts me off some Shimano gear components too. (and don't get me started on Sram. I had to order Rubbers for my still funtionally perfect X-Rays from America!) I have too many bikes I fear.

For my use though, I have had the same Square taper cranks (Suntour XC Pro MD1993 vintage I think) on my mountain bikes (currently a Giant XtC Team Edition) since 1998 and only stopped riding regularly last November. As I have changed frames I have kept some components because they are so well made. Shimano UN71 sealed bottom bracket, Hope Hubs and disks and Shimano Deore DX thumb shifters running an 8 speed Shimano Deore rear cluster. I change my chain after six months or 500 miles which ever comes first and have replaced the Casette once and the middle chain ring once.

Just in case you are wondering what my use of my bike was, I was a mountain bike instructor and leader for many years and trained hard on my road bike so that I could try and compete with the guys when I was out. Got to the point when the boys had to train to keep up with me for a while. Yet that was all so long ago now... I miss my mountain bike so much, even though it is currently only fifteen feet from where I am sat.

[northwind]

Originally Posted by Girth

ISIS is the worst of all the bottom brackets going!

No no no, that honour can only belong to the mighty POWERSPLINE! So bad, that when the one on my spare bike finally wears out (it's on its last legs after maybe 500 miles tops), I won't buy another, I'll replace the entire damn crankset with something that doesn't just suck. Some 90s-tech square taper number most likely, it's bendy but at least it turns.

[yorkie_chris]

Seen loads of whinging on the net about those. Are they just another propreitary type of shaft then?

What I don't get is when people are saying the sealed bearings in a BB has failed, why do they go and buy another unit, rather than just knock the bearings out and press in some new ones?
£3 for some koyo or NTN 2RS bearings rather than £50 for the housing... Confusing.


Anyway, I've ordered deore hollowtech 2 kit and getting some rockshox today too

[Jayneflakes]

Originally Posted by yorkie_chris

Anyway, I've ordered deore hollowtech 2 kit and getting some rockshox today too

Good choice of cranks. They will last you for a long while.

Originally Posted by yorkie_chris

What I don't get is when people are saying the sealed bearings in a BB has failed, why do they go and buy another unit, rather than just knock the bearings out and press in some new ones?
£3 for some koyo or NTN 2RS bearings rather than £50 for the housing... Confusing.

As for the bearings, they are often fitted in such a way that to remove them will be damaging to the Housing. I have a £100 headset that has sealed bearings and when they are finally worn the whole unit will have to go just because of how it is made. Mind you the average life of the unit is just over fifty years they claimed!

[yorkie_chris]

They had to put them in, there will be a way to get them out
Blind puller, arbor press, stuff like that.

Oh yeah, I need a headset. Mine's notched. (it seems the consumables on my bike are/were the cheng sh*t of the bicycle world.)

[Jayneflakes]

Originally Posted by yorkie_chris

They had to put them in, there will be a way to get them out
Blind puller, arbor press, stuff like that.

There are so few bike shops that are actually set up for this kind of kit, I doubt that most of them even have a bearing press to start with, I am fairly certain that that one I work for does not. I have hope hubs and to get the bearings changed in them is simply to knock them out and press them back in. However Hope are pretty unusual in that they actually design stuff that can be refitted. Saying that though, eleven years of hard use and still no play in the bearings. Says something about the quality of bearing used.

Originally Posted by yorkie_chris

Oh yeah, I need a headset. Mine's notched. (it seems the consumables on my bike are/were the cheng sh*t of the bicycle world.)

Try one of these for ultimate performance.


or try one of these.

Get some RockShox Tora, good travel and dampening that works and for good money! £140 I payed for some 318's from J.E. James Rotherham.

Deore Chainset should do a good job, me and my bro have the External Deore BB, have the carnk as well, he has some DMR cranks...

I dont think the Deore crank looks bad tbh.

[yorkie_chris]

What's going on with the cap on the top? Mine is threaded down a 28.6mm o/d threaded shaft (the steering stem coming up from forks). I think this is normal 1 1/8" standard?

What do I want ultimate performance for? I'm crap!

F*ck off £140!! I didn't pay that for the bike. Rockshox indys I think. £21.