Bontrager Select chainset on Trek 1200

The Spiderman

What interface/standard is the bottom bracket?
It looks like an old fashioned internal cartridge type bb but looks different to a Shimano Octalink or square taper with which I am more familiar.
Mine has some play and trying to determine what bb tool I need to tighten/ or remove the bb.

The Spiderman

Wondering if it might be ISIS? Can anyone confirm,and also what tool do I need?

Fat Head

it is indeed an ISIS

The Spiderman

In the abscence of a replacement Bontrager bbs will any Truvativ or indeed ISIS bb suit,if it needs replacing?

I assume I just need to match axle length and shell width?

Are mtb and road ISIS bbs the same?

I was considering a SKF BXC 300 as a more durable replacement?

gkerr4

when the BB went on my select chainset went on my trek pilot I realised that:

A) - generally speaking, ISIS BB's are junk and don't last any time at all

- The exception is some very expensive SKF BB's which seem to be decent in reputation but cost more than the chainset is worth!


I changed the whole lot for shimano hollowtechII and never looked back. Tiagra chainsets can be had for £40ish with the hollowtech BB cups around a tenner - the sora chainsets are even less - parkers were doing the sora HT2 compact chainset for £31! which means you can move to a more modern external bearing setup for as little as around £45 all-in. They need minimal tools, are stiffer and much much more reliable than ISIS - plus they are so easy to fit it is untrue and you can remove them easily for seasonal cleaning (if thats your thing)

ride_whenever

there are a few decent ISIS bb, the SKF ones are excellent. The crank brothers one (available with a Ti axle if you're feeling flush) and the ones from superstar components (which is pretty cheap)

gkerr4

yeah but - decent at what price?

the end of the day, ISIS is a flawed design, the bearings are too small and not well enough protected. you can move to the more modern Hollowtech2 for around £45 so I'm not sure that it is worth persevering with an older design BB - especially as you could easily be replacing it again before the end of this winter!

with HT2 - even if you did damage the BB over winter then they are a fraction of the price of ISIS, more readily available and much much quicker to change.

The Spiderman

Thanks for the replies.
I have an XT HT2 set up on my mtb,so am already sold on the conevnience and concept of outboard bearings.
I hadn`t realised that road versions are so cheap though by the time I have factored in the bb and a new chain,I worked out it would be nearer £70 ,with the recent Shimano price hike for something like Tiagra.I quite fancy a swap to compact too.
Will 10 speed chainsets work OK with a 9 speed set up.I have seen some cheaper 105 chainsets around,whcih might give me more options later when it comes to upgrades?
I have also seen some cheap R700 chainsets for around £50.
Are these equivalent to 105?

The Spiderman

Thanks for the replies.
I have an XT HT2 set up on my mtb,so am already sold on the conevnience and concept of outboard bearings.
I hadn`t realised that road versions are so cheap though by the time I have factored in the bb and a new chain,I worked out it would be nearer £70 ,with the recent Shimano price hike for something like Tiagra.I quite fancy a swap to compact too.
Will 10 speed chainsets work OK with a 9 speed set up.I have seen some cheaper 105 chainsets around,whcih might give me more options later when it comes to upgrades?
I have also seen some cheap R700 chainsets for around £50.
Are these equivalent to 105?

gkerr4

yes - my understanding is that different 'speeds' of chainset are compatible - so you could (i believe) happily use the sora 9-speed stuff on your 10-speed setup (although it might not be as perfect a shift as, say, an ultegra 10 item - but then, we all knew that anyway!)

this is such a bargain:
http://www.parker-international.co.uk/7 ... inset.html

(although I notice it has went up a fiver in the past week!)

akcc05

or you can do something nice to yourself for x'mas and upgrade to 10 speed. i upgraded the tiagra 9 on my 1200 to full ultegra 10. the shifting is so much smoother and never looked back. i think the older generation of trek sl frames (horizontal top tubes and super short head tubes) are good platforms for upgrading. there is of course a cheaper option of going 105, which has a lot of used bits on e-bay (or post a wanted thread here). if you have the cash sram rival seems good (i should have gone to rival rather than ultegra myself a year ago)