Help Required

[Stu1961]

OK...........I have just fitted a new rear wheel, Shimano Acera 8 sp Cassette, Shimano Alivio Crankset, Shimano BB and New Chain....problems are....

1 Chain seems far too long.

2 Crankset and Cassette seem way out of line and the Derailleurs are now way out.

I am summising that I may have got the wrong BB, as the one I took out was not a sealed cartridge type but, just had bearings at either end of a shaft.

I measured the total length and it came up at 128mm long.

The crankset I changed to is 22/32/42.......the old one was 28/38/48

These are the items I used..........

Bottom Bracket

Crankset

Cassette

Rear Wheel

Chain



......any help in solving my problem would be greatly appreciated.

Cheers

Stu

 

[rusty bearing]

Shimano design their chainsets for a particular length of BB. Just because your existing was 128 doesn't mean the new one should be. I can't remember ofhand which one for Alivio but I'd take a guess at 118mm. Shimano's website will provide the answer.
You've dropped six teeth per chainring, I'm not surprised the chains too long, you'll need to shorten it. Plenty of info on the web about this.
If you're still stuck tomorrow I'll try and find the right sizes for your BB unless someone else has the info to hand.....?

 

[rh100]

I think you may be right about the bb being the problem. That does sound a little long, the paperwork that came with the crankset should have specified what size bb was required, but have a look at this link and looking up Alivio shows a 110mm is req, shorter than what you have http://www.sheldonbrown.com/bbsize.html, however that chart may not be correct for your particular crankset. I put one of those sets on my hybrid last year and was totally ignorant at the time of proper bb sizes but seem to have got away with it basically the bb needs to match the chain set.As for chain length, I always understood it as follows: wrap the chain around the largest chain ring on the front and the largest cog on the back, but not through the derailliuer, pull the two ends together and add two links and that is the correct size, cut to size and fit it through the mech and should be tensioned ok, just avoid running on the large large combination or will pull the chain too tight. There may be other methods better at getting the correct size, but that does seem to be a popular method.Don't forget to reset the mechs high and low points to get the limits right to stop the chain coming off and check the tension on the gear cables is correct.Spend some time reading the sheldon brown articles and you won't go far wrong, let us know how you get on.

 

[rh100]

Rusty beat me to it, but what he says about the drop in chain ring size makes sense.

 

[rh100]

By the way, changing from the old style bb to sealed type makes no difference so long as the shaft length is the same

 

[Stu1961]

Thanks for the help guys.....ignorance = expense I suppose, should have posted here before I bought the stuff.

I will update this topic once I have got the correct BB (and chain, as I don't think you can shorten the one I bought....could be wrong again though)

Stu

 

[rh100]

= experience lol at least you'll get the satisfaction of doing the job yourselfYou need a chain splitter, a tool that drives the rivet out to separate the chain. You need special rivets to rejoin the chain, although I've never done this as I use power links to join them, it's just easier The Internet is rammed with articles and videos showing how stuff is done, well worth spending some time having a browse.

 

[brockers]

A good post in that you provided all the relevant info right from the outset! Chapeau!

 

[Stu1961]

First thing I bought was a toolkit which includes a chain splitter.

Looking at the chain I have, it has a quick coupler and it looks like I can shorten it (luckily).....

Doing the work myself IS satisfying, maddening when things go wrong but, interesting too..........hopefully my knowledge base, and skills, will grow as I do more and more work on the bike.

Thanks once again.

(Oh, it looks like it is the 110mm BB I need, ordered and hopefully will be here by Tuesday)

 

[Stu1961]

A good post in that you provided all the relevant info right from the outset! Chapeau!

Thank You brockers

 

[rh100]

Yep just use the quick coupler to join the chain after you've shortened it, just bear in mind about the male and female ends as described in another thread in this section.Your skills will definitely grow if your willing to have a go at it. Put it this way, two years ago all I had done was repair punctures as a teenager using spoons to remove the tyres, but as I got into cycling again I just asked loads of questions and read up on the net, and learnt by my mistakes, to date I have only paid an lbs to true a wheel, to fit one headset and today I got him to remove a stuck freewheel, everything else I've done myself which includes updating my hybrid, building a touring bike and stripping and refurbing and old 80's racer, I spending more time messing with bikes than riding them but it's a hobby I enjoy, any mistake made is an opportunity to learn. Biggest headache is figuring out what's compatible with each other.

 

[Stu1961]

Sounds much like myself...........I used to cycle when I was a kid, at that time all you needed was a Bike Spanner, 2 Spoons and a thumb for the 3 speed Sturmy Archer gears...........things have moved on since.

This bike was given to me (I do have a BSO which I am currently riding) by a friend, very light frame but had been abused by his son, rear wheel was dead, Cassette rusty, Crankset with bent and worn teeth, tyres ruined..........

It's not a 'Top Quality' bike but, because the frame has a lifetime warranty and was lightweight, I decided to 'build my own' and add better quality parts to the frame..........which is where I am now, once I get this little problem solved, it will be rideable and out for the test.

 

[rusty bearing]

Got to agree with RH, I always fit KMC, SRAM or Whipperman chains with links in. So much easier

 

[Stu1961]

OK

All fitted (110mm) and running, apart from the front derailleur needs sorting.

Many thanks to you guys