Trouble installing Triple Crank

[Charles.Plager]

I ordered Shimano Alivio M411 Hybrid Crankset (Black 170mm X 48/38/28) (http://www.amazon.com/gp/product/B004V25ZRQ/ref=oh_o03_s00_i00_details). I got it installed on the Sofrider smoothly. The issue is that the granny gear is too close to the frame and that the derailler can't push the chain over to it. If I push the chain by hand, everything is smooth (for whatever that's worth).

Do I need some sort of spacer? Does this mean I need another bottom bracket? Any ideas are most welcome.

Thanks,
Charles

 

[Doug Burton]

Sounds like you will need a different bottom bracket...

Which version Sofrider is this, 8 or 16 speed?

Measure the distance from the middle of the center chainring to the center of the boom tube. It should be 47 - 50mm for a mountain-type triple crank.

Road and MTB cranks tend to sit down over the BB axle differently. Usually the MTB crank will sit further out than a road crank on the same axle, but things vary a bit from manufacturer to manufacturer

Here's an article by The Master that explains this very well.

http://sheldonbrown.com/chainline.html

Cheers,

Doug

 

[Charles.Plager]

Hi,
It's the 16 speed

Hi,

It's the 16 speed cruzbike. The triple is (basically) a moutain=bike triple (they call it a hybrid, but it's mountain bike gearing and a 4 bolt pattern). I'll go and measure the distance now (the article is very helpful for exactly what to measure).

I'm assuming that I'm going to measure something that is too small. What do I do then?

Thanks,
Charles

 

[Charles.Plager]

I measured it and it looks

I measured it and it looks pretty close to 5 cm (could be a little smaller - the ruler I used isn't ideal).

 

[Charles.Plager]

One of the views for the

One of the views for the crankset says it needs 123mm bottom bracket. Will a 68 mm x 123mm bottom bracket fit on the Sofrider?

Thanks!

 

[Doug Burton]

Yes...

A 123mm English 68mm bottom bracket should fit fine.

The current BB may be difficult to remove, since the factory where the bike is assembled tends to be much warmer than the environment where you're working (the aluminum BB shell will contract with the temperature change.)

You may want to heat the BB shell with a heat gun to expand it before attempting to remove the BB. Heat it evenly around its circumference to a temperature where it is just beyond comfortable to touch.

Be careful not to melt the paint, it's easy to do with a heat gun.

 

[Kim Tolhurst]

hair blow drier

Hi, I have used a hair blow drier on full heat. (didn't have heat gun)

 

[Kim Tolhurst]

hair blow drier

Hi, I have used a hair blow drier on full heat. (didn't have heat gun)

 

[Charles.Plager]

Hi Kim,
Thanks!  (That's

Hi Kim,

Thanks! (That's exactly what I was planning on doing ).

Cheers,
Charles

p.s. And thanks for your videos of learning to ride a Cruzbike. After watching your videos and "flinstoning" for 30 minutes, I was off riding on roads with very little problem.

 

[Charles.Plager]

Success!

Update: I successfully installed a wider bottom bracket and then had no problem installing the triple crank and getting the front derailleur adjusted. Thank you for all of your help - the hair dryer worked very well!

Thanks,
Charles