Gearing down a Multistrada 1200

[martinlindhe]

OK - so I want to gear down my Multi 1200.
I have many reasons for this - and i know the vast majority disagrees with me (it's not needed blah blah) But I'm hell bent on getting even quicker to higher RPMs and I do a lot of 5-10 mph stop&go traffic juggling here in Seattle area.

Anyway, so since there are no 14 tooth front sprockets or >40 teeth rear sprockets to order for MTS1200's 530 chain - it seems the best option is to buy a whole chain/sprocket kit for 525 instead. This one seems to be good quality:

http://www.supersproxusa.com/products.php?cat=1490

My question is - would installing this 525 kit with 14t front sprocket be a problem with the overall design of the MTS1200? As in - would the steeper angle of the chain cause it to possible scrape against something? I mean, it would have be a problem at some point right - say 14t front and 45t rear? (-1 front, +5 rear)?

Anyone have a good educated guess on where the limit would be?

[Mr Sunshine]

I would skip going to a 525 and just got to a high quality tensile strength 520.  That would give you the same sprocket selection as the 1198 which means you are going to find the combo you want.

As to the chain rubbing....no guarentees it'll work until you do it.

[martinlindhe]

I would skip going to a 525 and just got to a high quality tensile strength 520.  That would give you the same sprocket selection as the 1198 which means you are going to find the combo you want.

I wouldn't know what the difference is between a 525 and a 520. Price? Quality?
All the combos that I can dream up are already available in 525.

I don't even know what the numbers (520, 525, 530) mean - I just figured that a number closer to the original (530) would be a better fit?

[Mr Sunshine]

The numbers is a reference to the pitch of the chain (http://www.gizmology.net/sprockets.htm)

What you will see if a 530 is wider than a 525 which is wider than a 520.  The narrower the chain the lighter it will be.  Traditionally the 520 chain is used in racing (at least the club level) because its the best lightness for the strength.  

So with a bike like the Multi which puts out good torque when you go to a 520 you need to check the tensile strength and make sure it is one of the higher ones (sorry I don't have good numbers off hand) so it can handle the torque.

525 is an odd size...I wonder if its a Duc thing since you said you can get the combo's you want in it.  

[Croak]

I'd be very particular on what chain you used if you dropped down to a 520 on a MTS1200.  It's hard to find a 1000cc twin rated 520, let alone one for a 1200cc twin.

Having been down that road in the quest for weight savings, I wouldn't recommend a 520 to anyone for a touring or commuting bike with more than 60 ft/lbs.  

525 is a nice compromise (and it's a fairly common STANDARD size for Aprilia).  Geometry shouldn't be hurt that bad if you're just dropping a tooth on the front or going up a couple in the rear, though it does tend to be exaggerated more on a long-travel suspension.  

Also worth your time to check out http://www.gearingcommander.com/  to see the projected wear on various sprocket combos, along with the very useful comparisons.