[Turbulence]

I have a 45T rear sprocket that I would like to use (with a 16T front). I wanted to check if anybody has run such a sprocket size? and if there is enough clearance to the chain guard?

or, could someone kindly measure the gap / clearance from their chain to the guard at the top of the rear sprocket.

My bike is in pieces and in multiple stages of refurb so not possible to mock it up just now.

Thanks

 

[yorkie]

I have a 45T rear sprocket that I would like to use (with a 16T front). I wanted to check if anybody has run such a sprocket size? and if there is enough clearance to the chain guard?

yes, and yes.

or, could someone kindly measure the gap / clearance from their chain to the guard at the top of the rear sprocket.

30mm give or take using a 42 rear sprocket and stock gen 1 chain guard. (note) gen 2's use a different design of guard.

One assumes you want to use this rear sprocket because you have one. however a 15 front and stock rear would produce the same gearing.
FYI, when I used a #45 rear 16 front I found the gearing a little low ok in town but a little under geared on the open road.
#15 front #41/2 rear produces gearing a little too tall ok for open road cruising but in town it seem to be always in the wrong gear. stock gearing seems about right. oh and you may find the 104 link chain needs to be longer no issue for me as I usually buy 110/120 link chains anyway then just cut to whatever I need.
hope this helps.

 

[Turbulence]

yes, and yes.

30mm give or take using a 42 rear sprocket and stock gen 1 chain guard. (note) gen 2's use a different design of guard.

One assumes you want to use this rear sprocket because you have one. however a 15 front and stock rear would produce the same gearing.
FYI, when I used a #45 rear 16 front I found the gearing a little low ok in town but a little under geared on the open road.
#15 front #41/2 rear produces gearing a little too tall ok for open road cruising but in town it seem to be always in the wrong gear. stock gearing seems about right. oh and you may find the 104 link chain needs to be longer no issue for me as I usually buy 110/120 link chains anyway then just cut to whatever I need.
hope this helps.

Thanks for the response. I should have stated a Gen 2 bike / guard.

Stock gearing on Gen 2 is 16T front - 41T rear. Was originally planning on 15T front and 42 rear this gives a 2.80 ratio and is done using standard parts. I came across the rear sprocket in an online sale at 80% reduced to clear. Ran it through a calculator and 16T front and 45T rear = 2.81 ratio. And requires 106 link chain.

I'm going for the more aggressive gearing as I mostly ride the country and mountain roads of Scotland or track days at Knockhill. The stock gearing was adequate but lacking punch out of slow corners or for overtaking. Top speed is not a concern as I can't remember requiring the need to be much over 100mph.

 

[yorkie]

Thanks for the response. I should have stated a Gen 2 bike / guard.

yeah should be fine the gen1 sort of wraps around the sprocket while the gen 2 is straight across the top.

Stock gearing on Gen 2 is 16T front - 41T rear. Was originally planning on 15T front and 42 rear this gives a 2.80 ratio and is done using standard parts. I came across the rear sprocket in an online sale at 80% reduced to clear. Ran it through a calculator and 16T front and 45T rear = 2.81 ratio. And requires 106 link chain.

yes of course it's similar, as a general rule one tooth on the front is equal to 3 on the back the difference in gearing between gen 1's and gen 2's 1 tooth on rear is to compensate for the bigger rims. so 15/43, 16/45. 14/38, are all similar gearing.