[al399]

I am curious to know if anyone went that way using Earle motors set up!
There are some lets say drawbacks. In order the rear tyre not hit the rear fender of the bike you have to install the wheelbase extender. That way the wheelbase increases by 3" about 7,5cms which means you need a 48 sprocket. Increasing the rear sprocket from 46 to 48 lowers the gearing even more...On the Desert Sled there many times looking for a 7th gear.
Also apart from rerouting brake lines, replacing rear fender etc the ABS won't work as well.

 

[Max Kool]

The 46 to 48 conversion just compensates for the bigger rear wheel.

you still gonna need a longer chain.

 

[al399]

Indeed but I'd prefer a 17T front...or a 16T front 47T rear...

 

[Max Kool]

To get one odd, and one even number of teeth? Spread the wear?

 

[al399]

To avoid lowering the gears even more!

 

[Max Kool]

Then leave it as is with an 18" rear wheel. That will actually raise gearing....

 

[al399]

I think if you install a 18 rear wheel you have to change the sprockets...Earle Motors suggests 46=>48T but that will drop the gearing too much. When you install the wheelbase extender so that an 18" rear becomes possible then you need longer chain and that leads I guess to bigger rear sprocket. Anyways I am waiting for his reply and input and I will share it...

 

[Max Kool]

You're forgetting going from a 17 to an 18" wheel actually raises the gearing (been there done that).The change from 46 to 48 ONLY compensates for that and doesn't make the revs go up at the same speed. This has nothing to do with the wheelbase being 3" longer.

The longer wheelbase requires 10-ish extra links in the chain anyway.... you're adding 3", chain pitch is 5/8'. Extra length is roughly 3/(5/8)*2..... and the larger rear sprocket may require an extra 2.

You'll never get away with the same chain length

I've seen the bike up close, and met Alex Earle a few times.

 

[al399]

You are right I missed that part. I thought that the longer chain means bigger sprocket. So if one wants to raise the gearing it is possible to install the extender, get the longer chain and leave the 46T sprocket...cool! Then the 6th gear may feel more like an overdrive gear...
Also do you think the abs deletion could be avoided using different abs rings?
Did you have the chance to ride that bike? It would be nice to share your impression.

 

[Max Kool]

Unfortunately I did not (wasn't finished then)

 

[al399]

According to me evidence a 1.85 21" 90/90 combined with 2.50 18 140/80 could work without abs errors or faults on 2017-2018 models. It is yet to find if there are changes on the 2019 regarding abs rings and function. I know that the 2019 model has cornering abs and off-road abs meaning option to let only the rear wheel block...so it may use different generation abs and the combo 21-18 won't work with the newer version abs.