Anybody swap out their chainring for a smaller one for better climbing?

John Thompson

Active Member
I never need more speed on my Jug Ultra but would love a little more help from Granny on my long climbs .... anyone done this?
 

Saratoga Dave

Well-Known Member
I went from a 48 tooth to a 42 last summer on my Giant gravel ebike... made a terrific difference on the steep stuff. Didn't give up anything on the top end, I was never in the top three cogs anyhow. Might be an issue on a road bike, but for me on a gravel grinder, no problem. 11-42 on the rear.
 

John Thompson

Active Member
I went from a 48 tooth to a 42 last summer on my Giant gravel ebike... made a terrific difference on the steep stuff. Didn't give up anything on the top end, I was never in the top three cogs anyhow. Might be an issue on a road bike, but for me on a gravel grinder, no problem. 11-42 on the rear.
That's exactly where I am too, Dave.
 

ExPatBrit

Active Member
I have the opposite question.
What is the max chainring recommended size, I find with my Ultra (44T) At about 20 ish mph in 9th gear my legs can’t keep up with the cadence required ? I want to be able to use PAS up till about 25 mph.
I find that I only use gears 4-9, even on the trail with steep inclines.

Could I go to 48T or 50T , need to install larger guard as well. Any issues with that?
 
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roshan

Well-Known Member
I have the opposite question.
What is the max chainring recommended size, I find with my Ultra (44T) At about 20 ish mph in 9th gear my legs can’t keep up with the cadence required ? I want to be able to use PAS up till about 25 mph.
I find that I only use gears 4-9, even on the trail with steep inclines.

Could I go to 48T or 50T , need to install larger guard as well. Any issues with that?
That depends on whether it'll clear the frame. Only one way to find out.
 

PedalUma

Well-Known Member
Region
USA
John, I am jumping in late. Sorry. Make sure that it does not have shifting ramps! A narrow/wide is best for eBikes with a single ring in front. Double check the BCD.
 

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John Thompson

Active Member
Hi fellas. So I ordered what I thought was a good replacement chainring based on what I *thought* was the chainring mounting pattern - four holes or five - but the ring I bought is too small - see pic. I completely glossed over @PedalUma and his recommendation to check the BCD - which for my uninitiated ears meant "buoyancy control device," lol. So, now I looked it up and measured, and my BCD is 130mm. Next step is using this info to order the correct ring with the right BCD ... any suggestions?
 

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Beebad

New Member
I just ordered Bcd104 adapter for the Ultra motor from Christini bicycles. I believe it will fit down to a 30 T chain ring! I'm starting with a 32T, not sure if that is going to be a mistake (too low). I ride 90% of the time in the woods and trails and when on the road I rarely if ever, go over 20 mph anyway. I'm coming from a 44T so it will be a huge change. When doing the math (if I'm correct) I should be going from 30 mph top end to 22mph top end but, it should have some serious down low crawling power! It should help tow a loaded trailer, and allow for really slow riding looking for game in the woods. Not a big deal if it's too small, I can always jump up to a 36T or 38T if needed. I'll give my buddy the 32T if it's a problem, It's all I can do to get him to go over 10mph!
 

Beebad

New Member
I just put the 32T chainring on, I now have a good selection of tools so it took about 1/2 hour. Oh, I had to only cut two links to fit new ring but, I think my chain was tight on the 44. I took it for a spin but had speed limited to 20 mph ( not sure why) it felt like it would’ve gone about 22 mph or so, so I wasn’t off on my math. I’m going to try it in the woods this coming weekend to see how it works out. I’m also going to try to do a long ride on the road to see how it’s going to effect the battery life there. Check the picture out, quite the difference In size!B41AFC53-F4EF-4E9D-9CE5-10AFF60485DD.jpeg
 

reed scott

Well-Known Member
I just put the 32T chainring on, I now have a good selection of tools so it took about 1/2 hour. Oh, I had to only cut two links to fit new ring but, I think my chain was tight on the 44. I took it for a spin but had speed limited to 20 mph ( not sure why) it felt like it would’ve gone about 22 mph or so, so I wasn’t off on my math. I’m going to try it in the woods this coming weekend to see how it works out. I’m also going to try to do a long ride on the road to see how it’s going to effect the battery life there. Check the picture out, quite the difference In size!View attachment 80387
Speaking of tools ...What is the tool for holding the 'inside' slotted nuts as you wrench the bolt side with Allen wrench? And have you any idea where to buy such a tool?
 

dougpnirv

New Member
Region
USA
Speaking of tools ...What is the tool for holding the 'inside' slotted nuts as you wrench the bolt side with Allen wrench? And have you any idea where to buy such a tool?
This tool holds the slotted nut :


In a pinch, I've also use a small screw driver jammed against the slot in the nut. Not ideal but works if you don't have the proper tool handy.

doug peterson