Bashan BS250Gy-9 "WIll" sprocket questons

[dossbag]

I look forward to hearing you results

[andyj812]

New sprocket and chain supposed to be delivered tomorrow. I rode 151 km today (as read by speedometer). Towards the end of the ride the speedometer started bouncing. When I arrived back home I did a little troubleshooting and noticed the lower front wheel side of the cable was a little loose and tightened it. Did another 20 minute ride and seemed to fix to the problem. If speedometer issue comes back I might see if I can find a reasonable new "Dash" speedometer with a magnetic pickup and tach on ebay. almost time for next oil change, may due that while I have bike on stand to replace sprocket.

[andyj812]

These were delivered today, I love Amazon Prime. Came in just before I left for work, hope to find some time tonight when after I get off to install if not maybe tomorrow but probably next week sometime, I'll keep you updated.

[Weldangrind]

That JT will last a long time. I'm looking forward to hearing about how the new ratio works for you.

[andyj812]

Originally Posted by Weldangrind

That JT will last a long time. I'm looking forward to hearing about how the new ratio works for you.

Thanks for everybody's help and input. I stayed up until 5 this morning installing the new sprocket and chain. (I don't get home from work until after 1 AM) My snap ring pliers are to small and would not spread the snap ring out far enough so it took me quite a while to get the snap ring back on with a pair of needle nose pliers pulling the handle apart in order to spread the ring but I finally got it. It was raining when I got done but took it for a short ride. low end it runs great not fishing or for gears anymore. After I got up to day I took it for a 15 mile ride before work. I don't have any more speed but rpms are but sounds and feels a lot better to ride. I think 44 tooth sprocket I ordered was to much though. I didn't get any noticeable speed increase but top speed is now in forth gear. It runs fine in fifth gear but the is 15 km reduction is speed over 4th gear as read by speedometer. I'm going to do some research and possibly put a 16 or 15 tooth in the front rather than fight that snap ring again. If I replace the front gear I may not have to take anymore links out of the new chain either and would definitely have to add links or get another new chain to change to rear. I don't think I'm going to get anymore top speed out of it but might as well lower the gearing in case I do off road it. I appreciate all the help everybody has giving me and anymore input is welcome and appreciated.

[andyj812]

Pictures of old and new sprockets together for comparison

[andyj812]

Looking at the sprocket calculator point out to me by Dossbag my original setup of 17-56 had a ratio of 3.29.

My new and current 17-44 ratio is 2.59

if I change the front to: 16-44 the ratio 2.75
15-44 2.93
14-44 3.14
13-44 3.38


since the 13 tooth (3.38) is close to my original ration and my current ration is 2.59 in the middle would be 15-44 or 2.93.

What is your opinion should I order the 15 tooth sprocket?

[Adjuster]

The front sprockets are so inexpensive and easy to change do what I did and get 3 sprockets in the range you are looking for. The size you want, one size smaller and one size bigger. Actually I think I wanted a 15 so I got a 15, 16 and 17. The 17 turned out was the best for me and the largest I can fit. They were only $9 each included shipping.


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[andyj812]

Originally Posted by Adjuster

The front sprockets are so inexpensive and easy to change do what I did and get 3 sprockets in the range you are looking for. The size you want, one size smaller and one size bigger. Actually I think I wanted a 15 so I got a 15, 16 and 17. The 17 turned out was the best for me and the largest I can fit. They were only $9 each included shipping.


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I thought about buying the 16 and 15 as you suggested but I'm cheap lol so was trying to figure out which one was the best. but on further inspection, my chain is way to close to my swing arm with my small rear sprocket, putting a smaller front sprocket on will only make it closer so I'm going to order a new rear sprocket and another chain.

Stopped at Harbor Freight today and picked up a bigger snap ring plier set. Only the best Chinese made tools for my china bike. lol

here are pics of my current setup for some reason they up loaded sideways.

[Adjuster]

Cant tell on your bike but some bikes the chain runs on a nylon/plastic type slider mounted to the swing arm.


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[SpudRider]

I own two Zongshen motorcycles. I love Harbor Freight.

A Chinese motorcycle deserves Chinese tools.

[andyj812]

Originally Posted by SpudRider

I own two Zongshen motorcycles. I love Harbor Freight.

A Chinese motorcycle deserves Chinese tools.

I was looking at digital speedometers the other day and the were all from China. I kept telling myself I don't want a Chinese speedometer. Then I laughed when I remembered its a Chinese bike.

[andyj812]

Originally Posted by Adjuster

Cant tell on your bike but some bikes the chain runs on a nylon/plastic type slider mounted to the swing arm.


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If you look close in the pictures you can see a rubber swing arm protecter(?) where the chain is actually touching right now. Can see where chain has dug into it a little. I notice it was close when I adjusted the chain but I get some tight on bottom loose on top after adjusting the chain and riding. I order a new JT chain and front and rear sprocket so all should match and elimate this I hope. I noticed there was a slight difference in my old 428 and chain and the new 428 JT chain that was delivered the other day. apparently 428 is different from brand to brand.

[dossbag]

I used my GPS to test mine today.. It was running at 61 - 63 mph, I think the 45 it's a tad slower than the 50.. My original instinct was to go for a 47 I might drop the front a notch and see what it does. Can't even remember what the original is now? No panic though. anything over 60 will keep me at normal traffic speeds. And there are always other mods to do. I just wish I had more time and $$ But living in Michigan, you get 6 months to do everything before the ice moves in... heaven forbid!!
Interesting stuff though.. thanks for the updates.

[andyj812]

Originally Posted by dossbag

I used my GPS to test mine today.. It was running at 61 - 63 mph, I think the 45 it's a tad slower than the 50.. My original instinct was to go for a 47 I might drop the front a notch and see what it does. Can't even remember what the original is now? No panic though. anything over 60 will keep me at normal traffic speeds. And there are always other mods to do. I just wish I had more time and $$ But living in Michigan, you get 6 months to do everything before the ice moves in... heaven forbid!!
Interesting stuff though.. thanks for the updates.

I appreciate the input. I went with the 50 this time. The original was a 56 and I put on a 44 so 50 is exactly in the middle. If I still don't like it ill know which way to go. Indiana weather about the same and its rained almost every day for the last 2 weeks here. Are you currently running a 17 or 16 front sprocket? I was using some of the posts on your bike as I guideline and assuming you had a 16 front. A 17-48 combo has a similar ratio to a 16-45 and I saw you post about thinking about a 47. A 17-50 and and 16-47 have the same ratio.