Bicycle Mechanics - N-Gear Jump Stop Problems

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cooleric1234
05-16-09, 09:03 AM
I just bought a new mtn. bike and put some of it together myself. I was having a hard time getting the front derailleur to shift into the smallest chainring without also dropping my chain and affecting shifting into the other gears. After much banging of my head I came to find out that this is a fairly common problem. Which is why such products as the N-Gear Jump Stop exist. I have a Windsor Cliff 29er Comp (http://www.bikesdirect.com/products/windsor/windsor_cliff29comp.htm) (which is practically the same as the Fuji Tahoe 29 Comp (http://fujibikes.com/Mountain/29er/Tahoe29Comp.aspx)) and a top-pull SRAM X.5 front derailleur. It turns out the welds on the bottom bracket area made it impossible to install the Jump Stop and have the front derailleur fit where it needed to (it was about 12-15 mm above the large chainring, instead of the recommended 1-2). So I took a dremmel to the top part of the Jump Stop, where it's curved in towards the bike. I think that's for reverse deraillment anyway, but I'm not sure. Like an idiot, after that I read the FAQ and that I can remove up to 1/3 of the front plastic portion. I did that too. Finally I was able to install the derailleur and it seems to work okay on the stand. Will this work well, or did I blow it by cutting the top part off? I tried to bend it, but that didn't provide enough clearance. It seems like the Jump Stop is still positioned high enough to prevent regular chain drop, but I thought I’d ask.
... Like an idiot, after that I read the FAQ and that I can remove up to 1/3 of the front plastic portion. I did that too. Finally I was able to install the derailleur and it seems to work okay on the stand. Will this work well, or did I blow it by cutting the top part off?
Considering that the Jump Stop is only $12 with shipping, you can get a new one and consider it as a tuition fee ;-)
BTW, I have Jump Stop of my Bike Friday and am very happy with it. It stops both the forward (when riding) and the reverse (when unfolding) chain drops.
Kam
I had the jump stop installed on my son's mountain bike and it solved his problems. As long as it still prevents the chain from dropping off, your cutting of the top should have no effect. As stated earlier, they are cheap enough to replace.
cooleric1234
05-16-09, 04:01 PM
Thanks for the replies. I'll take a ride and see how it goes, it appears it worked on the stand, but in real life it might be different. Also, even if I just cut the plastic loop and not the metal guide I'm not sure I could have gotten it low enough to not stop the front derailleur from going as far in as I'd like. I would have liked to have tried that first though to see :-)
Chris_W
05-17-09, 12:14 AM
To get around frame mounting issues, you could also give the Jtek DropStop (http://jtekengineering.com/dropstop.htm) a try, which mounts on your bottom bracket.
cooleric1234
05-17-09, 09:21 AM
To get around frame mounting issues, you could also give the Jtek DropStop (http://jtekengineering.com/dropstop.htm) a try, which mounts on your bottom bracket.
Thanks for the suggestion, that definitely looks like it would fit the bill. But $25? I guess I'll consider it if my jury-rigged Jump Stop doesn't work.
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