TCATBYU

I have a trek 1000 with bontrager triple 52-42-30. Would like to change to 53-39, can I put a double on this crankset? If not, what will fit for chain rings, I figured if I can't switch to doubles, I'll just run 53-39-30 triple. Trying to do this without buying a double crankset.

PolishGuy

You can do it but it'll cost you more money and/or money and time than it's worth for a TREK 1000. You may want to re-post this under the Bicycle Mechanics section. I did this on my 2002 TREK 1000 with the same set-up as you're describing. The simplest way is to use a Shimano 39T ring designed for "middle" application since it will have pins and ramps for clear shifting. The cost may be more than buying a 53/39 double on sale. A plain 39T ring from Nashbar etc will work but the shifting will balk; in other words, it won't be a clean upshift with the brifters. Replacing the triple crankset with a double will place the chainrings with a slightly different spacing and will require you to adjust the FD to shift properly and stop from dropping the chain from going down to the 30T ring position. I bought a Shimano Sora triple on sale from Nashbar for way less than a 39T ring would cost. The performance of the Shimano over the TREK supplied Sugino was like night and day. The final decision is yours. Good luck. PG.

johnny99

You should be able to remove the granny gear and replace the other 2 rings, though rings are not as cheap as you may want. Use the limit screw on your FD to avoid the granny position. This won't work quite as well as a real double setup (with short cage RD and shorter BB spindle), but well enough for an entry-level bike.

TCATBYU

Thanks for the replys, trying to do this the cheapest way. If I replace the chainrings, will shimano double rings fit?

barba

Two Shimano chain rings may end up costing more than a double crank on discount (though you will need a new BB if you go that way). Is there any particular reason you want to do this?

TCATBYU

39 gear will work better for almost all my riding routes. Figured I would change the 52 while I was at it.

barba

1 tooth on the big ring isn't going to do much for you one way or the other. I would skip that at least.

Spend the money if you like, but given that this is a 1000 I would just take it as a lesson learned and get a double when you eventually upgrade to a new bike.