Luke1977

I have a stock 1982 Trek 613 that I'm toying with converting to a triple crank up front (effectively making it a 620). Mine has the stock Suntour BL derailleurs, 52-40 crank, and 14-30 6-speed freewheel. Just trying to get an idea of weather I'll need new deraileurs also. Hard to find much info on the BlueLine stuff since it wasn't around very long. I have no complaints with them -- they shift fine enough and I'd like to keep them if they'll work.

illwafer

yes it will.


but you will need to upgrade the rear if you want to go beyond 7 speeds.

balindamood

Yes. Some Univegas (e.g. the Viva Sport) came with BL and a triple as OEM.

Little Darwin

If your rear derailleur is short cage it probably will need to be swapped for a long cage.... that is because of the amount of chain wrap needed.

strock 

My 1983 Univega Gran Turismo had BL derailleurs front and rear. The OEM crankset was a triple -- actually, it was a half-step plus granny (36-47-52, or something like that) -- and the freewheel was a 5-speed with a fairly modest range. Not surprisingly, when I installed a touring triple crankset (24-36-46) and a wider range (14-34) 7-speed freewheel, the rear derailleur didn't have nearly enough capacity. The other problem was that the cage on the front derailleur was narrower than some I've used, and so I had to trim it quite frequently in order to avoid chain rub. I eventually swapped both derailleurs out in favor of a pair of XT 737s. So, yes, the BL derailleurs will work with a triple crankset, but you have to stay within their capabilities.

wrk101

+1 I had a 1983 Gran Turismo with BL derailleurs as well. One of my favorite Suntour groups. The BL stuff is kind of a sleeper, buyers recognize Cyclone bits on ebay and drive the pricing up, but the BL bits sometimes get ignored. I have a set somewhere in my workshop to put on a bike. So far, I haven't been able to find them....

shipwreck

I am running a 24-38-52 front with a 14-32 seven speed rear, with original blueline on my Gran Turismo. It works, with enough to handle the big/big rings. you do have to trim a lot, but that does not bother me. I may go to a more modern setup and move the BL to a different bike, since it does work well.

scozim 

I agree - I swapped out my Ofmegas of the Gitane Tour de France for BL and love the way it shifts. My daughter's Trek 610 still has the original BL components and, again, no problems at all. Smooth, reliable shifting.

Luke1977

Thanks for the good info! I think I'll probably find a crank first and see what happens. If it works, great. If not, I'll look for some derailleurs -- they're not all the difficult to source on ebay/CL.

noobinsf 

Reviving an old thread...

Two posters above have different experiences with Suntour Blue Line. I have the same drivetrain that I plan to use for an upcoming build, but I am curious if anyone else has experience with going so far out of the BL's stated range.

The rear is rated for a 34-tooth max capacity, but one poster above has a 52-24 front and a 14-34 rear, which is a 48-tooth difference. It seems unlikely, and one other poster above noted that his setup with a smaller tooth difference (a 42-tooth difference) did *not* work.

Does anyone else have any first-hand experience with going 14 teeth above the stated capacity on one of these (or a similar Suntour GT)? Is it likely just a case of someone misstating what he actually had?

Salamandrine 

FWIW my 80s cross/touring bike had the BL short cage version that was rated for 24t. For touring use, I ran it with a 27t large cog and had no problems. So I would say they were conservatively rated. I never had the GT version myself but I did work on them.

34t would have been highly unusual when BL derailleurs were around. 32t was the usual big touring cog. 24t front chainrings would have been pretty freaky too, for that matter.

Precisely what gearing are you attempting to use? The "two above posters" cite two different tooth counts.

Circa 1984 the Univega 84 Gran Turismo used 14-32 five speed cluster with a 28/46/52 triple. That seems about right. I'm not sure I'd want to push it much further than this. Whether a derailleur will work a bit outside it's normal capacity depends a lot on chain length, chainline, and the skill of the mechanic.

Lascauxcaveman 

I was surprised to see that extreme range reported as a good to go, but I once set up Blue Line front and rear (long cage) on an old Peugeot with 48/38/28 up front and 14-28 out back and it all worked together just fine.

Cougrrcj

My '84 Univega Viva Sport came with a 52/42 Sakae CX double front and 13/28 6-speed rear - and was equipped with BL(f) and BL-GT(r). I sold them to a fellow BF member when I 'upgraded' to 1st gen Cyclone front and Cyclone short cage rear that handles the 13-21 six-speed freewheel.

My '84 Univega Gran Tourismo carries its original SunTour Mountech derailleurs and a 14/32 five speed freewheel and 50/42/28 Sugino GT crank. Not sure if I'll be keeping the Mountech due to internet rumors... I have an 'indestructible' VGT Luxe and a 13-26 six-speed freewheel standing by.