xcorrea

Hello! I am new to this forum and to fiddling with bicycles in general and was hoping to get some help.

I have what I believe to be a 1995 Forrest Green GT Arette. It seemed to be that green was only produced in 1995 and the serial has a 95 in it too. It is currently fitted with a Shimano altus c90 3x7 group-set with a 7-speed, 11-28 death cassette, Arya PX-35, 36-hole rims with 700x41c tires, and grip shift MRX-170 twist shifters.

My goal for this bike is to be able to upgrade the entire group-set/drivetrain to modern parts with lever shifters being most important to me (main aesthetics, but twist shifters and I never really got along). Eventually I would like to put a rear rack and fenders. I'll mainly be using this bike to commute to work.

My question is whether or not I will be able to fit this bike with a modern group-set/drivetrain and whether it will be possible to change from 3x7 to 2x10 or any other recommended gear ratio. I live downtown in a city where biking up steep hills is always guaranteed, but I'd also like to be able to go fast so a single speed commuter is not something I want. This bike also has vintage U-brake design and I am not sure if this will conflict with a modern group-set/drivetrain.

I understand that upgrading the drivetrain may not be worth it considering the price I paid for it, but I am looking to understand more about how bicycles function and because I really like the design of this bike (my previous gary fisher was stolen from my gated apartment right outside my front door ) I figured it would be fun to turn this into a little project.

All information to get me started as well as recommendations are welcome. Thanks and I hope to hear from you all soon

Bill Kapaun

What's the rear DO spacing.
IF 130mm or more, there shouldn't be a problem.
I'd keep the triple and go 9 speed, but I'm biased toward 3X9's.

xcorrea

It looks like it is indeed 130mm. What do you like about 3x9? Is there a set you would recommend?

Bill Kapaun

I like the cassette selection in 9 speed for my main reason. Just more usable combinations seem to be available for us that have no use for an 11T cog.
Chain & shifters are slightly less than 10.
More "robust" than 10.

ClydeClydeson

Are you sure the tires are 700x41c? GT had a funny habit of putting 700D rims and tires on their hybrid bikes in the 90s. THe size was never common and replacements are basically non-existent now. You may be able to switch to 650B size wheels, which are more common now than in the 90s.

xcorrea

So I took a look again and found that the tires are actually 700x40c and the rims are Araya Japan PX-635 700c rims. I'm planning on a Shimano Drivetrain, but I'm still stuck as to which one and if I will have to worry about any compatibility problems.

ClydeClydeson

40c vs 41c: no practical difference. 700C is currently the most common standard wheel size across most bikes. Any 130mm QR hub will fit in your frame. Modern bikes are moving towards thru-axles and disc brakes (no braking surface on the rims) so pretty much any road wheelset from ~20 years to ~2 or 3 years ago will work fine.

My preference would be to select a set of hubs (my favourite are Shimano 105 or Ultegra if you want 130mm spacing) and have them laced onto a set of wide-ish hybrid or touring rims like Alex DM18. You can choose more or less spokes depending on your durability requirements and hub/rim availability.

Iride01 

That's a hybrid bike with other than drops? Assuming you aren't going to convert it to drop bars (I wouldn't), then you might still be limited to road bike components with that 130 mm spacing on the back. As far as using new stuff. But Shimano does make Tiagra 10 speed and 105 11 speed with flat bar shifters.

So there is no apparent reason why you can't make it a 2x10 Tiagra or a 2x11 105 equipped bike. But 3 x 9 probably gives you everything you need. And there is still a 3x10 Tiagra option.

Steel frame? If so, then you might look into opening the rear spacing to 135 mm and then be able to put some of the components from Shimano's mountain bike line. They'll actually give you more choices in the way of shifters and such........ I think.

Whatever you do, don't think that you can't bring that easily up to 11 speeds on the rear if you want to. But I do agree with some others that if you want a 3x front chain set, then a 9 speed rear is more than good for most normal hilly terrain.

AllTheBikes

What did you end up doing with this? I have the exact same bike and am thinking about using it as a commuter to my new job. Mine needs new tires and at the very least shifters (not sure I'll do the whole drivetrain yet) and also fenders and a rack.

djb

Can't answer for the guy from 2 years ago, but want to mention that I have a similar age gt 7 speed hybrid and the freehub cannot take 9 speed cassettes, it is too short, so just kept it 7 speed, and as a commuter it's fine.
I'd have to change the freehub for a longer one or get a new rear wheel, and just didn't bother.

Get a bike store to check this before buying parts if you eventually think to change drivetrain. You should find used 7 speed trigger shifters easily at a used bike store, so many inexpensive bikes used use 7 still