What am I (chainring)

d0nkeychop

Hi,

IM trying to bring a 1998 Trek 7000zx back to life. Middle chain ring is chewed. I will measure it when I get home but is anyone familiar with these? Its not the weird one from a few years earlier that had a weird middle ring, they're fairly 'standard'. Wondering what compatibility options I've got in the current offerings and whether going away from Shimano will cause issues....

Thasnk

Ed

swod1

you'd be best measuring the bcd of the chain ring looks like 104 not sure when this came out.

chain rings look similar to what is used on todays deore middle rings so your bound to find something to fit.

Are you looking to keep it original as you could if the bb is a 68/73mm bsa threaded fit something like a 3 by deore crank with a hollowtech 2 bottom bracket?

fat daddy

I had that exact lot on my 1997 Klein .... I ditched the whole lot for a Race Face narrow wide with its own BB and cranks.

d0nkeychop

hmm interesting. I was going to just whack another ring on there as it runs ok for most of the rotation. I did think 104 but measure will confirm. Deore will do fine. I like the idea of changing the lot but this was supposed to be a thrifty revival. but if BB goes Id replace with somehting tasty if itd fit. I've put a 50mm spank riser bar on, cables, casings, trying to choose a saddle as the original tries to split my pelvis.

I did take it out for a ride before I dismantles it, was surprised how good it was down the trail, all except the silly narrow bars and saddle!

swod1

well measure it and just by another middle ring if it is 104, you might have to get handy with a metal file to make it fit but could be worth doing and then just buy an new bottom bracket.

new deore triple chainsets are about 50-60 or less if you look around and should come with a bottom bracket.

I'd get some better pedals though as well some wellgo v8 copies wont be much tenner?

02gf74

Replacing middle and outer rings can be expensive to the point where a new chain set makes more sense.

There is cheap but good set of 3 rings on eBay for £20 if you are interested

d0nkeychop

Chortle. I'm going to make do for now, I bought this on a whim. Was going to use it as a 'leave at the station overnight' bike at the other end of my commute but took a shine to it. I'm trying to only replace the absolutely necessaries.... ....the pedals look rough but they work, the mechs are in remarkable condition but not so surprising since it still has original tyres with tread on.

Really hadn't thought about updating it to hollowtech, no real need at moment but as you say, price difference isn't all that much.

Hmmmmmmmmm.

swod1

a bit of cleaning, re greasing and you should be good to go. only replace anything if you need to this will keep your costs down.

d0nkeychop

Finnished it this evening, for now....

Thanks, it was a 104. Deore middle ring on it working well. Front derailleur reinstalled (see image above where it's sitting too low). Seems happy sat a tad higher than I expected but I've only had a short test ride thus far.

Feck knows where the cassette that was on it came from, it was like a solid lump, it had shimano on it but in such a way as to look fake.

I still need a better saddle. I've put a brown leather studded narrow road saddle (Taiwan import 'Bwompton wepwica' , £20) on for now.

Brakes are fine.

Fork still has some squish. I'd like to upgrade it. Must resist.

I'm tempted by the flat pedal idea, mostly as it's a small frame and the saddle sits an inch or so higher than it should, looks chavvy, like the tracksuit bottoms tucked into socks thing that was de rigueur in the 90's for scallies but in bike form.... flat pedals should enable me to drop it a bit.


Short ride was awesome. Mostly the bars doing their thing to riding position and handling but I'm happy with it. Definitely keeping crankset, they feel great. Should get a proper ride out at weekend.

d0nkeychop

Pedals are going. The spd seized on right side. Found out when I went over handlebars. V8 copies on order.

02gf74

Really spd, you are aware that there usually is a screw to adjust the spring tension

d0nkeychop

Yep. These are from back in 'nam though and theres excessive friction. I can relieve it with lube but as i found out, when that wears off unpredictably its a bit of an issue.

Ive got various other spd's i could fit but like the idea of trying flats as i last used them in 1996. Good excuse to buy five tens too.