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gumby

My gumby green Performance is a little sad Crying or Very sad

, a late 90's makeover from the prior owner left Gumby with a Shimano 105 transmission that has 7/8 friction or index shifters, and an odd 27" front wheel, and the original rear wheel with 6 speed freewheel.

I want to have wheels built to remedy this and maybe bump it up to 7 or 8 speeds.

Don't hate me for not putting old French parts on the bike.

What is the rear spacing? I think it is not 130. Can it handle a 130 hub.

Any thoughts on this project would be appreciated.

Paul Wiseman

OK, are the shifters 7 speed or 8 speed? They can't be both, as they have different spacing.

If it's 7 speed that's good because it has 126mm rear axle spacing which will fit your frame. 8, 9, and 10 speed all use 130mm axle spacing. Yes you can squeeze it in, but it's a bad idea as it puts undue stress on the brake bridge and bottom bracket. It could cause your frame to crack. The only problem with running old shimano 7 speed is finding old cassettes to fit on your hub, but if you have those it's all good. Just beware, the 8,9 & 10 speed cassettes wont fit the old 7 speed hub. But you can (and should) use the 8 speed chains from shimano. The 'new' shimano screw-on clusters (freewheel) will work about 95%, as will a SACHS 7 speed screw-on cluster. The spacing on these is actually the same as shimano 8 speed.

If your shifters and derailleurs are 8 speed, then you have a different option. Assuming you're not taking the bike to a frame builder and having it re-spaced to 130mm as this is a very expensive option. Get a wheel with an older hub that takes a screw-on cluster. Use a SACHS 7-speed cluster, it has the same cog spacing as shimano 8 speed. It will shift perfectly, but you'll only have 7 gears. Set you limit screws on the derailleur to suit, and you simply can't pull the shifter back to the last 'click'. (what would have been 1st gear)

Whatever you do, I'd reccomend that you take both your frame and new wheel to a good wheel builder and get the wheel 'dished' for your frame. This means to get the rim in the dead centre so the wheels track straight.

Front wheel:
Is it just the wheel that is 27", or has the fork been replaced? If it's just the wheel then it's as simple as replacing it. If the bike has been given a 27" fork, then you need to replace that with a 700C fork as it will screw with the frame geometry, particularly the steering.

Good luck with the refurb. Hope to see some photos when you're done. On a personal note: Is it Gumby Green Gitane as in the "gumby" kids tv show? If so, here's some trivia - I have a cousin who looks so much like 'pokey' the horse it's scary.

gumby

Thanks for the thorough explanation. I looked at the shifters and they say 8sp on them. So I am running original rear wheel with six speed, freewheel (right?) and the mismatched changer and shifters. The shifters offer either SIS or friction option. I am running friction.

I have considered the stretching option, price isn't too bad. My LBS away from home is www.yellowjersey.org. They do full frame serivce and would stretch the frame if I wanted. Is that what I want?

Paul Wiseman

I'm not sure what they mean by "stretching". If they are just going to pull on the frame until it is wide enough to accomodate a 130mm axle, then you should save your cash and wreck your frame yourself. To do the job properly, they should heat and remove the brake bridge and the bridge behind the bottom bracket if you have one there. Then the joints at the seat post and bottom bracket are heated so the tubes can be re-aligned. Then brazed joints are touched up and bridged are re-brazed. All of this is done in a frame jig by a qualified frame builder. Not all bike mechanics are qualified to touch your frame. Not all bike mechanics are qualified to even wash your bike for that matter, but that's another long story. If you're unsure, and you want some professional advice, contact Richard Sachs (www.richardsachs.com). My opinion is that of a bike mechanic who is NOT a frame builder. My opinion however, is to err on the side of caution. This is a modification that will cost a bit, plus painting and decals etc. I'm sure the hospital won't be cheap if your frame breaks while riding it either.

I had a look at your link to yellow jersey - they look like they know what they're doing too.

Aside from any repairs or modification - make sure you get the paint matched before it gets burnt by the blow torch. The paint guy doesn't want to hear: well, it was kinda like a gumby sorta green ya know?

gumby

I am going to go a compromise direction. I bought a NOS 7 speed Shimano Hyperglide hub on ebay. I am going to send it off to Yellow Jersey and let them build me two new wheels (they have some good NOS French and Italian rims they just picked up). They will put a new 7 speed cassette on the wheel and send me a 7 speed chain. As I am friction shifting, I expect it should work out pretty well. Stay tuned and thanks for all the help.