GT750J front suspension improvements? Springs?

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GT750J front suspension improvements? Springs?

Post by Olafskii »

Does anyone know if better springs would improve the front end of these bikes? The existing ones felt kinda limp when I took them apart

-what is the stock spring length spec supposed to be? (the old ones measure 442mm)
-what is the stock spring rate?
-any recommendations for an uprated spring?

Is there anything else that can be done to improve these forks?

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Re: GT750J front suspension improvements? Springs?

Post by tz375 »

I don't have an answer on the spring, but the damping needs a major modification to change it. It's an old shuttle valve type design. Blanking off the old damping holes would be easy. It may be harder to replace the spring support rods with what we would consider to be conventional damper rods. I would speculate that it would not be too hard to machine later model damper rods or maybe GS damper rods with modern seals - as long as the fork tube bore is smooth enough stock.

If not, it may be necessary to convert GS750/1000 forks to work with a drum front wheel.
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Re: GT750J front suspension improvements? Springs?

Post by jabcb »

Cycle World magazine had an article about modifying the forks. Don’t know if this will work on the J models. ... AtHome.pdf

I have a stock & modified 75 GT750s. The GS-series forks on the modified bike are a huge improvement.
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Re: GT750J front suspension improvements? Springs?

Post by oldjapanesebikes »

You can fit progressive springs - the ones sold for the GT750 are for the later versions and need to be shortened for the J, or possibly you can match up the length from another model. The ones sold for the later GT750's (kit 11-1120 and 19.75 inches long) are actually for a Harley Davidson so finding something to fit the J should be possible. 8)

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