DMS TT500 Yamaha Versions

According to the information I have found, about 200 total of these chassis kits were made by Dick Mann. They evolved through a few different versions and refinements were incorporated along the total production run. I have come across 3 different variations, still looking for more examples, please let me know.

DMS TT500 Version 1

 The version 1 frame was introduced in 1976, Dick Mann jumped on this project fast since the first actual model run of the Yamaha TT500 was in the same year. I’m sure he quickly identified the best thing about a TT500, the fine motor!

 What it needed was an intense diet, tighter chassis and real suspension components to bring it together. Dick Mann designed this chassis to be exactly what this motor was meant to be used for, a do-it-all six days enduro bike with sharp handling and be a competent undercover MX’er. He designed it to take on all the stock components, which is desirable to the initial purchaser. You quickly find out that when you spend the time and money on a nice chassis kit, that there are far better options than stock TT500 components and this machine deserves them.

The version 1 chassis is easily identified by the cam adjust swing arm pivot. Not only was this to adjust the chain, it made a dramatic difference in the handling of the chassis. If you took the time to understand how it worked and used sprocket selection, chain guide and tensioner selection and possibly a half link to achieve your chain adjustment per the swingarm pivot location, you could achieve a broad range of handling preferences in addition to shock length used. Note the rear axle carrier to the left, it’s a fixed position.

The full chassis kit below included just about everything you needed to give your TT500 its well deserved frame-ectomy in strong, thin wall 4130 cro-moly tube.


This is the only example I have ever seen where the owner actually used mostly stock components! Its a fine example. VMX issue #10, 2001 article.


Click on the pictures for a larger view

The machine above and to the left was located near to where I live, not certain if it still is. The swing arm on this version 1 is angled. It has a 1974 (?) YZ alloy tank fitted with YZ fenders and hand made side panels with early YZ forks. The exhaust does not look at all like a Dick Mann unit. This looks like a pretty fresh build and Dick signed the side panels for him.


This version 1 above sports a set of Simons forks and Works shocks. It appears his swing arm is about 4 inches longer than the normal version 1. Wow, make an appointment and mark the calendar for the next corner!

DMS TT500 1sm DMS TT500 2sm
DMS TT500 3sm

This is my DMS Version 1, chassis #54. These photo’s were taken just after I first built it in late ‘78.

It was fitted with a 1979 YZ125 fuel tank and brand new 1979 YZ400 complete front end with huge cross 4 spokes on gold Hallman/Sun rims. Of course a 3.25 Trelleborg was mounted up front. The engine had a 36 mm EI carburetor with a Pro-Tec Hi comp. piston and Norris valve springs. It had Fox remote reservoir shocks and Preston Petty Tony D. MX fenders. The rear wheel was a 17” in a 2.75” width with a 5.30 Terraflex tire. Easily the heaviest rear wheel assembly I have ever had on a dirt bike!

My riding buddies said it shit boulders like a volcano with diarrhea. I didn’t have to follow it so I can’t verify that.

I hope to have some current details on mine as it comes together again. Its still in very fine shape today but its getting a face lift as time permits me to keep after it. Click here for the details.

DMS TT500 Version 2

The version 2 changes appear to be a revised rear fender loop, revised shock position and re-designed swingarm with stationary S/A pivot. This covers about the whole tail section. There seems to be different swingarm design variations and it looks to me the wheel base was growing considerably on this version. The footpegs appear to be lower in height than the version 1, probably to suit taller riders. I’m feeling fortunate Dick was a bit shorter of a man, I’m about the same size and the version 1 chassis fits me like a glove!

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The machine above was spotted on a U.K. web site that had it for sale. It actually looks like a fairly fresh, incomplete build at this time. Note the “pull” type chain adjusters on the S/A. Not sure why the downpipe was utilized on an off road platform and I would feel confident that Dick Mann only supplied his design up pipes with his kits, owners decision? The fuel tank appears to be a fiberglass copy of a BSA B-50 tank that Dick may have supplied later in the run of these kits and the side panels may be his design.

V2DMSM Hillsboro MCsm1

The machine on the left is part of a very large collection in Hillsboro, Oregon, USA belonging to Hillsboro Cycles, they run a very large on-line accessory outlet. This version 2 sports period correct Simons forks, Preston Petty Rear MX fender and Tony D MX front (cut short on the rear). The tank appears to be the fiberglass BSA B-50 type with modified stock type side panels. It also has “pull” type chain adjusters. A very large ignition coil is mounted up forward and high. It appears that the rear exhaust section is the standard mid level design that Dick seemed to favor at this time. It appears the rear brake is a desireable full floater for the period, YZ brakes/hubs front & rear?.

The version 2 machine below was spotted on for sale. The rear section of this fame has unfortunately been modified to great extent. It appears the frame was cut off just aft of the S/A pivot so the shocks could take on a radical cantilever position. It appears flat bar was used on each side of the upper shock mount to join them to the tail section and the shock lower mount position appears to be moved forward considerably with more side gussets added. The axle push bolt adjusters have been replaced with a snail type adjuster. It looks to me the wheelbase is very long, okay for high speed desert stability but might suffer in turning precision. Interesting forks though, possibly a Marzocchi magnesium?


DMS TT500 Yamaha Version 3

The final version is what I call version 3. This was the final version I am aware of and I understand that approximately 25 were made. This version seems more focused to MX work and would appear to make an excellent do it all bike just the same.

These pictures are from Tom Fitzgerald. He had this chassis for sale on asking $1800, It sold in one day to a very fortunate buyer. I hope it comes together as a fine example with the new owner. His comments regarding this chassis are below

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Tom Fitzgerald’s comments on the DMS Version 3

Dicks first version used all the stock parts, tank, seat, forks etc. Also wheel adj was done at swingarm pivot. I know where 2 of these are.

2nd version had a banana shaped swingarm. About the only parts you used were the stock TT seat, maybe wheels and forks too.

3rd version like the one I had used stock TT seat and BSA/Tri tank with the front part of tank dented to clear the Simons clamps and forks. When the supply of seats and tanks were gone he made fiberglass copies of seat pan and tank. I have never seen one yet. Also he did'nt put serial #s on his frames because that would have meant dealing with the goverment. They were sold as replacment frames. These last bits of info came from Dick himself over the phone. You can get his # from the AHRMA web page.



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