Vintage Dirt Bike Q & A

#1 - Would love advice on known upgrades/products that would benefit the MR175 being used as a hardcore trail bike on various trails we have in Alabama... quite a lot of them thankfully!

My bike came with what looks like a bran-spankin' new front fork assembly! I even have the old one, which I assume was the factory assembly. Can not tell if the rear shocks are new? Probably just the original ones that came from factory... the odom only shows 1,400+ miles... and I trust that reading cause the bike is pretty cherry, even tho it has had some repaint on the frame... the tank looks like factory fresh paint except for the few dents.

I am 52 years young - 145# - I would just love to have a dependable suspension that will not beat up my old bones as I encounter very rough parts of a trail or track. Since I plan on finding or building a vintage CB for road use, maybe next years project... I want to outfit the ole MR with a good off-road/trail suspension.

#2 Is there somewhere to buy a side cover kit that is like the CR250 factory covers that are the off-road/dirt style that could take vinyl lettering or numbering? Kinda thinking of outfitting it to look more like the CR250 instead of the stock enduro/dual-purpose Elsinore covers.

#3 I will think of more I am sure!

Thanks...
Nate

I remembered my:

#3 - Is there a better seat that is a bit more streamlined/smaller? The stock seat seems HUGE to me?

Thanks!

Nate,

The '74/'75 CR125M seat and tank will fit. I mention both because the MR tank is a lot wider than the CR seat, which looks and fits better to the CR tank.

I'm using '79 XR185 forks which are a direct bolt-on and work much better than the stockers, but try some ATF or Torco RFF20 oil in them and see how they work.

You can replace the rear shock oil. The original Showa oil is still available from Honda, but I used 3W Bel-Ray shock oil in mine. Here's more info:

http://vintagedirtbikeforums.alp-sys.com/viewtopic.php?f=21&t=2576&hilit=showa+360&sid=52026cd2fa162fb8f6ac111c2411bd3c

The '77 MR175 uses a LH number plate, with a rubber band that hooks to tabs on the '77 frame. The mid-70's CR250 and MR250 plates are nearly identical except for cosmetics.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

Yup... I like the looks of that '75 125 seat/tank combo alot better. The MR jus has a weird... almost military look to it... not sure how to describe it. The 125 looks like a more traditional teardrop/bike look and the 125 is only .10 gallons smaller than the MR.

I am thinking of going with a dark orange... Mars Orange maybe with dark blue accents and silver base for a color scheme.

I browsed around for those XR front forks... most I saw on Ebay are in pretty bad shape. Need to check some forums and see if I can find some in better shape. Thanks for the tip. I had been looking on racetech.com at their vintage conversion kits... wasn't sure if that would be worthwhile or not.

Nate

Well, my Clarke CR125M plastic tank holds just about 1 gallon from bone dry (I was pretty bummed), and I think the OEM CR steel tank is rated at 1.6? gallons. The OEM MR and Clarke universal tank I'm using on my other bike are definitely a lot bigger.

There are also late 70's / early 80's XL forks that may fit, but I haven't done any 'due diligence' on those to make sure - and even if the stanchion tubes are 31mm and the axle is 12mm, you won't really know if the LH slider fits the brake backing plate until you get them, or know for sure that someone else had already used them successfully (as was the case with the '79 XR forks).

I have the Race Tech emulators on one of my bikes. I had them machined to fit the tops of the damper rods better, instead of using the optional Race Tech spacers (which fit a little loose for my taste, and add significant spring preload). I used the recommended setting which was mega stiff, so I'll have to pull them out again at some point.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric