1993 Bridgestone MB-4
Part Diary, Part Technical Manual, Part Tips & Tricks

I saw an ad for a "super clean" MB-4 in one of my favorite Bridgetone colors - Metallic Light Blue. The bike was pretty clean for sure but had wear in unusual places, which suggests it wasn't ridden much, but was scratched up in storage. It also did not have the original saddle and seatpost, so I had the seller keep what was on there. A Kalloy seatpost and Avocet saddle should not be too hard to find. So on March 11, 2012, I bought my third MB, my fifth Bridgestone overall.

5/17/2012 - After I bought the bike, I realized that I happen to have a Ritchey 27.0 seatpost, so I put that on - it's not quite period correct, but it is a Ritchey. Then today, I just put on a black Turbo saddle to replace the Brooks B17 that I had on there for the past couple months. Now I have two Turbos on my two MB's.

2/24/2014 - Here is another example of an inexpensive bike that rides wonderfully and has served me so well over the years. My MB-3 frame was a tad small, this MB-4 is the same size as my MB-0, even though the geometry is nearly identical, but for some reason this bike fits me just a tad better. Perfect fit plus that great blue paint - definitely one of my favorite bikes.

1/2/2016 - Years later, this remains one of my favorite bikes. Been riding it at Water Dog, along coastal trails, and did an intense ride at Skeggs Point today. Surrounded by high tech modern bikes with 27.5 or 29 inch wheels, carbon frames, various suspension types, and disc brakes - I was riding a technological dinosaur. However the bike handled beautifully across a wide range of terrain and conditions. It handled the tight twisty singletrack easily, it climbed very well, the cantilever brakes were adequate to slow me down, and the shifting was just fine. Only in a couple sections of really rough rocky terrain did a suspension fork seem like a good idea. I would have appreciated slightly lower gearing at times. I realize I've been going backwards in technology. My first mtb was a Gary Fisher Joshua, a URT full suspension design. After that got stolen, I bought a Dean Jester softail bike. Lately I've been riding rigid mountain bikes exclusively. This is not me trying to make any kind of statement, its just how things happened, and I'm happy with where I'm currently at. I wonder if modern mountain bike owners ever had a chance to ride a pure rigid bike like this MB-4 and if they did, would they still opt for their modern rigs?

2/15/2016 - I found a nice Avocet saddle, so I installed it on the MB-4 and put the Turbo onto the MX-Z. I also ordered a Kalloy Laprade seatpost, so now the bike looks totally original, albiet 5 oz. heavier with the new untrimmed seatpost.

2/20/2017 - For almost a year, I've kept this bike at my parent's house, so I have something to ride when I visit them. I miss this bike, as it is one of my favorites. So this past weekend, I rode it up Brown Mountain twice, once on Saturday afternoon and then again on Sunday morning. I'm reminded once again how wonderful this bike is, it handled everything I threw at it. On the ascent, it occured to me how crisp and fast the shifting was, using humble thumb shifting LX technology from the early 90s. I had this image of Grant Peterson testing a bunch of components and objectively specifying the best performing components rather than going with the latest trend. Descending aggressively downhill in the foggy and damp conditions, the rear brake cable actually slipped a bit. I didn't realize this until the following day when I was cleaning up the bike that I only had about 30% of the rear brake power, better rear than front though...

8/4/2024 - I took the MB-4 for a ride and halfway through it, the rear tire got totally stredded and the tube popped. Turns out the tires were so old, the fibers were separating. Good thing I stopped riding the moment I felt something strange. So I ordered a pair of new MAXXIS tires, installed them and got to do another ride while I was in LA. These tires are a bit larger and have a good tread pattern for both road and trail riding.

Here are the specs:

Frame: 1993 Bridgestone MB-4, 52 cm (20.5"), Ishiwata triple-butted tubing, 130mm spacing. Serial Number: F223821. Metallic Light Blue.
Fork: 1993 Bridgestone fork, 1" threaded. Tange steel with 1-1/8" oval blades. Metallic Light Blue.
Front Hub: Shimano Exage 500LX HB-HG50, 32H.
Rear Hub: Shimano Exage 500LX FH-HG50, 32H.
Rims: Ritchey Vantage Expert, 32H, silver
Tires: MAXXIS IKON, 26" x 2.2", folding bead.
Cassette: Shimano 7spd, 13-30T.
Cranks: Sugino GP, 46x36x24, 175mm, 110/74 BCD.
Bottom Bracket: Tioga BB-401, 124.5mm spindle.
Front Derailer: Shimano Deore LX FD-M563, clamp-on.
Rear Derailer: Shimano Deore LX RD-M560.
Brakes: Dia-Compe 985.
Brake Levers: Dia-Compe SS-4.
Shifters: Shimano Deore II top-mount, SL-MT62.
Headset: Tange Levin CDS, 1" Threaded.
Chain: Shimano Hyperglide 50.
Stem: Ritchey Force, 30 degree rise, 1" threaded, 130mm, 25.4mm diameter. Black.
Handlebar: Hsin Lung, 6 degree, 54 cm, black.
Grips: Ritchey True Grip, black.
Pedals: Shimano PD-M520 SPD, black.
Seatpost: Kalloy Laprade, 27.0 x 350mm, silver.
Seatpost Clamp: Kalloy, quick-release.
Saddle: Avocet Racer I, black.

The bike weighs 27 lbs 0 oz as shown.

The following are OE parts that I am currently not using:

Pedals: Sakae Ringyo (SR) CTP-400, Low Fat, track cage.