Compatible with a wide range of vehicles from mopeds to out-of-print vehicles. NTB front fork boots for reliable use with original standard parts.

PR] Marunaka Yoko Text: Akira Kurita

Front fork boots, which are also installed on moped scooters, especially traditional and trail models, are important parts that protect the inner tube from dirt and rust. Boots that have been torn at the bellows due to age-related deterioration should be replaced as soon as possible. However, genuine parts may no longer be available for out-of-print models. ...... In such cases, NTB front fork boots can be relied upon. NTB's "standardized parts" offer the same performance and quality as genuine parts, and the dimensions, design, and fit are outstanding, so they are sure to come in handy for maintenance and restoration.

If the bellows tear, rain can accumulate and become a breeding ground for rust.

Front fork boots have been installed on old cars since the days when front fork springs were mounted on the outside of the inner tube, on out-of-print cars from the 1970s, and on current cars, including traditional models, off-road models, moped-class leisure bikes, and scooters. Their primary purpose is to protect the inner tube from bouncing rocks and rainwater, but they also play a small role in accentuating the old car style. However, the rubber material of such front fork boots sometimes hardens and cracks at the bellows due to age-related deterioration caused by ultraviolet rays and rainwater. The boot that looks like a torn lantern is a nuisance, and dust and rainwater that enters through the cracks can damage the lip of the oil seal and cause rust on the inner tube. If you ignore the problem and say, "It's just an old car, so it's inevitable," you will end up with a serious problem.

General-purpose products that may or may not work

In addition to genuine front fork boots, there are also general-purpose products that are compatible with various models. In most cases, the dimensions are determined by the overall length and upper and lower inner diameters, and users generally order them after measuring the dimensions of their car's boots. However, while it would be nice if these general-purpose products fit well, the reality is that this is often not the case. As can be seen by observing how the genuine parts are attached to the front forks, there should be ribs or stoppers on both the inner tube and bottom case sides, not just round holes, to prevent them from rolling up easily when the forks are stroked. Since the shape of the inner tube differs from model to model, general-purpose products cannot be used, and even if the inner tube diameter is correct, it may not fit the bottom case and must be additionally secured with an insulin lock or band, which are not included in the genuine parts. In other words, when choosing a general-purpose front fork boot, careful consideration must be made, and if purchased casually, the finished product may be unsatisfactory.

NTB's "standard parts" are designed completely for each model.

The front fork boot is a part that has more barriers between genuine parts and general-purpose parts than one might imagine, but Marunaka Yoko's standardized parts, which combine the same performance and quality as genuine parts, have a great feature and appeal in that they are completely compatible with genuine parts despite being developed independently. The overall length, number of bellows, inner tube diameter, and even the shape of the lower inner part that fits into the bottom case are all perfectly reproduced, allowing installation just like genuine parts without any special work or stress. The NTB logo mark on the lower part of the boot also clearly shows that it is manufactured by NTB. NTB's front fork boots are completely model-specific designs that are compatible with all four domestic manufacturers, and the lineup includes not only old and out-of-print vehicles, but also a wide variety of current models. NTB is continually adding to its lineup, so new products are being introduced one after another. NTB also offers a wide range of inner parts necessary for front fork overhaul, such as oil seals, dust seals, bushings, and drain bolt washers. These parts can be searched for on the "N.T.B Auto Parts Search" on the official Marunaka Yoko website, and even if you do not have a parts list, you can find out what parts are available in the NTB standard parts.

Excellent fit and tightening of the front forks.

Here, NTB's FBH-008 front fork boots were installed on a Honda GB250 Clubman; the stock boots on bikes manufactured more than 40 years ago had a ticking rubber, and silicone spray did not improve their shiny condition. In contrast, the newly manufactured NTB boots are incomparably more flexible and the rubber texture is outstanding. The ribs on the inside of the lower part fit perfectly into the bottom case fixing groove, and there was no floating or falling out even when the front forks stroked. A boot with a torn bellows is a source of inner tube trouble and looks bad, so it should be removed as soon as possible. However, the style of the boot is not very good as the genuine parts are no longer available. If the fork boots were not present from the beginning, it would not bother us, but if the parts that should be there are not, we would feel uncomfortable. This is when you can really appreciate the usefulness of NTB's front fork boots.

The lineup is diverse, ranging from scooters to out-of-print vehicles of yesteryear.

Marunaka Yoko has developed many of the parts required for maintenance and servicing, such as handlebar parts, engine parts, exterior parts, and electrical parts, as standardized parts. Marunaka Yoko also offers front fork boots for a wide range of models, from moped models to out-of-print vehicles, as shown below, and the lineup is constantly being updated. Currently, all products are available in black, but a color version for off-road models (XR250, Cerro 250, TT250R Raid) is under development. Variations will be blue/red/yellow/green, following the OEM colors of each manufacturer, and are scheduled for release in April or May after the product is unveiled at the 2026 motorcycle show. This will be a long-awaited new product for off-road users. Even for models not in the lineup below, Marunaka Yoko will consult with users who are having trouble obtaining genuine parts, so owners of out-of-print vehicles should contact the company for more information.

HONDA

FB-001 51611-GFC-771 Compatible model Applicable model Today AF61/AF67 Dio/Dio Cesta AF62/AF68 FB-003 51611-KZV-L01 Compatible model Applicable model Super Cub 50 Pro AA04 Super Cub 50 MD NBC50BNC Super Cub 110/ Pro JA10 Super Cub 110 MD NBC110BNC FBH-004 51611-GN1-762ZD Compatible model Super Cub 110 C110BN9 FBH-005 51611-K2E-T02/51611-K2E-T01 Compatible model Hunter Cub CT125A L/P FBH - 006 Compatible with 51611-K87-A31 Compatible with CMX250A L/2L/2M/P/2P Rebel 250/S FBH-007 Compatible with 51505-064-010B Compatible with ST50K1 to K4 ST70K1 to K4 Z50A/Z/J/J1 FBH-008 Compatible with 51611-KL8-003 51611-KL8-003 compatible with Clubman GB250 MC10 FBH-009 51611-KN8-003 compatible with GB400 NC20 GB500 PC16 CL400 NC38 FBH-010 51611-KW3-003ZL compatible with XR230 MD36 SL230 MD33 FBH-011 51611-KT1-305ZE Compatibility XR250 MD30 FBH-012 51611-300-000 Compatibility CB750 (K0-K2,K4) FBH-013 51611-K88-L02 Compatibility Super Cub 50 Pro AA07 Super Cub 110 Pro JA42/ JA61 Cross Cub 50 AA06 Cross Cub 110 JA45

YAMAHA

FBY-001 1JN-23191-00 Compatibility Applicable model SR400/500 3HT1/3～9/A～G FBY-002 3C5-23191-10 Compatibility Applicable model Cerro 250 XT250 DG11J/17J/31J 3C5 1～5/7 FBY-003 4GY-23191-51 Compatibility Applicable TT250R Raid 4GY1/4RR1/4RR2 FBY-004 4JG-23191-20 Compatible Applicable XT225 Sero 4JG2-6, 5MP1-4 FBY-005 13P-F3191-00 Compatible Applicable Jog SA57J/SA58J e-beano EF06A FBY-006 3 UH-F3191-00 Compatible Applicable model Axis Street SE53J Cygnus SE07J FBY-007 5CP-F3191-00 Compatible Applicable model Grand Axis SB01J/SB06J FBY-008 2TS-F3191-00 Compatible Applicable model Axis Z SED7J Jog 125 SEJ 5J FBY-009 2JS-F3191-00 Compatible Product Applicable model Bewith SEA6J/SED9J

SUZUKI

FBS-001 51571-25D70 Compatible Product Adaptation model: Glass Tracker TU250G

KAWASAKI

FBK-001 49006-0611 Compatible with W800/Meguro K3 EJ800B/E FBK-002 49006-1304 Compatible with Estrella BJ250A FBK-003 49006-1335 Compatible with W650 EJ650A W800 EJ800A

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