Velopedia Bicycle Archive
1998 Univega Jammer
Original specifications: Shimano Tourney drivetrain · 20" wheels · 29 lb published weight.
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At a glance
- Model year
- 1998
- Category
- Kids
- Original MSRP
- $199.00
- Sizes
- Boys 11", girls 11"
- Colors
- Freckle Black, Sapphire Blue
- Weight
- 29 lb
- Geometry
- Legacy reference
- In this record
- 26 specifications · archived image · original MSRP · geometry
- Archive ID
- 71606
Original buildHi-tensile steel · Shimano Tourney · 20" wheels
Frameset
| Frame Construction | TIG-welded |
|---|---|
| Frame Material | Hi-tensile steel |
| Fork | Univega Jr. ATB |
| Fork Material | Hi-tensile steel, unicrown crown |
Drivetrain
| Component Group | Shimano Tourney |
|---|---|
| Shifters | Grip Shift MRX-170 rear |
| Rear Derailleur | Shimano Tourney TY-22 |
| Crankset | 1-piece 5 1/2", 40 teeth |
| Bottom Bracket | One piece |
| BB Shell Width | American 24tpi |
| Rear Cogs | 6-speed, 14 - 28 teeth |
| Chain | KMC UG-50, 1/2 x 3/32" |
| Pedals | Resin |
Brakes
| Brakes | Aluminum cantilever brakes, resin/aluminum levers |
|---|
Cockpit & Contact Points
| Headset | 1" steel |
|---|---|
| Handlebar | Steel |
| Handlebar Extensions | Not included |
| Stem | Steel |
| Saddle | Padded vinyl |
| Seatpost | Pillar, steel, 25.4mm diameter |
Wheels & Tires
| Hubs | Steel, nutted |
|---|---|
| Rims | Weinmann 519, 36-hole |
| Spokes | Chung Nan steel, 2.0mm straight gauge |
| Spoke Nipples | Brass nipples |
| Front Tire | 20 x 2.00" multi-terrain |
| Wheel Size | 20" wheels |
Geometry
Model-level measurements; the frame size was not recorded. Use these as a historical reference, not for size-specific fit.
Reference frame view
Select an available measurement to locate it on the frame.
All geometry measurementsLegacy reference · 5 measurements
| Measurement | Legacy reference |
|---|---|
| Top tube | 425.4 mm |
| Head-tube angle | 70° |
| Seat-tube angle | 72° |
| Wheelbase | 893.1 mm |
| Fork offset / rake | 50 mm |
The preserved source contains one model-level geometry set without an identified frame size.
Gearing
Lower ratios provide more mechanical advantage for climbing. Higher ratios turn the rear wheel farther with each crank revolution.
Parts & serviceability
Find replacement parts

ENVE Twin Bolt Seatpost - 25mm Offset UD Carbon, 25.4mm
25.4mm
Replacement option · verify fit
Based on the original build. Confirm the model, size and fit before ordering; installed parts may differ. As an Amazon Associate I earn from qualifying purchases. Velopedia may also earn from qualifying eBay purchases. Velopedia may also earn from qualifying retailer purchases.
Bike-specific inspection checklist 19 checks based on 5 archived component groups Open checklistClose checklist
This checklist uses the archived equipment for this bike. It cannot confirm the condition, service history or later component changes of the example in front of you.
Identity and fit
Follow the full used-bike inspection order →Archived: 1998 Univega Jammer · Juvenile · Published sizes: Boys 11", girls 11"
Frame and fork
Inspect the frame and fork →Archived: Frame: TIG-welded · Fork: Univega Jr. ATB · Hi-tensile steel, unicrown crown
Drivetrain
Check drivetrain wear →Archived: Group: Shimano Tourney · Shifters: Grip Shift MRX-170 rear · Rear derailleur: Shimano Tourney TY-22 · Crankset: 1-piece 5 1/2", 40 teeth · Bottom bracket: One piece · Rear cogs: 6-speed, 14 - 28 teeth · Chain: KMC UG-50, 1/2 x 3/32"
Brakes
Inspect the brakes →Archived: Brakes: Aluminum cantilever brakes, resin/aluminum levers
Wheels and tires
Check wheels and tires →Archived: Wheel size: 20" wheels · Rims: Weinmann 519, 36-hole · Hubs: Steel, nutted · Front tire: 20 x 2.00" multi-terrain
Controls and contact points
Archived: Headset: 1" steel · Handlebar: Steel · Stem: Steel · Seatpost: Pillar, steel, 25.4mm diameter · Saddle: Padded vinyl · Pedals: Resin
Before and during the test ride
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Specifications are presented as a reference. Components may vary by market, size, production run, or later manufacturer revisions.
