Trek Color-Matched Carbon Seatmast Cap & 7mm Round Ears

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Trek Color-Matched Carbon Seatmast Cap & 7mm Round Ears

Model 559538

Offered in white and black and a variety of lengths and offsets, the mast cap includes hardware compatible with round saddle rails only. 7x10mm carbon rail-compatible hardware sold separately.

Product details

Ultra-light carbon construction
Direct fit on all Trek road bikes with round seat masts
Color matched for direct compatibility
One bolt head design offers easy fore-aft and infinite angle adjustment
Includes 7mm round saddle clamp ears, 10mm ears sold separately

"Lower weight and increase stiffness without the inherent drawbacks of fully integrated seatposts"

"As well as saving weight, it can flex more than in a traditional system"

"A new level of component integration for Trek"

"Trek took the extra step of making long and short seat mast tops available for personalized sizing"

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If for any reason you're not satisfied with a Bontrager or Trek aftermarket purchase, return the item, along with the original sales receipt to the original place of purchase within 30 days for an exchange or refund. Think of it as a 30-day test ride.

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Size	135mm x 5mm	135mm x 20mm	175mm x 5mm	175mm x 20mm
Length	135mm	135mm	175mm	175mm
Offset	5mm	20mm	5mm	20mm
Rail compatibility	7mm round	7mm round	7mm round	7mm round
Material	Carbon	Carbon	Carbon	Carbon
Weight	130g	130g	150g	150g

We reserve the right to make changes to the product information contained on this site at any time without notice, including with respect to equipment, specifications, models, colors, materials, and pricing. Due to supply chain issues, compatible parts may be substituted at any time without notice. Prices shown are manufacturer's suggested retail prices.

Weights are based off pre-production products at time of publication. Weights may vary in final production.